Adiponectin and incident coronary heart disease and stroke. A systematic review and meta-analysis of prospective studies.

The plasma concentration of adiponectin, an adipokine that has anti-inflammatory, anti-atherogenic and insulin sensitizing properties, is lower in obese subjects and could therefore be a target for therapy. In order to review and meta-analyse prospective cohort studies investigating adiponectin concentration and the risk for incident coronary heart disease (CHD) or stroke, a systematic search of MEDLINE, EMBASE and Cochrane databases was performed. Two independent reviewers selected prospective cohort studies investigating the relationship between adiponectin level and incident CHD or stroke using 'adiponectin' and 'cardiovascular disease' or 'stroke' and their synonyms, excluding patients with clinically manifest vascular disease. Random-effects models were used to calculate pooled relative risks (RRs) and 95% confidence intervals (95% CI). Generalized least squares regression was used to assess dose-response relationships for adiponectin concentrations from studies that provided RRs solely based upon categorical data regression. In total, 16 prospective cohort studies, comprising 23,919 patients and 6,870 CHD or stroke outcome events, were included in the meta-analyses. An increase of 1 standard deviation in log-transformed adiponectin did not lower the risk for CHD (RR 0.97; 95% CI 0.86-1.09). A 10 μg mL(-1) increase in adiponectin conferred a RR of 0.91 (95% CI 0.80-1.03) for CHD and a RR 1.01 (95% CI 0.97-1.06) for stroke. In conclusion, plasma adiponectin is not related to the risk for incident CHD or stroke.