A common variant in MTNR1B, encoding melatonin receptor 1B, is associated with type 2 diabetes and fasting plasma glucose in Han Chinese individuals.
Level 4 - case-series / case-control
Case-control genetic association study
PubMed 19241057 · doi:10.1007/s00125-009-1297-8
What was done
Investigators genotyped the *MTNR1B* single-nucleotide polymorphism rs10830963 in 1,165 patients with type 2 diabetes and 1,105 normoglycaemic control individuals of southern Han Chinese ancestry residing in metropolitan Shanghai. The association with type 2 diabetes risk was analyzed via logistic regression adjusted for age, sex, and BMI. Fasting plasma glucose association was analyzed in the normoglycaemic controls using multiple linear regression adjusted for age, sex, and BMI.
What was found
The rs10830963 risk allele was associated with higher odds of type 2 diabetes (OR 1.16, 95% CI 1.03–1.31, p = 0.015). In normoglycaemic controls, each risk allele was associated with a 0.068 mmol/l increase in fasting plasma glucose (95% CI 0.036–0.100, p = 4 x 10(-5)).
Why it matters
This study shows that the *MTNR1B* association with fasting glucose and type 2 diabetes, previously identified in European-ancestry cohorts, replicates in a Han Chinese population, supporting a cross-ethnic genetic mechanism.
Limits
The study used a retrospective case-control design, which cannot establish causality. Recruitment was restricted to the Shanghai metropolitan area, potentially limiting generalizability to other Chinese populations. Only a single polymorphism was evaluated, and the effect size on diabetes risk was modest.
Cited by
- supports Four human genetic studies published in 2009 showed that genetic variants in the melatonin receptor gene MTNR1B are associated with elevated fasting blood glucose and increased diabetes risk.