title: Ethnic-specific BMI and waist circumference thresholds.
abstract: BMI and waist circumference (WC) are used to identify individuals with elevated obesity-related health risks. The current thresholds were derived largely in populations of European origin. This study determined optimal BMI and WC thresholds for the identification of cardiometabolic risk among white and African-American (AA) adults. The sample included 2096 white women, 1789 AA women, 1948 white men, and 643 AA men aged 18-64 years. Elevated cardiometabolic risk was defined as ≥2 risk factors (blood pressure ≥ 130/85 mm Hg; glucose ≥100 mg/dl; triglycerides ≥150 mg/dl; high-density lipoprotein-cholesterol <40 mg/dl (men) or <50 mg/dl (women)). Receiver Operating Characteristic (ROC) curves were used to identify optimal BMI and WC thresholds in each sex-by-ethnicity group. The optimal BMI thresholds were 30 kg/m2 in white women, 32.9 kg/m2 in AA women, 29.1 kg/m2 white men, and 30.4 kg/m2 in AA men, whereas optimal WC thresholds were 91.9 cm in white women, 96.8 cm in AA women, 99.4 in white men, and 99.1 cm in AA men. The sensitivities at the optimal thresholds ranged from 63.5 to 68.5% for BMI and 68.4 to 71.0% for WC and the specificities ranged from 64.2 to 68.8% for BMI and from 68.5 to 71.0% for WC, respectively. In general, the optimal BMI and WC thresholds approximated currently used thresholds in men and in white women. There are no apparent ethnic differences in men; however, in AA women the optimal BMI and WC values are ~3 kg/m2 and 5 cm higher than in white women.
authors.affiliation: Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA. Peter.Katzmarzyk@pbrc.edu
authors.forename: Peter T
authors.initials: PT
authors.lastname: Katzmarzyk
authors.forename: George A
authors.initials: GA
authors.lastname: Bray
authors.forename: Frank L
authors.initials: FL
authors.lastname: Greenway
authors.forename: William D
authors.initials: WD
authors.lastname: Johnson
authors.forename: Robert L
authors.initials: RL
authors.lastname: Newton
authors.forename: Eric
authors.initials: E
authors.lastname: Ravussin
authors.forename: Donna H
authors.initials: DH
authors.lastname: Ryan
authors.forename: Claude
authors.initials: C
authors.lastname: Bouchard
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000208:ethnology* / Q000209:etiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012727:Sex Characteristics; D014481:United States / Q000453:epidemiology; D055105:Waist Circumference / Q000208:ethnology*; D044465:White People; D055815:Young Adult