Melatonin and its relationships with diabetes and obesity: a literature review

Significance: Obesity is a multifactorial disease with many risks to public health, affecting 39.6% of American adults and 18.5% of young people. Brazil ranks fifth in the world ranking, with about 18 million obese people. It is estimated that 415 million people live with diabetes in the world, which is roughly 1 in 11 of the world's adult population. This is expected to rise to 642 million people living with diabetes worldwide by 2040. In this scenario, Melatonin has evidenced an important function in the regulation of energy metabolism.

Objective: to carry out a broad narrative review of the literature on the main aspects of the influence of melatonin on Diabetes Mellitus and obesity.

Methods: Article reviews, systematic reviews, prospective studies, retrospective studies, randomized, double-blind, placebo-controlled trials in humans recently published were selected and analyzed. A total of 368 articles were collated and submitted to the eligibility analysis. Subsequently, 215 studies were selected to compose the textual part of the manuscript and 153 to compose the Narrative Review. Results and final considerations: Studies suggest a possible role of melatonin in metabolic diseases such as obesity, T2DM and metabolic syndrome. Intervention studies using this hormone in metabolic diseases are still unclear regarding a possible benefit of it. There is so far no consensus about a possible role of melatonin as an adjuvant in the treatment of metabolic diseases. More studies are necessary to define possible risks and benefits of melatonin as a therapeutic agent.

Keywords: Melatonin. Diabetes. Obesity. Metabolism. Clinical study. Systematic review..