title: Amyloid-β₄₂ is associated with cognitive impairment in healthy elderly and subjective cognitive impairment.
abstract: The aim of this study was to predict cognitive performance on the basis of the cerebrospinal fluid (CSF) biomarkers total tau (T-tau) and amyloid-β₄₂ (Aβ₄₂) in controls and patients at various impairment levels. Previous studies have found an association of CSF T-tau levels with cognitive symptoms, but it has been difficult to relate Aβ to cognition, and it has thus been hypothesized that Aβ reaches a plateau level prior to cognitive symptoms. A comprehensive battery of neuropsychological tests was subjected to factor analysis to yield aggregated cognitive domains. Linear regression models were performed for the total sample of the Gothenburg MCI study (n = 435) and for each level of impairment. Aβ₄₂ and T-tau accounted for a significant proportion of performance in all cognitive domains in the total sample. In controls (n = 60) and patients with subjective cognitive impairment (n = 105), Aβ₄₂ predicted a significant proportion of semantic and working memory performance. For patients with mild cognitive impairment (n = 170), T-tau had the most pronounced impact across cognitive domains, and more specifically on episodic memory, visuospatial, and speed/executive performance. For patients with dementia (n = 100), the most pronounced impacts of Aβ₄₂ were found in episodic memory and visuospatial functioning, while T-tau was substantially associated with episodic memory. Our results suggest that cognition is related to CSF biomarkers regardless of impairment level. Aβ₄₂ is associated with cognitive functions from a potentially early to a later disease phase, and T-tau is more indicative of performance in a later disease phase.
authors: Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden. sindre.rolstad@neuro.gu.se
authors: Sindre
authors: S
authors: Rolstad
authors: Anne Ingeborg
authors: AI
authors: Berg
authors: Maria
authors: M
authors: Bjerke
authors: Kaj
authors: K
authors: Blennow
authors: Boo
authors: B
authors: Johansson
authors: Henrik
authors: H
authors: Zetterberg
authors: Anders
authors: A
authors: Wallin