The research team assessed the degree of brain function loss caused by Alzheimer's disease in 342 patients attending a memory clinic. They then monitored the progress of the disease for almost three years. The average age of the patients was 73. Most were women.
In all, 129 patients had abnormal cholesterol levels, almost half of whom were being treated exclusively with statins. Of the remainder, 105 had abnormal untreated cholesterol , and 108 had normal cholesterol levels. Drug treatment included fibrates or statins, or a mixture of both.
During the three years, all the patients deteriorated, but the disease progressed significantly more slowly in the patients given cholesterol lowering drugs. Progression of the disease was rated at 1.5 points a year in those given the drugs, 2.4 in those whose cholesterol was not treated, and 2.6 in those with normal cholesterol levels.
The risk factor profile for Alzheimer's disease, including high blood pressure and diabetes, scarcely differed between the two groups with abnormal cholesterol levels.
The authors conclude that cholesterol lowering drugs may effectively slow progression of Alzheimer's disease, but suggest that a large trial will be needed to confirm their findings.
An accompanying editorial argues that it is still too early to definitively conclude that cholesterol lowering treatment is a valid option for patients with Alzheimer's disease.
The editorial also points out that the research was not able to isolate the potential advantages of the drugs other than their ability to lower cholesterol.