Aβ misfolding in blood plasma measured by immuno-infrared-sensor as an age-independent risk marker of Alzheimer's disease.

Introduction: Determining potential risk factors of amyloid beta (Aβ) misfolding in blood, a risk marker for clinical Alzheimer's disease (AD), could have important implications for its utility in future research and clinical settings.

Methods: Participants aged 50 to 75 years attending a general health examination were recruited for a prospective community-based cohort study in Saarland, Germany, in 2000 to 2002. For these analyses, participants with available Aβ misfolding measurements and clinical AD information at 17-year follow-up were included ( = 444).

Results: Age did not show any association with Aβ misfolding in plasma; however, a strong association of both age and Aβ misfolding with the incidence of clinical AD was evident. Education and cardiovascular diseases were likewise not associated with Aβ misfolding.

Discussion: Structural measurement of Aβ misfolding in blood plasma is an age-independent risk marker of clinical AD among older adults, supporting that risk of clinical AD is already largely determined before older adulthood.