Determining the Waist Circumference in African Americans Which Best Predicts Insulin Resistance

• Published in: Obesity (Silver Spring, Md.) Vol. 16; no. 4; pp. 841 - 846
• Main Authors: Sumner, Anne E, Sen, Sabyasachi, Ricks, Madia, Frempong, Barbara A, Sebring, Nancy G, Kushner, Harvey
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-04-2008
• Subjects: Abdomen; Adult; African Americans; African Americans - statistics & numerical data; Blacks; body fat distribution; Body Mass Index; Cardiovascular disease; Diabetes; Education; epidemiological studies; Epidemiology; Fatty acids; Female; gender differences; Glucose Intolerance - diagnosis; Glucose Intolerance - ethnology; Humans; Insulin Resistance; Life expectancy; Linear Models; Male; men; Middle Aged; Obesity; Obesity - diagnosis; Obesity - ethnology; Overweight; Overweight - diagnosis; Overweight - ethnology; prediction; Predictive Value of Tests; Sensitivity and Specificity; waist circumference; Waist-Hip Ratio; women; Womens health; United States > US; Maryland
• ISSN: 1930-7381; 1930-739X
• DOI: 10.1038/oby.2008.11

Total body size and central fat distribution are important determinants of insulin resistance. The BMI and waist circumference (WC) thresholds in African Americans that best predict insulin resistance are unknown. Our goal was to determine the BMI and WC values in African Americans, which optimally predict insulin resistance. The subjects were African Americans (68 men, 63 women), aged 35 ± 8 years (mean ± s.d.), with a BMI of 30.9 ± 7.5, in the range of 18.5–54.7 kg/m2, and with a WC of 98 ± 18, in the range of 69–173 cm. Insulin resistance was defined by the lowest tertile of the insulin sensitivity index (SI). The Youden index was calculated to determine the WC and BMI thresholds that predict insulin resistance with an optimal combination of sensitivity and specificity. In men the thresholds that optimally predicted insulin resistance were a BMI ≥30 kg/m2 or a WC ≥102 cm. For women, insulin resistance was best predicted by a BMI ≥32 kg/m2 or a WC ≥98 cm. In African Americans, insulin resistance (in men) was best predicted by a WC ≥102 cm, and in women by a WC ≥98 cm, or by a BMI value that fell in the obese category (men: ≥30 kg/m2, women: ≥32 kg/m2).