Abstract

Background:The role of systemic inflammation in COPD has been proved in recent studies. It is associated with increased level of inflammatory cytokines such as IL-6 (Interleukin 6) & inflammatory mediators such as hs-CRP (high sensitivity C Reactive Protein). There is also extensive evidence supporting the action of vitamin D in immunity & inflammation. Low blood levels of 25-hydroxyvitamin D have been associated with a higher risk of respiratory infections in general populations and higher risk of exacerbations of lung disease in people with asthma. Low levels of vitamin D have been shown in COPD. We evaluated levels of vitamin D, hs-CRP, IL-6 in different stages of COPD and its correlation with severity of disease & frequency of AECOPD. Methods:182 subjects of COPD and 20 controls were recruited. After clinical history & examination, Spirometry was performed. 6 Minute Walk Test (6MWT) was done & BODE index was calculated. Clinical COPD questionnaire (CCQ) and mMRC were used to assess functional status. Levels of vitamin D, IL-6 & hs-CRP were estimated by ELISA & correlated with disease severity and frequency of exacerbation during 6 month follow up. Results:IL-6 & hs-CRP were higher in study group than the normal controls & the difference was statistically significant with 'p' value of 0.024 & < 0.01 respectively whereas vitamin D was significantly lower in study group (p < 0.01). Levels of Vit D were found to be lower in severe COPD as compared to mild COPD. Levels of IL6 and hs-CRP were also seen to increase with the increasing severity of the disease. Vitamin D levels were lower in COPD and show moderate correlation to severity & frequency of AECOPD. hs-CRP levels were higher in COPD and showed weak correlation to disease severity & frequency of AECOPD. IL-6 levels were higher in study group but did not correlate with disease severity & frequency of AECOPD.

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