Suicide and biomarkers of gastrointestinal inflammation

Suicide and gastrointestinal inflammation

Suicide mostly occurs in association with neuropsychiatric disorders characterized by neuroinflammation (brain inflammation). Neuroinflammation often results from perturbations of the brain-gut axis, with pro-inflammatory immune signaling from the gut to the brain. An important study just published in Psychiatry Research offers data showing the connection between biomarkers of gastrointestinal inflammation and recent suicide attempt. The authors were motivated by the intent to validate biomarkers to help assess, treat and prevent suicide attempts.

Most attempting suicide have an illness associated with neuroinflammation

“Psychological autopsy and epidemiological studies indicate that more than 90% of people who die by suicide have a diagnosable psychiatric illness, particularly major depression, bipolar disorder, or schizophrenia…The identification of blood-based markers would provide for more personalized methods for the assessment and treatment, and ultimately prevention, of suicide attempts.”

It is an urgent clinical need to identify causes that promote dysregulated activation of the immune system against the neuronal antigens.

The GI tract is often the source of immune activation against the brain

Biomarkers of gastrointestinal inflammation are frequently increased in neuropsychiatric disorders.

“Many individuals with schizophrenia and mood disorders have evidence of immune activation suggesting that immune dysregulation may be part of the etiopathology of these disorders. Studies by our group and others indicate that the gastrointestinal tract is often the primary source of this immune activation as evidenced by increased levels of markers of gastrointestinal inflammation in individuals with serious mental illness.”

IBD (inflammatory bowel disease) and celiac disease appear to increase risk for suicide.

“Furthermore, increased rates of suicide and suicide attempts have been found in some populations of individuals with celiac disease or inflammatory bowel diseases.”

But previous studies have focused on a lifetime history rather than attempts, so the authors set out to:

“…examine the association between levels of markers of gastrointestinal inflammation and a recent suicide attempt in individuals with schizophrenia, bipolar disorder or major depressive disorder in comparison with non-psychiatric controls.”

Elevated IL-6

Interleukin-6 (IL-6), a key pro-inflammatory cytokine which can arise from the GI tract, is associated.

“Results from other investigators indicate that inflammation may be associated not only with a proclivity for a psychiatric disorder, but specifically with suicidal behavior. Studies have found an association between a suicide attempt history and the level of cytokines such as IL-6 which are cell signaling molecules involved in the immune response and which can arise from inflammation from many sources, including the gastrointestinal tract”

Gluten and brain inflammation

Neuroinflammation triggered by non-celiac gluten sensitivity is also implicated:

“Gliadin is a component of gluten, found in wheat and related cereals. Antibody response to dietary gliadin is associated with celiac disease, an immune-mediated enteropathy, and with non-celiac wheat sensitivity and is thought to indicate intestinal inflammation and/or intestinal barrier dysfunction. We have found increased levels of antibodies to gliadin in individuals with schizophrenia and with bipolar disorder and in individuals with acute mania during a hospital stay…”

Additionally, loss of tolerance to a commensal yeast may promote neuroinflammation.

“We also have studied the antibody response to yeast mannans represented by antibodies to Saccharomyces cerevisiae (ASCA), a commensal organism present in some foods and in the intestinal tract of many individuals. Elevated ASCA levels are associated with increased intestinal inflammation. We have previously found increased levels of ASCA in individuals with mood disorders.”

Pathogens and loss of immune tolerance

Various pathogens present at low levels can elicit a persistent cross-reaction to self-antigens, including brain antigens, in individuals disposed to loss of immune tolerance.

“An association between elevated antibodies to Toxoplasma gondii, an apicomplexan parasite, and suicide attempts have also been reported. In a recent study, we found that individuals with serious mental illness who had a lifetime history of a suicide attempt had elevated levels of IgM class antibodies to Toxoplasma gondii and Cytomegalovirus (CMV); we also found an association between the levels of these antibodies and the number of suicide attempts.”

Significant link found

Association between suicide and markers of GI inflammation

The authors examined data for 282 participants: 90 with schizophrenia, 72 with bipolar disorder, 48 with major depressive disorder, and 72 non-psychiatric controls; who were enrolled in ongoing studies of the role the immune response to infections in individuals with serious psychiatric disorders. Biomarkers measured included IgA antibody to yeast mannan from Saccharomyces cerevisiae (ASCA), IgG antibody to gliadin, IgA antibody to bacterial lipopolysaccharide (LPS) from E. coli O111:B4, Pseudomonas aeruginosa, and Klebsiella pneumoniae, and levels of C-Reactive protein.

“We found a statistically significant difference between the recent attempters and the control group in levels of IgA ASCA; the level in the recent attempt group was significantly higher…We also found that the level of IgG antibodies to gliadin was significantly higher in the recent attempters vs. the control group…We also found that the level of IgA antibodies to bacterial lipopolysaccharide (LPS) was significantly higher in the recent attempters vs. the control group…In terms of CRP, we found that there was a significantly higher level in the past attempter group.”

Predicting risk and protecting patients

These findings offer a valuable opportunity for clinicians to gauge and ameliorate risk of suicide in patients with serious neuropsychiatric disorders.

“The markers of gastrointestinal inflammation are of interest because they can be readily measured in blood samples. In addition, some of the markers studied here may be an attractive target for therapeutic intervention since intestinal inflammation can be modulated by dietary interventions as well as the administration of available prebiotic, probiotic, and antibiotic medications.”

The authors conclude:

“Suicide, for which a previous suicide attempt is the greatest risk factor, is a major cause of death worldwide and is highly prevalent in patients with serious mental illness. Unfortunately, the ability to predict suicide remains limited and no reliable biological markers are available. The identification of blood-based markers should provide for more personalized methods for the assessment and treatment, and ultimately prevention, of suicide attempts in individuals with serious mental illnesses.”

For additional categories of importance in evaluating neuropsychiatric risk see The Parents’ Guide to Brain Health.

Prediabetes, chronic inflammation and hemoglobin A1c

PrediabetesPrediabetes, blood glucose is slightly higher than normal but not enough to qualify for diabetes, is associated with an increased systemic burden of inflammation and elevated risk for cardiovascular, cancer, dementia and other diseases. The first study described in this post, published in the European Journal of Nutrition, highlights the link between prediabetes, chronic inflammation and mortality from a range of diseases tied to HgbA1c (hemoglobin A1c, glycosylated hemoglobin), the key biomarker for glucose regulation. The authors state:

Chronic inflammation is associated with increased risk of cancer, cardiovascular disease (CVD), and diabetes. The role of pro-inflammatory diet in the risk of cancer mortality and CVD mortality in prediabetics is unclear. We examined the relationship between diet-associated inflammation, as measured by dietary inflammatory index (DII) score, and mortality, with special focus on prediabetics.”

Pro-inflammatory diet plus prediabetes (increased HgbA1c)

Of great significance is the effect they reveal when a pro-inflammatory diet, measured by the dietary inflammatory index (DII) score, is consumed when there is elevated HgbA1c. They categorized 13,280 subjects between the ages 20 of and 90 years according to whether or not they were prediabetic, which they defined as a HgbA1c percentage of 5.7–6.4. Their data highlighted this connection between all-cause mortality, a pro-inflammatory diet and prediabetes:

“The prevalence of prediabetes was 20.19 %. After controlling for age, sex, race, HgbA1c, current smoking, physical activity, BMI, and systolic blood pressure, DII scores in tertile III (vs tertile I) was significantly associated with mortality from all causes (HR 1.39, 95 % CI 1.13, 1.72), CVD (HR 1.44, 95 % CI 1.02, 2.04), all cancers (HR 2.02, 95 % CI 1.27, 3.21), and digestive-tract cancer (HR 2.89, 95 % CI 1.08, 7.71). Findings for lung cancer (HR 2.01, 95 % CI 0.93, 4.34) suggested a likely effect.”

The authors conclude:

“A pro-inflammatory diet, as indicated by higher DII scores, is associated with an increased risk of all-cause, CVD, all-cancer, and digestive-tract cancer mortality among prediabetic subjects.”

