Do inhaled corticosteroids for asthma increase diabetes risk?

Posted on January 17, 2011 by Dr. Jonathan

Oral corticosteroids such as prednisone have well-known side effects that include increased insulin resistance and risk for diabetes, but what if they are inhaled for chronic inflammatory respiratory conditions such as asthma? A study recently published in The American Journal of Medicine addresses this question. The authors first observe:

“Systemic corticosteroids are known to increase diabetes risk, but the effects of high-dose inhaled corticosteroids are unknown. We assessed whether the use and dose of inhaled corticosteroids increase the risk of diabetes onset and progression.”

The authors examined a cohort of 388,584 patients treated for respiratory disease during 1990-2005, then followed them through 2007 or until diabetes onset. (A subcohort treated with oral blood sugar lowering medication was followed until they developed diabetes.) They evaluated their data to estimate the rate ratios of diabetes onset and progression associated with ‘current’ inhaled corticosteroid use and adjusted for the relevant variables. Their data showed that among their study cohort…

“…30,167 had diabetes onset during 5.5 years of follow-up (incidence rate 14.2/1000/year), and 2099 subsequently progressed from oral hypoglycemic treatment to insulin (incidence rate 19.8/1000/year). Current use of inhaled corticosteroids was associated with a 34% increase in the rate of diabetes and in the rate of diabetes progression. The risk increases were greatest with the highest inhaled corticosteroid doses, equivalent to fluticasone 1000 μg per day or more.”

The authors’ conclusion should be considered not only for the case management of asthma (before significant markers for pre-diabetes and diabetes emerge), but for the metabolic and endocrine effects beyond respiratory disease:

“In patients with respiratory disease, inhaled corticosteroid use is associated with modest increases in the risks of diabetes onset and diabetes progression. The risks are more pronounced at the higher doses currently prescribed in the treatment of chronic obstructive pulmonary disease.”

More evidence to give your children vitamin D to prevent flu

Posted on October 7, 2010 by Dr. Jonathan

You’re probably aware of the profound importance of vitamin D for immune system regulation, and some of the earlier science that supports its use to prevent opportunistic infections. Now research just published in the American Journal of Nutrition adds more evidence for the use of vitamin D supplementation to prevent flu in kids attending school.

“From December 2008 through March 2009, we conducted a randomized, double-blind, placebo-controlled trial comparing vitamin D3 supplements (1200 IU/d) with placebo in schoolchildren. The primary outcome was the incidence of influenza A, diagnosed with influenza antigen testing with a nasopharyngeal swab specimen.”

The data showed that while 18.6% of the children in the placebo group came down with influenza A, only 10.8% in the vitamin D3 group did. Naturally…

“The reduction in influenza A was more prominent in children who had not been taking other vitamin D supplements…”

Their data yielded another interesting finding:

“In children with a previous diagnosis of asthma, asthma attacks as a secondary outcome occurred in 2 children receiving vitamin D3 compared with 12 children receiving placebo.”

That’s an 83% reduction in the relative risk of having an asthma attack. This is biologically plausible considering the importance of vitamin D for immune inflammatory disorders. The authors conclude by stating:

“This study suggests that vitamin D3 supplementation during the winter may reduce the incidence of influenza A, especially in specific subgroups of schoolchildren.”

Bear in mind, however, that individual needs vary greatly. The best way to objectively know that your child’s vitamin D needs are being met (or your own) is with a blood test for 25-hydroxy vitamin D.

Vitamin D for mold allergies

Posted on August 19, 2010 by Dr. Jonathan

Mold allergies are a vexing problem for many whose immune system is compromised, especially when exposure at home or work is unavoidable. Research just published in The Journal of Clinical Investigation provides welcome evidence that Vitamin D substantially reduces the allergic response to mold and promotes tolerance.

“The development of Th2 responses, as in asthma and allergic bronchopulmonary aspergillosis (ABPA), is driven by both genetic and environmental factors. Mechanistically, inhaled allergens are presented by lung DCs [dendritic cells] to naive T cells, which leads to induction of allergen-specific Th2 cells…In patients with ABPA, immunological responses to a variety of A. fumigatus [mold] antigens result in a heightened Th2 response and an elevated IgE level.”

To determine what determines a Th2 allergic response as opposed to Treg (regulatory T cell) tolerance the authors compared a groups of cystic fibrosis patients suffering from ABPA and and another group without it by measuring several key immune factors. Their findings have great practical significance:

“Furthermore, we discovered that ABPA correlated with vitamin D deficiency, and supplementation with vitamin D potentiated Treg-mediated regulation of Th2 reactivity…Patients with ABPA had significantly lower 25-OH vitamin D (the major circulating form of vitamin D3) levels compared with non-ABPA controls, and the mean level was significantly below the recommended level of 30 ng/ml in CF.”

Any doctor who is diligently testing their patients for Vitamin D insufficiency knows that suboptimal levels are surprisingly common. Could this have something to do with relative malnutrition, time of year or geographic location? The authors’ data says “no”:

“Notably, there was no significant difference in BMI or vitamin A and E levels between ABPA and non-ABPA patients, suggesting that the relative vitamin D deficiency was not associated with relative malnutrition… To exclude potential environmental/geographical differences in our cohort, we used geographical information systems (GIS) mapping to determine whether there was geographical clustering of ABPA patients versus non-ABPA patients; however, this analysis did not identify significant clustering… Finally, there was no significant difference in terms of month of accrual in the study between the ABPA or non-ABPA cohort… Taken together, these findings strongly suggest that the relative 25-OH vitamin D deficiency observed in ABPA patients was not a surrogate marker of another variable…”

This research adds to the immense body of evidence regarding the importance of Vitamin D for immune regulati0n and the treatment of allergies and autoimmune diseases (along with a host of other conditions). How can you reliably know your Vitamin D status? Ask your doctor for a 25-hydroxy vitamin D blood test, and look for a level closer to the middle of the typical lab’s reference range rather than toward the bottom.

Vitamin D intake in pregnancy reduces eczema and asthma in infants

Posted on November 18, 2009 by Dr. Jonathan

This study in the European Respiratory Journal concludes: “Higher vitamin D intake during pregnancy may be protective against childhood wheeze and eczema.”

Autism, type 1 diabetes, allergies, asthma and leaky gut in children

Posted on November 14, 2009 by Dr. Jonathan

This interesting paper published in the journal Acta Pædiatrica discusses the link between disruption of the tight junction barrier of the intestinal lining (leaky gut) and the systemic inflammatory response that is fundamental to type 1 diabetes, inflammatory bowel disease, allergies, asthma and autism in children. Because of the massive presence of immune system tissue in the gut, intestinal barrier integrity is a critical element in the functional medicine approach to these pediatric conditions. We can evaluate allergy, food sensitivity, chronic infection and other factors with the appropriate laboratory tests and procedures.

Breathing technique very effective for severe asthma (and more)

Posted on November 4, 2009 by Dr. Jonathan

I don’t usually report on items in lay publications because these are readily available to you, but this article published today in the New York Times deserves special attention. It describes the Buteyko method of breathing and how it works: by correcting the very common tendency to breathe out too much carbon dioxide, which (counter-intuitively) results in less oxygen delivered to all tissues including the brain. It also dysregulates the autonomic nervous system (the part that runs the internal organs) contributing to asthma, anxiety, cardiovascular symptoms and many other complaints. As Lapis Light patients know, we have advanced this method here with capnography—breathing training using biofeedback based on direct measurements of exhaled CO2 (end-tidal CO2). Breathing effectively is very powerful medicine.