A study of nearly 284,000 people has found that both type 1 and type 2 diabetes are associated with a significantly higher risk of developing dementia — but the connection appears to be considerably stronger for those with type 1.
Researchers found that people with type 1 diabetes were nearly three times as likely to develop dementia compared to people without diabetes. Those with type 2 diabetes were twice as likely.
The study was published in Neurology, the medical journal of the American Academy of Neurology.
Also Read: Assam’s Transformation Flows Through Waterways, Brahmaputra Emerges as Growth Lifeline: Himanta
The study tracked 283,772 participants with an average age of 64, following them for an average of 2.4 years. Of that group, 5,442 had type 1 diabetes and 51,511 had type 2 diabetes.
During the follow-up period, 2,348 people developed dementia. The breakdown by group was telling:
2.6% of people with type 1 diabetes developed dementia (144 people)
1.8% of people with type 2 diabetes developed dementia (942 people)
0.6% of people without diabetes developed dementia (1,262 people)
Researchers also estimated that around 65% of dementia cases among people with type 1 diabetes could be attributed to the condition itself.
Type 1 diabetes is relatively rare, accounting for roughly 5% of all diabetes diagnoses. For a long time, its connection to dementia received far less attention than type 2.
But that is changing, as improved medical care means people with type 1 diabetes are living longer — and increasingly reaching the age at which dementia risk rises.
"As advances in medical care have extended the lives of people with type 1 diabetes, it's becoming increasingly important to understand the relation of type 1 diabetes to the risk of dementia," said lead study author Jennifer Weuve, MPH, ScD, of Boston University.
"We have known that type 2 diabetes is linked to an increased risk of dementia, but this new research suggests that, unfortunately, the association may be even stronger for those with type 1 diabetes," she added.
Weuve was careful to place the findings in context, noting that because type 1 diabetes is uncommon, it accounts for only a small share of all dementia cases overall.
"But for the growing number of people with type 1 diabetes who are over 65 years old, these findings underscore the urgency of understanding the ways in which type 1 diabetes influences dementia risk and how we can prevent or delay it," she said.
One limitation worth noting: diabetes and dementia diagnoses in this study were identified through electronic health records and survey data, which may not capture every case.
Importantly, the study shows an association between diabetes and dementia — it does not prove that diabetes directly causes dementia.