| Melatonin is a physiological indoleamine secreted from the
pineal gland into the bloodstream. This hormone has antioxidant
effects in cardiovascular disease, but the evidence regarding
its effects on blood pressure (BP) has not been conclusive.
Therefore, we assessed the impact of melatonin supplementation
on systolic BP (SBP) and diastolic BP (DBP) through a systematic
review and meta—analysis of available randomized
controlled trials (RCTs). Medline, Scopus, Web of Science,
Cochrane library, and Google scholar (until May 2018) were
searched to identify potential RCTs with information on melatonin
supplementation and BP. Mean Differences (MD) were
pooled using a random-effects model. Standard methods were
used for assessment of heterogeneity, sensitivity analysis, and
publication bias. Pooling 5 RCTs (6 treatment arms) together
identified significant reduction for SBP (MD: − 3.43 mmHg,
95 % confidence interval (CI): − 5.76 to − 1.09, p = 0.004) and
DBP (MD: − 3.33 mmHg, 95 % CI: − 4.57 to − 2.08, p < 0.001)
after supplementation with melatonin compared with control
treatment. The sensitivity analysis indicated that the results
were robust. We did not observe any evidence regarding publication
bias. The findings of this meta-analysis support the
overall favorable effect of melatonin supplementation on BP
regulation. |