 Prediabetes and cardiovascular risk

Research published in The BMJ (British Medical Journal) focusses on the substantial impact of prediabetes on the risk of heart attack and ischemic stroke. The authors set out to…

“…evaluate associations between different definitions of prediabetes and the risk of cardiovascular disease and all cause mortality…”

…by analyzing 53 prospective cohort studies with 1,611,339 individuals that passed the screening tests for validity. In this study they applied several definitions of prediabetes:

“Prediabetes was defined as impaired fasting glucose according to the criteria of the American Diabetes Association (IFG-ADA; fasting glucose 5.6-6.9 mmol/L = 101-124 mg/dL), the WHO expert group (IFG-WHO; fasting glucose 6.1-6.9 mmol/L = 110-124 mg/dL), impaired glucose tolerance (2 hour plasma glucose concentration 7.8-11.0 mmol/L = 141-198 mg/dL during an oral glucose tolerance test), or raised haemoglobin A1c (HbA1c) of 39-47 mmol/mol [5.7-6.4%] according to ADA criteria or 42-47 mmol/mol [6.0-6.4%] according to the National Institute for Health and Care Excellence (NICE) guideline.”

Their data show that prediabetes with a ‘mildly’ elevated HgbA1c was clearly associated with increased cardiovascular risk:

“Compared with normoglycaemia, prediabetes (impaired glucose tolerance or impaired fasting glucose according to IFG-ADA or IFG-WHO criteria) was associated with an increased risk of composite cardiovascular disease (relative risk 1.13, 1.26, and 1.30 for IFG-ADA, IFG-WHO, and impaired glucose tolerance, respectively), coronary heart disease (1.10, 1.18, and 1.20, respectively), stroke (1.06, 1.17, and 1.20, respectively), and all cause mortality (1.13, 1.13 and 1.32, respectively). Increases in HBA1c to 39-47 mmol/mol [5.7-6.4%] or 42-47 mmol/mol [6.0-6.4%] were both associated with an increased risk of composite cardiovascular disease (1.21 and 1.25, respectively) and coronary heart disease (1.15 and 1.28, respectively), but not with an increased risk of stroke and all cause mortality.”

Interestingly, risk of stroke does not emerge from these data, suggesting other factors promoting vascular inflammation. The authors conclude:

“…we found that prediabetes defined as impaired fasting glucose or impaired glucose tolerance is associated with an increased risk of composite cardiovascular events, coronary heart disease, stroke, and all cause mortality. There was an increased risk in people with fasting plasma glucose as low as 5.6 mmol/L [100 mg/dL]. Additionally, the risk of composite cardiovascular events and coronary heart disease increased in people with raised HbA1c. These results support the lower cut-off point for impaired fasting glucose according to ADA criteria as well as the incorporation of HbA1c in defining prediabetes.”

HgbA1c and risk of all-cause and cause-specific mortality without diabetes

Similar results were obtained in a study published in Scientific Reports. Here the authors concluded:

“We found evidence of a non-linear association between HbA1c and mortality from all causes, CVD and cancer in this meta-analysis. The dose-response curves were relatively flat for HbA1c less than around 5.7%, and rose steeply thereafter. This fact reveals a clear threshold effect for the association of HbA1clevels with mortality. In addition, from the perspective of mortality benefit and health care burden, it suggests that the most appropriate HbA1c level of initiating intervention is approximately 5.7%…higher HbA1c level is associated with increased mortality from all causes, CVD, and cancer among subjects without known diabetes. However, this association is influenced by those with undiagnosed diabetes or prediabetes .Because of limited studies, the results in relation to cancer mortality should be treated with caution, and more studies are therefore warranted to investigate whether higher HbA1c level is associated with increased cancer mortality.”

 

Brain health is maintained by immune system activity

the-scientistDramatic advances in understanding how brain health is maintained by the immune system are described in an excellent article published recently in The Scientist that accompanies the brief video presentation by neuroscientist Michal Schwartz shown below. Only recently has it been recognized that brain immune function is integrated with the systemic immune system.

Until recently, the brain and the spinal cord were considered immune-privileged sites, strictly cordoned off from immune cells unless something went terribly wrong. Researchers knew, for example, that multiple sclerosis (MS) was caused by T cells that breach the selective border called the blood-brain barrier (BBB), enter the CNS, and attack the myelin sheath covering neurons. Even microglia, specialized macrophage-like immune cells that scientists had recognized as normal CNS residents since the 1960s, were mainly studied in the context of disease.”

Now the pervasive role of the immune system in brain function and maintenance is being observed:

“But over the past two decades, researchers have recognized that the entire immune system is very much a part of a functional CNS, with vital roles in cognition, injury repair, neurodegenerative disease, and sensory systems. Microglia pervade the CNS, including the white and gray matter that constitute the organ’s parenchyma. Other immune cells, including T cells, monocytes, and mast cells, reside in the brain and spinal cord’s outer membranes, known as the meninges, and circulate in cerebrospinal fluid (CSF).”

Immune cells in the brain help repair damage

It was formerly thought that immune cell activity in the brain was only harmful.

Macrophages, for example, can damage neurons by secreting cytokines, proteases, or reactive oxygen species, but in rat and mouse models of spinal cord injury, they also produce transforming growth factor-beta (TGFβ), which promotes wound healing,5 and interleukin 10 (IL-10) which helps resolve inflammation. By the late 2000s, researchers recognized that different subtypes of macrophages can benefit neuronal growth in rodents, and that some were critical to recovery. Views also began to change on the clinical side after the 2004 Corticosteroid Randomization After Significant Head Injury (CRASH) study showed that corticosteroids didn’t help brain injury patients recover, but increased their risk of disability and death.”

Cells of the adaptive immune system residing in the tissue lining of the ventricles can also assist in repair.

Her team also showed that T cells present in this lining, called thechoroid plexus, secrete cytokines such as interferon gamma (IFNγ), which allows selective passage of CD4+ T cells and monocytes from the blood into CSF within the ventricles.  In a model of spinal cord bruising, mice deficient for the IFNγ receptor had reduced immune cell trafficking across the choroid plexus and poor recovery of limb movement. And last year, Kipnis’s team reported that IL-4 produced by CD4+ T cells in the CNS signals neurons to regrow axons after spinal cord or optic nerve injury.”

Immune cells in the brainAn intact blood-brain barrier (BBB), however, is essential:

“His team also found that microglia reinforce the BBB, which is composed of endothelial cells, pericytes, and astrocytes. Microglia fill in spaces left by astrocytes killed or damaged during injury. Without a robust barrier, McGavern says, unwanted immune cells may flood the parenchyma and do more harm than good.”

Immune cells residing in the CSF and choroid plexus

Immune cells residing in the CSF and choroid plexus

Brain needs both anti-inflammatory and pro-inflammatory activity for cognition

Neuroinflammation is well known to be a core feature of neurodegenerative disorders, but inflammatory immune activity is also required for healthy cognition.

“…Rivest used two-photon microscopy to monitor monocytes in blood vessels of living mouse brains, and he watched as the cells migrated toward and cleared amyloid-β deposits within veins. When the researchers selectively depleted monocytes, the mice developed more amyloid-β plaques in the cortex and hippocampus. And when they knocked out the innate immune signaling protein MyD88, which mediates signals from several monocyte-activating receptors, the mice also experienced more amyloid-β accumulation, accompanied by accelerated cognitive decline.”

Even in the classic disease of neuroinflammation, MS, immune cell activity is necessary:

“Rivest’s team found that microglia-forming monocytes are beneficial in a model of MS, where microglia are found within the inflammatory lesions. Last year, the researchers reported that inhibiting monocytes from entering the CNS reduced the clearance of damaged myelin and impeded proper remyelination.”

Evidence for the immune system’s role in preventing neurodegeneration continues to mount:

“Schwartz has similarly found evidence for the immune system’s ability to protect against neurodegeneration. Last year, she and her colleagues reported that the choroid plexus epithelium was less permissive to immune cell trafficking in a mouse model of Alzheimer’s disease than in wild-type mice, due to anti-inflammatory signals produced by regulatory T cells (Tregs). They found that depleting Tregs in Alzheimer’s mice allowed macrophages and CD4+ T cells into the brain, reduced the number of amyloid-β plaques, and improved cognition. Similarly, blocking the T-cell checkpoint protein PD1, which normally supports Treg survival while suppressing the activity of other T cells, reduced amyloid-β plaques in mouse brains and improved the animals’ scores in a learning and memory water maze test.”

Clinicians should be alert to evaluate and support balance

Too much neuroinflammation is clearly adverse.

“But there’s a reason that scientists have believed that immune activity contributes to Alzheimer’s damage: microglia, perhaps best known for trimming back synapses, have the potential to become overzealous, and excessive synapse pruning can cause neural damage in a variety of CNS diseases. By blocking the cells’ proliferation in mice, Diego Gomez-Nicola of the University of Southampton in the U.K. has successfully alleviated symptoms of Alzheimer’s disease, amyotrophic lateral sclerosis, and prion disease. And earlier this year, Beth Stevens of the Broad Institute and her colleagues reported that inhibiting a protein that tags synapses for microglial pruning halted over-pruning and loss of synapse signaling strength in two mouse models of Alzheimer’s disease.”

