[Cholesterol and statins in Alzheimer disease].

Two recent observational studies have demonstrated a 60-73% reduction in the prevalence of Alzheimer's disease in patients treated with statins. In two further studies a polymorphism in the CYP46 gene encoding the cholesterol-24 hydroxylase was found to be associated with a significant increase in the risk of late-onset Alzheimer's disease. The question arises whether or not statins may exert a prophylactic effect on the incidence of Alzheimer's disease. Statins pass the blood-brain-barrier to a different degree and may reduce the cerebral cholesterol turnover. Statins may also influence the CSF concentration of tau protein, and, to a minor extent, that of A beta. Further studies are warranted to find out which statins are most suitable for reducing cerebral amyloid metabolism and whether statins may also lower the severity of Alzheimer's disease.