Effects of melatonin in the prevention of cardiovascular diseases: a systematic review

Abstract

Introduction: Obesity represents a multifactorial disease that causes major public health problems. There are about 2.0 billion overweight and obese people in the world, represented by 39.6% of adults. Melatonin may provide cardioprotection at low pharmacological doses. Melatonin's ability to improve cardiovascular function and its hypotensive effect because of its direct and receptor-dependent antioxidant actions suggest that melatonin may have some beneficial effects in controlling diabetic vascular complications. Objective: It was to carry out a systematic review of the main effects of melatonin in the treatment of obesity and diabetes mellitus, as well as in the prevention of cardiovascular diseases. Methods: The present study followed a concise systematic review model (PRISMA). The literary search process was carried out from April to May 2023 and was developed based on Scopus, PubMed, Science Direct, Scielo, and Google Scholar, using scientific articles until 2023. The low quality of evidence was attributed to case reports, editorials, and short communications, according to the GRADE instrument. The risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: A total of 168 studies were found for eligibility analysis, and so 46 of a total of 68 studies were selected for this systematic review. According to the GRADE instrument, most studies showed homogeneity in their results, with X2 =90.4%>50%. The Funnel Plot showed a symmetrical behavior, not suggesting a significant risk of bias in studies with smaller sample sizes. It was concluded that melatonin can reduce body weight and fat mass and regulate energy expenditure, glucose/lipid metabolism, and insulin secretion; therefore, it can play an effective role in weight management. There is a growing consensus that the antioxidant and anti-inflammatory properties of melatonin are of great importance in preserving the body's function and homeostasis. In adulthood, disturbances in melatonin production negatively impact the progression of cardiovascular risk factors and promote cardiovascular and neurodegenerative diseases. The consumption of melatonin supplements can be effective in controlling blood pressure and anthropometric indices (as predictors of obesity) in patients with T2DM. Furthermore, melatonin has significant effects on ischemia-reperfusion injury, myocardial injury, pulmonary hypertension, hypertension, vascular diseases, valvular heart diseases, and lipid metabolism. As an inexpensive and well-tolerated drug, melatonin could be a new therapeutic option for cardiovascular diseases.