A study by Gererman researchers shows that taking the diabetes drug Actos (pioglitazone) for more than two years is associated with a 47% lower risk of dementia.

The finding is notable on two levels. Firstly it suggests that existing treatments exist to help prevent dementia, a condition closely linked with type 2 diabetes. Secondly, it breathes extra life into pioglitazone, a type 2 diabetes drug which has been experiencing a noted drop in how often it is prescribed in recent years.

The study was led by Michael T. Heneka, MD, Professor of Clinical Neuroscience at the German Center for Neurodegenerative Diseases (DZNE) in Bonn, Germany. Data was provided by the Scientific Research Institute of the German public health insurance company, AOK.

The data of 145,928 people with diabetes was statistically analyzed. Subjects were 60 years or above and at the start of the study period were free of dementia and not treated with insulin. The study period ran between 2004 and 2010.

<h2>Marked decrease in risk</h2>

The results of the analysis showed that the people taking pioglitazone had a 47% reduced risk of dementia compared with people without diabetes. This reduction in risk is in marked contrast to the people with diabetes that were not taking pioglitazone. Those with diabetes but not on the drug had a 23% higher risk of dementia compared with non-diabetics.

The study also showed that metformin use corresponded with a lower risk dementia risk, although the risk reduction was not as great as for pioglitazone.

<h2>Drug with a checkered past</h2>

Actos (pioglitazone) is in a class of drugs known as thiazolidinediones which are commonly referred to as insulin sensitizers as the drugs improve the body’s sensitivity to insulin.

Actos has been prescribed less and less in recent years as the drug’s side effects include gradual weight gain and rarer side effects include bladder cancer and heart failure. Doctors had been less willing to prescribe the drug as growing evidence of the side effects appeared to be outweighing the benefits of improved blood sugar levels.

However, if evidence continues to show Actos as being preventative against dementia, the drug may come back into fashion again, particularly within the treatment of people with type 2 diabetes with a family history of Alzheimer’s disease.

<h2>Is Actos the answer to Alzheimer’s?</h2>

The study suggests Actos has a potent effect in reducing the risk of dementia but side effects will need to be considered and there may be alternative drugs that can also reduce dementia risk with fewer side effects.

Another class of drugs that has shown potential in preventing Alzheimer’s disease is the GLP-1 receptor agonists drug class. Studies on mice have shown that these type 2 diabetes drugs may also reduce the risk of Alzheimer’s disease and it will be interesting to see whether a similar effect is observed within humans. The way in which the drugs work certainly suggests this as a good possibility.