Low concentrations of serum 25-hydroxyvitamin D associated with increased risk for chronic bronchitis among US adults.
Br J Nutr. 2011 Sep 8:1-7. Epub 2011 Sep 8. PMID: 21899806
Division of Adult and Community Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, 4770 Buford Highway, Mailstop K67, Atlanta, GA 30341, USA.
Increasing evidence suggests that vitamin D benefits both innate and adaptive immunity, thereby eliciting an anti-inflammatory effect and reducing the risk of infectious disease. The present study examined the association between serum 25-hydroxyvitamin D (25(OH)D) levels and the risk of chronic bronchitis among US adults. We analysed data from 6872 US adults aged≥ 20 years who participated in the 2003-6 National Health and Nutrition Examination Survey. Prevalence and OR with 95 % CI of having self-reported chronic bronchitis were estimated by quintiles of 25(OH)D or vitamin D-deficiency status after adjustment for potential confounders. The results showed that the adjusted prevalence of chronic bronchitis ranged from 2·4 (95 % CI 1·4, 3·3) % among adults in the highest quintile of 25(OH)D ( ≥ 30 ng/ml) to 4·1 (95 % CI 2·5, 5·6) % among adults in the lowest quintile ( < 15 ng/ml; P for trend < 0·01). The adjusted OR for chronic bronchitis was 1·85 (95 % CI 1·06, 3·24) in adults with< 15 ng/ml 25(OH)D and 1·77 (95 % CI 1·19, 2·65) in those with 15 to< 20 ng/ml 25(OH)D compared with adults with ≥ 30 ng/ml 25(OH)D. Additionally, the adjusted OR for chronic bronchitis was 1·52 (95 % CI 1·03, 2·26) among adults with vitamin D deficiency ( < 20 ng/ml 25(OH)D) compared with those with ≥ 20 ng/ml 25(OH)D. For every 1 ng/ml increase in 25(OH)D, the likelihood of having chronic bronchitis fell by 2·6 % (P = 0·016). In conclusion, low serum 25(OH)D levels are associated with the increased risk of chronic bronchitis among US adults. The present results provide support for continuing research on the role of vitamin D in lung diseases.