PROSPECTIVE-STUDY OF INCREASED PLATELET MEMBRANE FLUIDITY AS A RISK FACTOR FOR ALZHEIMERS-DISEASE - RESULTS AT 5 YEARS

Objective: The primary goal of this study was to evaluate increased pl atelet membrane fluidity as a putative risk factor for Alzheimer's dis ease. Method: This report describes the initial results of a prospecti ve, longitudinal study of 330 initially asymptomatic, first-degree rel atives of probands with Alzheimer's disease. Results: Five incident ca ses of Alzheimer's disease were detected during the first 1,582 subjec t-years of the follow-up period. The age-specific incidence of Alzheim er's disease was several-fold higher than corresponding figures that w ere obtained in two prospective community studies. Most important, bot h age and increased platelet membrane fluidity made significant indepe ndent contributions to the risk of developing Alzheimer's disease. Con clusions: These results validate age and a family history of Alzheimer 's disease as risk factors for this disorder and provide the first pro spective evidence of increased platelet membrane fluidity as a biologi cal risk factor for Alzheimer's disease.