1.
The effect of melatonin supplementation on lipid profile and anthropometric indices: A systematic review and meta-analysis of clinical trials.
Loloei, S, Sepidarkish, M, Heydarian, A, Tahvilian, N, Khazdouz, M, Heshmati, J, Pouraram, H
Diabetes & metabolic syndrome. 2019;(3):1901-1910
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.
2.
The effects of melatonin supplementation on inflammatory markers among patients with metabolic syndrome or related disorders: a systematic review and meta-analysis of randomized controlled trials.
Akbari, M, Ostadmohammadi, V, Tabrizi, R, Lankarani, KB, Heydari, ST, Amirani, E, Reiter, RJ, Asemi, Z
Inflammopharmacology. 2018;(4):899-907
Abstract
OBJECTIVE This systematic review and meta-analysis of randomized controlled trials (RCTs) was carried out to determine the effect of melatonin supplementation on the inflammatory markers among individuals with metabolic syndrome (MetS) and related disorders. METHODS We searched the following databases up to March 2018: PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials. Three reviewers independently assessed study eligibility, extracted data, and evaluated risk of bias of included primary studies. Statistical heterogeneity was assessed using Cochran's Q test and I-square (I2) statistic. Data were pooled using the random effect model and standardized mean difference (SMD) was considered as the summary effect size. RESULTS Six trials of 317 potential reports were identified to be suitable for our meta-analysis. The pooled results using random effects model indicated that melatonin supplementation significantly reduced C-reactive protein (CRP) (SMD = - 1.80; 95% CI - 3.27, - 0.32; P = 0.01; I2: 95.2) and interleukin 6 (IL-6) concentrations (SMD = - 2.02; 95% CI - 3.57, - 0.47; P = 0.01; I2: 91.2) among patients with MetS and related disorders; however, it did not affect tumor necrosis factor-α (TNF-α) concentrations (SMD = - 1.87; 95% CI - 3.81, 0.07; P = 0.05; I2: 94.4). CONCLUSIONS In summary, the current meta-analysis showed the promising effect of melatonin administration on reducing CRP and IL-6, but not TNF-α levels among patients with MetS and related disorders. Additional prospective studies are recommended using higher supplementation doses and longer intervention period.