Association of Cognitive Impairment in Patients on 3-Hydroxy-3-Methyl-Glutaryl-CoA Reductase Inhibitors

BACKGROUND: Atherosclerotic cardiovascular diseases are the leading cause of death in the United States. A reduction in cholesterol with 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors (statin) significantly reduces mortality and morbidity. Statins may be associated with cognitive impairment or dementia. Our aim was to study the association of cognitive impairment or dementia in patients who were on a statin. METHODS: Electronic medical records of 3,500 adult patients in our suburban internal medicine office were reviewed. RESULTS: There were 720 (20.6%) patients in the statin treatment group. Dementia or cognitive impairment was an associated comorbid condition in 7.9% patients in the statin treatment group compared to 3.1% patients in the non-statin group (P < 0.001). Analysis of all of the patients with cognitive impairment or dementia showed that among the age ranges of 51 years through 100 years, the patients in the statin treatment group had a higher prevalence of cognitive impairment or dementia compared to the non-statin group. In the statin treatment group, we found significantly higher prevalence of hyperlipidemia (86.3%), hypertension (69.6%), diabetes mellitus (36.0%), osteoarthritis (31.5%), coronary artery disease (26.1%), hypothyroidism (21.5%) and depression (19.3%) compared to the non-statin group (P < 0.001). About 39.9% of the patients with dementia or cognitive impairment were on statin therapy compared to 18.9% patients who had no dementia or cognitive impairment and were on statin therapy (P < 0.001). Among the patients with cognitive deficit or dementia in the statin treatment group, the majority of the patients were either on atorvastatin (43.9%) or simvastatin (35.1%), followed by rosuvastatin (12.2%) and pravastatin (8.8%). We found greater odds of dementia or cognitive impairment with each year increase in age (1.3 times), in women (2.2 times), African American race (2.7 times), non-consumption of moderate amount of alcohol (two times), diabetes mellitus (1.6 times), hypothyroidism (1.7 times), cerebrovascular accident (3.2 times), and other rheumatological diseases (1.8 times). CONCLUSIONS: The association of dementia or cognitive impairment was significantly higher in the patients who were on statin therapy compared to the patients who were not on a statin.