TOPLINE:

The risk for dementia is nearly threefold higher in older adults with type 1 diabetes (T1D) and double in those with type 2 diabetes (T2D) than in those without the disease, a new prospective cohort study showed. Although diabetes had been linked previously to increased risk for dementia, the link between dementia and T1D specifically had been understudied, investigators noted.

METHODOLOGY:

• A prospective cohort study used previously collected data from surveys and electronic health records (EHRs) of nearly 284,000 participants aged 50 years or older (mean age, 65 years; 57% female; 60% non-Hispanic White individuals) from the All of Us Research Program cohort, a convenience sample in the US (2017-2023).
• Investigators developed an algorithm to distinguish diabetes type based on the count of T1D EHR encounters, validated against self-reported diabetes type and C-peptide levels.
• About 1.9% of the participants had T1D at baseline, defined as having one or more T1D EHR encounter, and 18.1% had T2D.
• Outcomes included incident all-cause dementia, identified using EHRs, over a mean follow-up of 2.4 years.

TAKEAWAY:

• Nearly 2348 participants developed dementia during the follow-up period. The risk for dementia was higher among participants with T1D (sociodemographic-adjusted hazard ratio [aHR], 2.82) and T2D (aHR, 2.08) than among those without diabetes.
• Results were similar across sex and race or ethnicity subgroups, with T1D associated with increased dementia incidence in both women (HR, 3.04) and men (HR, 2.59), and in Hispanic/Latino (HR, 3.29), non-Hispanic White (HR, 2.98), and non-Hispanic Other (HR, 2.38) individuals.
• There was also a 6% prevalence of T1D among all participants who developed dementia, and 64.5% of dementia cases among individuals with T1D could be attributed to having T1D.

IN PRACTICE:

“Type 1 diabetes is not common, so this condition accounts for a small fraction of all dementia cases. 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,” study investigator Jennifer Weuve, ScD, Boston University, Boston, said in a press release.

SOURCE:

The study was led by Anna M. Pederson, Boston University School of Public Health, Boston. It was published online on March 18 in Neurology.

LIMITATIONS:

The study relied on preexisting EHR and survey data to classify diabetes status, which may have led to the misclassification of diabetes. Assessment of all-cause dementia relied on EHR-based diagnoses, which may have entailed misclassification of dementia status. Even modest misclassification in the developed algorithm could bias estimates given that T1D is rare.

DISCLOSURES:

The study was funded by the National Institute on Aging and the National Institute of Diabetes and Digestive and Kidney Diseases. The investigators reported having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.