Treatment with simvastatin in patients with Alzheimer's disease lowers both alpha- and beta-cleaved amyloid precursor protein

We investigated the clinical and biological effects of cholesterol-lowering treatment with a statin in 19 patients with Alzheimer's disease. They received simvastatin 20 mg/day for 12 weeks in an open trial. Primary efficacy parameters were the changes after 12 weeks in the cerebrospinal fluid (CSF) levels of beta-amyloid(42) (Abeta(42)), alpha-secretase-cleaved amyloid precursor protein (alpha-sAPP), beta-secretase-cleaved APP (beta-sAPP), tau, phospho-tau and the plasma levels of Abeta(42). A secondary efficacy parameter was the change in the Alzheimer's Disease Assessment Scale-Cognition (ADAS-cog) score. After 12 weeks, CSF alpha-sAPP and CSF beta-sAPP were significantly reduced (p < 0.001), but the CSF levels of tau, phospho-tau, Abeta(42) and the plasma levels of Abeta(42) were unchanged. The ADAS-cog score was slightly increased (p < 0.05). The results suggest that simvastatin acts directly on the processing of APP by inhibiting both the alpha- and the beta-secretase pathways.