Head-to-head comparison of fibrates versus statins for elevation of circulating adiponectin concentrations: a systematic review and meta-analysis

BackgroundElevation of adiponectin levels is a potential therapeutic tool against cardiovascular and metabolic diseases. Clinical evidence suggests differences between fibrates and statins in improving circulating concentrations of adiponectin.AimTo compare the efficacy of fibrates vs. statins on circulating concentrations of adiponectin by meta-analysis of randomized head-to-head trials.MethodsA systematic literature search of Medline was conducted to identify randomized head-to-head comparative trials investigating the efficacy of fibrates vs. statins on circulating levels of adiponectin. Inverse variance-weighted mean differences (WMDs) and 95% confidence intervals (CIs) were calculated for net changes in adiponectin concentrations using a random-effects model. Random-effects meta-regression was performed to assess the effect of putative moderators on adiponectin levels.ResultsSix trials with a total of 326 subjects (166 in the fibrate and 160 in the statin group) met the eligibility criteria and were selected for this meta-analysis. The estimated effect size for fibrate versus statin therapy was 0.42 μg/mL (95% CI: − 0.34–1.17). This effect size was robust in the leave-one-out sensitivity analysis and not sensitive to any single study. Meta-regression indicated a borderline significant association between duration of treatment and the effect of fibrates vs. statins on adiponectin concentrations (slope: − 0.20; 95% CI: − 0.41–0.01; p = 0.06). However, baseline body mass index, glucose and lipid levels did not predict the effect of fibrate vs. statin therapy on circulating adiponectin concentrations (p > 0.05).ConclusionsMonotherapy with either fibrates or statins has comparable effects on circulating concentrations of adiponectin. Thus, differential effects of statins and fibrates on the occurrence of cardiovascular events may not be attributed to the corresponding changes in adiponectin levels.