Platelet secretion of β-amyloid is increased in hypercholesterolaemia

Tissue accumulation of the cytotoxic β-amyloid peptide (Aβ) occurs in Alzheimer’s disease (AD), one possible source being the platelet. AD and cardiovascular disease may share some risk factors, including hypercholesterolaemia which is associated with increased platelet activity. We examined platelet Aβ release under resting and collagen-stimulated conditions in normocholesterolaemic and hypercholesterolaemic individuals. Resting platelet Aβ efflux was greater in hypercholesterolaemics than in normocholesterolaemics. Collagen-stimulated Aβ release was concentration-dependent and increased in hypercholesterolaemics. Resting Aβ release correlated positively with plasma total cholesterol and low-density lipoprotein (LDL) cholesterol, and inversely with platelet count. These data indicate that abnormal platelet Aβ release occurs in hypercholesterolaemia.