Evaluation of waist circumference to predict cardiova scular risk factors in an overweight Tehranian population: findings from Tehran Lipid and Glucose Study

This study was conducted to evaluate the waist circumference (WC) cut-off points to predict cardiovascular risk factors in the overweight Tehranian population. Anthropometric measures, blood pressure, and biochemical analyses were evaluated for the 15,005 participants of the Tehran Lipid and Glucose Study. Three thousand sixty-five subjects aged 18-74 years with a body mass index of 25-29.9 were enrolled in this study. Abdominal obesity was defined as WC > or =102 cm for men and > or =88 cm for women. Sensitivity of WC > or =102 cm to detect various cardiovascular risk factors for men aged 35-54 years was between 5% and 14%, and for men aged 55-74 years, was between 12% and 19%. The specificity of this cut-off point was between 93% and 98% and between 86% and 96% for corresponding age-categories, respectively. WC > or =88 cm had a sensitivity of between 28% and 41 % for identifying cardiovascular risk factors in women aged 18-34 years. Sensitivity tended to increase with age and specificity tended to decrease with age in both genders. These cut-off points had the highest positive predictive value for the more prevalent risk factors in both genders. The negative predictive values were different for various risk factors among age groups. The classic cut-off points of WC failed to provide adequate evidence for the use of WC in detecting cardiovascular risk factors. Further studies should be conducted to determine optimal WC cut-off points for Iranians.