Older diabetes treatment appears to have anti-dementia effect

Researchers report a link between use of glitazones to treat type 2 diabetes and a 22% reduced risk of dementia. The findings appeared on Oct 11, 2022 in BMJ Open Diabetes Research & Care.

“These findings may help inform medication selection for [older] patients with [type 2 diabetes] at high risk of dementia,” the authors said.

As background, the authors noted that type 2 diabetes and dementia share physiological patterns. This has led to prior studies investigating whether diabetes drugs could prevent or treat dementia. To date, findings have been inconclusive.

In this new retrospective study, the researchers compared dementia risk among older people with type 2 diabetes who had been treated with either sulfonylurea or thiazolidinedione (TZD) monotherapy or with metformin monotherapy.

The investigators evaluated data from the electronic health records of 559,106 subjects from the national Veteran Affairs (VA) Health System diagnosed with type 2 diabetes.

Eligibility included age 60 years or older at first prescription of metformin or a sulfonylurea (tolbutamide, glimepiride, glipizide, or glyburide) or a TZD (rosiglitazone or pioglitazone), between January 2001 and December 2017.

Subjects were followed for an average of nearly 8 years.

After at least 1 year of drug treatment, therapy with TZD monotherapy was associated with a 22% lower risk of dementia onset compared with metformin monotherapy.

They also reported an 11% lower risk of dementia among subjects treated with metformin and TZD dual therapy, compared to metformin monotherapy.

They found a 12% higher risk of dementia for subjects treated with sulfonylurea monotherapy compared to metformin monotherapy.

Additional analysis of the suggested that subjects under 75 at enrollment had more anti-dementia benefit from a TZD than older patients.

The authors concluded, “Among patients with T2D, TZD use was associated with a lower risk of dementia, and SU [sulfonylurea] use was associated with a higher risk compared with MET [metformin] use. Supplementing SU with either MET or TZD may partially offset its prodementia effects.”