Sex differences in the association between amyloid and longitudinal brain volume change in cognitively normal older adults

Nicole M. Armstrong, Chiung Wei Huang, Owen A. Williams, Murat Bilgel, Yang An, Jimit Doshi, Guray Erus, Christos Davatzikos, Dean Foster Wong, Luigi Ferrucci, Susan M. Resnick

Research output: Contribution to journalArticle

Abstract

Objective: Amyloid positivity is a biomarker of AD pathology, yet the associations between amyloid positivity and brain volumetric changes, especially in the hippocampus, are inconsistent. We hypothesize that sex differences in associations may contribute to inconsistent findings among cognitively normal older adults. Methods: Using linear mixed effects models, we examined the association of amyloid positivity with prospective volumetric changes (mean = 3.3 visits) of parahippocampal gyrus (phg), hippocampus, entorhinal cortex (erc), precuneus, and fusiform gyrus among 171 Baltimore Longitudinal Study of Aging participants aged ≥55 years. Amyloid positivity was defined by a mean 11 C-Pittsburgh Compound B (PiB) distribution volume ratio (DVR) cut-off of 1.062. All analyses included age, race, sex, education, APOE e4 carrier status, and two-way interactions of these covariates with time. Two-way interaction between sex and PiB+/− status and three-way interaction of sex and PiB+/− status with time were added to assess whether sex modified associations. Results: PiB+ status was associated with greater volumetric declines in the phg (β = −0.036, SE = 0.011, p = 0.001) and erc (β = −0.019, SE = 0.009, p = 0.045). Sex modified the association of PiB+ status and rates of volumetric declines in fusiform (β = −0.117, SE = 0.049, p = 0.019). PiB+ males had steeper rates of volumetric declines in phg (β = −0.051, SE = 0.013, p < 0.001) and erc (β = −0.029, SE = 0.012, p = 0.014) than PiB- males, while there was no difference in rates of volumetric change between PiB+ and PiB- females. Conclusions: Amyloidosis is a marker of entorhinal and parahippocampal volume loss. Amyloid positivity is a predictor of volume loss in brain regions affected by early AD pathology in men, but not women.

Original languageEnglish (US)
Article number101769
JournalNeuroImage: Clinical
Volume22
DOIs
Publication statusPublished - Jan 1 2019

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Keywords

  • Amyloid
  • Neurodegeneration
  • PET
  • Pittsburgh compound B
  • Sex differences

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Neurology
  • Clinical Neurology
  • Cognitive Neuroscience

Cite this

Armstrong, N. M., Huang, C. W., Williams, O. A., Bilgel, M., An, Y., Doshi, J., ... Resnick, S. M. (2019). Sex differences in the association between amyloid and longitudinal brain volume change in cognitively normal older adults. NeuroImage: Clinical, 22, [101769]. https://doi.org/10.1016/j.nicl.2019.101769