Statins and dementia.

The incidence and prevalence of dementia are increasing. Dementia is a major cause of disability. Alzheimer's disease (AD) is the most common type of dementia. There are no good prevention or treatment options. Experimental animal and laboratory studies have suggested that cholesterol metabolism in the brain is important in the causal pathway for dementia, possibly by modifying amyloid metabolism. A few studies have showed a possible relationship between mid-life blood cholesterol levels and risk of dementia, including AD. Case-control studies report that patients with AD were less likely to use lipid-lowering drugs, especially statins. Longitudinal epidemiology studies have not demonstrated a decreased risk of AD among statin users versus nonusers. Two clinical trials of statin therapy to reduce cardiovascular disease have not shown any reduction in risk of cognitive decline or dementia. The results of two secondary prevention trials will be reported shortly. In spite of negative studies, the possibility remains that statin therapy may reduce risk of dementia and AD. Primary prevention trials are difficult and expensive and will likely not be done in the United States.