Inflammation's connection to dementia proves complex
■ A new study finds that heavier use of nonsteroidal anti-inflammatory drugs may boost the risk of dementias but also could delay onset.
Despite findings from earlier research suggesting that Alzheimer's disease may be caused by inflammation, a new study has found that heavy use of nonsteroidal anti-inflammatory drugs actually may heighten the risk for that disease and other dementias.
The study demonstrates the complex relationship between NSAIDs and Alzheimer's and indicates the need for further investigation, the study authors conclude (link).
The authors of the piece in the April 22 online issue of Neurology, the journal of the American Academy of Neurology, also note that their study enrolled people who were older than those involved in earlier studies. The new findings may reflect a delayed onset of Alzheimer's disease among heavy NSAID users.
The researchers, who are from the University of Washington, the Veterans Affairs Medical Center and Group Health Cooperative, all in Seattle, studied 2,736 enrollees who were dementia-free at the onset of the study.
During the study, which followed the enrollees for 12 years, 476 people developed Alzheimer's disease or dementia. The risk of developing dementia among heavy NSAID users was 66% higher than among people with little or no NSAID use, according to the findings.
Pharmacy dispensing records indicated which participants were low, moderate or heavy users of NSAIDs.
Lead author John C. Breitner, MD, MPH, professor and head of the Geriatric Psychiatry Division at the University of Washington, cautioned that his findings were just one interpretation of the results and that other explanations are possible.
"A key difference between this study and most of those done earlier is that our participants were older," he said. "It has been argued for some time that NSAID use delays the onset of Alzheimer's disease. It would follow that studies looking at younger people who use NSAIDs would show fewer cases of Alzheimer's, while in groups of older people there might be more cases, including those that would have occurred earlier if they had not been delayed."