Dr. Tin-Tse Lin of Taiwan and colleagues examined whether statin use was associated with new diagnoses of dementia from a random sample of 1 million patients covered by Taiwan's National Health Insurance.
From this they identified 57,669 patients age 65 and older, who had no history of dementia in 1997 and 1998. The analysis included pre-senile and senile dementia but excluded vascular dementia.
"Statins are widely used in the older population to reduce the risk of cardiovascular disease. But recent reports of statin-associated cognitive impairment have led the U.S. Food and Drug Administration to list statin-induced cognitive changes, especially for the older population, in its safety communications," Lin said in a statement.
The study found 5,516 new diagnoses of dementia during approximately 4.5 years of follow-up. The remaining 52,153 patients age 65 and older formed the control group.
Subjects were divided into tertiles -- thirds -- according to their mean daily equivalent dosage and total equivalent dosage.
The adjusted risks for dementia were significantly inversely associated with increased total or daily equivalent statin dosage.
For example, "patients who received the highest total equivalent doses of statins had a three-fold decrease in the risk of developing dementia. Similar results were found with the daily equivalent statin dosage," Lin said. "It was the potency of the statins rather than their solubility 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."
The findings were presented at the European Society of Cardiology Congress in Amsterdam.