Association between serum adiponectin concentrations and chronic obstructive pulmonary disease: a meta-analysis

Background: Adiponectin has been implicated to play a role in the pathophysiology of chronic obstructive pulmonary disease (COPD). Many studies have assessed serum adiponectin concentrations in COPD patients. However, results from different reports were not consistent. To assess the association of serum adiponectin concentrations and COPD, a meta-analysis was performed. Methods: PubMed, Embase, Web of Science and Cochrane Library were searched for eligible studies. Data were extracted, and then standard mean differences (SMDs) and 95% confidence intervals (CI) were calculated. Results: Thirteen studies involving a total of 1131 cases and 689 controls were included in this meta-analysis. Combined data indicated that the serum adiponectin levels were higher in COPD patients than those in controls (SMD: 1.09, 95% CI [0.73-1.45], P < 0.001). In the subgroup analyses by disease period, there were similar results in stable COPD patients (SMD: 0.77, 95% CI [0.47-1.07], p < 0.001; I-2 = 83.9%, P < 0.001), AECOPD patients (SMD: 2.51, 95% CI [0.71-4.30], P = 0.006; I-2 = 95.2%, P < 0.001) and mixed COPD patients (SMD: 1.21, 95% CI [0.67-1.75], P < 0.001). Furthermore, the serum adiponectin levels were higher in AECOPD patients than those in stable COPD patients (SMD: 1.06, 95% CI [0.13-1.99], P = 0.026). Conclusions: This meta-analysis indicates that patients with COPD have higher serum adiponectin concentration than healthy controls.