Horm Metab Res 2018; 50(11): 783-790
DOI: 10.1055/a-0752-8462
Review
© Georg Thieme Verlag KG Stuttgart · New York

The Effects of Melatonin Supplementation on Glycemic Control: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Amin Doosti-Irani
1   Department of Epidemiology, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran
2   Modeling of Noncommunicable Diseases Research Center, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran
,
Vahidreza Ostadmohammadi
3   Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, Iran
,
Naghmeh Mirhosseini
4   School of Public Health, University of Saskatchewan, Saskatoon, SK, Canada
,
Mohammad Ali Mansournia
5   Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
,
Russel J. Reiter
6   Department of Cellular and Structural Biology, UT Health San Antonio, TX, USA
,
Maryam Kashanian
7   Department of Gynecology and Obstetrics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
,
Maryam Rahimi
7   Department of Gynecology and Obstetrics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
,
Maryamalsadat Razavi
8   Department of Gynecology and Obstetrics, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran
,
Zatollah Asemi
3   Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, Iran
› Author Affiliations
Further Information

Publication History

received 07 September 2018

accepted 25 September 2018

Publication Date:
05 November 2018 (online)

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Abstract

This systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to clarify the effect of melatonin supplementation on glycemic control. Databases including PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials were searched until July 30th, 2018. Two reviewers independently assessed study eligibility, extracted data, and evaluated the risk of bias for included trials. Heterogeneity among included studies was assessed using Cochran’s Q test and I-square (I2) statistic. Data were pooled using random-effect models and mean difference (MD) was considered as the overall effect size. Twelve trials out of 292 selected reports were identified eligible to be included in current meta-analysis. The pooled findings indicated that melatonin supplementation significantly reduced fasting glucose (MD=–6.34; 95% CI, –12.28, –0.40; p=0.04; I2: 65.0) and increased the quantitative insulin sensitivity check index (QUICKI) (MD=0.01; 95% CI, 0.00, 0.02; p=0.01; I2: 0.0). However, melatonin administration did not significantly influence insulin levels (MD=–1.03; 95% CI, –3.82, 1.77; p=0.47; I2: 0.53), homeostasis model assessment of insulin resistance (HOMA-IR) (MD=–0.34; 95% CI, –1.25, 0.58; p=0.37; I2: 0.37) or HbA1c levels (MD=–0.22; 95% CI, –0.47, 0.03; p=0.08; I2: 0.0). In summary, the current meta-analysis showed a promising effect of melatonin supplementation on glycemic control through reducing fasting glucose and increasing QUICKI, yet additional prospective studies are recommended, using higher supplementation doses and longer intervention period, to confirm the impact of melatonin on insulin levels, HOMA-IR and HbA1c.