Asian Americans have greater prevalence of metabolic syndrome despite lower body mass index

Objective: To examine the relationship between bodymass index (BMI) and metabolic syndrome for Asian Americans and non-Hispanic Whites (NHWs), given that existing evidence shows racial/ethnic heterogeneity exists in how BMI 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 NHW) were analyzed in a mixed-payer, outpatient-focused health-care organization in the San Francisco Bay Area. Results: Metabolic syndrome prevalence is significantly higher in Asians compared with NHWs for every BMI category. For women at the mean age of 55 and BMI of 25 kg m(-2), the predicted prevalence of metabolic syndrome is 12% for NHW women compared with 30% for Asians; similarly for men, the predicted prevalence of metabolic syndrome is 22% for NHWs compared with 43% of Asians. Compared with NHW women and men with a BMI of 25 kg m(-2), comparable prevalence of metabolic syndrome was observed at BMI of 19.6 kg m(-2) for Asian women and 19.9 kg m(-2) for Asian men. A similar pattern was observed in disaggregated Asian subgroups. Conclusions: In spite of the lower BMI values and lower prevalence of overweight/obesity than NHWs, Asian Americans have higher rates of metabolic syndrome over the range of BMI. Our results indicate that BMI ranges for defining overweight/obesity in Asian populations should be lower than for NHWs. International Journal of Obesity (2011) 35, 393-400; doi:10.1038/ijo.2010.152; published online 3 August 2010