Diabetes, coronary artery disease, and risk of dementia – a cohort study from Western Denmark

Abstract Background Diabetes patients have a higher risk of both ischemic stroke and dementia compared to non-diabetes patients. Coronary artery disease (CAD) is associated with an increased risk of ischemic stroke. We hypothesized that diabetes and CAD are independent, and additive, risk factors for ischemic stroke and dementia. Purpose We examined the risk of dementia and ischemic stroke in diabetes and non-diabetes patients with and without CAD by coronary angiography. Methods We conducted a cohort study of all patients ≥65 years, who underwent coronary angiography between 2003–2016 in Western Denmark. Patients diagnosed with dementia or early cognitive decline at the time of CAG were excluded. Patients were stratified by diabetes and CAD. Outcomes were dementia and ischemic stroke. We estimated the cumulative incidence of a combined endpoint of dementia and ischemic stroke accounting for the competing risk of death. Follow-up was capped at the 75th percentile of overall follow-up (9.2 years). We estimated adjusted hazard ratios (aHRs) using patients without diabetes and CAD as reference. We also examined the association between extent of CAD and dementia in subgroup analysis of diabetes patients. Results A total of 62,372 patients were included, of whom 10,417 (16.7%) had diabetes and 43,023 (69.0%) had obstructive CAD. Median follow-up was 5.8 years. Patients with both diabetes and CAD had the highest risk of dementia (aHR 1.47, 95% CI 1.27–1.71), including Alzheimer's dementia (aHR 1.26, 95% CI 1.01–1.56) and vascular dementia (aHR 2.60, 95% CI 1.78–3.80), as well as ischemic stroke (aHR 2.02, 95% CI 1.77–2.32). Patients with either diabetes or CAD were at intermediate risk of dementia and ischemic stroke (Figure). We did not find a significant trend between the extent of CAD and risk of dementia in diabetes patients (p for trend=0.0687). Conclusions Both diabetes and CAD were independent risk factors of dementia and ischemic stroke in patients ≥65 years after angiography. Patients with combined diabetes and CAD had a particularly high risk of cognitive impairment and ischemic stroke. Figure 1 Funding Acknowledgement Type of funding source: Public hospital(s). Main funding source(s): Department of Cardiology, Aarhus University Hospital