Relationships between plasma β-amyloid peptide 1-42 and atherosclerotic risk factors in community-based older populations

Background: Recent studies have suggested that atherosclerosis contributes to the development of dementia of the Alzheimer's type ( DAT). Convenient and valid biochemical markers of DAT are needed to control risk factors for this disease. The aims of the present study were thus ( 1) to determine the distribution of plasma beta- amyloid peptide1 - 42 ( Abeta1 - 42) levels in an older population and ( 2) to investigate factors correlating with plasma levels of this amyloid peptide. Our data support the hypothesis that atherosclerosis plays a role in the pathogenesis of DAT. Methods: 759 Japanese community residents participated in a municipal medical health evaluation; a subset of 280 was selected at random for the measurement of physiological, psychosocial and life- style variables, together with the analysis of blood specimens for cell counts, hematocrit, Abeta1 - 42, and other biochemical markers. Results: Log- transformed plasma Abeta1 - 42 concentrations showed a Gaussian distribution. Quartiles of log(10) ( Abeta1 - 42) concentrations correlated significantly with age categories, but not with other sociopsychological and life- style variables. Plasma Abeta1 - 42 was significantly correlated with systolic and diastolic blood pressure ( DBP; r = 0.19, p = 0.002 and r = 0.16, p = 0.007, respectively), pulse pressure ( r = 0.13, p = 0.036), total cholesterol ( r = 0.15, p = 0.011), log10 ( triacyl glycerol) ( r = 0.14, p = 0.021), and log(10) ( hemoglobin A1c) [ log(10) ( HbA1c)] ( r = 0.14, p = 0.020). Stepwise multiple regression analysis showed significant independent effects of DBP, and log(10) ( HbA1c) on plasma Abeta1 - 42 concentrations. Conclusions: Our findings suggest that conventional atherosclerotic risk factors are associated with plasma Abeta1 - 42 levels. This observation may be important in the detection and prevention of DAT. Copyright (C) 2003 S. Karger AG, Basel.