Regulation of stress is critical

Stress has a major effect on which way the ‘two-edged sword’ swings.

“Kipnis says regulation of stress may be linked to T cells’ role in learning. Stress can signal macrophages to secrete proinflammatory cytokines, some of which block a protein called brain-derived neurotrophic factor (BDNF), which astrocytes need to support learning and memory. CD4+ T cells in the meninges make more IL-4 cytokine after mice have been trained in a water maze—a stressful exercise for the animals—suggesting the signaling molecule might let macrophages know when the brain is dealing with the stress of learning something new, not the stress of an infection. “They tell macrophages, ‘Don’t overshoot,’” says Kipnis. In mice whose meninges are depleted of CD4+ T cells and thus deficient for IL-4, macrophages secrete proinflammatory factors unchecked in times of stress, disrupting their ability to learn and form memories.”

But excess suppression of inflammatory activity in the brain could have unwanted consequences as in the case of mast cells:

“Best known for their involvement in allergic responses in the upper airway, skin, and gastrointestinal tract, mast cells have been found in the meninges as well as in perivascular spaces of the thalamus, hypothalamus, and amygdala. They are known to quickly recruit large numbers of other immune cell types to sites of inflammation, and to play a role in MS. But mast cells also release serotonin into the hippocampus, where the molecule aids neurogenesis, supports learning and memory, and regulates anxiety.”

A ‘goldilocks zone’ for immune activity in the brain

As in every condition clinical evaluation must embrace the whole context…

“Thus, like microglia, mast cells are a double-edged sword when it comes to neural health. It’s a reflection of the entire immune system’s love-hate relationship with the CNS, Kipnis says. “Saying the immune system is always good for the brain, it’s wrong; saying it’s always bad for the brain, it’s wrong. It depends on the conditions.”

Neuroscientist Michal Schwartz — Breaking The Wall Between Body and Mind

 

Leaky gut: inflammation, chronic fatigue and depression

Neuroendocrinology Letters--leaky gut and chronic fatigueLeaky gut‘ is abnormal intestinal permeability that occurs when the epithelial tissues that comprise the gut barrier have been damaged. When intact the gut barrier prohibits antigenic contents of the intestines from access to the gut-associated lymphoid tissue (GALT) right on the other side of the intestinal wall. Gut barrier integrity (absence of leaky gut) is crucial to prevent loss of immune tolerance (autoimmunity) since the GALT comprises 60-80% of all immune tissue in the body.

Normalization of leaky gut improves chronic fatigue

LPS (lipopolysaccharide from bacterial cell walls) is so highly antigenic that it’s used as an adjuvant in vaccines. Translocation of LPS across a damaged gut barrier elicits systemic inflammation, accompanied by oxidative and nitrosative stress. A study published in Neuroendocrinology Letters demonstrates how normalization of the antibody responses to LPS not only ameliorates but can predict the clinical outcome in chronic fatigue syndrome (CFS). The authors state:

“There is now evidence that an increased translocation of LPS from gram negative bacteria with subsequent gut-derived inflammation, i.e. induction of systemic inflammation and oxidative & nitrosative stress (IO&NS), is a new pathway in chronic fatigue syndrome (CFS).”

They investigated this by measuring serum concentrations of IgA and IgM to LPS of several gram-negative enterobacteria CFS patients, both before and after intake of natural anti-inflammatory and anti-oxidative substances (NAIOSs), such as glutamine, N-acetyl cysteine and zinc, while consuming a leaky gut diet during 10-14 months. They also measured corresponding result with the Fibromyalgia and Chronic Fatigue Syndrome Rating Scale in 41 patients with CFS before and after 10-14 months on the NAIOSs.

Good clinical response to lowered IgA and IgM

The improvement in CFS scores that they documented was very gratifying:

Subchronic intake of those NAIOSs significantly attenuates the initially increased IgA and IgM responses to LPS of gram negative bacteria. Up to 24 patients showed a significant clinical improvement or remission 10-14 months after intake of NAIOSs. A good clinical response is significantly predicted by attenuated IgA and IgM responses to LPS, the younger age of the patients, and a shorter duration of illness (< 5 years).”

The authors’ comments on their data can hardly be overemphasized for clinicians participating in case management of chronic fatigue and fibromyalgia:

“The results show that normalization of the IgA and IgM responses to translocated LPS may predict clinical outcome in CFS. The results support the view that a weakened tight junction barrier with subsequent gut-derived inflammation is a novel pathway in CFS and that it is a new target for drug development in CFS. Meanwhile, CFS patients with leaky gut can be treated with specific NAIOSs and a leaky gut diet.”

High IgA response to normal gut bacteria fires up inflammation in CFS

Journal of Affective DisordersAn interesting study published in the Journal of Affective Disorders documents how LPS from commensal gut bacteria that translocates into the GALT provokes inflammation that drives CFS. The authors note:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is accompanied by a) systemic IgA/IgM responses against the lipopolysaccharides (LPS) of commensal bacteria; b) inflammation, e.g. increased plasma interleukin-(IL)1 and tumor necrosis factor (TNF)α; and c) activation of cell-mediated immunity (CMI), as demonstrated by increased neopterin.”

These authors investigated the IgA/IgM responses to the LPS of 6 different enterobacteria by measuring serum IL-1, TNFα, neopterin, and elastase in 128 patients with ME/CFS and chronic fatigue (CF). When they correlated with biomarkers for inflammation, CMI and the symptoms of ME/CFS the results were noteworthy:

“Serum IL-1, TNFα, neopterin and elastase are significantly higher in patients with ME/CFS than in CF patients. There are significant and positive associations between the IgA responses to LPS and serum IL-1, TNFα, neopterin and elastase. Patients with an abnormally high IgA response show increased serum IL-1, TNFα and neopterin levels, and higher ratings on irritable bowel syndrome (IBS) than subjects with a normal IgA response. Serum IL-1, TNFα and neopterin are significantly related to fatigue, a flu-like malaise, autonomic symptoms, neurocognitive disorders, sadness and irritability.”

This is extremely important in clinical practice due to the great functional significance of both systemic inflammation and autonomic nervous system regulation. The authors conclude:

“The findings show that increased IgA responses to commensal bacteria in ME/CFS are associated with inflammation and CMI activation, which are associated with symptom severity. It is concluded that increased translocation of commensal bacteria may be responsible for the disease activity in some ME/CFS patients.”

Autoimmune attack on serotonin production

Another fascinating paper also published in the Journal of Affective Disorders reveals that bacterial translocation through the gut barrier into immune lymphoid tissue can provoke antibodies that attack 5-HT, the precursor of serotonin, contributing to chronic fatigue and depression. The authors state:

“Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is accompanied by activation of immuno-inflammatory pathways, increased bacterial translocation and autoimmune responses to serotonin (5-HT). Inflammation is known to damage 5-HT neurons while bacterial translocation may drive autoimmune responses. This study has been carried out to examine the autoimmune responses to 5-HT in ME/CFS in relation to inflammation and bacterial translocation.”

The examined 117 patients with ME/CFS for autoimmune activity against 5-HT, measuring plasma interleukin-1 (IL-1), tumor necrosis factor (TNF)α, neopterin and the IgA responses to Gram-negative bacteria. This was correlated with the fibromyalgia and chronic fatigue syndrome rating scale. Their data show a strong association:

“The incidence of positive autoimmune activity against 5-HT was significantly higher (p<0.001) in ME/CFS (61.5%) than in patients with CF (13.9%) and controls (5.7%). ME/CFS patients with 5-HT autoimmune activity displayed higher TNFα, IL-1 and neopterin and increased IgA responses against LPS of commensal bacteria than those without 5-HT autoimmune activity. Anti-5-HT antibody positivity was significantly associated with increased scores on hyperalgesia, fatigue, neurocognitive and autonomic symptoms, sadness and a flu-like malaise.”

This is very significant for clinicians involved in case management of fatigue, depression, chronic pain and autonomic dysregulation. The authors sum it up:

“The results show that, in ME/CFS, increased 5-HT autoimmune activity is associated with activation of immuno-inflammatory pathways and increased bacterial translocation, factors which are known to play a role in the onset of autoimmune reactions…These results provide mechanistic support for the notion that ME/CFS is a neuro-immune disorder.”

