Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring (Sep 2015)

Oral glucose tolerance testing to modulate plasma amyloid levels: A novel biomarker

  • Esther S. Oh,
  • Christopher M. Marano,
  • Jeannie‐Marie Leoutsakos,
  • Rebecca W. Lee,
  • Robert A. Rissman,
  • Gwenn S. Smith,
  • Suzanne Craft,
  • Constantine G. Lyketsos

DOI
https://doi.org/10.1016/j.dadm.2015.06.002
Journal volume & issue
Vol. 1, no. 3
pp. 311 – 315

Abstract

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Abstract Introduction Plasma levels of amyloid‐beta (Aβ) do not correlate well with different stages of Alzheimer's disease (AD) in cross‐sectional studies. Measuring the changes in Aβ plasma levels with an acute intervention may be more sensitive to distinguishing individuals in earlier stages of AD (mild cognitive impairment [MCI]) from normal controls. Methods A total of 57 participants (18 with AD/MCI and 39 cognitively normal controls) underwent oral glucose tolerance testing (OGTT). Blood samples were obtained over a 2‐hour period. Changes in plasma Aβ40 and 42 levels were measured from either baseline or 5 minutes to the 10‐minute time‐point. Results Compared with normal controls, subjects with AD/MCI had significantly less change (Δ) in plasma levels for both Aβ40 (−3.13 [40.93] vs. 41.34 pg/mL [57.16]; P = .002) and Aβ42 (−0.15 [3.77] vs. 5.64 pg/mL [10.65]; P = .004). Discussion OGTT combined with measures of plasma Aβ40 and 42 is potentially useful in distinguishing aging individuals who are in different stages of AD.

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