title: Sexual dimorphism in ratio of second and fourth digits and its relationship with metabolic syndrome indices and cardiovascular risk factors.
abstract: BACKGROUND
  Ratio of second and fourth digit (2D:4D) is known to be germane in analyzing utero concentrations of testosterone and estrogen in human and other vertebrates. 2D:4D had been linked to several traits like athletes' abilities, reproductive success, risk of cancer and cardiovascular disease (CVD). Metabolic syndrome (MetS) is a clustering of several cardiovascular risk factors. Waist circumference (WC), neck circumference (NC), body mass index (BMI) and waist-to-height ratio (WHtR) are important in measuring MetS. This study investigated sexual dimorphism in 2D:4D and its relationship with MetS indices and CVD factors among adult residing in Ilorin, North central Nigeria.
  
  
  METHODS
  This is a cross-sectional, stratified multi-staged sampling study. Participants residing in different neighborhoods were visited at home where finger lengths and anthropometric traits were measured. Participants include 801 healthy adults aged 18-44 years (56% male) who had been living in the area for more than 3 years.
  
  
  RESULTS
  Males showed significantly lower 2D:4D than females (unpaired t-test; t [699] = 11.49, P = 0.001). A significant positive correlation was observed in MetS markers and 2D:4D. WHtR showed the highest correlation with 2D:4D in male (r = 0.461, P ≤ 0.001) and female (r = 0.408, P ≤ 0.001) when compared with BMI, NC and WC. All positive correlations recorded in this study were high in male and right hand.
  
  
  CONCLUSIONS
  Our results showed that 2D:4D is sexual dimorphic and right hand 2D:4D as a predictor of MetS is better. We concluded that 2D:4D is a proxy for MetS and CVD risk factors in Ilorin.
authors.affiliation: Department of Zoology, Cell Biology and Genetics Unit, University of Ibadan, Ibadan, Oyo State, Nigeria.
authors.forename: Bolaji Fatai
authors.initials: BF
authors.lastname: Oyeyemi
authors.affiliation: Department of Zoology, University of Ilorin, P.M.B. 1515, Ilorin, Kwara State, Nigeria ; Department of Molecular Biology & Biotechnology, University of Sheffield, Firth Court, S10 2TN Sheffield, United Kingdom.
authors.forename: Oluyinka Ajibola
authors.initials: OA
authors.lastname: Iyiola
authors.affiliation: Department of Physiology, College of Medicine, Madonna University, Elele, Rivers State, Nigeria.
authors.forename: Adekunle Wahab
authors.initials: AW
authors.lastname: Oyeyemi
authors.affiliation: Department of Biology, Federal College of Education, Okene, Kogi State, Nigeria.
authors.forename: Kokori Audu
authors.initials: KA
authors.lastname: Oricha
authors.affiliation: Department of Zoology, University of Ilorin, P.M.B. 1515, Ilorin, Kwara State, Nigeria.
authors.forename: Abass Toba
authors.initials: AT
authors.lastname: Anifowoshe
authors.affiliation: Department of Zoology, Cell Biology and Genetics Unit, University of Ibadan, Ibadan, Oyo State, Nigeria.
authors.forename: Nanfizat Abiket
authors.initials: NA
authors.lastname: Alamukii
keywords: Cardiovascular disease; digit ratio; metabolic syndrome; sexual dimorphism