COMBINATION of diabetes and coronary artery disease (CAD) is associated with a significantly elevated risk for dementia, particularly vascular dementia. Diabetes is a well-established risk factor for dementia, but it is unclear to the extent that this risk is mediated by atherosclerotic cardiovascular disease (CVD). Therefore, the study used CAD as a marker of systemic atherosclerotic CVD to test the hypothesis that patients with diabetes and coexisting atherosclerotic CVD are at a substantially higher risk of developing dementia.
Researchers conducted a real-world study composed of 103,859 patients ≥ 65 years of age who underwent coronary angiography and were stratified by diabetes and CAD from the Danish National Patient Registry. Of the 103,859 patients, 3,876 (4%) had diabetes, 61,020 (59%) had CAD, and 15,774 (15%) had diabetes and CAD. The study used a group of 23,189 (22%) patients without diabetes or CAD as a reference group to estimate adjusted hazard ratios (aHRs). Outcomes tracked in the study were all-cause dementia, Alzheimer’s dementia, and vascular dementia. The median follow-up for study participants was 6.3 years.
Findings from follow-up revealed that 5,592 patients (5.5%) were diagnosed with all-cause dementia. Patients with diabetes in conjunction with CAD had the highest aHR and were significantly more likely to be diagnosed with all-cause dementia (aHR = 1.37; 95% confidence interval [CI], 1.24-1.51), Alzheimer’s dementia (aHR = 1.41; 95% CI, 1.23-1.62) and vascular dementia (aHR = 2.03; 95% CI, 1.69-2.45) compared to patients with neither condition. Researchers also found that the rate of all-cause dementia was modestly higher in either diabetes or CAD alone when compared to the reference group. Furthermore, the relative excess risk due to the interaction between diabetes and CAD was elevated for vascular dementia (0.69; 95% CI, 0.25-1.12), indicating a “synergistic effect”.
The results from this study led the authors to conclude that diabetes and CAD alone only modestly increased all-cause dementia risk, while diabetes and CAD in combination significantly elevated dementia risk, especially vascular dementia. Therefore, “diabetes-related risk of dementia is partly mediated through concomitant atherosclerotic CVD”, showcasing the significance of preventing atherosclerotic CVD to intervene in dementia development.
Reference:
T Olesen, K.K. et al. Diabetes and coronary artery disease as risk factors for dementia. European Journal of Preventive Cardiology, 2024;p.zwae153.
