Ethnic disparities in the association of body mass index with the risk of hypertension and diabetes.

Despite having lower body mass index (BMI) compared to other ethnic groups, Asians continue to develop significant metabolic diseases such as hypertension and diabetes. To evaluate the disparate association of BMI and risk of hypertension and diabetes in Asians. We retrospectively studied 150,753 adults from the 1985-2011 California Behavioral Risk Factor Survey. Trends in prevalence of obesity, hypertension, and diabetes were stratified by ethnicity. Multivariate logistic regression models evaluated the incremental effect of one unit BMI increase on risk of hypertension and diabetes and the disparate risks of hypertension and diabetes at different BMI thresholds. Asians had the lowest BMI among all groups. However, the impact of increasing BMI on risk of hypertension and diabetes was significantly greater in Asians. For each one unit increase in BMI, Asians were significantly more likely to have hypertension (OR 1.15; 95% CI 1.13-1.18) compared to non-Hispanic whites, blacks, and Hispanics. Similar trends were seen for diabetes (Asians: OR 1.15; 95% CI 1.13-1.18). The risk of hypertension in Asians with BMI ≥ 22 was similar to non-Hispanic whites with BMI ≥ 27 and blacks with BMI ≥ 28. The risk of diabetes in Asians with BMI ≥ 28 was similar to non-Hispanic whites with BMI ≥ 30. Despite lower overall BMI compared to other groups, weight gain in Asians is associated with significantly higher risks of hypertension and diabetes. Compared to other ethnic groups, similar risks of hypertension and diabetes are seen in Asians at much lower BMI.