Lower White Matter Volume and Worse Executive Functioning Reflected in Higher Levels of Plasma GFAP among Older Adults with and Without Cognitive Impairment.

Abstract

OBJECTIVE:

There are minimal data directly comparing plasma neurofilament light (NfL) and glial fibrillary acidic protein (GFAP) in aging and neurodegenerative disease research. We evaluated associations of plasma NfL and plasma GFAP with brain volume and cognition in two independent cohorts of older adults diagnosed as clinically normal (CN), mild cognitive impairment (MCI), or Alzheimer's dementia.

METHODS:

We studied 121 total participants (Cohort 1: n = 50, age 71.6 ± 6.9 years, 78% CN, 22% MCI; Cohort 2: n = 71, age 72.2 ± 9.2 years, 45% CN, 25% MCI, 30% dementia). Gray and white matter volumes were obtained for total brain and broad subregions of interest (ROIs). Neuropsychological testing evaluated memory, executive functioning, language, and visuospatial abilities. Plasma samples were analyzed in duplicate for NfL and GFAP using single molecule array assays (Quanterix Simoa). Linear regression models with structural MRI and cognitive outcomes included plasma NfL and GFAP simultaneously along with relevant covariates.

RESULTS:

Higher plasma GFAP was associated with lower white matter volume in both cohorts for temporal (Cohort 1: β = -0.33, p = .002; Cohort 2: β = -0.36, p = .03) and parietal ROIs (Cohort 1: β = -0.31, p = .01; Cohort 2: β = -0.35, p = .04). No consistent findings emerged for gray matter volumes. Higher plasma GFAP was associated with lower executive function scores (Cohort 1: β = -0.38, p = .01; Cohort 2: β = -0.36, p = .007). Plasma NfL was not associated with gray or white matter volumes, or cognition after adjusting for plasma GFAP.

CONCLUSIONS:

Plasma GFAP may be more sensitive to white matter and cognitive changes than plasma NfL. Biomarkers reflecting astroglial pathophysiology may capture complex dynamics of aging and neurodegenerative disease.

• Authors: Breton M Asken, Lawren VandeVrede, Julio C Rojas, Corrina Fonseca, Adam M Staffaroni, Fanny M Elahi, Cutter A Lindbergh, Alexandra C Apple, Michelle You, Sophia Weiner-Light, Nivetha Brathaban, Nicole Fernandes, Adam L Boxer, Bruce L Miller, Howie J Rosen, Joel H Kramer, Kaitlin B Casaletto
• Journal: Journal of the International Neuropsychological Society : JINS (J Int Neuropsychol Soc) Vol. 28 Issue 6 Pg. 588-599 (07 2022) ISSN: 1469-7661 [Electronic] England
• PMID: 34158138 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural)

Chemical References

• Biomarkers
• Glial Fibrillary Acidic Protein
• Neurofilament Proteins

Topics

• Aged
• Aged, 80 and over
• Alzheimer Disease (diagnosis)
• Biomarkers
• Cognitive Dysfunction (diagnosis)
• Executive Function
• Glial Fibrillary Acidic Protein
• Humans
• Intermediate Filaments
• Middle Aged
• Neurodegenerative Diseases
• Neurofilament Proteins
• White Matter (diagnostic imaging)