The effect of melatonin supplementation on lipid profile and anthropometric indices: A systematic review and meta-analysis of clinical trials

Abstract Background Epidemiological evidence suggests that melatonin has some effects on the serum lipid. However, these results are controversial. The aim of this systematic review and meta-analysis is to examine the effect of melatonin supplement on dyslipidemia and anthropometric indices. Methods We searched electronic databases including Medline, Embase, Scopus, Web of Science and Cochrane Library up to Des 2018 without any language restriction. To compare the effects of melatonin with placebo, differences in standardized means difference (SMD) with 95% confidence intervals (95% CI) were pooled using random effects model. Results Twelve trials including 641 participants included in meta-analysis finally. The dose of melatonin was reported at 0.8–30 mg. Comparing with the control group, melatonin may improve low density lipoprotein cholesterol (LDL-C) (−0.31 mmol/L, 95% CI (−0.61, 0.01), P = 0.049, I2 = 42%) and triglyceride (TG) level (SMD = −0.45 mmol/L; 95% CI, −0.77, −0.13, P = 0.006, I2 = 47%). No significant effect of melatonin on high density lipoprotein cholesterol (HDL-C) and anthropometric indices was found. Conclusions The results of our systematic review and Meta-analyzes showed that supplementation of melatonin could be effective in improving lipid parameters and should be considered in the prevention of cardiovascular disease, although the effect of this supplement on anthropometric indices needs further investigation.