Interethnic differences in the accuracy of anthropometric indicators of obesity in screening for high risk of coronary heart disease

Abstract

Obesity is a recognized risk factor for the development of cardiovascular diseases and for allcause mortality among ethnic groups in the United States.1,2 Also among Latin Americans, that is, Hispanics living in their country of origin, obesity doubles the risk of coronary heart disease (CHD)3 and seems to contribute to an excess of 18 to 49% in the risk of coronary events.4 In view of the large impact of obesity on cardiovascular risk, anthropometric indicators of obesity are commonly used as a tool to identify individuals and populations at high risk of cardiovascular events. Body mass index (BMI) is a measure of overall obesity, whereas waist circumference (WC) and waist-to-hip ratio (WHR) are used as indicators of abdominal obesity. Although these obesity indicators have been independently associated with CHD incidence and mortality in different populations,5-7 several investigators and public health organizations have recently questioned whether cut points derived from Whites from Europe and the United States are appropriate for use in other populations.8-10 For instance, the World Health Organization (WHO) has recently suggested lowering BMI action cut points to 23 and 27.5 kg/m2 for Asians, 8 and the International Diabetes Federation’s guidelines for assessing metabolic syndrome recommends the use of South Asian’s WC cut points for Latin Americans and makes no recommendation for cut points among Blacks from the United States.11 In this study we used data from six Latin-American countries and from the United States National Health and Nutrition Examination Survey (NHANES) to compare the accuracy of BMI, WC and WHR, that is, their ability to correctly classify individuals as having a high or a low risk of CHD. We also estimated ethnic and gender-specific optimal cut points for these anthropometric indicators when they are used in screening for high risk of CHD