Leaky gut, LPS and depression

Yet another study in the same journal investigated increased IgA and IgM antibodies aimed at gut commensal bacteria specifically in depression. The authors measured antibodies directed against Hafnia alvei, Pseudomonas aeruginosa, Morganella morganii, Pseudomonas putida, Citrobacter koseri, and Klebsiella pneumoniae in depressed patients and normal controls, and found a very significant correlation to symptoms of depression and fatigue:

“The prevalences and median values of serum IgM and IgA against LPS of these commensals were significantly higher in depressed patients than in controls. The IgM levels directed against the LPS of these commensal bacteria were significantly higher in patients with chronic depression than in those without. The immune responses directed against LPS were not associated with melancholia or recurrent depression. There was a significant correlation between the IgA response directed against LPS and gastro-intestinal symptoms.”

Clinical note

The treatment of chronic fatigue and depression demands a holistic, multidisciplinary approach. A core feature with a number of potential contributing causes that can vary in each case is up-regulation of immune pathways driving inflammation in the brain and against elements in neurotransmitter production. The authors highlight these considerations in their discussion:

“The results indicate that increased bacterial translocation with immune responses to the LPS of commensal bacteria may play a role in the pathophysiology of depression, particularly chronic depression…The findings suggest that “translocated” gut commensal bacteria activate immune cells to elicit IgA and IgM responses and that this phenomenon may play a role in the pathophysiology of (chronic) depression by causing progressive amplifications of immune pathways.”

Compounds that modulate neuroinflammation induced by LPS

Neurochemistry InternationalA wide range of therapeutic resources are available to the functional practitioner to employ, depending on the individual case, that can ameliorate autoimmune inflammation triggered by reactions to the LPS of bacteria translocated through a leaky gut. By way of one example among many, a paper published in Neurochemistry International shows that anthocyanins (polyphenolic compounds imparting a blue color, found in vegetation such as blueberries) can ameliorate inflammation triggered by reactions to LPS.

“Several studies provide evidence that reactive oxygen species (ROS) are key mediators of various neurological disorders. Anthocyanins are polyphenolic compounds and are well known for their anti-oxidant and neuroprotective effects. In this study, we investigated the neuroprotective effects of anthocyanins (extracted from black soybean) against lipopolysaccharide (LPS)-induced ROS-mediated neuroinflammation and neurodegeneration in the adult mouse cortex.”

This benign intervention produced a gratifying result:

“The immunoblotting and morphological results showed that anthocyanins treatment significantly reduced LPS-induced-ROS-mediated neuroinflammation through inhibition of various inflammatory mediators, such as IL-1β, TNF-α and the transcription factor NF-kB…Anthocyanins also prevent overexpression of various apoptotic markers, i.e., Bax, cytosolic cytochrome C, cleaved caspase-3 and PARP-1. Immunohistochemical fluoro-jade B (FJB) and Nissl staining indicated that anthocyanins prevent LPS-induced neurodegeneration in the mouse cortex.”

Of particular note to the clinician:

“Our results suggest that dietary flavonoids, such as anthocyanins, have antioxidant and neuroprotective activities that could be beneficial to various neurological disorders.”

Calcium supplementation may increase risk for dementia

NeurologyCalcium supplementation continues to come under scrutiny as evidence accumulates that it can increase the risk of inflammatory disorders, most notably cerebrovascular disease, likely by opposing the anti-inflammatory effects of magnesium. A study just published in the journal Neurology offers evidence that supplementation can increase the risk for dementia in women with cardiovascular disease. The authors set out to…

“…determine whether calcium supplementation is associated with the development of dementia in women after a 5-year follow-up.”

700 dementia-free women aged 70–92 years were examined at baseline and at follow-up 5 years later with comprehensive neuropsychiatric and physical examinations. 447 underwent CT scans at baseline. Dementia was diagnosed according to DSM-III-R criteria, and this was correlated with information on the use and dosage of calcium supplements.

Calcium supplementation dramatically increased the risk for dementia

Neurology 2The risk more was increased almost 7 times for the subset of women with a history of stroke, and tripled for those with white matter lesions, in comparison to similar subjects who did not supplement:

Women treated with calcium supplements (n = 98) were at a higher risk of developing dementia (odds ratio [OR] 2.10) and the subtype stroke-related dementia (vascular dementia and mixed dementia) (OR 4.40) than women not given supplementation (n = 602)….supplementation was associated with the development of dementia in groups with a history of stroke (OR 6.77) or presence of white matter lesions (OR 2.99), but not in groups without these conditions.”

Correspondence with previous studies

This was a relatively small study, but the findings correspond to earlier evidence that supplementation can increase the burden of systemic inflammation (some have been written about here). It opposes the absorption and action of magnesium, a likely mechanism accounting for these observations. Recall that osteoporosis is not a calcium deficiency disorder, rather a failure to maintain the protein matrix of bone to which the minerals attach. Though it was only subjects with a history of cerebrovascular disease or white matter lesions for whom the risk of dementia was markedly increased, clinicians should consider very carefully before recommending supplementation. The authors conclude:

Calcium supplementation may increase the risk of developing dementia in elderly women with cerebrovascular disease.”

Alzheimer’s disease and blood-brain barrier leakage

RadiologyAlzheimer’s disease is not a unitary condition but variable in causation at the individual level like all complex chronic disorders. Neuroinflammation, metabolic damage, vascular compromise, accumulation of noxious debris (amyloid β and tau), impairments in brain CSF and lymphatic drainage and other causes can all variously contribute to Alzheimer’s and other dementias. Now original research recently published in the journal Radiology demonstrates that leakiness of the blood-brain barrier (BBB) can permit an environment hostile to neuronal health that contributes to cognitive decline, Alzheimer’s and other dementias. The authors state:

“Evidence is increasing that impairment of the cerebral microvasculature is a contributing factor in the pathophysiology of Alzheimer disease (AD). However, the exact pathway remains unclear. Results of histologic evaluation and albumin sampling studies show that an increased permeability of the blood-brain barrier (BBB) is likely a key mechanism.”

An intact blood-brain barrier is essential for brain health

The BBB is a collection of cells and other structures in the cerebrovascular wall that when healthy permits only privileged access into the brain from the extra-cerebral blood compartment.

“It regulates the delivery of important nutrients to the brain through active and passive transport mechanisms and prevents neurotoxins from entering the brain. It also has a clearance function, meaning that it removes surplus substances from the brain. A well-functioning BBB is essential to keeping the brain tissue in a healthy condition. Results of previous studies suggest that deterioration of the BBB can cause an ill-conditioned environment for neuronal cells and other pathologic changes such as small-vessel abnormality, protein deposits, inflammation, and neuronal cell death. These changes eventually may lead to cognitive decline and dementia.”

Early Alzheimer’s shows abnormal BBB permeability

Blood-brain barrier degradation has earlier been demonstrated in advanced Alzheimer’s disease. Here the authors examined whether or not BBB leakage contributes to the early stages of disease.

“To investigate whether BBB leakage contributes to the early pathophysiology of AD, we hypothesized that patients with early forms of AD already show increased BBB permeability in comparison with age-matched control subjects. For this pilot study, we used a dedicated dynamic contrast-enhanced MR imaging acquisition protocol with dual-time resolution that separates the filling of the blood vessels from the leakage. We also investigated differences in local blood plasma volume fraction, and the relationship between BBB permeability and global cognition.”

The analyzed data for patients diagnosed with mild cognitive impairment (MCI) due to AD or patients or patients with early AD (a continuum of cognitive decline who had been referred by general practitioners because of memory concerns, in comparison with healthy controls. Individuals with dementia of vascular origin were excluded, as were those with major cardiovascular and neuropsychiatric disorders, Parkinson’s, MS, trauma, major structural abnormalities of the brain, and alcohol or drug abuse. They indeed demonstrated a marked distinction between their study subjects and controls:

“The BBB leakage rate was significantly higher in patients compared with that in control subjects in the total GM (grey matter) and cortex but not in the WM, normal-appearing WM, deep GM, or WM hyperintensities…When adjustments were made for all covariates, the patients exhibited a significantly higher leakage volume in the WM and GM and also in the normal-appearing WM, deep GM, cortex, but not in WM hyperintensities…The median blood plasma volume was significantly lower in the patients than in the control subjects in all tissue classes.”

