title: Associations of polymorphisms in circadian genes with abdominal obesity in Chinese adult population.
abstract: Circadian rhythm, which is controlled by circadian genes, regulates metabolic balance including the circulating levels of glucose, fatty acids, triglycerides, various hormones and so on. The study aimed to investigate the impact of potential polymorphisms in circadian genes on abdominal obesity among Chinese Han adults.
  
  
  
  A total of 260 cases with abdominal obesity and 260 controls were recruited by individual matching. Demographic characteristics and lifestyle information were collected by a validated questionnaire, and anthropometric parameters was measured by physical examination. Twenty-three single nucleotide polymorphisms (SNPs) in three circadian genes, CLOCK, CRY1 and CRY2, were genotyped by MassArray technique.
  
  
  
  Five SNPs significantly deviated from Hardy-Weinberg equilibrium (HWE) among controls, so eighteen SNPs were taken into logistic regression analysis. Independently, CLOCK rs10002541 (CC genotype vs. TT genotype: OR: 0.45, 95% CI: 0.23-0.86), CLOCK rs6850524 (CC genotype vs. GG genotype: OR: 0.50, 95% CI: 0.25-0.99) and CRY1 rs10861688 (TT genotype vs. CC genotype: OR: 0.50, 95% CI: 0.25-0.97) were negatively associated with the risk of abdominal obesity. Haplotype analysis showed that the haplotypes of CG and TG for CLOCK rs10002541 and rs4864546 had significant associations with abdominal obesity. Compared with the carriers of TA, those of CG were observed to have a lower risk (OR: 0.74, 95% CI: 0.56-0.99) of abdominal obesity, and those of TG presented a higher risk (OR: 1.70, 95% CI: 1.03-2.81).
  
  
  
  Our findings suggest that CLOCK and CRY1 polymorphisms might be involved in individual susceptibility to abdominal obesity in Chinese Han population.
authors.affiliation: Department of Epidemiology and Health Statistics, Zhejiang University School of Public Health, Hangzhou, China.
authors.forename: Ding
authors.initials: D
authors.lastname: Ye
authors.affiliation: Department of Epidemiology and Health Statistics, Zhejiang University School of Public Health, Hangzhou, China; Xiamen Second Hospital, Xiamen, China.
authors.forename: Shaofang
authors.initials: S
authors.lastname: Cai
authors.affiliation: Department of Epidemiology and Health Statistics, Zhejiang University School of Public Health, Hangzhou, China.
authors.forename: Xiyi
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Department of Epidemiology and Health Statistics, Zhejiang University School of Public Health, Hangzhou, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Ding
authors.affiliation: Department of Epidemiology and Health Statistics, Zhejiang University School of Public Health, Hangzhou, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Chen
authors.affiliation: Zhejiang Medical College, Hangzhou, China.
authors.forename: Chunhong
authors.initials: C
authors.lastname: Fan
authors.affiliation: Department of Epidemiology and Health Statistics, Zhejiang University School of Public Health, Hangzhou, China. Electronic address: jinmj@zju.edu.cn.
authors.forename: Mingjuan
authors.initials: M
authors.lastname: Jin
mesh_terms: D000328:Adult; D000483:Alleles; D044466:Asian People / Q000235:genetics*; D056926:CLOCK Proteins / Q000235:genetics*; D002681:China; D002940:Circadian Rhythm / Q000235:genetics*; D056931:Cryptochromes / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D056128:Obesity, Abdominal / Q000235:genetics*; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide
chemical_list: C538963:CRY1 protein, human; D056931:Cryptochromes; D056926:CLOCK Proteins; C538943:CLOCK protein, human
keywords: Abdominal obesity; Circadian genes; Circadian rhythm; Haplotype; Polymorphism