Ibuprofen Use Linked to Reduced Parkinson's Disease Risk

 

February 18, 2010 — A new prospective analysis using data on more than 136,000 people participating in the Nurses' Health Study (NHS) and the Health Professionals Follow-up Study (HPFS) suggests that use of ibuprofen, but not other nonsteroidal anti-inflammatory drugs (NSAIDs), is associated with a reduction in Parkinson's disease (PD) risk on the order of 40%.
Neuroinflammation is thought to play a role in PD, said lead author Xiang Gao, MD, from Harvard School of Public Health, Boston, Massachusetts, "but our results showed only ibuprofen and not other agents seems to be protective for PD.
"This suggests that specific effects of ibuprofen not shared by other NSAIDs play a role in this protective effect, but we don't know the exact mechanism at this time," Dr. Gao told Medscape Neurology.
The results were published online February 17 in advance of their presentation at the upcoming American Academy of Neurology 62nd Annual Meeting in Toronto, Ontario, Canada, April 10-17, 2010. The abstract is posted at www.aan.com.
Addressing Neuroinflammation?
Neuroinflammation may contribute to the pathology of Parkinson's disease, the study authors note, and use of NSAIDs in general, and ibuprofen in particular, has previously been linked to reduced risk of the disease. For example, a previous paper presented by Dr. Gao's Harvard School of Public Health colleague Albert Ascherio, MD, using data from the American Cancer Society's Cancer Prevention Study II Nutrition Cohort, showed that ibuprofen users had a reduced PD risk of about 35%.
In the present study, Dr. Gao and colleagues analyzed data on 136,197 men and women included in the prospective cohorts of the NHS of women and the HPFS of men who were free of PD and other diseases at baseline in 1998 for the NHS and 2000 for the HPFS. The use of NSAIDs was assessed by questionnaire.
During 6 years of follow-up, there were 291 incident cases of PD. The study authors report that users of ibuprofen had a significantly lower risk of developing PD than nonusers and, further, that there was a dose-response relationship between the number of tablets taken per week and PD risk (P for trend = .01)
Table 1. Risk for Parkinson's Disease for Ibuprofen Users vs Nonusers

Comparison	Relative Risk (95% CI)	P Value
Ibuprofen use vs nonuse	0.62 (0.42 – 0.92)	.02

CI = confidence interval
Conversely, there was no significant relationship between use of aspirin, other NSAIDs, or acetaminophen and PD risk.
Table 2. Risk for Parkinson's Disease Associated With Use of Other Pain Relievers

Pain Reliever	Relative Risk	P Value
Aspirin	0.98	.86
Other NSAIDs	1.26	.24
Acetaminophen	0.87	.39

NSAIDs = nonsteroidal anti-inflammatory drugs
They also performed an additional meta-analysis of 5 prospective studies, Dr. Gao added. "We found similar results," he said. "The use of ibuprofen is associated with around 30% lower risk of PD in this meta-analysis."
Table 3. Meta-Analysis: Risk for PD With Ibuprofen Use vs No Ibuprofen Use

Comparison	Relative Risk (95% CI)	P Value
Ibuprofen use vs nonuse	0.73 (0.63 – 0.85)	< .001

CI = confidence interval
Dr. Gao said it will be important to have these findings confirmed in other independent populations and would like to see whether ibuprofen might also affect disease progression in people who already have PD.
First though, he said, "I think the most important thing is to try and find out the mechanism; why ibuprofen is protective against Parkinson's disease."
Extension of Earlier Studies
Asked for comment on these findings, Kapil Sethi, MD, professor of neurology and director of the Movement Disorders Program at the Medical College of Georgia in Augusta and a member of the Medscape Neurology editorial advisory board, said these findings are an extension of earlier studies documenting an inverse relationship between use of anti-inflammatory drugs and PD.
"However, the reduced risk was associated only with the use of ibuprofen and not the other [NSAIDs], suggesting that it is the drug and not the underlying conditions for which the [NSAIDs] are administered that is responsible for the risk reduction," Dr. Sethi noted.
"The relative number of individuals treated with ibuprofen vs the other agents is not mentioned in the news release," he added, "but we look forward to the complete report."
The study was funded by grants from the National Institutes of Health/National Institute of Neurological Disorders and Stroke. The study authors have disclosed no relevant financial relationships.
American Academy of Neurology (AAN) 62nd Annual Meeting: Abstract 1347. Presented April 10-17, 2010.