High dose statins linked to a three-fold decreased risk of developing dementia
The wide use of statins among seniors has been shown to reduce the risk of cardiovascular disease. According to Dr. Tin-Tse Lin National Taiwan University Hospital past studies have considered statin therapy to exert a beneficial effect on dementia. “But few large-scale studies have focused on the impact of statins on new-onset, non-vascular dementia in the geriatric.”
In this current study Dr. Lin and Dr. Cho Kai Wu examined the association between the use of statins and the risk for new onset dementia (excluding vascular dementia) in an elderly population.
The study included a random sample of one million patients covered by Taiwan's National Health Insurance. From this sample researchers identified 57, 699 patients over 65 years of age without a history of dementia between 1997 and 1998. New diagnoses of dementia including pre-senile and senile dementia were determined for elderly subjects. The study subjects were divided into tertiles according to mean daily dosage and total dosage of each statin and mean equivalent and total equivalent doses.
During the 4.5 year follow-up there were 5,516 new diagnosed cases of dementia among the participants. . The remaining 52,153 participants made up the control group.
The adjusted hazard ratios (HRs) for dementia were significantly inversely associated with increased daily or total equivalent statin dosage. The HRs for the three tertiles of mean equivalent daily dosage (lowest to highest) were 0.622, 0.697 and 0.419 vs control (p<0.001 for trend). The HRs for the three tertiles of total equivalent dosage (lowest to highest) were 0.773, 0.632 and 0.332 vs control (p<0.001 for trend). The protective effect of statins remained in different age, gender and cardiovascular risk subgroups.
According to Dr. Lin “patients who received the highest total equivalent doses of statins had a 3-fold decrease in the risk of developing dementia. Similar results were found with the daily equivalent statin dosage.”
He adds “It was the potency of the statins rather than their solubility (lipophilic or hydrophilic) which was a major determinant in reducing dementia. High potency statins such as atorvastatin (Lipitor) and rosuvastatin (Crestor) showed a significant inverse association with developing dementia in a dose-response manner. Higher doses of high potency statins gave the strongest protective effects against dementia."
In their conclusion the team writes “Independent of traditional risk factors, newly diagnosed cases of dementia decreased in elderly patients who had received statins in either higher daily or total dosage. Highly potent statins seemed to have an even stronger advantage in the prevention of dementia.”
Dr. Lin remarks “the results were consistent when analyzing daily doses of different kinds of statins. Almost all the statins (except lovastatin) decreased the risk for new onset dementia when taken at higher daily doses. A high mean daily dosage of lovastatin was positively associated with the development of dementia, possibly because lovastatin is a lipophilic statin while the anti-inflammatory cholesterol lowering effect of lovastatin is not comparable to that of atorvastatin and simvastatin."
He concludes “to the best of our knowledge, this was the first large-scale, nation-wide study which examined the effect of different statins on new onset dementia (except vascular dementia) in an elderly population. We found that high doses of statins, particularly high potency statins, prevent dementia."
Each statin was assigned an appropriate equivalent dose according to the following formula; lovastatin (Mevacor) and pravastatin (Pravachol0 at 40mg, simvastatin (Zocor) 20mg, atorvastatin (Lipitor) 10mg, fluvastatin (Lescol) and rosuvastatin (Crestor) 5mg.
This new research was presented at the European Society of Cardiology in Amsterdam.