BBB leakage rate shown in early Alzheimer's

BBB leakage rate shown on the right, with some periventricular hot spots

BBB leakage in early Alzheimer’s is widespread

The leakage is not due to vascular abnormalities, and leakage volume was even more striking than rate:

The results of this study showed increased BBB leakage in patients with early AD. The leakage was globally distributed throughout the cerebrum and was associated with declined global cognitive performance. By using dynamic contrast-enhanced MR imaging with dual-time resolution, we found an increased BBB leakage rate in the GM of patients with early AD. By also showing very subtle BBB impairment in the WM, leakage volume proved to be even more sensitive to the differences in BBB leakage than was the leakage rate. Not only did this show that the differences between patients with early AD and healthy control subjects were in the extent of the BBB leakage rather than the rate (ie, strength), but it also showed that the leakage was widespread rather than localized to a single tissue class such as WM hyperintensities, normal-appearing WM, or cortex. In addition, the BBB impairment did not fully originate from vascular abnormality, because adding diabetes and other noncerebral vascular diseases to the analysis model did not change the results. This suggested that the BBB impairment stemmed from the AD abnormality instead of from vascular comorbidities.”

Breakdown in tight junctions like the intestinal barrier

The intestinal barrier, critical for healthy immune system regulation, loses integrity with a breakdown of the tight cellular junctions. So too with the blood-brain barrier.

“The leakage observed in this study can be explained as a breakdown of the BBB tight junctions. It has been shown in rodents that tight junction damage allows gadolinium leakage through the BBB. The regions with high BBB leakage were diffusely distributed throughout the brain, showing that BBB tight junctions were globally impaired. This could have allowed the passage of small and lipophilic molecules that could not cross a healthy BBB. The loss of tight junctions also changes cell polarity, which influences the expression of transporter complexes and thus indirectly affects active transport across the BBB. Therefore, both passive and active transport mechanisms may be impaired in patients with early AD, possibly disturbing homeostasis.”

Toxic accumulations in the brain and cognitive impairment

The authors have demonstrated that BBB leakage tracks cognitive impairment in early Alzheimer’s:

“We found that cognitive decline was associated with stronger BBB leakage, and both the patients with MCI and those with early AD showed increased BBB leakage. These observations suggest that BBB impairment may be a contributing factor in the early pathophysiology of AD. A possible mechanism is that loss of tight junctions impairs the filter function of the BBB, leading to a toxic accumulation of substances in the brain. This, combined with the altered active transport systems, might add up to a substantial effect on neuronal function that eventually leads to dementia.”

BBB and amyloid β

Clearance of amyloid β is also impaired:

“…amyloid β is actively transported across the BBB, whereas gadolinium leaks passively through the tight junctions. Previous work with positron emission tomographic data has shown that clearance of amyloid β is also impaired in patients with AD. An impaired clearance of amyloid β would mean that the BBB is impaired in different ways, contributing to the pathologic cascade leading to AD.”

Most importantly…

“Therefore, BBB leakage may help to provide a biomarker for early diagnosis, or at least a marker indicating vulnerability for the development of dementia. Successful prediction of dementia eventually might lead to optimized treatment, delay, or even prevention of the disease.”

Clinical note

Early diagnosis is key here, and for those of us without dynamic gadolinium contrast-enhanced MR imaging at hand I highly recommend the Blood Brain Barrier Permeability™ screen from Cyrex Labs (Array 20) which offers the clinician the ability to detect early changes in BBB permeability. Clinicians experienced in rehabilitation of the gut barrier will be familiar with resources to evaluate and remediate inflammation and other insults to the blood-brain barrier.

The authors conclude:

“…in this pilot study, MR imaging was used to show global, diffusely distributed BBB leakage in patients with early AD, which suggests that a compromised BBB is part of the early pathology of AD and might be part of a cascade of pathologic events that eventually lead to cognitive decline.”

  • “Patients with early Alzheimer disease have significantly more tissue characterized by blood-brain barrier leakage than do healthy control subjects, both in the normal-appearing white matter and in the gray matter.
  • Blood-brain barrier leakage in the gray matter correlates with lower scores on the Mini-Mental State Examination.”

Mood disorders and thyroid autoimmunity

PLOS ONEMood disorders and thyroid autoimmunity are linked by aberrant levels of hematopoietic/neuronal growth factors in an excellent study just published in PLOS One (Public Library of Science). Their fascinating data show how, even before hypothyroidism has developed, and also in relatives of thyroid autoimmunity subjects, growth factors necessary for healthy brain function are at levels associated with a range of mood disorders including bipolar, depression and psychosis. They also include an important reminder that antibodies can predict clinical disease years in advance.

Hypothyroidism predicted years in advance

The authors state:

“Autoimmune hypothyroidism is characterized by a combination of clinical features, elevated serum TSH with reduced free T4 (FT4) levels, the presence of serum antibodies against thyroid antigens, and reduced echogenicity of the thyroid sonogram. It is the most common organ-specific autoimmune disorder with an estimated prevalence of 2%, with a higher prevalence in women and depending on iodine intake. Thyroid peroxidase (TPO) is the major autoantigen and TPO antibodies (TPO-Abs) are present in almost all patients with autoimmune hypothyroidism and precede the clinical phase of autoimmune hypothyroidism by many years. Subclinical autoimmune hypothyroidism (the presence of TPO-Abs with raised TSH and normal FT4 levels) is even more prevalent and affects about 9% of the population. In the Whickham follow-up study, women with TPO-Abs had an eight-fold higher risk of developing clinically overt hypothyroidism over 20 years than did antibody-negative women.”

And family members have a pronounced risk of thyroid autoimmunity showing up down the road:

“In our own studies on the Amsterdam AITD [autoimmune thyroid disease] cohort (euthyroid females with at least one first or second degree relative with a documented autoimmune hyper- or hypothyroidism) TPO-Ab positivity at the start of the study also represented a higher risk to develop overt hypothyroidism in a follow-up of 5 years. In addition, there was a higher conversion rate from TPO-Abs negativity to positivity, showing a familial proneness for thyroid autoimmune reactivity.”

And in another earlier study normal thyroid relatives showed a slew of abnormalities including a ‘background’ higher inflammatory state:

“We concluded that euthyroid females within AITD families show a characteristic pattern of abnormalities in serum levels of growth factors, chemokines, adhesion molecules and cytokines, suggesting an already compromised thyroid-immune system interaction in the euthyroid family members. Also, pre-seroconversion stages might be predicted using serum analytes pointing to a higher inflammatory state.”

Mood disorders and AITD

The emerging evidence shows that depression in association with autoimmune thyroid disease is caused by more than lower thyroid hormone in the brain. Just the presence of anti-thyroid antibodies while thyroid hormone levels are still normal is associated with increased risk of anxiety and mood disorders.

“Autoimmune hypothyroidism is commonly accompanied by depressive symptoms. A large epidemiological Danish nationwide, prospective cohort study showed that various autoimmune diseases including AITD, are associated with subsequent lifetime mood disorder diagnosis (e.g. bipolar affective disorder, unipolar depression, psychotic depression and other remaining mood disorders). In hypothyroid patients the lack of thyroid hormone in the brain is likely an important determinant for these mood disturbances. However, a deficit of thyroid hormone may not be the only cause, as even subjects with TPO-Abs with normal thyroid function have a higher risk to develop anxiety disorders and mood disorders.”

And further evidence supports the assertion of a shared pathogenesis for autoimmune thyroid disease and mood disorders:

“Also offspring of patients with a bipolar affective disorder have a higher prevalence of TPO-Abs, even if they are not affected by the psychiatric disorder. In addition, a higher prevalence of TPO Abs and autoimmune hypothyroidism has been reported in patients with bipolar affective disorder, irrespective of the usage of lithium. Taken together, these associations might imply a shared immune pathogenesis for both AITD and mood disorders.”

Brain growth factors and AITD

To explore this relationship the authors examined data for 64 TPO-Ab-negative females with relatives with AITD. 32 of these subjects did and 32 did not seroconvert to TPO-Ab positivity in their 5-year follow-up. These were compared with 32 healthy controls (HCs). Importantly, they measured serum levels of brain-derived neurotrophic factor (BDNF), Stem Cell Factor (SCF), Insulin-like Growth Factor-Binding Protein 2 (IGFBP-2), Epidermal Growth Factor (EGF) and IL-7.

“We therefore additionally determined, in the sera used in the previous study, 5 growth and differentiation factors that have repeatedly* been shown to be abnormally expressed in the circulation of mood disorder patients and that are capable of influencing both immune and/or neuronal cell growth, i.e. SCF, IGFBP-2, EGF, BDNF and IL-7. In addition we studied the inter relationship of these factors with the previously determined factors using a cluster analysis to study patterns of TPO-Ab seroconversion.”

* Authors’ emphasis.

