Study: No Link Found between Statin Use and Cognitive Decline, Dementia in Older Adults

The use of statin therapy in adults aged ≥65 years may not be associated with incident dementia or a decline in neurocognitive health, according to a new observational study published in the Journal of the American College of Cardiology.

“With statins being increasingly prescribed to older adults, their potential long-term effects on cognitive decline and dementia risk have attracted growing interest,” lead author Zhen Zhou, PhD, Menzies Institute for Medical Research, University of Tasmania, Australia, said in a press release. “The present study adds to previous research by suggesting that statin use at baseline was not associated with subsequent dementia incidence and long-term cognitive decline in older adults.”

With the use of statins among older adults expected to rise, it is important to determine the effects of statin therapy on cognition in this patient population to help physicians weigh their benefits against associated risks, according to study authors.

To investigate the potential neurocognitive effects of statin use, Zhou and colleagues analyzed data from the ASPirin in Reducing Events in the Elderly (ASPREE) trial.

The ASPREE trial was a large prospective, randomized, placebo-controlled trial of daily low-dose aspirin among 19 114 eligible participants aged ≥65 years with no prior cardiovascular disease event, dementia, or major physical disability. Inclusion also required a score of ≥78 on the Modified Mini-Mental State Examination test. The trial was conducted between 2010 and 2014 in Australia and the US.

For the current analysis, Zhou and colleagues excluded adults with missing values for cognitive test scores and/or covariates at baseline, resulting in 18 846 participants. Researchers grouped participants by their baseline statin use vs non-statin use, with approximately 31% (n=5898) of patients taking statins.

Outcome measures included dementia and its subclassifications (ie, probable Alzheimer disease and mixed presentations), mild cognitive impairment (MCI), and changes in domain-specific cognition.

After a median follow-up of 4.7 years, there were 566 incident cases of dementia, including probable Alzheimer disease and mixed presentations. Compared with no statin use, statin use was not associated with dementia, MCI, or changes in cognitive function scores over time.

Also, researchers found 380 incident cases of MCI over the median follow-up. Compared to no statin use, statin use was not associated with risk of MCI, MCI consistent with Alzheimer disease, or other MCI.

There was no statistically significant difference in the change of composite cognition and any individual cognitive domains between statin users and non-statin users.

In addition, there were no differences found in any of the outcomes between hydrophilic and lipophilic statin users. Researchers did find, however, interaction effects between baseline cognitive ability and statin therapy for all dementia outcomes.

Study limitations included observational study bias, lack of data on the length of prior use of statins, and the dose of statins was not recorded in the ASPREE trial, so researchers could not fully explore their effects.

Zhou and colleagues concluded that the study must be interpreted with caution, and they are awaiting confirmation from ongoing randomized trials designed specifically to explore neurocognitive effects of statins in older adults.