Reduced fat mass and increased lean mass in response to one year of melatonin treatment in postmenopausal women: A randomized placebo controlled trial.
Clin Endocrinol (Oxf). 2015 Sep 9. Epub 2015 Sep 9. PMID: 26352863
Anne Kristine Amstrup
OBJECTIVE: 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.
DESIGN/METHODS: In a double blind, placebo controlled study we randomised 81 post-menopausal women to one year of treatment with melatonin (1 or 3mg nightly) or placebo. Body composition was measured by DXA. Measures were obtained at baseline and after one year of treatment along with leptin, adiponectin and insulin. Markers of glucose homeostasis were measured at the end of the study.
RESULTS: In response to treatment, fat mass decreased in the melatonin group by 6.9% (95%CI: 1.4%; 12.4%, p=0.02) compared to placebo. 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), p=0.08). After adjusting for BMI, lean mass increased by 2.6% (95%CI: 0.1; 5.0, p=0.04) in the melatonin group. Changes in body weight and BMI did not differ between groups. Adiponectin increased borderline significantly by 21% in the melatonin group compared to placebo (p=0.08). No significant changes were observed for leptin, insulin, or markers of glucose homeostasis.
CONCLUSION: Our results suggest a possibly 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. This article is protected by copyright. All rights reserved.