Plasma Alzheimer's biomarkers and brain amyloid in Hispanic and non-Hispanic older adults

Alzheimers Dement. 2024 Jan;20(1):437-446. doi: 10.1002/alz.13456. Epub 2023 Sep 6.

Abstract

Introduction: Alzheimer's disease studies often lack ethnic diversity.

Methods: We evaluated associations between plasma biomarkers commonly studied in Alzheimer's (p-tau181, GFAP, and NfL), clinical diagnosis (clinically normal, amnestic MCI, amnestic dementia, or non-amnestic MCI/dementia), and Aβ-PET in Hispanic and non-Hispanic older adults. Hispanics were predominantly of Cuban or South American ancestry.

Results: Three-hundred seventy nine participants underwent blood draw (71.9 ± 7.8 years old, 60.2% female, 57% Hispanic of which 88% were Cuban or South American) and 240 completed Aβ-PET. P-tau181 was higher in amnestic MCI (p = 0.004, d = 0.53) and dementia (p < 0.001, d = 0.97) than in clinically normal participants and discriminated Aβ-PET[+] and Aβ-PET[-] (AUC = 0.86). P-tau181 outperformed GFAP and NfL. There were no significant interactions with ethnicity. Among amnestic MCI, Hispanics had lower odds of elevated p-tau181 than non-Hispanic (OR = 0.41, p = 0.006).

Discussion: Plasma p-tau181 informs etiological diagnosis of cognitively impaired Hispanic and non-Hispanic older adults. Hispanic ethnicity may relate to greater likelihood of non-Alzheimer's contributions to memory loss.

Highlights: Alzheimer's biomarkers were measured in Hispanic and non-Hispanic older adults. Plasma p-tau181 related to amnestic cognitive decline and brain amyloid burden. AD biomarker associations did not differ between Hispanic and non-Hispanic ethnicity. Hispanic individuals may be more likely to have non-Alzheimer causes of memory loss.

Keywords: Alzheimer's; GFAP; Hispanic; NfL; amyloid PET; dementia; ethnicity; p-tau181; plasma biomarkers.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alzheimer Disease*
  • Amnesia
  • Amyloid beta-Peptides
  • Amyloidogenic Proteins
  • Biomarkers
  • Brain / diagnostic imaging
  • Cognitive Dysfunction*
  • Female
  • Humans
  • Male
  • Middle Aged
  • tau Proteins

Substances

  • Amyloidogenic Proteins
  • Biomarkers
  • Amyloid beta-Peptides
  • tau Proteins