Diabetes, Kidney Disease, and Cardiovascular Outcomes in the Jackson Heart Study

Abstract

Background and objectives: Blacks have high rates of cardiovascular disease and mortality. Diabetes and CKD, risk factors for cardiovascular mortality in the general population, are common among blacks. We sought to assess their contribution to cardiovascular disease and mortality in blacks.

Design, setting, participants, & measurements: This observational cohort study was of 3211 participants in the Jackson Heart Study (enrolled 2000-2004). Rates of incident stroke, incident coronary heart disease, and cardiovascular mortality were quantified in participants with diabetes, CKD (eGFR<60 ml/min per 1.73 m(2), urine albumin-to-creatinine ratio ≥30 mg/g, or both), or both through 2012, with a median follow-up of 6.99 years.

Results: Four hundred fifty-six (14.2%) participants had only diabetes, 257 (8.0%) had only CKD, 201 (6.3%) had both, and 2297 (71.5%) had neither. Diabetes without CKD was associated with excess risks of incident stroke, incident coronary heart disease, and cardiovascular mortality after adjustment for demographic and clinical covariates, including prevalent cardiovascular disease (excess incidence rates, 2.6; 95% confidence interval, 0.5 to 4.7; 2.6; 95% confidence interval, 0.3 to 4.8; and 2.4; 95% confidence interval, 0.4 to 4.3 per 1000 person-years, respectively). CKD without diabetes was associated with comparable nonsignificant excess risks for incident stroke and coronary heart disease (2.5; 95% confidence interval, -0.1 to 5.2 and 2.4; 95% confidence interval, -0.8 to 5.5 per 1000 person-years, respectively) but a larger excess risk for cardiovascular mortality (7.3; 95% confidence interval, 3.0 to 11.5 per 1000 person-years). Diabetes and CKD together were associated with greater excess risks for incident stroke (13.8; 95% confidence interval, 5.3 to 22.3 per 1000 person-years), coronary heart disease (12.8; 95% confidence interval, 4.9 to 20.8 per 1000 person-years), and cardiovascular mortality (14.8; 95% confidence interval, 7.2 to 22.3 per 1000 person-years). The excess risks associated with the combination of diabetes and CKD were larger than those associated with established risk factors, including prevalent cardiovascular disease.

Conclusions: The combination of diabetes and kidney disease is associated with substantial excess risks of cardiovascular events and mortality among blacks.

Keywords: African Americans; Albumins; Follow-Up Studies; Humans; Renal Insufficiency, Chronic; cardiovascular disease; cardiovascular mortality; chronic kidney disease; coronary artery disease; creatinine; diabetes mellitus; stroke.

Figure 1.

Risk differences for incident stroke, coronary heart disease (CHD), and cardiovascular mortality (per 1000 person-years) by clinical risk factor in the Jackson Heart Study. Incidence rates were calculated using Poisson regression. Absolute risk differences were estimated by comparing the incidence rates in each group with those in the reference group (participants with no diabetes or CKD) using Poisson regression and adjusted for age, age², sex, hypertension, hyperlipidemia, smoking, and prevalent cardiovascular disease (CVD). Participants with a prior stroke were excluded from the analyses where the outcome was incident stroke; participants with prior CHD were excluded from the analyses where the outcome was incident CHD. CVD refers to a combination of stroke and CHD. CV death, cardiovascular death; DM, diabetes mellitus.