Association of Hypoxia-Inducible Factor (HIF)-1a and Asymmetric Dimethylarginine(ADMA) in patients with COPD and controls.

Background: HIF-1α is a dimeric protein complex that plays an integral role in the body9s response to low oxygen concentrations. ADMA is a risk factor and major endogenous inhibitor of nitric oxide synthase that increases with oxidative stress triggers. The role of HIF-1α and ADMA in COPDdue to smoking is lacking. Aim: To determine the role & correlation of ADMA and HIF-1α in smoker COPDpatients as compared to healthy population. Method: In this cross-sectional study, we recruited 87 subjects, 57 were smokers with COPD,15 were smokers without COPDand other 15 were non-smoker healthy control. The mean age was 54.6± 9.32 (cases 57.08±8.15; controls 50.0± 9.8). There were 62% smokers, 25% non-smokers,7% tobacco chewers and 6%ex-smokers. Enzyme-linked immune sorbent assay (ELISA) method was used for analyzing serum samples wherein HIF-1α was analyzed by Sandwich-ELISA and ADMA biomarker was analyzed by competitive-ELISA. Results: In smokerCOPD patients, a significantly higher HIF-1α level showed positive association with hypoxia, smoking status and severity of disease (p=0.03), irrespective to the ADMA level in all categories was observed. The mean value of HIF-1α and ADMA was not significant different in smokers without COPDand healthy controls. Conclusion: HIF-1α level increase in smoking COPD, but not in smokers without COPDsuggesting that development of COPDdrive the HIF-1α pathway and this correlates with severity of disease.