New research has found two types of drugs used to treat type 2 diabetes could lower the risk of dementia and Alzheimer’s disease.

Researchers looked at data from 1.5 million people with type 2 diabetes and found that those taking metformin and sodium glucose co-transporter-2 inhibitors (SGLT-2i) were less at risk of cognitive decline compared to people being treated with other antidiabetic drugs.

The team behind the findings say it offers “significant clinical implications” for diabetes management.

Previous studies have found that people with type 2 diabetes have a 50% greater risk of dementia.

With both type 2 diabetes and dementia posing a major global health problem, experts have set out to explore the links between the two.

Lead investigator Yeo Jin Choi, from Kyung Hee University in Korea, said: “As the prevalence of both diabetes and dementia continues to rise each year, and with mounting evidence suggesting a strong correlation between diabetes and dementia, the need for comprehensive research in dementia risk associated with antidiabetic treatment becomes increasingly imperative.

“Understanding the potential cognitive effects of antidiabetic medications is not only crucial for optimising patient care but also for informing regulatory decisions and clinical practice guidelines to prioritise patient safety and promote public health.”

Prior studies had indicated some antidiabetic drugs, such as sulfonylurea and alpha-glucosidase inhibitors which carry higher hypoglycaemic risks, may raise the risk of dementia.

Until now, little was known about SGLT-2 inhibitors and dementia risk.

For this latest research, the team analysed data from 16 studies to compare the risk of dementia and Alzheimer’s disease linked to six antidiabetic drug types: DPP4 inhibitors, metformin, SGLT-2 inhibitors, sulfonylureas, alpha-glucosidase inhibitors, and thiazolidinediones.

The researchers found that people on metformin had the lowest risk of dementia and Alzheimer’s disease. SGLT-2 inhibitors, including Farxiga and Jardiance, were linked to a lower risk of dementia and Alzheimer’s disease as well as bringing cardiovascular benefits.

For people aged under 75, the dementia risk linked to SGLT-2 inhibitors was on a par with other diabetes drugs.

The dementia risk was significantly higher, however, with dipeptidyl peptidase IV (DPP4) inhibitors, metformin, sulfonylureas, and thiazolidinedione (TZD) in comparison with SGLT-2 inhibitors in people aged 75 years or older.

Another key finding was that in women, dementia risk was substantially lower with SGLT-2 inhibitors compared to sulfonylureas.

The study adds to growing evidence that both metabolic and cognitive health outcomes should be considered by clinicians when deciding on treatment plans, and adds weight to the importance of personalised healthcare plans.

Read more in the American Journal of Preventive Medicine.

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