The Development of Appropriate Waist-to-Hip Ratio Cut- off Points: Survey in Large Iranian Adult Population

Introduction & Proportion of Waist-to-Hip Ratio (WHR) is an indicator of abdominal obesity, which is supported by some studies but rejected by others. The aim of this study was to examine the accuracy of the WHR and obtain suitable cut- off points for detecting obesity among adult Iranians. In this cross-sectional-descriptive study the sample consisted of 19366 adults. The data collection took place from 2009 to 2014, using Bioelectrical Impedance Analysis (BIA). The following data were obtained: WHR, Percentile of Body Fat (PBF), To-tal Fat (TF), and Soft Lean Mass (SLM). Sensitivity and specificity, based on World Health Organization’s Gold Standards were calculated for both sexes at three age groups. The data analysis included t-test, chi-square, ROC curve, and linear regression. All study variables were correlated with each other. Age was only correlated with the WHR. Percentages of sensitivity and Negative Predictive Value (NPV) were 84.2% and 85.6% in women; 21% and 50.7% in men. Increase in age was associated with increase in sensitivity in men and women, and NPV in men. The suitable cut-off points for men and women were found to be 87.5% and 83.5%, respectively. Waist-to-Hip ration is a suitable indictor of obesity for Iranian women but not men, especially among those who are under 59 years old.