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 impairment or dementia in observational studies and improve cognitive 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 cognitive impairment initially.

MEASUREMENTS

Odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for the maximum number of covariates from each study, were used to summarize data on the incidence of dementia and cognitive impairment in observational studies. Standardized mean differences (SMDs) were used for cognitive test scores in RCTs.

RESULTS

Of 2,341 potentially eligible articles, eight studies were included and provided data for 36,196 participants without dementia or cognitive impairment at baseline (mean age 66, 63% female). After adjusting for a median of three potential confounders over a median follow-up period of 6 years, chronic use of low-dose aspirin was not associated with onset of dementia or cognitive impairment (5 studies, N = 26,159; OR = 0.82, 95% CI = 0.55-1.22, P = .33, I = 67%). In three RCTs (N = 10,037; median follow-up 5 years), the use of low-dose aspirin was not associated with significantly better global cognition (SMD=0.005, 95% CI=-0.04-0.05, P = .84, I = 0%) in individuals without dementia. Adherence was lower in participants taking aspirin than in controls, and the incidence of adverse events was higher.

CONCLUSION

This review found no evidence that low-dose aspirin buffers against cognitive decline or dementia or improves cognitive test scores in RCTs.