Patterns of Statin Therapy Use and Associated Outcomes in Older Veterans Across Kidney Function

Background Despite significant morbidity and mortality related to atherosclerotic cardiovascular disease, to date, most major clinical trials studying the effects of statin therapy have excluded older adults. The objective of this analysis was to evaluate the effect of initiating statin therapy on incident dementia and mortality among individuals 75 years of age or older across the complete spectrum of kidney function. Methods We conducted a retrospective cohort study of 640,191 VA health system patients who turned 75 years of age between 2000 and 2018. Patients on statin therapy received the medication for an average of 6.3 years (standard deviation 4.6 years). The primary outcome of interest included incident dementia diagnosis during the study period. The secondary outcome was all-cause mortality. Cox-proportional hazard analysis was used to evaluate the adjusted association of statin initiation with these outcomes. Results There was a higher rate of incident dementia in the No Statin group (4.7%) versus the Statin group (3.2%). Additionally, we observed a 22% all-cause mortality benefit associated with statin therapy. We did not observe a treatment effect with respect to primary or secondary outcomes across varying levels of kidney function. Conclusion This large cohort study did not reveal an association between the initiation of statin therapy and incident dementia. A survival benefit was seen in statin users compared to non-users. Prospective studies in more diverse populations including older adults will be needed to verify these findings.