Diabetes drug may lower risk of DEMENTIA by up to a third, study suggests

A common type 2 diabetes drug may lower the risk of dementia, a study suggests. 

Diabetes has long been linked to an increased risk of dementia, which is thought to be due to low blood sugar levels damaging areas of the brain, as well as diabetes’ link to high blood pressure.

Scientists in South Korea found an association between taking pioglitazone — sold under the brand name Actos — and lower rates of dementia for type 2 diabetics.

The study tracked 91,000 adults in their 60s, including 3,500 who took the drug, over 10 years. The longer patients had been taking the drug, the lower their risk of dementia. 

Those on the drug for more than four years appeared to be 37 percent less likely to be diagnosed with the condition.

The study was only able to detect a correlation and could not prove that pioglitazone was reducing patients’ risk of dementia. 

Pioglitazone is available on prescription for type 2 diabetes patients. 

It is prescribed to around 3million Americans and more than a million Britons every year.

Past studies have also linked the drug with a reduced risk of dementia and even suggested it can help to prevent hospitalization and death from Covid.

Pioglitazone has been available since 1985.

Doctors often prescribe the drug alongside a healthier diet and exercise, to further help boost the body’s sensitivity to insulin.

It works by increasing the body’s sensitivity to insulin, a natural substance that helps control blood sugar levels.

When blood sugar is not well controlled, studies suggest that high levels can lead to more amyloid beta proteins forming in the brain.

These are a key risk factor for dementia, because they can clump together and become stuck between nerve cells — blocking the signals.

But the scientists suggested that when patients are using pioglitazone, the better controlled sugar levels reduce the risk of these proteins forming, in turn reducing the risk of dementia.

They added that the drug could also reduce patients’ risk of dementia by lowering inflammation levels in the body.

In the latest study, researchers at Yonsei University in Seoul analyzed diabetes data froma national health database for people newly diagnosed with diabetes between 2002 and 2017.

They included data on 91,218 people, of which 3,467 were prescribed pioglitazone.

Patients were about 60 years old on average and none had dementia when their diabetes was diagnosed.

Results showed that among those who were prescribed pioglitazone, eight percent later developed dementia.

For comparison, in the group not prescribed the drug, 10 percent went on to develop the debilitating condition.

After adjusting for factors including high blood pressure, smoking and physical activity, they found that people taking the drug were 16 percent less likely to develop the disease compared to those who did not.

The length of time someone was on the drug appeared to reduce the risk further.

Participants who were on pioglitazone for one to two years had a 22 percent reduced risk of dementia.

But among those taking the pills for four years or more, they were 37 percent less likely to develop the debilitating disease. 

The study also found that participants with a history of heart disease or stroke who took the drug were 54 percent and 43 percent, the scientists found.

Scientists cautioned patients with diabetes should not all rush to take the drug because it can cause serious side effects. These include weight gain, bone loss and congestive heart failure.

Dr Eosu Kim, a psychiatrist at Yonsei University who led the research, said: ‘Since dementia develops for years before diagnosis, there may be an opportunity for intervening before it progresses.

‘These results may suggest that we could use a personalized approach to preventing dementia in people with diabetes in the case that they have a history of ischemic heart disease or stroke.’

She added: ‘In some previous studies of people with dementia or at risk of cognitive decline who did not have diabetes, pioglitazone did not show any protection against dementia.

‘So it’s likely that a critical factor affecting the effectiveness is the presence of diabetes.’

Scientists suggested that diabetes raises the risk of dementia through several mechanisms.

It is already known to raise the risk of heart disease and high blood pressure, in turn making it more likely someone will have a stroke — a risk factor for dementia.

Low blood sugar episodes are also known to raise the risk of dementia because they can lead to damage to the hippocampus, the area of the brain dedicated to memory.

Previous studies also warn that insulin has a role in how much amyloid beta collects in the brain, a cause of dementia.

The scientists warned the paper had several limitations including that it was based on insurance claims, meaning some people buying the drug themselves would not have been recorded in the data.

It was also possible that patients were not taking the drug as prescribed.

The study was funded by the Korean Ministry of Health and Welfare and the National Research Foundation of Korea.

It was published in the journal Neurology, the medical journal of the American Academy of Neurology.