Abstract
BACKGROUND: Circulating adiponectin (ADPN) levels are inversely associated with disease severity in patients with chronic obstructive pulmonary disease (COPD), while studies assessing the relationship between ADPN and lung function in subjects from the general population have shown diverging results. Accordingly, we hypothesized that ADPN would be associated with lung function in a population-based sample and tested how abdominal adiposity, metabolic syndrome, and systemic inflammation influenced this association. METHODS: We measured total ADPN in serum, forced vital capacity (FVC) and forced expiratory volume during the 1st second (FEV(1)) in 529 participants (median 50 years, 54.6% males) recruited from the general population. We assessed the association between ADPN and lung function by multivariate linear regression analyses and adjusted for age, gender, height, smoking habits, weight, body mass index, waist-hip ratio, metabolic syndrome, obstructive sleep apnoea (OSA) and C-reactive protein. RESULTS: The median (interquartile range) level of serum ADPN was 7.6 (5.4-10.4) mg/L. ADPN levels were positively associated with FVC % of predicted (beta 3.4 per SD adiponectin, p < 0.001)) in univariate linear regression analysis, but the association was attenuated in multivariate analysis (standardized beta 0.03, p = 0.573)). Among co-variates only WHR significantly attenuated the relationship. ADPN levels were also associated with FEV(1)% of predicted in bivariate analysis that adjusted for smoking (beta 1.4, p = 0.042)), but this association was attenuated and no longer significant in multivariate analysis (standardized beta -0.06, p = 0.254)). CONCLUSION: In this population-based sample no association between ADPN and lung function was evident after adjustment for covariates related to adiposity.