A common type 2 diabetes drug may lower the risk of dementia in diabetics, 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 among 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 the cause of the reduced dementia risk.
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. It works by increasing the body’s sensitivity to insulin, a natural substance that helps control blood sugar levels.
In the latest study, researchers at Yonsei University in Seoul analyzed diabetes data froma national health database for people newly diagnosed with diabetes between 2004 and 2012, and tracked until 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.
Middle-aged people with type 2 diabetes may be four times more likely to get dementia
Diabetes is linked to dementia, with experts suspecting it can lead to the build-up of potentially harmful proteins in the brain.
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 hallmark of Alzheimer’s.
The scientists warned the paper had several limitations including that it was based on insurance claims. It was also possible for some people not to take the drugs as prescribed.
Healthcare is not free in South Korea, but the Government does cover 50 to 80 percent of medical costs for patients depending on their need.
Medical providers recover the costs by submitting claims to the country’s National Health Insurance plan.
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.
What is pioglitazone?
Pioglitazone is a drug available on prescription to diabetes patients to help control their blood sugar levels.
In the United States, it is sold under the brand name Actos.
It works by making cells more responsive to insulin,
How is the drug prescribed?
Doctors will prescribe one pill to be taken orally with water every day.
It can be taken with or without food.
Diabetes patients given the drug are usually put on it for life.
Some medical organizations may also prescribe the drug with a plan to improve a patient’s exercise and diet.
Are there any side effects?
Doctors warn that side-effects of the drug include swelling, gaining weight, bone loss and congestive heart failure.