Mediators of the Racial Disparity in Diabetes Incidence—The Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study

Objective: To identify the contribution of individual and neighborhood factors to the racial disparity in diabetes incidence among older adults. Methods: This study included 7,304 black and white adults, aged 45-91 years at baseline (2003-07), without prevalent diabetes. Incident diabetes was assessed at the 2nd in-home exam (2014-16) using plasma glucose or use of diabetes medications. Modified Poisson regression, stratified by sex, was used to obtain risk ratios. Mediation analyses using the change in beta coefficient method and bootstrapping were done to evaluate the contribution of socioeconomic, anthropometric, lifestyle, clinical and neighborhood factors, grouped separately and all factors combined. Results: The risk of diabetes was 75% higher for black women compared with white women and 35% higher for black men compared with white men (Table). Among men, only lifestyle factors were significant mediators of the racial disparity. In contrast, among women, all grouped factors, except clinical, were significant mediators. When taking into account all factors combined, only 4.2% and 28.1% of the racial disparity was explained for men and women, respectively. Conclusion: Although the factors underlying the racial disparity varied by sex, the excess diabetes risk for black vs. white adults remained after accounting for individual and neighborhood factors. Disclosure A.P. Carson: Research Support; Self; Amgen Inc.. D. Long: None. A. Cherrington: Advisory Panel; Self; AstraZeneca. Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc.. Consultant; Self; Novo Nordisk Inc.. G.R. Dutton: None. V.J. Howard: None. T. Brown: Research Support; Self; Amgen Inc., AstraZeneca. C. Moy: None. M. Cushman: None. M. Safford: None. G. Howard: None.