Table 3 Comparison of plasma Aβ1–40, Aβ1–42, and Aβ1–42/Aβ1–40 ratios between Aβ− and Aβ+ participants.

From: Plasma glial fibrillary acidic protein is elevated in cognitively normal older adults at risk of Alzheimer’s disease

 

Aβ−

(95% CI)

Aβ+

(95% CI)

p

pa

All participants

n = 62

 

n = 33

   

 Aβ1–40

95.19 ± 14.78

(91.27–99.10)

98.37 ± 16.88

(93.00–103.74)

0.344

0.659

 Aβ1–42

21.96 ± 4.58

(20.70–23.22)

19.54 ± 5.74

(17.81–21.27)

0.027

0.022

 Aβ1–42/Aβ1–40 ratio

0.232 ± 0.042

(0.221–0.243)

0.200 ± 0.050

(0.184–0.215)

0.001

0.004

SMC

n = 50

 

n = 25

   

 Aβ1–40

95.62 ± 14.74

(91.19–100.05)

98.67 ± 17.54

(92.41–104.94)

0.430

0.624

 Aβ1–42

22.05 ± 4.69

(20.58–23.52)

19.12 ± 6.17

(17.02–21.19)

0.024

0.015

 Aβ1–42/Aβ1–40 ratio

0.232 ± 0.044

(0.218–0.245)

0.195 ± 0.056

(0.176–0.214)

0.003

0.003

Non-SMC

n = 12

 

n = 8

   

 Aβ1–40

93.39 ± 15.48

(83.96–102.83)

97.41 ± 15.68

(85.86–108.97)

0.578

0.093

 Aβ1–42

21.57 ± 4.26

(19.02–24.12)

20.89 ± 4.11

(17.77–24.01)

0.727

0.634

 Aβ1–42/Aβ1–40 ratio

0.232 ± 0.039

(0.213–0.252)

0.214 ± 0.017

(0.190–0.238)

0.230

0.244

  1. Plasma Aβ1–40 and Aβ1–42 concentrations measured using the Amyblood test (ADx Neurosciences), and their ratio (Aβ1–42/Aβ1–40) were compared between cognitively normal individuals with low brain Aβ load (Aβ−) and high brain Aβ load (Aβ+) using linear models. All participants were further categorised into subjective memory complainers (SMC, n = 75) and non-SMC (n = 20). Data are presented in mean ± SD in pg/mL. p values in bold font were considered significant (p < 0.05).
  2. ap represents p values adjusted for age, sex, and APOE ε4 status.
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