A link between the pathology of Alzheimer's disease (AD) and cholesterol metabolism has been suggested by a number of human and animal studies, according to background information in the article. In addition, some epidemiological studies have shown that prior use of statins (cholesterol-lowering drugs) for the treatment of risk of coronary artery disease also may reduce the risk of Alzheimer's disease later in life.

The current study is a small-scale trial of the cholesterol-lowering medication atorvastatin calcium for positive effects on cognitive and behavioral deterioration in mild to moderate Alzheimer's disease.

Small, One-Year Trial

D. Larry Sparks, Ph.D., of the Sun Health Research Institute, Sun City, Arizona, and colleagues enrolled individuals with mild to moderate Alzheimer's disease in a double-blind, placebo-controlled, randomized one-year trial of treatment with atorvastatin.

Patients were evaluated at baseline, three, six, nine and twelve months to determine the effect of atorvastatin on cognitive and/or behavioral decline, using standard measures of cognitive function, psychiatric symptoms, activities of daily living and cholesterol levels.

Sixty-seven individuals were randomized to receive either atorvastatin calcium or placebo; 63 patients were evaluated at the three-month visit; 56 patients completed the 6-month visit; 48 patients completed the 9-month visit; and 46 completed the one-year study, 25 receiving atorvastatin and 21 receiving placebo.

Proof of Concept

"We have found that daily administration of 80 mg of atorvastatin calcium significantly reduces circulating cholesterol levels and may have a positive effect on the progressive deterioration of cognitive function and behavior anticipated in mild to moderate AD," the authors write.

"As a pilot proof-of-concept study, significant differences were not expected, but benefits identified tend to support the trial's rationale based on the hypothesis that excess brain cholesterol-promoting amyloid beta production [excess amyloid beta protein deposits are a hallmark of AD] and, subsequently, the symptoms of AD come from the blood because of increased circulating levels," they explain.

"Finally, although the results clearly hold promise, this was a pilot proof-of-concept trial with a small number of participants," the authors conclude. "We believe that we provide evidence for proof of concept, and establishment of similar benefit of atorvastatin in a multicenter trial investigating the effect in a much larger population may provide proof of therapy. Two such studies are ongoing."