Long-Standing Diabetes Significantly Increases Dementia Risk in Heart Attack Survivors, Study Finds
Korea: A large-scale Korean study has found that the length of time a person has had diabetes may significantly influence their risk of developing dementia after a heart attack. The research, led by Dr. Dae Young Cheon and colleagues from the Division of Cardiology at Dongtan Sacred Heart Hospital, was published in Diabetology & Metabolic Syndrome.
Drawing on data from the Korean National Health Insurance Database, the team followed 43,561 individuals who had experienced a myocardial infarction (MI) but had no prior dementia diagnosis. Participants were grouped according to their blood sugar status: normal glucose levels, impaired fasting glucose, newly diagnosed diabetes, and established diabetes of less than five years or five years or longer. The study tracked them from 2009 to 2018 to assess the development of all-cause dementia, Alzheimer’s disease (AD), and vascular dementia (VaD).
The key findings of the study were as follows:
- Over a median follow-up of 7.6 years, 10.1% of participants developed dementia.
- Individuals with diabetes for five years or more had about a 52% higher risk of all-cause dementia compared to those with normal blood sugar levels.
- Participants with diabetes for less than five years had a 23% higher risk of all-cause dementia.
- Alzheimer’s disease risk was 22% higher in the short-duration diabetes group and 50% higher in the long-duration group.
- Vascular dementia risk was 38% higher in the short-duration group and 58% higher in the long-duration group.
- Younger participants under 65 with long-standing diabetes faced an especially high risk of developing dementia.
While the findings are robust, the authors acknowledge several limitations. Dementia diagnoses relied on insurance claims data and prescriptions for anti-dementia medications, potentially missing early or untreated cases. The classification of diabetes and prediabetes was based on single fasting glucose measurements, without accounting for longer-term glycemic control markers such as HbA1c or glucose variability. Additionally, the study did not adjust for certain dementia-related factors such as education level, baseline cognitive function, or family history.
Information on specific post-MI treatments and classes of antidiabetic medications—particularly newer agents like GLP-1 receptor agonists or SGLT2 inhibitors—was also unavailable. However, the authors note that the use of such drugs in Korea was limited during the study period, so their absence is unlikely to have substantially affected the results.
Despite these constraints, the research is among the most comprehensive examinations of the link between diabetes duration and dementia risk in heart attack survivors. It reinforces the need for vigilant cardiovascular and metabolic care not only to protect the heart but also to safeguard brain health.
“Our findings suggest that the longer a patient has diabetes after a heart attack, the greater their risk of dementia,” said Dr. Cheon. “This highlights the importance of early detection and long-term management of diabetes to help prevent cognitive decline.”
Reference:
Cheon, D.Y., Han, K., Yang, Y.S. et al. Diabetes status, duration and risk of dementia in patients with myocardial infarction. Diabetol Metab Syndr 17, 296 (2025). https://doi.org/10.1186/s13098-025-01863-w
