New International Measuring Stick for Defining Obesity in Non-Europeans

Abstract

Body mass index (BMI) is a useful way of classifying the degree of excess weight in an individual. Defining BMI cut points at which adverse cardiovascular outcomes, diabetes mellitus, and other comorbidities are more likely to occur affords clinically relevant guidelines for patient care. Expert panels from both the National Institutes of Health and the World Health Organization1–3 have developed such cut points, which define overweight as a BMI (weight [in kilograms]/height [in meters squared]) of 25.0 to 29.9 kg/m2, mild or grade I obesity as a BMI of 30 to 34.9 kg/m2, grade II or more severe obesity as a BMI of 35 to 39.9 kg/m2, and extreme or grade III obesity as a BMI ≥40 kg/m2. Epidemiological studies focusing on persons of European descent have verified that these cut points are, indeed, associated with incremental risk for cardiovascular events and all-cause death.4–6 An awareness that appropriate BMI cut points for Asians may differ from those of Europeans has been largely based on observations that cardiovascular and metabolic risk in Asians occur at a lower BMI than in Europeans. For example, there is increasing evidence of a high prevalence of type 2 diabetes mellitus and elevated cardiovascular risk in certain Asian countries, despite an average BMI in these countries that is <25 kg/m2.7,8 Even for Asian-Americans, the prevalence of diabetes mellitus after adjustment for BMI is 60% higher than in their European counterparts.9 Article p 2111 The definition of clinically useful BMI cut points in Asian populations has been difficult, at least in part because of the limitations of previously used methodologies. Two general methodological approaches have been taken in the past to derive these BMI cut points in Asians: (1) recalculation of BMI cut …