Impact of statin therapy on plasma leptin concentrations: a systematic review and meta-analysis of randomized placebo-controlled trials

ObjectivesThe effects of statins on insulin sensitivity, metabolic homeostasis and adipokines in humans are controversial. Several studies have investigated the impact of statin therapy on plasma leptin concentrations but the results have been inconsistent. The aim of the present study was to conduct a systematic review and meta-analysis of available evidence to calculate the effect size of statin therapy in changing serum leptin concentrations. MethodsA systematic search in PubMed-Medline, SCOPUS, Web of Science and Google Scholar databases was performed to identify randomized placebo-controlled trials investigating the effect of statins on plasma leptin concentrations. A random-effects model and generic inverse variance method were used for meta-analysis. Sensitivity analysis, risk-of-bias evaluation and publication bias assessment were carried out using standard methods. Random-effects meta-regression was used to evaluate the impact of treatment duration on the estimated effect size. ResultsSix trials, with a total of 425 subjects, met the eligibility criteria. Overall, statin therapy had no significant effect on leptin levels (weighted mean difference -0.32ng ml(-1), 95% confidence nterval: -2.94, 2.30, P = 0.813). This effect was robust in the sensitivity analysis and in subgroup analyses of trials with <12 or 12weeks' duration. There was no association between the duration of statin therapy and changes in plasma leptin levels. Furthermore, there was no differential effect of hydrophilic and lipophilic statins on plasma leptin concentrations. ConclusionUnless more consistent evidence becomes available in the future, the hypothesis of a relationship between statin use and serum leptin concentrations seem to be unfounded.