The role of melatonin in type 2 diabetes and obesity

Abstract

Melatonin is a hormone mainly synthesised in the pineal gland which is responsible for regulation of circadian and seasonal rhythms, as well as sleep. The highest concentration of melatonin in the plasma is attained during the night, whereas significantly lower concentration is reached during the day. In recent years scientists have been paying special attention to the contribution of melatonin in the metabolism of carbohydrates and lipids, in maintaining the fasting glucose level and in the pathogenesis of type 2 diabetes and other civilization diseases. It was also established that there is a connection between statistically frequent variants of the gene MTNR1B, which encode the melatonin MT2 receptor (for instance rs10830963 SNP), and the development of type 2 diabetes. These reports are of significant importance because of the fact that the supplementation of agonists of melatonin receptors is widespread in the society, as these medicaments may be purchased in drug stores without any prescription in order to improve sleep initiation. These drugs are also applied to shift workers and people exposed to often changes of time zones. The mentioned groups of people have the disrupted circadian rhythm and are significantly vulnerable to the development of civilization diseases. Because of widespread use of these medicaments it is necessary to conduct research into the safety and efficacy of melatonin agonists among people who are burdened with risk factors of glucose tolerance disorders or obesity. In this article the actual knowledge about the role of melatonin in the regulation of glucose metabolism and in the pathogenesis of some civilization diseases is summarized. Furthermore, the connection between the presence of variants of the MTNR1B locus and the risk of developing type 2 diabetes among the people who are carriers of these loci is highlighted. Moreover, the potential therapeutic interventions are presented based on signaling pathway mediated by melatonin which could prevent from developing the civilization diseases. Also in the article there are proposed some ways to individualise therapies and suggestions about lifestyle changes which should be implemented especially in people being in high risk of developing the civilization diseases.

Keywords

• melatonin
• diabetes
• civilization diseases
• lipid metabolism
• glucose metabolism