Abstract P056: Sex Differences in the Association of Diabetes With Cardiovascular Disease Outcomes Among African Americans in the Atherosclerosis Risk in Communities (ARIC) Prospective Cohort: 1987-2013
Epidemiologic studies have consistently shown in whites that the relative risk of diabetes for coronary heart disease (CHD) is greater for women than for men. However, little is known whether this differential sex association is mirrored among African Americans. We hypothesized that, similar to whites, there would be a multiplicative sex by diabetes interaction for cardiovascular disease (CVD) incidence among African Americans in the ARIC cohort. We conducted a prospective cohort analysis of 14,058, 27% African American and 73% white, participants from the ARIC study initially recruited in 1987-1989 and followed for incident cardiovascular events through 2013. CVD was defined as CHD, total stroke, peripheral artery disease (PAD), or heart failure. Race-specific Poisson regression was used to calculate incidence rates of CVD stratified by diabetes status and sex. Race-specific Cox proportional hazards models were run in three stages; stage 1 examined baseline diabetes status, stage 2 examined baseline diabetes status with the competing risk of non-CVD death, and stage 3 incorporated a time-varying model that updated diabetes status during follow-up and included a competing risk of non-CVD death. At each stage, three sequential models were run adjusting for potential confounders including age, body mass index (BMI), smoking status, physical activity, alcohol consumption, education, hypertension, LDL cholesterol, HDL cholesterol, and kidney function. There were 1,073 incident CVD events among African Americans and 2,475 among whites. In stage 1 analysis among African Americans with baseline diabetes, the CVD incidence rate was nearly identical in women and men, 26.8 and 28.1 per 1000 person years, respectively. Women with diabetes were at 2.3-fold increased hazard (95% CI: 2.0 to 2.7) of CVD compared to women without diabetes after adjustment for age, whereas the corresponding hazard ratio for men was 1.8 (95% CI: 1.5 to 2.1) (p for sex by diabetes interaction=0.014). After full adjustment for potential confounders, the diabetes hazard ratio was attenuated to 2.0 (95% CI: 1.8 to 2.3) in women and remained at 1.8 (95% CI: 1.5 to 2.1) for men (interaction p-value =0.058). This finding of synergy between being a woman and having diabetes on CVD risk was consistent across stages 2 and 3 with marginally significant p-values for interaction. The interaction of diabetes by sex was somewhat weaker among whites. Efforts to prevent diabetes and control CVD risk factors are important to both African American men and women, but are particularly relevant in women. While diabetes and CVD risk factor management have improved over the last several decades, there is a higher relative risk of CVD among African American women with diabetes compared with diabetic men, mirroring the sex differences seen in whites.
Author Disclosures: K.M. George: None. E. Selvin: None. J.S. Pankow: None. B. Windham: None. A.R. Folsom: None.
- © 2017 by American Heart Association, Inc.