1 RESEARCH ARTICLE
Amstrup AK1, Sikjaer T1, Bønløkke Pedersen S1,2, Heickendorff L3, Mosekilde L1, Rejnmark L1,2.
– Apart from regulating the circadian rhythm, melatonin exerts a variety of actions in the living organism.
– Among these functions, melatonin is believed to have a positive effect on body weight and energy metabolism.
– So far, the evidence for this relies mainly on animal models.
– In this study we aimed to determine the effects of melatonin on body composition, lipid and glucose metabolism in humans.
– Double blind, placebo controlled study; 81 post-menopausal women to 1 year of treatment with melatonin (1 or 3mg nightly) or placebo
– Body composition was measured by DXA. Measures were obtained at baseline and after 1year of treatment along with leptin, adiponectin and insulin.
– Markers of glucose homeostasis were measured at the end of the study.
(1) In response to treatment, fat mass decreased in the melatonin group by 6.9% (95%CI: 1.4%; 12.4%) compared to placebo.
(2) A borderline significant increase in lean mass of 5.2% was found in the melatonin group compared to placebo (3.3%, (IQR:-1.7; 6.2) vs. -1.9%, (IQR:-5.7; 5.8))
(3) After adjusting for BMI, lean mass increased by 2.6% (95%CI: 0.1; 5.0,) in the melatonin group.
(4) Changes in body weight and BMI did not differ between groups.
(5) Adiponectin increased borderline significantly by 21% in the melatonin group compared to placebo
(6) No significant changes were observed for leptin, insulin, or markers of glucose homeostasis.
– Our results suggest a possible beneficial effect of melatonin on body composition and lipid metabolism as one year of treatment reduces fat mass, increases lean mass and is associated with a trend towards an increase in adiponectin.