Even relatives of AITD patients are at higher risk of mood disorders

Their data showed an eye-opening correlation:

BDNF was significantly lower (8.2 vs 18.9 ng/ml, P<0.001), while EGF (506.9 vs 307.6 pg/ml, P = 0.003) and IGFBP-2 (388.3 vs 188.5 ng/ml, P = 0.028) were significantly higher in relatives than in HCs. Relatives who seroconverted in the next 5 years had significantly higher levels of SCF than non-seroconverters (26.5 vs 16.7 pg/ml, P = 0.017). In a cluster analysis with the previously published growth factors/cytokines SCF clustered together with IL-1β, IL-6 and CCL-3, of which high levels also preceded seroconversion.”

Serum levels of growth and differentiation factors

Serum levels of growth and differentiation factors in healthy controls (C), Seroconverting (SC) and Non-Seroconverting (NSC) family members.

In other words, abnormal levels of growth factors necessary for brain health and higher levels of biomarkers for inflammation were both observed. Bear in mind that BDNF (brain derived neurotrophic factor) in particular has been identified as important for neurogenesis, plasticity and synaptic transmission. BDNF deficiency is associated with disorders of mood, cognition and memory. And an increase in BDNF is though to be a mechanism by which exercise (and certain medications) exert a beneficial effect on brain-based conditions.

“It is of note that the 5 studied factors have been highlighted as serum biomarkers for major mood disorders in several studies and are involved in neurogenesis, neuroprotection and hematopoietic differentiation. This is in particular known for BDNF. Neurotrophic factors, like BDNF, play an important role in neuronal plasticity, modulating not only axonal and dendritic growth and remodeling, but also neurotransmitter release and synapse formation.”

This makes striking the finding that even euthyroid (normal thyroid) relatives of autoimmune thyroid subjects are at higher risk of mood disorders with markedly lower levels of BDNF.

“The present study shows that euthyroid females, who are relatives of AITD patients and at risk of developing AITD, have an aberrant serum level of 4 of the 5 tested hematopoietic/neuronal growth and differentiation factors, i.e. of BDNF, IGFBP-2, EGF and SCF. BDNF levels were significantly lower and IGFBP-2 and EGF higher expressed in sera of the relatives of the AITD patients (in both SCs and NSCs) than in healthy controls. IL-7 levels were normal. We also found in the healthy relatives, who converted in the following 5 years to TPO-Ab positivity, significantly higher serum levels of SCF than in relatives who did not.”

Earlier diagnosis

This certainly underscores the clinical significance of predictive (low levels of) anti-thyroid antibodies. It also invites the possibility of even earlier diagnoses and interventions as stated by the authors:

“This study and the previous one therefore underscore the widespread changes in immune-neuro-endocrine molecular networks that apparently precede the appearance of TPO-Abs, which opens avenues for developing assays for the detection of individuals at risk for thyroid autoimmunity.”

Moreover…

“We assume that the generally low expression in NSCs in cluster A reflects an immune suppressive state preventing autoimmunity, while a rise of these pro-inflammatory compounds precedes a conversion to TPO-Ab positivity and thus may reflect a very early stage of thyroid auto reactivity.”

Clinical Note

This presents the tantalizing possibility of very early diagnosis and the opportunity to intervene in thyroid and mood disorders at the earliest possible stage when easiest to treat. Meanwhile, clinicians should be attentive to even low levels of anti-thyroid antibodies.

The authors summarize:

“We conclude that subjects at risk for AITD show changes in growth and differentiation factors in serum, which are both active as neuronal and hematopoietic growth and differentiation factors and are abnormally expressed in patients with mood disorders. This suggests that shared growth and differentiation defects in both the hematopoietic and neuronal system may underlie both thyroid autoimmunity and mood disorders.”

Colleagues interested in our practice model incorporating predictive antibodies and bioidentical (human recombinant) low dose BDNF are welcome to contact.

Insulin in the brain affects cognition, appetite and weight

Nature Reviews EndocrinologyInsulin has long been known as crucial for muscle, liver and adipose tissue metabolism. It’s effect in the brain on cognition, behavior and physiology is a more recent focus described in an excellent paper published recently in Nature Reviews Endocrinology.

The brain is sensitive to insulin

Since glucose uptake into the brain occurs independently it took a while to recognize the function of the receptors that are found there. The first clue came with the brain-specific knockout mouse model of the insulin receptor.

“Such knockout mice became obese due to increased food intake and developed whole-body insulin resistance with increased plasma levels of insulin and dyslipidaemia.”

Insulin-sensitive brain areasThen investigations comparing infusion of insulin versus saline on human brain activity has widespread effects.

“…these studies provided strong evidence that systemic insulin administration modulates cortical brain activity in humans…not only homeostatic areas (as shown in animal studies) but also higher functional areas involved in sensory and cognitive processes.”

And intranasal administration was shown to affect basal and evoked brain activity. How does it naturally get there?

Whole body insulin resistance affects the brain

“…various studies in animals clearly demonstrated that insulin was transported across the blood–brain barrier by a saturable transport system…”

And it humans it gets from the CSF (cerebrospinal fluid) through the BBB (blood brain barrier).

“Concentrations of insulin in the CSF increase when the hormone is administered into the bloodstream, again indicating transport across the blood–CSF barrier.”

Importantly, insulin resistance in the rest of the body affects the brain, and this has been associated with Alzheimer’s disease.

Insulin transport into CSF is attenuated in individuals with reduced whole-body insulin sensitivity, which suggests that insulin resistance at the blood–CSF barrier could impair transport of the hormone into the brain. Accordingly, insulin concentrations in CSF are lower in individuals with obesity, who are generally more insulin resistant, than in people without obesity. Furthermore, insulin concentrations within brain tissue and CSF are reduced in older individuals…In Alzheimer disease, a condition often associated with insulin resistance, insulin levels in the CSF have been reported to be reduced.”

 

Circadian rhythms of inflammation

Arthritis Research & TherapyCircadian variation of symptoms caused by inflammation is common to conditions including rheumatoid arthritis, polymyalgia rheumatica, ankylosing spondylitis, asthma, depression and many more. The adrenal circadian rhythm is an important factor when serum cortisol is inadequate relative to inflammation. An excellent paper published in Arthritis Research & Therapy examines the dynamics and clinical significance of circadian variation in inflammation associated with glucocorticoid regulation, an important consideration for anti-inflammatory treatment.

Brain’s central circadian oscillator connects with immune system

The suprachiasmatic nucleus of the hypothalamus that generates the circadian rhythm connects profusely to other brain centers and to the immune system through the HPA axis.

“The circadian activity of this particular nucleus is transferred to the immune system via the hypothalamic hypothalamic-pituitary-adrenal (HPA) axis, leading to the typical undulation of clinical symptoms in chronic inflammatory diseases with a maximum in the early morning hours. In this review we will describe circadian rhythms in rheumatoid arthritis (RA) and other rheumatic and chronic inflammatory diseases, dysfunction of the HPA axis in RA and other rheumatic and chronic inflammatory diseases, the problem of adrenal suppression by glucocorticoid (GC) therapy, and whether or not chronotherapy with prednisone is more effective and aggravates adrenal suppression.”

This pertains to the classic aggravation of stiffness and pain in the morning as well as the oscillation of other symptoms caused by inflammation, including neuropsychiatric disorders.

Nocturnal inflammation, melatonin and cortisol

As melatonin goes up at night cortisol, which ‘keeps a lid on’ inflammation, goes down and inflammatory biomarkers are seen to increase.

“Classical symptoms of RA, such as morning stiffness and swelling, show a clear temporal relationship with nocturnally elevated levels of proinflammatory cytokines, as a consequence of a cascade of increased nocturnal inflammation. Several of these cytokines, such as tumor necrosis factor (TNF) alpha and interleukin (IL)-6, are highly increased in patients with active RA in the early hours of the day, but are found at very low levels after noon.”

This is characteristic of a healthy cortisol rhythm…

“Also, the cortisol rhythm – which is also present in healthy individuals, and therefore is primary, with low levels at night – may explain nocturnal inflammation. Since cortisol is the strongest endogenous anti-inflammatory substance, its downregulation during the evening and night is linked to an increase of inflammation during the early morning, and its upregulation in the early morning is most probably related to inhibition of inflammation during the day. The early morning inflammatory signs, typical for many inflammatory rheumatic conditions, can thus be explained.”

Polymyalgia rheumatica, ankylosing spondylitis and asthma

These conditions too have cyclic undulations that correspond to the circadian rhythm of immune activity, with implications for treatment.

