Australasian Science: Australia's authority on science since 1938

Diabetes Drug Prevents Parkinson’s

By Stephen Luntz

Diabetes is a major risk factor for developing Parkinson’s disease, with some diabetes drugs affecting the development of the latter.

An enormous study of the Taiwanese population has brought together two of the developed world’s fastest-growing diseases: Type 2 diabetes and Parkinson’s disease. The good news is that the same medication may work against both.

Monash University Emeritus Professor Mark Wahlqvist is the lead author of a paper published in Parkinsonism and Related Disorders that looked at data from 800,000 Taiwanese collected through the National Health Insurance Database. The sample size was so large that it was possible to break the group into statistically useful blocks by age, sex, Type 2 diabetes diagnosis and medication.

Over 12 years the study found that diabetes was a major risk factor for developing Parkinson’s disease. Furthermore, Wahlqvist demonstrated that sulfonylureas, which are commonly used as medication for diabetes, increased this risk further.

However, another diabetes drug, metformin, decreased the chance of developing Parkinson’s Disease. Where people were taking both medications together the net effect was a reduced risk of Parkinson’s disease.

Previously Wahlqvist used the same database and found that both sulfonylureas and metformin reduce the likelihood of developing dementia. “This means metformin may be considered a relevant therapy for the prevention of dementia as well,” Wahlqvist says.

He suggests that pre-diabetic people should be taking metformin for protective purposes.

Metformin is produced from French lilac, and has a low risk of side-effects – other than for people with kidney damage. Wahlqvist says, however, that since it is out of patent its use has sometimes been displaced by drugs promoted by pharmaceutical companies.

Wahlqvist acknowledges that epidemiological studies cannot explain how the medications work, but speculates that it relates to energy balance. He also suspects that the complex behaviour of sulfonylureas may relate to effects on insulin in the brain.

Wahlqvist is keen to promote the potential of data from national health programs for epidemiological research. “Australia has a national health insurance program very similar to Taiwan’s, but the database has barely been used for research such as this. It is a very under-utilised resource,” he says. “This is a cohort study, not an intervention study, but no one will ever be able to do an intervention study of this size.”