Relationship between Body Fat Percent and Obesity Indices in Short Stature Women

Abstract

Background: Body mass index (BMI) is frequently used as an index to assess obesity. However, BMI has limitations in accurately predicting body fat mass in terms of stature intervals. Therefore, we analyzed the relationship between body fat % and three obesity indices; BMI, waist circumference (WC) and waist circumference to height ratio (WHtR) in short stature women. Methods: Korean women (N= 317) of 19-60 years of age with short stature, defined by 1-10th percentile stature, were enrolled as subjects. Correlation analysis was used to evaluate relationship of body fat % and the obesity indices. After defining obesity as body fat % over 30, area under curve (AUC), sensitivity and specificity of the indices were obtained by receiver operating characteristic (ROC) analysis. Additionally, optimal cutoff values of the indices and sensitivity, specificity at that time were obtained. Results: There was statistically significant and positive correlation between body fat % and the indices (r= 0.804 for BMI, 0.763 for WC, 0.768 for WHtR). All indices showed moderate diagnostic accuracy according to AUC (0.888 for BMI, 0.885 for WC, 0.889 for WHtR). Both sensitivity and specificity of WHtR was high (0.758, 0.885 respectively). Specificity of BMI and WC was higher than WHtR but, their sensitivity was lower than WHtR. The optimal cutoff values were 22.6 kg/m for BMI, 75.5 cm for WC, 0.50 for WHtR. Conclusion: Among the obesity indices, we observed WHtR 0.5 to be superior to BMI 25 or WC 85 cm as an index to diagnose obesity in women of short stature.