title: Second to fourth digit ratio (2D:4D) and coronary heart disease.
abstract: BACKGROUND
  Sex steroid exposure during human development may influence disease susceptibility. Second to fourth digit ratio (2D:4D) is thought to be a putative biomarker for prenatal hormone level during foetal life. Recently there has been a great deal of interest in 2D:4D and risk of disease in adulthood.
  
  
  METHODS
  We explored the relationship between 2D:4D ratio and coronary heart disease. Photocopies of the two hands of 310 males (controls: 155; patients: 155) were collected at Yin chuan city, in the Ningxia province of China. Left hand, right hand, mean hand and right minus left 2D:4D (Dr-l) were analysed.
  
  
  RESULTS
  The mean values of 2D:4D ratio in patients were higher than those of CSIN controls. The patients showed significantly higher 2D:4D (left hand: P < 0.01; right hand, mean hand: P < 0.05) than controls. In patients, 2D:4D (especially left hand 2D:4D) were inversely associated with age at diagnosis (left hand: P < 0.001; right hand, mean hand: P < 0.05). No association between Dr-l and age or age at presentation of disease was observed in the groups.
  
  
  CONCLUSIONS
  2D:4D may correlate particularly with risk of coronary heart disease in Chinese men.
authors.affiliation: Ningxia Medical University, Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education, Key Laboratory of Reproduction and Genetics, Department of Medical Genetic and Cell Biology, Yinchuan 750004, PR China.
authors.forename: Hong
authors.initials: H
authors.lastname: Lu
authors.affiliation: Ningxia Medical University, Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education, Key Laboratory of Reproduction and Genetics, Department of Medical Genetic and Cell Biology, Yinchuan 750004, PR China.
authors.forename: Zhanbing
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Medical Reproductive Center, General Hospital, Ningxia Medical University, Yinchuan 750004, PR China.
authors.forename: Junli
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Ningxia Medical University, Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education, Key Laboratory of Reproduction and Genetics, Department of Medical Genetic and Cell Biology, Yinchuan 750004, PR China. Electronic address: huozhh@163.com.
authors.forename: Zhenghao
authors.initials: Z
authors.lastname: Huo
mesh_terms: D000328:Adult; D000368:Aged; D002681:China; D003327:Coronary Disease / Q000209:etiology*; D005385:Fingers; D006801:Humans; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D012727:Sex Characteristics
keywords: 2D:4D; CHD; Coronary heart disease; Second to fourth digit ratio