Speed of cognitive decline in biomarker stratified SCD subgroups

Abstract

AbstractBackgroundSubjective cognitive decline (SCD) is associated with an increased risk of cognitive decline and dementia, specifically in cases in the Alzheimer’s continuum (amyloid positive, A+). In the present study we tested, if further stratification with additional markers is useful for identifying fast progressors within SCD‐A+.MethodThe analysis is based on 170 SCD case of the multicenter memory clinic based DELCODE study in Germany. The following markers were used as predictors of cognitive decline: number of SCDplus criteria, CSF Aß42/Aß42, tTau, pTau181, APOE status and hippocampal volume. The outcome was the preclinical Alzheimer’s cognitive composite 5 (PACC5) over up to 5 years. Univariate and multivariate hierarchical regression models were calculated with continuous (a) and dichotomized (b) variables.ResultIn the univariate analyses significant or close to significant associations of Aß42/Aß42 (a:p = 0.012; b:p = 0.040), tTau (a:p = 0.034; b:p = 0.053) and pTau181 (a:p = 0.057; b:p = 0.019) with cognitive decline were observed. In the hierarchical model with continuous variables, only Aß42/Aß40 reached significance (p = 0.016); while dichotomized variables Aß42/Aß40 (p = 0,074) and pTau181 (p = 0.068) reached trend level significance.ConclusionWithin SCD‐A+, those who are also pTau positive show greatest decline. This finding is in agreement with the concept of A+ and T+ indicating full Alzheimer’s disease pathology and is important for the design of clinical trials in SCD.