“Furthermore, in polymyalgia rheumatica (PMR), symptoms of pain and stiffness typically are most prominent during the early morning, similar to RA…Of note, in ankylosing spondylitis – another inflammatory arthritic condition – pain and stiffness also seem to be most prominent during the early morning hours. Finally, it is now also evident that symptoms of diseases such as RA, which is T helper 1 dependent, but also asthma, which is T helper 2 dependent, are influenced by diurnal rhythms and natural regulatory T cells. In particular, secretion of IL-2, interferon gamma and IL-10 by naïve CD4+ T cells follows a diurnal rhythm.”

This ties together the nervous, immune and hormonal systems that interact in a rhythmic fashion:

“All of these processes are closely linked to regulatory interactions between the endocrine, nervous and immune systems, with distinct 24-hour daily rhythms (neuroendocrine immunology).”

HPA axis dysfunction in chronic inflammatory disorders

HPA axis function in inflammationNormally the adrenocortical response should track the circadian oscillator or inflammation. The authors describe a fascinating study in which the cortisol response to infusions of the pro-inflammatory cytokine IL-6 were delineated:

“In a fairly heroic study in 18 healthy young men, either saline or low or high doses of recombinant human IL-6 were infused into one femoral artery for 3 hours. Subjects experienced clinical symptoms such as shivering and discomfort during high-dose IL-6 administration, but were asymptomatic during low-dose IL-6 administration. Plasma cortisol concentrations did not change during infusion of saline but markedly increased during both high and low doses of IL-6. While concentrations of plasma cortisol declined after 2 hours of infusion in low doses of IL-6, they remained elevated in high doses of IL-6 at 3 hours of infusion…The increase of cortisol levels in reaction to IL-6 infusion is provoked by activation of the HPA axis. Remarkably, the relation between IL-6 levels and the adrenocorticotropic hormone (ACTH)/cortisol levels is linear. In a study of 15 healthy young men in which recombinant IL-6 was applied subcutaneously, plasma ACTH concentrations and plasma cortisol levels increased dose dependently, and the ratio of hormone to IL-6 serum levels was constant.”

By contrast however, in chronic inflammation levels of cortisol are insufficient to ‘put out the fire.’

In chronic inflammation, cortisol secretion appears to be inadequate in relation to inflammation. In a retrospective study with 34 patients with RA, 46 patients with reactive arthritis and 112 healthy subjects, the authors measured serum levels of IL-6, TNF and cortisol. The absolute levels of IL-6 were lower in healthy controls than in reactive arthritis and RA patients. However, the ratio of serum cortisol to serum cytokines was much higher in healthy controls than in reactive arthritis and RA patients, due to similar cortisol levels in all groups.”

And in another RA study…

“…comparing the circadian course of ACTH and cortisol levels in patients with RA and in healthy subjects, despite 10 times higher serum levels of cytokines in patients with RA, serum level curves of ACTH and cortisol were identical. The ACTH/cortisol hormone secretion in patients with RA is thus inadequate in relation to inflammation.”

And giant cell arteritis…

“In a study comparing serum values of ACTH, cortisol and CRP in patients with PMR/giant cell arteritis and controls, ACTH and cortisol levels were not different in patients with PMR/giant cell arteritis and controls, whereas the ratios of serum ACTH/serum CRP and serum cortisol/serum CRP were significantly lower in PMR/giant cell arteritis patients than in healthy controls. Thus, in PMR/giant cell arteritis there also appears to be an inadequate cortisol secretion in relation to inflammation in terms of relative adrenal insufficiency.”

The liver-HPA-kidney axis in chronic inflammation

In important observations that call to mind principles of traditional Chinese medicine (TCM), the authors delineate the function of hepato-hypothalamic-pituitary-adrenal-renal axis:

“Recently, evidence has accumulated, been reviewed and presented as a concept that dysfunction of the HPA axis in chronic inflammation is not simply an adaptation to chronic stress, but may be due to increased negative feedback of active cortisol on the HPA axis. The HPA axis has been recognized to be extendable to a hepato-hypothalamic-pituitary-adrenal-renal axis by GC [glucocorticoid] metabolism.”

The liver in chronic inflammation

HPA axis dysfunction in inflammationThe kidney inactivates cortisol to protect its receptor from over-stimulation and subsequent suppression, and the liver turns it back on:

“Active cortisol is converted to inactive cortisone mainly by the kidney, via 11β-hydroxysteroid dehydrogenase (11β-HSD) type 2, in order to protect the nonspecific mineralocorticoid receptor from activation by cortisol. On the other hand, the major organ for converting inactive cortisone to active cortisol is the liver, via 11β-HSD1.”

Pro-inflammatory cytokines over-activate the liver 11β-HSD1 enzyme:

Expression of 11β-HSD1 is markedly enhanced by TNF and proinflammatory cytokines. The liver therefore becomes an important player in systemic inflammation, even if the conversion also occurs in multiple other tissues including the brain, adipocytes, vascular cells, osteoblasts and fibroblasts. Given the role of the 11β-HSD1 in GC metabolism, its effect on the HPA axis and its interaction with inflammatory cytokines, it is hypothesized that in chronic inflammatory diseases, cytokine-induced increased expression of 11β-HSD1 induces a change in the HPA axis. Increased negative feedback of active cortisol on the HPA axis induced during inflammation may thus be the mechanism of dysfunction of the HPA axis in chronic inflammation.”

Tertiary adrenal insufficiency

Synthetic glucocorticoids such as prednisone suppress adrenal function through the same negative feedback mechanism:

“During the physiological regulation of the HPA axis, cortisol release is terminated by negative feedback regulation of cortisol on the hypothalamus and anterior pituitary. Also, synthetic GCs – as applied in GC therapy – can cause negative feedback regulation, leading to adrenal suppression in terms of tertiary adrenal insufficiency.”

Besides the clinical presentation, this can be confirmed by low cortisol and ACTH levels and lack of increase in plasma cortisol with the corticotropin-releasing hormone (CRH) or ACTH stimulation test. The magnitude of the dose matters:

“The frequency of adrenal suppression increases with increasing GC dosages. In arthritis and asthma patients treated with prednisone equivalent doses ranging from 5 to 20 mg, cortisol response in the ACTH test was normal (that is, cortisol rise ≥7 μg/dl) in all of the patients taking a single morning dose of 5 to 7.5 mg prednisone, was blunted (that is, cortisol rise <7 μg/dl) in 33% and 47% of the patients taking 10 to 12.5 mg and 15 mg prednisone, respectively, and was suppressed (no rise) in 44% of the patients taking 20 mg prednisone.”

Duration also takes its toll:

After 12 weeks of 7.5 mg prednisolone, the mean values for the 60-minute response to ACTH were reduced by 35%. Following treatment, 46% of patients taking 7.5 mg prednisolone failed to reach the normal maximum cortisol response to ACTH, even if the HPA axis response generally remained within the normal range.”

Chronotherapy with prednisone

Primary concerns are maximizing effectiveness while minimizing adrenal suppression through negative feedback regulation. Several daily divided doses worsen the tendency to suppression:

“In the 1960s several studies confirmed that splitting the daily dose into several divided doses strongly increases the risk of adrenal suppression. For example, whereas endogenous cortisol secretion was not altered with a single dose of 8 mg triamcinolone given at 8:00 a.m., application of four divided 2 mg doses resulted in marked suppression of cortisol levels.”

Timing of the single dose also matters:

“The time point of application of the single daily dose also plays a role for adrenal suppression. This can be explained easily: circadian GC secretion exhibits two peaks, one large peak in the morning around 8:00 a.m. and a smaller peak in the afternoon around 2:00 p.m. Of note, cortisol levels are high during the first peak in the morning, causing downregulation of ACTH levels via negative feedback regulation. In consequence, cortisol secretion is also downregulated. At a certain point, reduced cortisol levels cause upregulation of ACTH again, leading in turn also to upregulation of cortisol secretion during the second peak in the afternoon. If exogenous GCs were applied in the evening, the so-called quiet period for the adrenal gland, this would cause a negative signal on ACTH and therefore also cortisol secretion in the morning.”

Note: With a healthy cortisol rhythm the afternoon “bump” in cortisol may be barely discernible. A single daily dose is easier to manage but many patients require two to control inflammation.

Several studies evaluating nocturnal doses at 2:00 a.m. yielded better results for morning stiffness than conventional morning doses. But the impracticality of dosing at 2:00 am plus questions about HPA suppression led to the development of a modified-release (MR) prednisone tablet that releases the dose four hours after ingestion (2 a.m. if taken at 10 p.m.).

