title: The waist circumference of risk in black South african men is lower than in men of European ancestry.
abstract: BACKGROUND
  Central obesity measured by waist circumference is a cardiovascular disease (CVD) risk factor; however, the waist circumference of risk in populations of African descent has not been identified. The International Diabetes Federation currently suggests that cutoffs established in men of European descent be applied to sub-Saharan men-a waist circumference ≥94 cm.
  
  
  METHODS
  Participants were 203 South African black men with type 2 diabetes mellitus (T2DM). They were divided into quartiles of waist circumference (>88 cm, 88-94 cm, 95-103 cm, >103 cm). Cardiovascular risk factors, including insulin resistance (IR), measured by modified homeostasis model assessement of IR (HOMA-IR), and the triglycerides-to-high-density lipoprotein cholesterol (TG-to-HDL-C) ratio, were compared across quartiles.
  
  
  RESULTS
  Age, duration of diabetes, glycosylated hemoglobin (HbA1c), blood pressure, urinary albumin excretion, and smoking were similar across waist circumference quartiles. Overall, for both lipids and measures of IR, there was variation across waist circumference quartiles, but no significant differences between quartiles 2 and 3. Therefore, data from these two quartiles were pooled. Between the first and second+third (88-103 cm) quartiles, there were significant differences in HDL-C (1.30±0.43, 1.10±0.43 mmol/L, P=0.003), TG (medians 1.10, 1.60 mmol/L P<0.001), low-density lipoprotein cholesterol (LDL-C; 2.40±0.93, 2.85±1.03 mmol/L, P=0.01), non-HDL-C (3.05±1.18, 3.70±1.16 mmol/L, P=0.002), HOMA-IR (medians 0.90, 2.10, P<0.001), and TG-to-HDL-C ratio (medians 0.89, 1.17, P<0.001). Additional comparisons were made between men with waist circumference <90 cm and 90-93 cm. Values for each lipid and for IR parameters were more favorable in the <90-cm group (all P<0.05).
  
  
  CONCLUSIONS
  For black South African diabetic men, CVD risk substantially increased with waist circumference >90 cm. The waist circumference cut point of >94 cm has the potential to misclassify many black South African diabetic men at risk for CVD.
authors.affiliation: Department of Medicine University of the Witwatersrand, Johannesburg, South Africa. john.kalk@tst.nhs.uk
authors.forename: W John
authors.initials: WJ
authors.lastname: Kalk
authors.forename: Barry I
authors.initials: BI
authors.lastname: Joffe
authors.forename: Anne E
authors.initials: AE
authors.lastname: Sumner
mesh_terms: D000328:Adult; D000368:Aged; D044383:Black People / Q000706:statistics & numerical data; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000208:ethnology / Q000209:etiology; D015331:Cohort Studies; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000453:epidemiology / Q000208:ethnology; D050177:Overweight / Q000150:complications / Q000453:epidemiology / Q000208:ethnology; D012307:Risk Factors; D013019:South Africa / Q000453:epidemiology; D055105:Waist Circumference / Q000208:ethnology* / Q000502:physiology; D044465:White People / Q000706:statistics & numerical data