Table 4.

Comparison of the effect of APOE ε4 status and brain Aβ status on plasma Aβ₁₋₄₂ levels and blood biomarker ratios.

APOE ε4 status
Aβ1−42	ε4–	ε4+	p(F)#	pa(Fa)#
All	0.337 ± 0.077	0.308 ± 0.068	0.013 (6.297)	0.031 (4.746)
APP669−711/Aβ1−42	ε4–	ε4+	p(F)	pa(Fa)
All	0.839 ± 0.131	0.943 ± 0.139	<0.001 (19.936)	<0.001 (15.129)
Aβ1−40/Aβ1−42	ε4–	ε4+	p(F)	pa(Fa)
All	25.10 ± 3.62	27.22 ± 3.72	0.001 (11.077)	<0.001 (14.582)
Brain Aβ status
Aβ1−42	Aβ-	Aβ+	p(F)#	pa(Fa)#
All	0.343 ± 0.077	0.305 ± 0.068	0.001 (11.733)	0.001 (11.876)
APP669−711/Aβ1−42	Aβ-	Aβ+	p(F)	pa(Fa)
All	0.811 ± 0.117	0.963 ± 0.128	<0.001 (54.898)	<0.001 (54.199)
Aβ1−40/Aβ1−42	Aβ-	Aβ+	p(F)	pa(Fa)
All	24.38 ± 3.47	27.83 ± 3.28	<0.001 (36.509)	<0.001 (36.304)

Plasma Aβ₁₋₄₂ and the ratios APP_669−711/Aβ₁₋₄₂ and Aβ₁₋₄₀/Aβ₁₋₄₂ were compared with regards to APOE ε4 genotype status (ε4–/ε4+), and brain amyloid status (Aβ-/+) using general linear models. Brain amyloid deposition was measured using positron emission tomography. Plasma Aβ₁₋₄₂ data were natural log transformed to better approximate normality and variance homogeneity (#). p^a(F^a) represents p-values adjusted for age and sex. P < 0.05 (italic) was considered significant. Data are presented in mean ± SD.