Mahyar Etminan, from the Royal Victoria Hospital, Montreal, Canada, together with colleagues at the University of Toronto and the University of Washington, Seattle, carried out a meta-analysis of nine studies that correlated risk of developing Alzheimer's with NSAID use in volunteers over 55 years of age. Pooling the data from these studies, Etminan and colleagues calculate that the overall relative risk (RR) of developing AD was significantly lower in those taking the drugs (RR = 0.72). Breaking the results down by duration of use revealed lower risk for those who were taking the drugs long-term-relative risks of 0.95, 0.83, and 0.27 were calculated for those on NSAIDs for less than one month, up to two years, or more than two years, respectively. It is worth noting that this data is for all NSAIDs, not just those that lower levels of Aβ42; evidence suggests the latter are a better prophylactic (see ARF related news story). The authors found that taking aspirin can also lower the risk for AD, though this result was not statistically significant.

Etminan cautions that these observational studies may suffer from bias, and he notes that no randomized controlled trial has ever looked at the use of NSAIDs in AD prevention. This shortcoming will be addressed, at least for two NSAIDs, once data from the Alzheimer's Disease Anti-inflammatory Prevention Trial (ADAPT) are released (see ARF related news story).-Tom Fagan.

Reference:
Etminan M, Gill S, Samii A. Effect of non-steroidal anti-inflammatory drugs on risk of Alzheimer’s disease: systematic review and meta-analysis of observational. Brit. Med. J. 2003 July 19;327:128-131. Abstract