An unexpected interaction between diabetes and cardiovascular diseases on cognitive function: A cross-sectional study

Objective: Impaired cognitive function in older individuals significantly affects quality of life. The interaction between comorbid diabetes and cardiovascular disease (CVD) and its impact on cognitive impairment remains unclear. Methods: This study analyzed 2564 subjects from the National Health and Nutrition Examination Survey dataset. Cognitive function was measured using various scores, including CERAD Total Score, CERAD Delayed Recall Score (CDRS), Animal Fluency Total Score, and Digit Symbol Score. Multiple regression models were constructed to explore the relationship between different diseases and cognitive function, considering covariates such as age, sex, education, body mass index, alcohol intake, smoking, physical activity, kidney function, and hypertension. Results: After adjusting for multiple factors, the presence of CVD, diabetes, or both showed a significant negative association with the total cognitive score. The CDRS was associated with both CVD and diabetes. The Digit Symbol score was associated with the presence of CVD, diabetes, or both. No significant differences were found between patients with diabetes and CVD in cognitive test results. An interaction between CVD and diabetes was observed in relation to the CDRS but not in other test scores or the total score. Conclusion: The individual impact of each disease on cognitive function was not significant. However, an interaction between CVD and diabetes was found when both diseases coexisted, specifically in relation to delayed learning ability.