Reduced fat mass and increased lean mass in response to 1 year of melatonin treatment in postmenopausal women: A randomized placebo-controlled trial.
Level 2 - randomized trial
Individual double-blind randomized controlled trial
PubMed 26352863 · doi:10.1111/cen.12942
What was done
In a double-blind, placebo-controlled trial, 81 postmenopausal women were randomized to receive 1 year of nightly melatonin (1 mg or 3 mg) or placebo. Body composition was assessed at baseline and after 1 year using dual-energy X-ray absorptiometry (DXA). Blood markers including leptin, adiponectin, insulin, and markers of glucose homeostasis were also evaluated.
What was found
Compared to placebo, melatonin treatment resulted in a 6.9% decrease in fat mass (95% CI: 1.4% to 12.4%, P = 0.02). Lean mass showed a borderline increase overall (5.2% vs placebo, P = 0.08) that became statistically significant after adjusting for BMI (2.6% increase, 95% CI: 0.1% to 5.0%, P = 0.04). Changes in total body weight and BMI did not differ between groups. Adiponectin showed a borderline increase of 21% (P = 0.08), with no significant changes observed for leptin, insulin, or markers of glucose homeostasis.
Why it matters
This study provides randomized human evidence that 1 year of nightly melatonin supplementation may favorably shift body composition by reducing fat mass and increasing lean mass in postmenopausal women, independent of total weight change.
Limits
The study was small (81 participants) and exclusively conducted in postmenopausal women, limiting generalizability to other populations. The abstract pools results for the 1 mg and 3 mg doses without reporting dose-specific outcomes, and findings for adiponectin and unadjusted lean mass reached only borderline statistical significance.
Cited by
- supports Randomized controlled trials show that melatonin supplementation increases lean mass.