Drugs used to treat type 2 diabetes could lower risks of dementia and provide greater benefits from longer treatment, a study published in The British Medical Journal has suggested.
Experts said the idea of repurposing existing drugs to treat diseases that cause dementia “is one that has huge potential”.
The Korean study of 110,885 diabetics indicated that medication used to treat type 2 diabetes was linked to a 35 per cent lower risk of dementia.
The number of people with dementia globally is expected to reach 78 million by 2030 and type 2 diabetes is associated with a greater risk of developing dementia, the World Health Organisation says.
Patients in the study were either taking sodium-glucose cotransporter-2 (SGLT-2) inhibitors or dipeptidyl peptidase 4 (DPP-4) inhibitors.
The study found SGLT-2 inhibitors were linked to a 35 per cent lower risk of dementia compared with DPP-4 inhibitors.
Researchers also found a 39 per cent reduced risk for Alzheimer’s disease, and a 52 per cent reduced risk for vascular dementia associated with SGLT-2 inhibitors compared with DPP-4 inhibitors.
The effect of the SGLT-2 inhibitors also seemed more pronounced with longer treatment duration, the study found.
As the study was observational, the researchers have called for controlled and randomised trials.
“This association was similarly observed for Alzheimer’s disease and vascular dementia and was also consistent across subgroups,” researchers said.
“We observed a greater association with treatment duration longer than two years. These findings underscore the need for future randomised controlled trials.”
Dr Jacqui Hanley, head of research at Alzheimer’s Research UK, also called for the findings to be confirmed through “robust clinical trials”.
“It will also be important to investigate the mechanisms behind this apparent effect, as this could give researchers clues for other treatment approaches,” she said.
“It is encouraging to see large studies exploring whether drugs that have already been licensed could be repurposed as dementia treatments.
“Since these drugs have already been shown to be safe for use in people, this could potentially speed up the process of testing them in clinical trials against dementia, as well as making it significantly cheaper.
“More broadly, the idea of repurposing existing drugs to treat the diseases that cause dementia is one that has huge potential.”
Professor William Whiteley, associate director of the British Heart Foundation Data Science Centre, warned the findings could be down to a “quirk of the study design”.
One can never be sure about the effects of a medicine by looking at health record data.
About 1.5 million deaths are attributed to diabetes each year.
The overwhelming majority of people with the condition have type 2 diabetes, the form that develops later in life and is often the result of lifestyle factors, primarily an unhealthy diet or lack of exercise.
Type 2 diabetes involves glucose levels in the blood rising dangerously high.
In the Middle East, dementia rates are expected to increase by 367 per cent, affecting 13.8 million people by 2050.
