title: Differential obesity indices identify the metabolic syndrome in Black men and women in Cape Town: the CRIBSA study.
abstract: OBJECTIVE
  To determine the obesity indices, specifically waist circumference (WC), that identified ≥2 other metabolic syndrome (MS) components (2009 criteria) in 25- to 74-year-old Africans in Cape Town.
  
  
  METHODS
  Data were collected from a cross-sectional sample by administered questionnaires, clinical measurements and biochemical analyses. The obesity cut points were estimated by the Youden Index. Logistic regression analyses determined whether obesity cut points identifying ≥2 MS components occurred at true inflection points.
  
  
  RESULTS
  Among the 1099 participants, the calculated cut points and 95% confidence intervals (CI) were: men, WC 83.9 cm (81.6-86.2), waist-to-hip ratio (WHR) 0.89 (0.87-0.90), waist-to-height ratio (WHtR) 0.50 (0.48-0.52) and body mass index (BMI) 24.1 kg/m(2) (22.0-26.1); women, WC 94.0 cm (92.6-95.3), WHR 0.85 (0.83-0.87), WHtR 0.59 (0.57-0.60) and BMI 32.1 kg/m(2) (29.7-34.6). Raised WC was significantly associated with ≥2 MS components in men: WC 84.0-93.9 cm (odds ratio (OR): 3.19, 95% confidence interval (CI): 1.73-5.85) and WC ≥94.0 cm (OR: 8.50, 95% CI: 4.44-16.25) compared with WC <84.0 cm, and in women: WC 80.0-93.9 cm (OR: 2.93, 95% CI: 1.32-6.54) and WC ≥94.0 cm (OR: 5.33, 95% CI: 2.40-11.85) compared with WC <80.0 cm. In the logistic model with BMI for women, obesity (OR: 3.60, 95% CI: 1.82-7.10) but not overweight (P = 0.063) was significantly associated with ≥2 MS components.
  
  
  CONCLUSIONS
  Obesity cut points for Africans should be re-evaluated and adjusted accordingly.
authors.affiliation: Non-communicable Diseases Research Unit, South African Medical Research Council, Durban, 4001, South Africa Department of Medicine, University of Cape Town, Cape Town, 8001, South Africa.
authors.forename: N
authors.initials: N
authors.lastname: Peer
authors.affiliation: Chronic Disease Initiative for Africa, Department of Medicine, University of Cape Town, Cape Town, 8001, South Africa.
authors.forename: K
authors.initials: K
authors.lastname: Steyn
authors.affiliation: Chronic Disease Initiative for Africa, Department of Medicine, University of Cape Town, Cape Town, 8001, South Africa Division of Diabetic Medicine and Endocrinology, Department of Medicine, University of Cape Town, Cape Town, 8001, South Africa.
authors.forename: N
authors.initials: N
authors.lastname: Levitt
mesh_terms: D000328:Adult; D000368:Aged; D044383:Black People / Q000706:statistics & numerical data; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D024821:Metabolic Syndrome / Q000175:diagnosis / Q000453:epidemiology*; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology*; D012737:Sex Factors; D013019:South Africa / Q000453:epidemiology; D011795:Surveys and Questionnaires; D065927:Waist-Height Ratio; D049629:Waist-Hip Ratio / Q000706:statistics & numerical data
keywords: BMI; Black; South Africa; obesity; obesity threshold; urban; waist circumference