According to a recent study involving 973 North American patients, Vitamin D levels are not related to acute exacerbations of chronic obstructive pulmonary disease, AECOPD, in patients with sever COPD.
In the study, a secondary analysis of data from a randomzed controlled trial of the effects of azithromycin, an antibiotic used to treat certain bacterial infections, on the frequency of AECOPD. No relationship was found between Vitamin D levels and time time to first AECOPD or between Vitamin D levels and AECOPD exacerbation rates.
"Vitamin D insufficiency and deficiency are common in patients with COPD, and patients with severe COPD are at the highest risk for exacerbations, so we hypothesized that low vitamin D levels might increase the risk of AECOPDs," Ken M. Kunisaki, M.D., of the Minneapolis Veterans Affairs Medical Center, was quoted as saying. "Our negative results are in contrast with earlier studies in which lower vitamin D levels were associated with higher rates of respiratory infections in adults and more frequent asthma exacerbations in children."
Having severe Vitamin D defenciacy was defined as a complex of respiratory symptoms, increased or new-onset, of at least one of the following: coughing, sputum, wheezing, dyspnea or chest tightness with a duration of at least three days and requiring treatment with an antibiotic or system iccorticosteroid.
In the primary analysis, vitamin D levels had no relationship to time to first AECOPD.
Patients with severe vitamin D deficiency had a higher mean rate of AECOPDs, but this difference was not statistically significant. Patients with severe vitamin D deficiency did not exhibit faster time to first AECOPD than other patients.
The study had some limitations. Vitamin D levels were only assessed at baseline, and so may have changed during the study period. Seasonal changes in vitamin D levels may also have occurred.
"Contrary to what we expected, baseline vitamin D levels were not related to the risk of subsequent AECOPDs in this large group of COPD patients at high risk of AECOPD," Kunisaki was quoted as saying. "Vitamin D supplementation is unlikely to have an effect on AECOPD risk in these patients."
SOURCE : American Thoracic Society's American Journal of Respiratory and Critical Care Medicine, November 4, 2011