Low vitamin D levels associated with worse adult asthma

January 01, 0001

Low vitamin D levels associated with worse adult asthma

Patients with asthma exhibit variable response to inhaled corticosteroids (ICS). Vitamin D is hypothesized to exert effects on phenotype and glucocorticoid (GC) response in asthma. The aim of this study by US researchers was to determine the effect of vitamin D levels on phenotype and glucocorticoid (GC) response in asthma. 54 nonsmoking adult asthmatics were enrolled and the association was assessed between serum 25(OH)D (vitamin D) concentrations and lung function, airway hyperresponsiveness (AHR) and GC response.

Higher vitamin D levels were associated with greater lung function, with a 21.0 (mean) increase in FEV1 for each ng per mL increase in vitamin D (significant). Participants with vitamin D insufficiency ( less than 30 ng per mL) demonstrated increased AHR, with a PC20 FEV1 of 1.03 mg per mL versus 1.92 in those with vitamin D less than 30 ng per mL (significant). In ICS-untreated participants DEX-induced MKP-1 expression increased with higher vitamin D levels, with a 0.05-fold increase (significant) in MKP-1 expression observed for each ng per mL increase in vitamin D, a finding which occurred in the absence of a significant increase in IL-10 expression.

The researchers concluded: "In asthma, reduced vitamin D levels are associated with impaired lung function, increased airway hyperresponsiveness and reduced glucocorticoid response, suggesting that supplementation of vitamin D levels in patients with asthma may improve multiple parameters of asthma severity and treatment response."

A very interesting finding and a clinical concept worth watching.

For the full abstract, click here.

Am J Respir Crit Care Med published online 14 January 2010 (doi:10.1164/rccm.200911-1710OC)
© 2010 American Thoracic Society
Vitamin D Levels, Lung Function and Steroid Response in Adult Asthma. E. Rand Sutherland, Elena Goleva, Leisa P. Jackson, Allen D. Stevens, and Donald Y.M. Leung. Correspondence to: E. Rand Sutherland: sutherlande@njc.org.

Category: R. Respiratory Keywords: asthma, vitamin D, glucocorticoids, treatment, cohort study, journal watch.
Synopsis edited by Dr Stephen Wilkinson, Melbourne, Australia. Posted on Global Family Doctor 28 January 2010

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.