New research shows that type 2 diabetes occurs significantly more often in Native Hawaiians, Latinos, African-Americans, and Japanese-Americans than in whites, regardless of body weight - suggesting, the researchers say, that genetics plays a role in the development of the disease.

Type 2 diabetes is closely tied to obesity. “Everyone who is really overweight has a high risk for developing diabetes,” study chief Dr. Gertraud Maskarinec noted in a press release from the Center for the Advancement of Health. However, being overweight, it seems, is not the only contributing factor.

Maskarinec, from the Cancer Research Center of Hawaii in Honolulu and colleagues estimated the prevalence of diabetes in roughly 187,000 adults from five ethnic groups who participated in the Multiethnic Cohort Study of Diet and Cancer.

Overall, almost 12 percent of the cohort reported that they had diabetes. The prevalence of diabetes was roughly 16 percent in Native Americans and Latinos, 15 percent in African-Americans and 10 percent in Japanese-Americans, compared with just 6 percent in whites.

Regardless of body weight, “the prevalence of diabetes was at least two-fold higher in all ethnic groups than among Caucasians,” Maskarinec and colleagues point out in the journal Ethnicity and Disease.

Ethnic differences in the prevalence of diabetes were observed even among normal-weight and underweight adults, they report.

The findings, the investigators say, support a role for genetics in the development of type 2 diabetes. “Clearly, genes are involved,” Matt Petersen, of the American Diabetes Association added in the press statement. Regardless of ethnic group, avoiding obesity and staying physically active can help stave off type 2 diabetes, he noted.

SOURCE: Ethnicity and Disease, Winter issue 2009.