Diabetes Drug Lowered Parkinson’s Disease Risk Significantly, Study Finds

People with diabetes who use a group of drugs called glitazones are 28 percent less likely to develop Parkinson’s disease, report researchers from the University of Bergen (UiB) in Norway.

But the study, published in the journal Movement Disorders, did not offer any insights into why that might be, and scientists are now set to examine potential mechanisms of the protective effect of such drugs — information that might offer a breakthrough in the understanding of Parkinson’s disease processes.

To conclude that the drug lowered the risk of Parkinson’s disease, the team, led by senior study author Charalampos Tzoulis, PhD, used an extensive register, holding all drugs prescribed for the entire Norwegian population. The database held information on 102,745 patients who were treated with either one of the two diabetes drugs metformin or glitazone over a 10-year period.

Their study, “Glitazone use associated with reduced risk of Parkinson’s disease,” compared the two groups, and noted that the 8,396 patients on glitazone were 28 percent less likely to develop Parkinson’s disease.

This comparison did, naturally, not offer any insights into the mechanisms behind a potential protective effect. But researchers speculated the effect might be brought on by glitazones improving the function of mitochondria — tiny cellular power plants that convert nutrients to energy.

Several studies have suggested that mitochondrial abnormalities might be involved in Parkinson’s disease. Studies also show that glitazones boost the production of new mitochondria. But anti-inflammatory or antioxidant actions also might be contributing.

The interest for diabetes drugs in Parkinson’s research is, however, not new. The team mentioned that two earlier studies, which followed patients treated with glitazones over time, came to different conclusions. One could see a protective effect while the other could not.

And recently, British researchers reported that the diabetes drug Byetta (exenatide) protected from disease progression among patients who already had developed Parkinson’s in a Phase 2 clinical trial (NCT01971242).

Yet another diabetes drug, Victoza (liraglutide), is evaluated in another, ongoing Phase 2 trial (NCT02953665) in Parkinson’s patients. This trial, taking place at Cedars-Sinai Medical Center in Los Angeles, is recruiting participants.