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

To examine the relationship between body mass 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.

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.

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.

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.