The Complex Relationship of Serum Adiponectin to COPD Outcomes

BackgroundCOPD is a chronic inflammatory disorder with high risk of cardiovascular morbidity and mortality. Adiponectin is a hormone that has antiinflammatory, antidiabetic, and antiatherogenic activities. We investigated the relationship of serum adiponectin to health outcomes in COPD.MethodsWe measured adiponectin levels in serum samples from participants of the Lung Health Study, who were smokers with mild to moderate airflow limitation. We determined the relationship of serum adiponectin to hospitalization and mortality using a Cox proportional hazards model and to baseline lung function measurements and bronchial reactivity using multiple regression methods.ResultsSerum adiponectin concentrations were inversely related to hospitalizations and mortality from coronary heart disease (hazard ratio [HR], 0.73; 95% CI, 0.62-0.86) and to cardiovascular disease (HR, 0.83; 95% CI, 0.73-0.94) and positively related to deaths from respiratory causes (HR, 2.09; 95% CI, 1.41-3.11). However, serum adiponectin concentrations were not significantly related to total mortality (HR, 1.10; 95% CI, 0.93-1.29) or cancer-related mortality (HR, 1.11; 95% CI, 0.92-1.34). Serum adiponectin concentrations were significantly related to increased bronchial reactivity and an accelerated decline in lung function (both P < .0001). Smoking status had no material influence on serum adiponectin concentrations.ConclusionsAdiponectin is a complex serum biomarker in COPD that is associated with decreased risk of cardiovascular events but increased risk of respiratory mortality. Because serum adiponectin is not significantly influenced by smoking status, it is a very promising biomarker of cardiovascular outcomes in COPD.