Effect of Statin Therapy on Cognitive Decline and Incident Dementia in Older Adults.
Level 3 - non-randomized controlled study
Prospective observational cohort analysis nested within a randomized trial
PubMed 34167639 · doi:10.1016/j.jacc.2021.04.075
What was done
This prospective cohort analysis evaluated 18,846 participants aged 65 years or older without prior cardiovascular events, major physical disability, or dementia who were enrolled in a randomized trial of aspirin and followed for 4.7 years. The study compared baseline statin users with nonusers for incident dementia and its subclassifications (probable Alzheimer's disease, mixed presentations), mild cognitive impairment (MCI) and its subclassifications, and changes in domain-specific cognition (global cognition, memory, language and executive function, psychomotor speed, and composite score). Associations were analyzed using multivariable Cox proportional hazards models and linear mixed-effects models, also examining statin lipophilicity and effect modifiers.
What was found
Statin use versus nonuse was not associated with incident dementia, MCI, their subclassifications, or changes in cognitive function scores over time (p > 0.05 for all; exact hazard ratios, effect estimates, and confidence intervals were not reported in the abstract). There were no differences in any outcomes between hydrophilic and lipophilic statin users. Baseline neurocognitive ability was an effect modifier for the associations of statins with dementia (p for interaction < 0.001) and memory change (p for interaction = 0.02).
Why it matters
In a large cohort of older adults, statin therapy neither increased the risk of cognitive decline nor provided neuroprotective benefits against incident dementia over medium-term follow-up.
Limits
Statin use was evaluated observationally rather than via randomized assignment, introducing risk of confounding by indication. Follow-up was 4.7 years, which may be insufficient to detect long-term neurocognitive effects. The abstract reports no numerical effect sizes or confidence intervals, nor data on statin dosage, adherence, or pre-baseline exposure duration.
Cited by
- supports Clinical trial evidence shows no difference between lipophilic (hydrophobic) and hydrophilic statins with respect to dementia and Alzheimer's disease outcomes.