Objective: To examine the association of statin drug use on cognitive and MRI change in older adults.
Methods: Participants in the Cardiovascular Health Study, a longitudinal study of people age 65 or older, were classified into three groups determined by whether they were taking statin drugs on a continuous basis, intermittently, or not at all. The untreated group was further divided into categories based on National Cholesterol Education Program recommendations for lipid-lowering treatment. Participants with prevalent or incident clinical TIA or stroke or with baseline Modified Mini-Mental State Examination (3MS) scores at or below 80 were excluded. Outcomes examined included rate of change on the 3MS over an average observational period of 7 years, along with changes in MRI white matter grade and measures of atrophy.
Results: Three thousand three hundred thirty-four participants had adequate data for analysis. At baseline, the untreated group in which lipid-lowering drug treatment was recommended were slightly older, less likely to be on estrogen replacement, and had higher serum cholesterol and lower 3MS scores than the statin-treated group. The rate of decline on the 3MS was 0.48 point/year less in those taking statins compared with the untreated group for which treatment was recommended (p = 0.069) and 0.49 point/year less in statin users compared with the group in which lipid-lowering treatment was not recommended (p = 0.009). This effect remained after controlling for serum cholesterol levels. One thousand seven hundred thirty participants with baseline 3MS scores of > 80 underwent cranial MRI scans on two occasions separated by 5 years. There was no significant difference in white matter grade change or atrophy measures between groups.
Conclusion: Statin drug use was associated with a slight reduction in cognitive decline in an elderly population. This relationship could not be completely explained by the effect of statins on lowering of serum cholesterol.