Effect Of Metformin On Serum Leptin Levels In Patients With Polycystic Ovary Syndrome: A Meta-analysis

BackgroundMetformin is an effective treatment for insulin resisitance in patients with polycystic ovary syndrome(PCOS), but previous studies assessing the effect of metformin on serum leptin level in the patients yielded conflicting results. In this study, we conducted a meta-analysis to determine whether metformin therapy could reduce serum leptin level.MethodsPub Med, EMBASE and SCI databases were used to identify all prospective clinical trials evaluating serum leptin level pre- and post-metformin treatment in PCOS women by two independent reviewers. Rev Man(version 5.2) was used to perform data synthesis. Subgroup analysis was done to access the impacts of treatment duration of metformin(<4 months and ≥4 month) and body mass index(BMI<30 and ≥30).ResultsA total of 9 studies involving 170 participants were included. Meta-analysis showed that the standard mean difference(SMD) for leptin level was 0.41 units(95 % confidence interval(CI) 49 0.19 to 0.63, P<0.05) post- and pre-metfirmin therapy. Subgroup analysis showed that leptin was decreased significantly within 4 months after the therapy(SMD, 0.38, 95 % CI, 0.06 to 0.70, P<0.05), and it was more significantly reduced after 4 months therapy(SMD, 0.43, 95 % CI: 0.14 to 0.73, P<0.05). Meanwhile, the analysis also reveals that leptin level was decreased significantly in obese PCOS patients after the therapy, and it was decreased more significantly in non-obese PCOS patients after the therapy.ConclusionsThis meta-analysis suggests that leptin level was significantly reduced by metformintherapy in PCOS patients and the leptin level may be clinically recognized as a valuable indicator for PCOS treatment, but the clinical significance of this finding as it relates to diabetes and cardiovascular risk reduction in PCOS patients warrants further study.