Exogenous melatonin decreases circadian misalignment and body weight among early types

source extracted confidence: high 2026-04-09
#body-weight #circadian-rhythm #female #humans #melatonin

Exogenous melatonin decreases circadian misalignment and body weight among early types

Marqueze et al., 2021 | J Pineal Res | Rct

Citation

Marqueze Elaine C, Nogueira Luciana F R, ... Moreno Claudia R C. Exogenous melatonin decreases circadian misalignment and body weight among early types. J Pineal Res. 2021-Sep;71(2):e12750. doi:10.1111/jpi.12750

Abstract

Shift workers experience chronic circadian misalignment, which can manifest itself in reduced melatonin production, and has been associated with metabolic disorders. In addition, chronotype modulates the effect of night shift work, with early types presenting greater circadian misalignment when working night shift as compared to late types. Melatonin supplementation has shown positive results reducing weight gain in animal models, but the effect of exogenous melatonin in humans on body weight in the context of shift work remains inconsistent. The aim of this study was thus to evaluate the effects of exogenous melatonin on circadian misalignment and body weight among overweight night shift workers, according to chronotype, under real-life conditions. We conducted a double-blind, randomized, placebo-controlled, crossover trial where melatonin (3 mg) or placebo was administered on non-night shift nights for 12 weeks in 27 female nurses (37.1 yo, ±5.9 yo; BMI 29.9 kg/m2 , ±3.3 kg/m2 ). Melatonin (or placebo) was only taken on nights when the participants did not work night shifts, that is, on nights when they slept (between night shifts and on days off). Composite Phase Deviations (CPD) of actigraphy-based mid-sleep timing were calculated to measure circadian misalignment. The analyses were performed for the whole group and by chronotype. We found approximately 20% reduction in circadian misalignment after exogenous melatonin administration considering all chronotypes. Moreover, melatonin supplementation in those who presented high circadian misalignment, as observed in early chronotypes, reduced body weight, BMI, waist circumference, and hip circumference, without any change in the participants' calorie intake or physical activity levels.

Key Findings

Moreover, melatonin supplementation in those who presented high circadian misalignment, as observed in early chronotypes, reduced body weight, BMI, waist circumference, and hip circumference, without any change in the participants' calorie intake or physical activity levels.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size See abstract
Age Range See abstract
Condition sleep

MeSH Terms

  • Body Weight
  • Circadian Rhythm
  • Female
  • Humans
  • Melatonin
  • Shift Work Schedule
  • Sleep

Evidence Classification

  • Level: Rct
  • Publication Types: Journal Article, Randomized Controlled Trial
  • Vertical: melatonin-sleep

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09