A type of drug used to treat diabetes may reduce the risk of developing Parkinson’s disease, according to a new study published in PLOS Medicine.
The research, led by the London School of Hygiene & Tropical Medicine, found that diabetes patients taking glitazone antidiabetes drugs (either rosiglitazone or pioglitazone) had a 28% lower incidence of Parkinson’s disease than people taking other treatments for diabetes who had never taken glitazones.
Glitazones are a class of drug that activate the peroxisome proliferation-activated gamma (PPARγ) receptor, which is found inside cells in many different body organs. PPARγ activation by glitazones leads to reduced insulin resistance, which has been useful for treating people with diabetes, but the receptor has many other functions that have not been studied as thoroughly in humans.
Although the potential effect of glitazones on Parkinson’s disease had previously been demonstrated in rodents and in vitro, the authors believe this is the first study to show the relationship between glitazone use and incidence of Parkinson’s disease in humans.
The study, which was funded by The Michael J Fox Foundation for Parkinson’s Research, looked at more than 160,000 diabetes patients in the UK. Researchers used electronic health records from the UK Clinical Practice Research Datalink to match 44,597 glitazone users with 120,373 people using other antidiabetic drugs. Glitazone users were matched by age, sex, GP practice, and diabetes treatment stage with up to five users of other diabetic treatments.
Patients were followed up from 1999 (when glitazones were introduced to treat diabetes) until 2013, to determine how many were diagnosed with Parkinson’s disease during that period.
The results showed a 28% reduction in incidence of Parkinson’s disease among people taking glitazones compared with those taking other antidiabetic treatments. Adjustments for risk factors associated with Parkinson’s disease (including smoking and head injury) had no impact on the findings.
The results suggest that the reduced risk of Parkinson’s disease was only associated with current treatment with glitazones, and that there is little or no longer lasting benefit if people have taken the drug in the past before stopping or switching to another medication.