Melatonin in type 2 diabetes mellitus and obesity.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing genetic, preclinical, and clinical literature without systematic review methodology
PubMed 30531911 · doi:10.1038/s41574-018-0130-1
What was done
This narrative review summarizes post-GWAS preclinical and clinical evidence concerning genetic variation in the MTNR1B locus (which encodes the melatonin MT2 receptor) and evaluates the impact of melatonin and its receptors on glucose homeostasis, obesity, and type 2 diabetes mellitus.
What was found
The abstract reports no numerical data. It reports that common and rare variants in the MTNR1B locus play an established role in regulating fasting plasma glucose and modifying type 2 diabetes risk, with minor effects on obesity. It notes that existing studies have not resolved whether melatonin signaling is beneficial or detrimental to metabolic outcomes.
Why it matters
Melatonin is widely used globally as an over-the-counter supplement and prescribed medication. Determining its precise effects on glucose control is essential for assessing safety and evaluating melatonin receptors as potential therapeutic targets.
Limits
The abstract provides no sample sizes, search strategy, or quantitative effect estimates. It relies on a narrative synthesis, and direct clinical trial evidence resolving the direction of melatonin's effect on glucose regulation is not reported.
Cited by
- supports Genome-wide association studies identified mutations in the melatonin receptor associated with obesity and type 2 diabetes risk.