MR prednisone produced a clinically relevant reduction of morning stiffness of the joints in addition to all known therapeutic effects of immediate-release prednisone…These results lead to the question of whether chronotherapy with MR prednisone affects adrenal suppression. The influence of long-term, low-dose chronotherapy with MR prednisone on the HPA axis was investigated by CRH tests in a subgroup of 28 patients in the CAPRA-1 study…There were no measurable differences in mean cortisol changes after CRH injection between baseline and the end of the study. Furthermore, there was no indication that changing treatments from immediate-release prednisone to MR prednisone increased the risk of HPA axis insufficiency, or resulted in deterioration of preexisting suppression.There was thus no difference between immediate-release prednisone and MR prednisone in numbers of normal/suppressed/no response reactions. In addition, no adverse events that could be attributed to HPA axis insufficiency were observed during treatment with low-dose MR prednisone for the entire treatment period of 12 months.”

Dosing at 2:00 a.m. (by modified release) may even benefit HPA axis activity:

“A recent study showed an increase of endogenous cortisol after 2 weeks of MR prednisone therapy in patients with active RA who had received no GCs by any route in the preceding 3 months. MR prednisone released at 2:00 a.m. suppressed the pathological early morning rise in plasma IL-6 in RA. The nocturnal rise in plasma cortisol was not suppressed but was enhanced with a peak value increase from 14.1 to 19.3 μg/dl, consistent with a changing relationship between HPA axis and immune system activation. This observation may be an indication that the HPA axis is preserved and is activated even more during MR prednisone treatment compared with pre-MR prednisone treatment.”

Clinical Note

Nutrition JournalMinimizing adrenal suppression while enhancing anti-inflammatory effectiveness by circadian dosing of prednisone also implies that effect of other anti-inflammatory agents can be enhanced by chronotherapeutic timing. Curcumin is one of the most extensively researched natural anti-inflammatory agents. A study published in the Nutrition Journal on the comparative absorption of curcumin formulations demonstrates that a newer preparation markedly extends the plasma concentrations of bioactive components including the key metabolite tetrahydrocurcumin.

“The potential health benefits of curcumin are limited by its poor solubility, low absorption from the gut, rapid metabolism and rapid systemic elimination. The purpose of this study was the comparative measurement of the increases in levels of curcuminoids (curcumin, demethoxycurcumin, bisdemethoxycurcumin) and the metabolite tetrahydrocurcumin after oral administration of three different curcumin formulations in comparison to unformulated standard.”

A curcumin phytosome formulation (CP), a formulation with volatile oils of turmeric rhizome (CTR) and a formulation of curcumin with a combination of hydrophilic carrier, cellulosic derivatives and natural antioxidants (CHC) were compared to a standardized curcumin mixture (CS). There was a dramatic result in favor of the CHC preparation.

“Total curcuminoids appearance in the blood was 1.3-fold higher for CTR and 7.9-fold higher for CP in comparison to unformulated CS. CHC showed a 45.9-fold higher absorption over CS and significantly improved absorption over CP (5.8-fold) and CTR (34.9-fold, all p < 0.001).”

Plasma concentrations time-curves for curcumin productsTetrahydrocurcumin is particularly valuable…

“Tetrahydrocurcumin plays an important role in the antioxidant mechanism of curcumin and has been shown to be the most potent antioxidant of the curcuminoids measured in this study. In addition, tetrahydrocurcumin has been reported to have health promoting benefits. It has been shown to have greater anti-inflammatory potency than curcumin in carrageenan-induced paw edema.”

The data shows that the CHC preparation yields high levels of curcuminoids that would sustain through the night into the morning if taken at bedtime to cover the critical inflammatory period when cortisol levels are naturally low. Adrenal suppression is, of course, not a concern with curcumin. This is advantageous not just for rheumatological disorders but all conditions involving chronic inflammation.

The authors of the first study conclude:

“From a GC perspective, circadian rhythms of the HPA axis and connected subsystems, including the immune system, appear to be essential for understanding of pathophysiology and treatment in rheumatology. The circadian rhythm of the HPA axis in chronic inflammatory diseases may be defective in terms of not bringing the body into a position to overcome the signs and symptoms of the disease. GC therapy serves as a necessary aid to overcome the disease and perhaps restore the deranged circadian rhythm. In a number of patients (around 50%), GC therapy causes adrenal suppression, probably mainly due to as yet undefined individual factors (apart from dose, substance and duration of therapy). In order not to aggravate adrenal suppression, GC therapy should be applied in accordance with the circadian rhythm, to achieve greatest efficacy along with highest safety. It has been suggested that when the single morning dose is not effective enough to achieve sufficient disease control, especially in patients with strong night symptoms and morning stiffness, split doses in the morning and afternoon, or chronotherapy with MR prednisone, can to some extent avoid aggravation of adrenal suppression.”

Evidence lacking for most common ADHD drug

Cochrane LibraryADHD in kids is most often medicated with methylphenidate (Ritalin®, Concerta®), but a comprehensive Cochrane Review finds there is little evidence showing that it really benefits. Because of the potential for harm experts urge caution. The authors note:

“Attention deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed and treated psychiatric disorders in childhood. Typically, children with ADHD find it difficult to pay attention, they are hyperactive and impulsive…Methylphenidate is the drug most often prescribed to treat children and adolescents with ADHD but, despite its widespread use, this is the first comprehensive systematic review of its benefits and harms.”

They set out to assess the beneficial and harmful effects of methylphenidate for children and adolescents by reviewing all randomised controlled trials (RCTs) comparing methylphenidate versus placebo (or no intervention) in children and adolescents aged 18 years and younger. They mined comprehensive data from six databases (CENTRAL, Ovid MEDLINE, EMBASE, CINAHL, PsycINFO, Conference Proceedings Citations Index), and two trials registers and contacted the pharmaceutical companies that manufacture methylphenidate for their published and unpublished data.

“We found 185 randomised controlled trials (RCTs; studies in which participants are randomly assigned to one of two or more treatment groups), involving 12,245 children or adolescents with a diagnosis of ADHD. Most of the trials compared methylphenidate to a placebo – something designed to look and taste the same as methylphenidate but with no active ingredient. Most trials were small and of low quality. Treatment generally lasted an average of 75 days (range 1 to 425 days), making it impossible to assess the long-term effects of methylphenidate. Seventy-two of the 185 included trials (40%) were funded by industry.”

Some ADHD symptoms might improve but the evidence is poor

Methylphenidate can have side effects including sleep problems and loss of appetite, and there is no scientific data on its long term effects—a grave consideration for a brain-modifying drug.

The quality of the evidence was very low for all outcomes. It was possible for people in the trials to know which treatment the children were taking, the reporting of the results was not complete in many trials and for some outcomes the results varied across trials. These considerations limit our confidence in the overall results of the review.

The lead authors lOle Jakob Storebø, PhD, clinical psychologist, Region Zealand, Roskilde, Denmark, and Morris Zwi, MBBCh, consultant child and adolescent psychiatrist, Whittington Health, London, UK, are quoted in Medscape Medical News:

“The evidence is not as convincing as many clinicians have believed regarding the benefits of methylphenidate…In general, our findings raise concerns about how much we should expect of this medicine, and there needs to be more caution when prescribing methylphenidate.”

Furthermore…

Clinicians need to weigh what we now believe to be an uncertain degree of benefit against the many adverse events that are known to be associated with methylphenidate, such as appetite suppression and sleep difficulties. The general perception of methylphenidate as an effective drug for all children with ADHD seems out of step with the new evidence. This new information from our review should challenge the mindset of clinicians because there is more uncertainty to factor in to balancing the benefits and risks of this medication.”

Clinical Note

Practitioners participating in case management of ADHD should overcome any bias and consider the authors’ conclusions:

“At the moment, the quality of the available evidence means that we cannot say for sure whether taking methylphenidate will improve the lives of children and adolescents with ADHD. Methylphenidiate is associated with a number of non-serious adverse events such as problems with sleeping and decreased appetite. Although we did not find evidence that there is an increased risk of serious adverse events, we need trials with longer follow-up to better assess the risk of serious adverse events in people who take methylphenidate over a long period of time.”

Improving brain health by treatment plans that target dysfunction and deficiencies with appropriate objective tests is preferable to medicating a stimulant that has side effects, uncertain benefit and unknown long term effects. For a list of fundamental methods of assessing brain physiology that can form the basis of a rational treatment plan download the free Parents’ Guide To Brain Health from Useful Links on the right.