Dados do Trabalho

Título

Can melatonin supplementation improve cardiometabolic parameters of overweight night workers?

Introdução

Night work leads to the suppression of melatonin production due to exposure to light at night. Work at night is also associated with cardiometabolic disturbances. This raises the hypothesis that supplementation of this hormone might be used to reduce the deleterious effects caused by this exposure. However, studies assessing the effectiveness of this treatment in humans are scarce.

Objetivo

To verify whether melatonin supplementation improves cardiometabolic parameters in overweight night workers.

Métodos

A randomized clinically controlled double-blind crossover trial involving 26 nursing professionals working permanent night shifts (12 hours on, 36 hours off) was conducted. The intervention was carried out in two stages (each lasting 3 months) and entailed administration of 3 mg of fast-releasing melatonin or placebo on nights of non-working days or of days off. Cardiovascular and metabolic parameters (glucose, glycated hemoglobin, insulin, total cholesterol, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, triglycerides, blood pressure and heart rate at rest) were assessed at baseline and after each stage. Variability in cardiometabolic parameters was determined by the difference between means test.

Resultados

Mean age of participants was 37.8 (SE = 1.1 years-old). Most participants worked as nurses (53.8%) and were married (65.5%). Mean time working night shifts was 4.8 (SE = 0.8 years). After melatonin supplementation, no significant effects were found in the improvement of cardiometabolic parameters.

Conclusões

The intermittent supplementation of 3 mg of melatonin for 3 months was not effective to improve the cardiometabolic parameters of overweight night workers. Further studies are needed to investigate the individual level of melatonin in order to adjust the dose and time of supplementation.

Palavras-chave

Melatonin, Clinical trial, Night workers, Cardiometabolic parameters, Excess weight.