Asian-Americans don't have to be heavy to develop diabetes

When the lower average body mass index of Asian-Americans is taken into account, this group has a 60% higher risk of developing type 2 diabetes than do Caucasians, according to a study published in the January Diabetes Care.

The study found that both races have similar rates of prevalence but that Asian-Americans seemed to develop the disease at lower weights.

"You don't have to be as heavy to be at the same risk," said Marguerite J. McNeely, MD, MPH, lead author and assistant professor of medicine at the University of Washington, Seattle.

Experts widely praised the study for turning the diabetes spotlight on a group that has long been thought of as having a higher risk for the disease. That risk, however, has been hard to quantify because of Asian-Americans' smaller average body mass index in comparison with Latinos or African-Americans.

"More of these studies need to be done," said William Hsu, MD, co-director of the Asian-American Diabetes Initiative at the Joslin Diabetes Center in Boston. "The Asian population living in the United States has grown very fast, and it is an important public health issue."

Many prevalence studies put Asians in the "other" category, and Latinos and African-Americans tend to be targets of minority diabetes prevention efforts because their significantly higher risk has long been documented. Dr. McNeely's study found that Asian-Americans' risk was not as high as these minorities but was still higher than Caucasians. In response, some suggest that Asian-Americans should be targeted for diabetes interventions as well and that physicians should screen for the disease in this group at lower weights and at younger ages than they would for other populations.

"With Asian-Americans, our association of diabetes with obesity should be changed somewhat," said James Mulinda, MD, chief of the diabetes and endocrinology section at Pennsylvania Hospital in Philadelphia. "When have you a lean, slender Asian-American in front of you, it doesn't mean they have a lower risk of diabetes in comparison to a lean Caucasian. Even when they look like they may not fit the typical profile for type 2 diabetes, you should check them, especially if they are over 30."

Many suspect, however, that the problem is even bigger than this study found, and that the 60% figure is probably an underestimation. The study reached only people who had phones and could speak English or Spanish. People with limited English fluency or a lower socioeconomic status could have been missed. In addition, the survey relied on subjects' self-reporting of weight and a physician diagnosis of diabetes. Several studies have suggested that about a third of diabetes is undiagnosed.

"We know that the rate is higher," said Dr. Hsu.

But many also said that standards based on research primarily involving Caucasian participants may have limited relevance to other races.

"The federal guidelines are really geared towards a Western population," said Thomas Tsang, MD, MPH, medical director of the Charles B. Wang Community Health Center, which provides primary care for Asian-Americans in New York City. "We have to be very careful about applying these guidelines towards an Asian-American and Pacific Islander subset."

Some public health agencies are starting to take note. Last month, a World Health Organization panel's report in The Lancet concluded that widely accepted BMI cutoff points defining overweight and obesity should be retained but that efforts should be directed toward a process through which individual countries, particularly Asian ones, would develop weight standards more applicable to their populations. The issue is a particularly thorny one because of the desire to keep standards simple while still addressing the wide diversity among Asian groups.

"We don't know that all Asians with a particular BMI have the same risk for diabetes," said Dr. McNeely. "It might be more realistic to increase awareness that while BMI is an important tool to assess diabetes risk, it has limitations."