Associations of Cardiometabolic Multimorbidity with All-Cause and Coronary Heart Disease Mortality among Black Adults in the Jackson Heart Study

Importance: A combination of diabetes, coronary heart disease (CHD), and stroke has multiplicative all-cause mortality risk compared with any individual morbidity in White populations, but there is a lack of studies in Black populations in the US. Objective: To examine the association of cardiometabolic multimorbidity (diabetes, stroke, and CHD) individually and collectively with all-cause and CHD mortality. Design, Setting, and Participants: This cohort study included Black adults in the Jackson Heart Study followed over a median of 15 years. Baseline examinations were performed between 2000 and 2004, with follow-up on all-cause and CHD mortality through May 31, 2018. Participants were categorized into mutually exclusive groups at baseline: (1) free of cardiometabolic morbidity, (2) diabetes, (3) CHD, (4) stroke, (5) diabetes and stroke, (6) CHD and stroke, (7) diabetes and CHD, and (8) diabetes, stroke, and CHD. Data were analyzed from 2019 to 2021. Exposure: Cardiometabolic disease alone or in combination. Main Outcomes and Measures: The main outcomes were all-cause mortality and CHD mortality. Cox models estimated hazard ratios (HRs) with 95% CIs adjusted for sociodemographic and cardiovascular risk factors. Results: Among 5064 participants (mean [SD] age, 55.4 [12.8] years; 3200 [63%] women) in the Jackson Heart Study, 897 (18%) had diabetes, 192 (4%) had CHD, and 104 (2%) had a history of stroke. Among participants with cardiometabolic morbidities, the crude all-cause mortality rates were lowest for diabetes alone (24.4 deaths per 1000 person-years) and highest for diabetes, CHD, and stroke combined (84.1 deaths per 1000 person-years). For people with only 1 cardiometabolic morbidity, risk for all-cause mortality was highest for people with stroke (HR, 1.74; 95% CI, 1.24-2.42), followed by CHD (HR, 1.59 (95% CI, 1.22-2.08) and diabetes (HR, 1.50; 95% CI, 1.22-1.85), compared with no cardiometabolic morbidities. There were also increased risks of mortality with combinations of diabetes and stroke (HR, 1.71; 95% CI, 1.09-2.68), CHD and stroke (HR, 2.23; 95% CI, 1.35-3.69), and diabetes and CHD (HR, 2.28; 95% CI, 1.65-3.15). The combination of diabetes, stroke, and CHD was associated with the highest all-cause mortality (HR, 3.68; 95% CI, 1.96-6.93). Findings were similar for CHD mortality, but with a larger magnitude of association (eg, diabetes, stroke, and CHD: HR, 13.52; 95% CI, 3.38-54.12). Conclusions and Relevance: In this cohort study, an increasing number of cardiometabolic multimorbidities was associated with a multiplicative increase in risk of all-cause mortality among Black adults, with a greater magnitude of association for CHD mortality.