title: Body mass index cut-points to identify cardiometabolic risk in black South Africans.
abstract: OBJECTIVE
  To determine optimal body mass index (BMI) cut-points for the identification of cardiometabolic risk in black South African adults.
  
  
  METHODS
  We performed a cross-sectional study of a weighted sample of healthy black South Africans aged 25-65 years (721 men, 1386 women) from the North West and Free State Provinces. Demographic, lifestyle and anthropometric measures were taken, and blood pressure, fasting serum triglycerides, high-density lipoprotein (HDL) cholesterol and blood glucose were measured. We defined elevated cardiometabolic risk as having three or more risk factors according to international metabolic syndrome criteria. Receiver operating characteristic curves were applied to identify an optimal BMI cut-point for men and women.
  
  
  RESULTS
  BMI had good diagnostic performance to identify clustering of three or more risk factors, as well as individual risk factors: low HDL-cholesterol, elevated fasting glucose and triglycerides, with areas under the curve >.6, but not for high blood pressure. Optimal BMI cut-points averaged 22 kg/m2for men and 28 kg/m2for women, respectively, with better sensitivity in men (44.0-71.9 %), and in women (60.6-69.8 %), compared to a BMI of 30 kg/m2(17-19.1, 53-61.4 %, respectively). Men and women with a BMI >22 and >28 kg/m2, respectively, had significantly increased probability of elevated cardiometabolic risk after adjustment for age, alcohol use and smoking.
  
  
  CONCLUSIONS
  In black South African men, a BMI cut-point of 22 kg/m2identifies those at cardiometabolic risk, whereas a BMI of 30 kg/m2underestimates risk. In women, a cut-point of 28 kg/m2, approaching the WHO obesity cut-point, identifies those at risk.
authors.affiliation: Centre of Excellence for Nutrition, North-West University, Potchefstroom, 2520, South Africa. salome.kruger@nwu.ac.za.
authors.forename: H Salome
authors.initials: HS
authors.lastname: Kruger
authors.affiliation: Hypertension in Africa Research Team, North-West University, Potchefstroom, South Africa.|Medical Research Council Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa.
authors.forename: Aletta E
authors.initials: AE
authors.lastname: Schutte
authors.affiliation: Department of Nutrition and Dietetics, University of the Free State, Bloemfontein, South Africa.
authors.forename: Corinna M
authors.initials: CM
authors.lastname: Walsh
authors.affiliation: Medical Research Council Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa.|Africa Unit for Transdisciplinary Health Research, North-West University, Potchefstroom, South Africa.
authors.forename: Annamarie
authors.initials: A
authors.lastname: Kruger
authors.affiliation: School of Life and Medical Sciences, University of Hertfordshire, Hertfordshire, UK.
authors.forename: Kirsten L
authors.initials: KL
authors.lastname: Rennie
mesh_terms: D000328:Adult; D000368:Aged; D044383:Black People; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology*; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000150:complications; D012307:Risk Factors; D012959:Socioeconomic Factors; D013019:South Africa / Q000453:epidemiology; D014280:Triglycerides / Q000097:blood; D055105:Waist Circumference
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D014280:Triglycerides
keywords: Black adults; Body mass index; Cardiometabolic risk; Sub-Saharan Africa