Aspirin, ibuprofen don’t affect Parkinson’s progression, data show
Scientists studied the incidental use of NSAIDs after diagnosis
The use of over-the-counter pain medicines like ibuprofen and aspirin do not appear to influence the clinical progression of Parkinson’s disease, a recent study reveals.
The study, “Non-steroidal anti-inflammatory drug use and markers of Parkinson’s disease progression: A retrospective cohort study,” was published in the Journal of the Neurological Sciences. It was funded by the Canadian Institutes of Health Research.
Non-steroidal anti-inflammatory medications, or NSAIDs, are a class of medicines commonly available without prescription and used to relieve pain and ease inflammation. Ibuprofen and aspirin are well-known examples of NSAIDs.
Some studies have suggested that people who use NSAIDs are less likely to develop Parkinson’s disease, though other research has challenged this idea. The connection between NSAIDs and Parkinson’s risk remains inconclusive.
Although prior research has suggested there might be a connection between NSAIDs and Parkinson’s risk, there hasn’t been much investigation into whether NSAIDs might affect the course of Parkinson’s in people who already have the disease.
To learn more, a team of scientists in Canada and the U.S. analyzed data from two studies: a clinical trial called DATATOP, which followed 800 Parkinson’s patients for a median of more than six years; and the Parkinson’s Progression Markers Initiative (PPMI), a large ongoing study that is collecting data on the clinical course of Parkinson’s. At the time of this analysis, data from 423 Parkinson’s patients in PPMI were available, of whom 342 had been followed at least four years.
Using the data from DATATOP, the researchers first looked at whether use of NSAIDs — derived from healthcare records and interviews collected during the study — were associated with an increased risk of mortality. Results showed no significant associations. However, this analysis did not have a lot of statistical power since the total mortality was low at the end of the study (13 deaths).
Seeking more statistical power, the researchers then looked at data from DATATOP patients out to 13 years of follow-up, at which point 293 patients had died. Results of this analysis still showed no significant associations between mortality risk and NSAID use, though the researchers highlighted that for this analysis they didn’t have access to concrete data on NSAID use after the original trial had ended.
“We attempted to account for the missing exposure data after the last DATATOP study visit by using a range of assumptions about exposure including minimum, maximum, and a projected exposure based on previous use, but the [lack of statistical connection between NSAID use and mortality] was unchanged and did not differ between exposure assumptions. We believe this is a reasonable attempt to address the missing data but regardless, this result should be interpreted with caution,” the researchers wrote.
Examining dopamine transporter scan data
The scientists then looked at dopamine transporter scan data collected by the PPMI study. These imaging data track damage to the dopamine-making cells in the brain that causes Parkinson’s.
Results showed no statistically significant associations between the use of NSAIDs and patterns of brain damage over the first four years in the study.
The scientists also performed exploratory analyses looking for associations between NSAID use and various measures of motor function and cognitive ability. They found that, in DATATOP, patients who used NSAIDs tended to have poorer scores on cognitive tests.
“This finding was unexpected and warrants further study,” the researchers wrote.
Data from PPMI showed no association between NSAID use and cognitive scores, however, and the researchers noted that “the associations [in DATATOP] were small, unlikely to be clinically meaningful, and not replicated in both cohorts.”
More generally, the scientists noted this study was limited by its small size and the fact that it’s difficult to collect accurate data on the use of non-prescription medications, which often are used irregularly or as-needed in large populations of people. The researchers also noted that the number of people using ibuprofen specifically was low in these populations, making it impossible to draw firm conclusions about that specific NSAID.
“Despite these limitations, it does not appear that the incidental use of NSAIDs after diagnosis has a robust impact on [Parkinson’s] progression,” the scientists concluded.