title: A common polymorphism rs3781637 in MTNR1B is associated with type 2 diabetes and lipids levels in Han Chinese individuals.
abstract: BACKGROUND
  Several studies have shown that common variants in the MTNR1B gene were associated with fasting glucose level and type 2 diabetes. The purpose of this study was to examine whether tagging single nucleotide polymorphisms (SNPs) in the MTNR1B region were associated with type 2 diabetes and related traits in a Han Chinese population.
  
  
  METHODS
  We investigated the association of polymorphisms in the MTNR1B gene with type 2 diabetes by employing a case-control study design (1118 cases and 1161 controls). Three tagging SNPs (rs10830963, rs3781637, and rs1562444) with R2>0.8 and minor allele frequency>0.05 across the region of the MTNR1B gene were studied. Genotyping was performed by matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy using a MassARRAY platform.
  
  
  RESULTS
  The polymorphism rs3781637 was associated with type 2 diabetes adjusted for age, sex and body mass index (BMI) in the additive model and recessive model (OR = 1.22, 95% CI 1.01-1.46, p = 0.038 and OR = 2.81, 95% CI 1.28-6.17, p = 0.01, respectively). In the non-diabetic controls, rs3781637 was nominally associated with plasma triglyceride, total cholesterol and low density lipoprotein cholesterol (LDL-C) levels in the recessive model (p = 0.018, 0.008 and 0.038, respectively). After adjustment for multiple comparisons, the associations of rs3781637 with total cholesterol and LDL-C remained significant in the recessive model (the empirical p = 0.024 and 0.045, respectively), but the association between rs3781637 and triglyceride became non-significant (the empirical p = 0.095). The associations of rs10830963 and rs1562444 with type 2 diabetes and related traits were not significant in the additive, dominant and recessive models.
  
  
  CONCLUSIONS
  The rs3781637 A/G polymorphism of the MTNR1B gene is associated with type 2 diabetes, plasma, total cholesterol and LDL-C levels in the Han Chinese population.
authors.affiliation: Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Ling
authors.forename: Xiaomu
authors.initials: X
authors.lastname: Li
authors.forename: Qian
authors.initials: Q
authors.lastname: Gu
authors.forename: Hongyan
authors.initials: H
authors.lastname: Chen
authors.forename: Daru
authors.initials: D
authors.lastname: Lu
authors.forename: Xin
authors.initials: X
authors.lastname: Gao
mesh_terms: D044466:Asian People / Q000235:genetics*; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D008055:Lipids / Q000097:blood*; D008297:Male; D013058:Mass Spectrometry; D020641:Polymorphism, Single Nucleotide; D044123:Receptor, Melatonin, MT2 / Q000235:genetics*
chemical_list: D008055:Lipids; D044123:Receptor, Melatonin, MT2