Asian Americans Have Greater Prevalence of Metabolic Syndrome Despite Lower Body Mass Index

OBJECTIVE: To examine the relationship between body mass index and metabolic syndrome for Asian Americans and non-Hispanic Whites, given that evidence shows racial/ethnic heterogeneity exists in how body mass index predicts metabolic syndrome. RESEARCH DESIGN AND METHODS: Electronic health records of 43 507 primary care patients aged 35 years and older with self-identified race/ethnicity of interest (Asian Indian, Chinese, Filipino, Japanese, Korean, Vietnamese, or non-Hispanic White) were analyzed in a mixed-payer, outpatient-focused healthcare organization in the San Francisco Bay Area. RESULTS: Metabolic syndrome prevalence is significantly higher in Asians compared to non-Hispanic Whites for every body mass index category. For women at the mean age of 55 and body mass index of 25 kg/m(2), the predicted prevalence of metabolic syndrome is 12% for non-Hispanic White women compared to 30% for Asians; similarly for men, the predicted prevalence of metabolic syndrome is 22% for non-Hispanic Whites compared to 43% of Asians. Compared to non-Hispanic White women and men with a body mass index of 25 kg/m(2), comparable prevalence of metabolic syndrome was seen at body mass index of 19.6 kg/m(2) for Asian women and 19.9 kg/m(2) for Asian men. A similar pattern was seen in disaggregated Asian subgroups. CONCLUSIONS: Despite lower body mass index values and lower prevalence of overweight/obesity than non-Hispanic Whites, Asian Americans have higher rates of metabolic syndrome over the range of body mass index. Our results indicate that body mass index ranges for defining overweight/obesity in Asian populations should be lower than for non-Hispanic Whites.