Washington: Researchers, who examined the effect of different statins on new onset dementia (except vascular dementia) in an elderly population, have revealed that high doses of statins, particularly of high potency, prevent dementia.
Dr Lin said that previous studies had 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 population.
Accordingly, the current study examined whether statin use was associated with new diagnoses of dementia. The researchers used a random sample of 1 million patients covered by Taiwan`s National Health Insurance. From this they identified 57,669 patients aged more than 65 years who had no history of dementia in 1997 and 1998. The analysis included pre-senile and senile dementia but excluded vascular dementia.
It was found that 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.
The HRs for the three tertiles of total equivalent dosage (lowest to highest) were 0.773, 0.632 and 0.332 vs control. The protective effect of statins remained in different age, gender and cardiovascular risk subgroups.
Dr Lin said that the adjusted risks for dementia were significantly inversely associated with increased total or daily equivalent statin dosage. 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.
"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 and rosuvastatin 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, he said.
Dr Lin added that the results were consistent when analysing 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.