Statin use reduced the incidence for dementia in older adults after a concussion, according to a study published in JAMA Neurology.
Researchers of this population-based, double cohort study analyzed physician billing data from the Ontario Health Insurance Plan and computerized health care records for the risk of dementia after a concussion, with and without the use of statins, in an older adult population. Patients 66 years of age or older who had been diagnosed with having a concussion but not a severe brain injury were included in this study.
Statin use was determined using the Ontario Drug Benefit Program database and included atorvastatin, cerivastatin, fluvastatin, lovastatin, pitavastatin, pravastatin, rosuvastatin, and simvastatin. Dementia was diagnosed by physicians according to the International Classification of Diseases, Ninth Revision criteria. A parallel double cohort analysis evaluated the rate of dementia occurring after an ankle sprain with or without the use of a statin, with the aim of distinguishing between outcomes in neurologic injury and peripheral orthopedic injury.
Of the 28,815 patients diagnosed as having a concussion, the median age was 76 years old, 61.3% were women, and 24.5% received a statin. Of the 4727 patients that developed dementia, 1050 were receiving statins, and 3677 were not receiving statins. Statin use reduced the risk for developing dementia by 13% (95% CI, 7%-19%; P <.001) when compared with patients not receiving statins. An increase in total prescriptions, physician visits, prior hospitalizations, lower socioeconomic status, urban home location, and older age was associated with an increased risk of dementia.
After adjusting for these confounding variables, statin use reduced the risk for dementia by 16% (95% CI, 10%-22%; P <.001). When analyzing specific statin types, rosuvastatin had the largest risk reduction (relative risk [RR] 0.78; 95% CI, 0.67-0.91) and simvastatin had the smallest risk reduction (RR 0.93; 95% CI, 0.81-1.08).
Of the 307,890 patients with an ankle sprain, 25.3% received a statin. Of the 25,956 patients that developed dementia, 6239 were receiving statins, and 19,717 were not receiving statins. Statin use reduced the risk for developing dementia by 5% (95% CI, 3%-8%; P <.001).
Limitations of this study include the observational nature of the study, potential covariates not being considered, and only including older adults.
Researchers concluded that “older adults had a substantial long-term risk [for] dementia after a concussion, which was associated with a modest reduction among patients receiving a statin.”
Redelmeier DA, Manzoor F, Thiruchelvam D. Association between statin use and risk of dementia after a concussion [published online May 20, 2019]. JAMA Neurol. doi: 10.1001/jamaneurol.2019.1148