Is Waist Circumference a Better Predictor of Insulin Resistance Than Body Mass Index in U.S. Adolescents?

Abstract

Purpose-To determine whether waist circumference (WC) is a better predictor of insulin resistance (IR) compared with body mass index (BMI) in US adolescents 12-18 years.Methods-Using data from the National Health and Nutrition Examination Survey (NHANES) 1999-2002, we evaluated an ethnically diverse sample of 1571 adolescents with BMI, WC, and fasting glucose and insulin levels. Children were classified as having IR if they had a homeostasis model assessment of insulin resistance (insulin (μU/ml) × glucose (mmol/l))/22.5) greater than 4.39. We created receiver operating characteristic (ROC) curves predicting IR across various thresholds of WC and BMI, and area under the curve (AUC) was compared.Results-The prevalence of IR for the population was 11.8%. Measures of test performance (sensitivity and specificity) for predicting IR were similar for abnormal BMI and WC thresholds; i.e. thresholds of BMI 85 th % and WC 75 th %, and thresholds of BMI 95 th % and WC 90 th % were quite similar. There were no significant differences in AUC for WC versus BMI 0.85 (95% CI 0.83-0.88) (p=0.84) for the overall population or for specific racial groups.Conclusions-WC does not appear to provide a distinct advantage over BMI for identifying adolescents with IR.

Predictors of Metabolic Risk in Childhood Obesity

“…Among normal or overweight children, the degree of general or central adiposity, expressed as the Z score of BMI (Z-BMI) and WC or WtH-r, is a good marker of the presence of MS [67,68]. In contrast, among obese children and adolescents the Z-BMI, WC, WtH-r and skinfold thickness, though showing positive associations with MS and its components, are only moderate predictors of these co-morbidities [38,69,70,71,72,73].…”

“…For example, even though a WtH-r cut-off of 0.6 has been proposed to detect obese children with metabolic impairments [38,73], data from the National Health and Nutrition Examination Survey provide evidence that a high percentage of subjects affected by metabolic co-morbidities (about 50%) is under this threshold despite a real increased risk associated with a WtH-r >0.6, due to the unsatisfactory accuracy of this criterion [73]. Interestingly, among both normal and obese children and adolescents, traditional surrogate measures of visceral adiposity like WC and Wt-H-r do not perform better than BMI or Z-BMI as markers of metabolic co-morbidities [68,69,70]. This can be convincingly explained by recent evidence that during childhood and adolescence, BMI and WC are very highly correlated and have similarly sized associations with intra-abdominal adipose tissue [74,75].…”

In Nonobese Girls, Waist Circumference as a Predictor of Insulin Resistance Is Comparable to MRI Fat Measures and Superior to BMI

“…These findings highlight the need for reliable and cost-effective methods to identify youth at greatest risk for metabolic consequences of obesity. Currently, there is lack of consensus whether body mass index (BMI), waist circumference (WC), or another anthropometric measure provides a superior screening approach (4, 5). Development of consensus is complicated by evidence that the metabolic effects exerted by a given amount of fat vary with race and ethnicity (6, 7), and that WC and BMI fail to directly quantify site-specific fat deposition.…”

Circunferência da cintura como marcador para triagem de doença hepática gordurosa não alcoólica em adolescentes obesos

“…, 20 In fact, in this study insulin resistance was higher in the 3rd and 4th quartiles when compared with the 1st quartile of WC in obese adolescents.…”

“…, 20 De fato, neste estudo a resistência à insulina foi maior no 3° e 4° quartis, quando comparada com o primeiro quartil de CC em adolescentes obesos.…”