discoveries magazine

Diabetes Disparity

Genetic Differences Might Drive Diabetes Development

Illustration: Davide Bonazzi

Diabetes disproportionately affects African-Americans and Mexican-Americans, with rates as high as 13 and 14 percent, respectively, compared to 7 percent for non-Latino whites. Lifestyle factors and insulin resistance play major roles in Type 2 diabetes, but could other genetic and physiological causes explain the discrepancy?

In a recent study, investigators at the Sports Spectacular Diabetes and Obesity Wellness and Research Center at Cedars-Sinai found that African-Americans have more trouble with hepatic insulin clearance—the rate at which the liver removes insulin from the system—than other populations. To eliminate lifestyle as a potential cause, the team also studied results obtained from African-American children. The data was clear: “We saw the same thing in children, which suggests that trouble with insulin clearance is likely genetic,” says Richard Bergman, PhD, the center’s director and the Alfred Jay Firestein Chair in Diabetes Research.

Mark Goodarzi, MD, PhD, director of Endocrinology, Diabetes and Metabolism, noticed the same phenomenon in a separate study. Using data collected from more than 2,000 Mexican-American adults, his team concluded that genetically driven problems with insulin clearance could be one reason why Type 2 diabetes is more common in this population.

“This finding helps us understand the disease better,” says Goodarzi, the Eris M. Field Chair in Diabetes Research. “As studies delve deeper and we learn more about insulin clearance, new treatments may be on the horizon.”

Today, patients manage diabetes with medication, lifestyle changes, and insulin therapy—which may continue to be the right course for many. But for those whose diabetes is at least partially caused by genetic clearance disorders, treatments that help the liver purge insulin might make a big difference. Both researchers caution that genetics provides only part of the answer. “Lifestyle matters, and Type 2 diabetes results from the interplay between genes and environment,” Goodarzi says.