In the Journals Plus

Modifiable factors explain difference in type 2 diabetes incidence between blacks, whites

Show Citation

December 29, 2017

Michael Bancks
Michael P. Bancks

The risk for incident type 2 diabetes is higher among black compared with white adults; however, after adjustment for modifiable biological, neighborhood, psychosocial, socioeconomic and behavioral factors, the difference in risk no longer remains, according to study results published in JAMA.

“Traditional risk factors for diabetes, such as obesity and low socioeconomic status, are more common among blacks as compared with whites,” Michael P. Bancks, PhD, MPH, a postdoctoral fellow in preventive medicine at Northwestern University Feinberg School of Medicine in Chicago, told Endocrine Today. “Our study describes how the unequal rates of these traditional diabetes risk factors explain or account for the higher rates of diabetes among blacks.”

Bancks and colleagues evaluated data from the Coronary Artery Risk Development in Young Adults study on 4,251 adults (mean age, 25 years; 49% black; 54% women) without diabetes at baseline (1985-1986) observed through 2015 to 2016 to determine the associations of modifiable factors on racial disparity in diabetes incidence. Follow-up was a mean of 24.5 years.

There were 315 incident cases of diabetes among black participants and 189 incident cases among white participants over follow-up. The unadjusted incidence of diabetes was lower among white participants (86 cases per 1,000 people) compared with black participants (152 cases per 1,000 people) for an excess of 66 cases per 1,000 people for black compared with white participants. The risk difference estimate was 67 cases per 1,000 people for black compared with white participants after adjustment for age, sex and field center.

After adjustment for biological, neighborhood, psychosocial, socioeconomic and behavioral factors measured over time, there was no longer disparity in the risk for diabetes between black and white middle-aged adults (HR = 0.79; 95% CI, 0.55-1.14 for women; HR = 0.92; 95% CI, 0.62-1.38 for men).

“We show that we can explain the disparity in diabetes incidence when we account for differences in well-known health factors and their changes over time, particularly measures of obesity in general and around the waist,” Bancks said. “In our study, black women and men developed diabetes to a much greater extent already by middle age than white women and men. This will lead to greater mortality and complications in blacks than in whites in middle and older age. Prior research by our team has shown that black adults live in neighborhoods that have higher rates of poverty, fewer grocery stores and safe places for physical activity. These neighborhood factors contribute directly to the health behaviors, such as physical activity and diet, that can lead to obesity and diabetes.

“As a result of our study, we know the answer to why rates of diabetes are higher in blacks as compared to whites,” he said. “Our study provides a starting point to conversations with community members, policymakers and health care providers about the types of strategies that are needed to prevent the development of obesity and diabetes.” – by Amber Cox

For more information:

Michael P. Bancks , PhD, MPH, can be reached at michael.bancks@northwestern.edu.

Disclosures: Bancks reports no relevant financial disclosures. One author reports she received grants from Amgen outside the submitted work. The other authors report no relevant financial disclosures.