Racial Disparities of Type 2 Diabetes Through Exercise: The Multi-Ethnic Study of Atherosclerosis

Persistent racial and ethnic disparities exist for Type 2 diabetes in the U.S. Racial and ethnic minorities have a higher risk of Type 2 diabetes, and studies suggest that they engage in less exercise than White population. This study examined whether and to what degree racial differences in Type 2 diabetes were explained by exercise.

Adults aged 45-84 years without Type 2 diabetes at baseline (2000-2002) were included from the Multi-Ethnic Study of Atherosclerosis cohort and followed through 2020. Associations between race and Type 2 diabetes were examined using multivariable Cox proportional hazard regression. The effects of exercise were assessed using natural mediation effects. Analyses were conducted in 2023.

Controlling for confounders, Hispanic (adjusted hazard ratio [95% CI]=2.02 [1.74, 2.34]), Chinese (1.50 [1.24, 1.82]), and Black (1.66 [1.44, 1.93]) participants had higher Type 2 diabetes risks than White participants. Hispanic (β [SE]= -0.29 [0.04] square root of MET-hour/day, p<0.001) and Chinese (-0.25 [0.04], p<0.001) participants had lower habitual intentional exercise than White participants; this was not true for Black participants (-0.01 [0.03], p=0.85). Habitual intentional exercise explained Type 2 diabetes excess risk by 13.6% for Hispanic and 13.2% for Chinese participants but not for Black participants, compared with that for White participants.

Habitual intentional exercise accounted for one tenth of the racial differences in Type 2 diabetes when comparing Hispanic or Chinese populations with White populations. Interventions promoting exercise are crucial to decrease Type 2 diabetes risk for all racial groups but may also narrow disparities in Type 2 diabetes among Hispanic and Chinese populations.