Diabetes
Racial and ethnic disparities of type 2 diabetes in the United States: the pathways through exercise in the Multi-Ethnic Study of Atherosclerosis Tong Xia* Tong Xia Roch A. Nianogo QingZhao Yu Tamara Horwich Preethi Srikanthan Kosuke Inoue Matthew Allison Karol E. Watson Liwei Chen
Introduction: In the United States, racial/ethnic minorities have persistently higher risks of type 2 diabetes (T2D) than White individuals. Engaging in less exercise may explain part of the differences. We aimed to examine whether and to what degree racial/ethnic differences in T2D were explained by variation in exercise.
Methods: We included adults (45–84 years) from the Multi-Ethnic Study of Atherosclerosis (MESA) cohort who were free of T2D in 2000–2002 (baseline) and followed until 2020 for incident T2D. We examined associations of race/ethnicity with T2D using Cox proportional hazard regressions. We assessed the proportion of racial/ethnic differences in T2D risk explained by habitual exercise (i.e., the average of exercise from baseline to develop T2D or until last contact if censored) using a causal mediation analysis approach.
Results: Among 5772 participants, 41.7%, 26.0%, 20.4%, 11.9% were Whites, Blacks, Hispanics, and Chinese Americans, respectively. Controlling for age, gender, and family history of diabetes, Hispanics [hazard ratio (HR) (95% confidence interval, CI): 2.02 (1.74–2.34)], Chinese Americans [1.50 (1.24–1.82)], and Blacks [1.66 (1.44–1.93)] had higher T2D risk than Whites. Compared to Whites, Hispanics [β (SE): -0.96 (0.15), P<0.001] and Chinese Americans [-1.07 (0.18), P<0.001] had lower exercise (metabolic equivalent of task-hour/day) levels, while Blacks [0.26 (0.16), P=0.11] had the same exercise level. Exercise explained 10.8% and 11.3% of racial/ethnic differences in T2D, comparing Hispanics and Chinese Americans to Whites, but did not explain racial/ethnic differences in T2D comparing Blacks to Whites.
Conclusions: Exercise may explain about one tenth of racial differences in T2D comparing Hispanics and Chinese Americans to Whites. Interventions on increasing exercise among Hispanics and Chinese Americans may help narrow racial/ethnic disparities in T2D and promote health equity.