Low-Dose Aspirin Use and Cognitive Function in Older Age: A Systematic Review and Meta-analysis

OBJECTIVES: To investigate whether low-dose aspirin(<300 mg/d) can influence the onset of cognitive impair-ment or dementia in observational studies and improvecognitive test scores in randomized controlled trials(RCTs) in participants without dementia.DESIGN: Systematic review and meta-analysis.SETTING: Observational and interventional studies.PARTICIPANTS: Individuals with no dementia or cogni-tive impairment initially.MEASUREMENTS: Odds ratios (ORs) and 95% confi-dence intervals (CIs), adjusted for the maximum numberof covariates from each study, were used to summarizedata on the incidence of dementia and cognitive impair-ment in observational studies. Standardized mean differ-ences (SMDs) were used for cognitive test scores in RCTs.RESULTS: Of 2,341 potentially eligible articles, eightstudies were included and provided data for 36,196 partic-ipants without dementia or cognitive impairment at base-line (mean age 66, 63% female). After adjusting for amedian of three potential confounders over a median fol-low-up period of 6 years, chronic use of low-dose aspirinwas not associated with onset of dementia or cognitiveimpairment (5 studies, N = 26,159; OR = 0.82, 95%CI = 0.55-1.22, P = .33, I2= 67%). In three RCTs(N = 10,037; median follow-up 5 years), the use of low-dose aspirin was not associated with significantly betterglobal cognition (SMD=0.005, 95% CI=-0.04-0.05,P = .84, I2= 0%) in individuals without dementia. Adher-ence was lower in participants taking aspirin than in con-trols, and the incidence of adverse events was higher.CONCLUSION: This review found no evidence that low-dose aspirin buffers against cognitive decline or dementiaor improves cognitive test scores in RCT