Statins not effective in reducing dementia risk

According to a recently published study, the use of statins and other lipid-lowering agents by older adults is not associated with a reduced risk of Alzheimer's disease or other types of dementia.

Although statins may reduce cardiovascular risk by inhibiting cholesterol synthesis or through anti-inflammatory effects, they do not appear to affect the biological mechanisms which may play a role in the development of dementia, in particular Alzheimer's disease.

It has been suggested in previous studies that statins may have a protective effect on the process of dementia, by preventing or delaying the onset.

In a Cardiovascular Health Study, Thomas D. Rea, M.D., M.P.H., of the University of Washington, Seattle, and colleagues assessed data on 2,798 participants 65 years or older who underwent baseline magnetic resonance imaging (MRI) and took a standardized mental test to determine that they were free of dementia when enrolled in the study, between 1991 and 1994.

At the outset information on their health status, cognitive function and medication use, as well as laboratory assessments and diagnostic testing was collected.

Participants were then monitored annually to assess their health status, medication use and whether they had developed dementia.

It was found there were 480 cases of dementia, including 245 attributable to Alzheimer's disease alone.

After controlling for other known or suspected risk factors, the researchers found that patients who had used statins had no reduction in their risk of developing dementia from any cause compared with those who had never used statins.

The study authors say that there are several factors which may explain why statin use was not associated with a lower risk of dementia.

The participants were on average 75 years of age, and statin use was assessed for a median of five years. Statin exposure may possibly need to occur earlier in adulthood or for longer periods to prevent dementia.

The authors concluded that in this particular study statin therapy was not associated with a lower risk of dementia, and additional investigation is needed to determine whether, and for whom, statin use may affect dementia risk.

The study is published in the July issue of Archives of Neurology.