A new study from New York City finds that immigrants from the Indian subcontinent have the highest rates of diabetes in the city -- a fact that may be masked by their being grouped with other Asians in assessments of community health risks, researchers say. Using data from the New York City Department of Health and Mental Hygiene, the authors found that foreign-born South Asians -- including people from India, Pakistan, Bangladesh, Sri Lanka, Nepal and Bhutan -- have the highest rate of diabetes of any ethnic group in New York. It is nearly double that of other foreign-born Asians. The differences between the city\'s ethnic groups in diabetes rates were greatest among people with a normal body mass index (BMI) -- a ratio of height to weight -- suggesting that standard BMI categories may be poor indicators of risk, at least for South Asians, the authors note in the journal Diabetes Care. The results of the study indicate that people of South Asian descent should be aware of these differences, and watch their weight especially carefully, said study author Leena Gupta of the city\'s health department. Given their increased risk for diabetes, she added, \"\"it is important for South Asians to be screened for diabetes, regardless of their body weight.\"\" Gupta and colleagues from the New York City and Washington, D.C. health departments looked at data for more than 54,000 participants in the annual New York City Community Health Survey between 2002 and 2008, to see how common diabetes was across different racial and ethnic groups. Overall, nine percent of the people surveyed said that they had been diagnosed with diabetes by a doctor, and the condition was generally more common in people born in other countries than in those born in the US. Among foreign-born South Asians, 13.6 percent had diabetes -- compared with 7.4 percent of \"\"other Asians\"\" and 5.6 percent of U.S.-born non-Hispanic whites. U.S.-born Hispanics had a diabetes rate of 14.4 percent and among U.S.-born non-Hispanic blacks, it was 11.8 percent. When the researchers started comparing people within BMI categories to each other, however, foreign-born South Asians had the highest diabetes rates in most groups. Among people with a BMI in the \"\"normal\"\" range (18.5 to 25 kilograms per square meter of height), the rate of diabetes in foreign-born South Asians was nearly five times as high as the rate in whites, and two and a half times as high as the rate in people from other parts of Asia. South Asians also had the highest rate of diabetes among overweight New Yorkers. U.S.-born Hispanics had the highest diabetes rate in the obese group, but South Asians were a very close second. Moreover, when the authors adopted World Health Organization BMI categories tailored for specific regions and races to define who was overweight and obese, foreign-born South Asians had a higher rate of diabetes at lower BMI levels than all other racial and ethnic groups. That result is important, Gupta\'s team notes, because it demonstrates that standard BMI cutoffs typically used in the U.S. and Europe do not accurately capture the health risks of being overweight or obese for South Asians. The findings highlight the importance of understanding the health differences between different Asian sub-populations, said Dr. Lartha Palaniappan, an associate investigator at the Palo Alto Medical Foundation in California, who was not involved in the study. Future studies and clinical guidelines should account for the differences between different ethnic subgroups, and not group all Asian people into one large category, she told Reuters Health. \"\"This study underlines the importance of using Asian-specific BMI for diabetes risk assessment,\"\" as suggested by the World Health Organization, said Dr. Grishma Parikh, an endocrinologist at the Mount Sinai Medical Center in New York.