Table 3.

Plasma biomarker concentration in samples collected in the morning and evening

Plasma Biomarkers [units]	Morning concentration	Evening concentration	Differences evening-morning	% Change	F (df1, df2) a	P-value corrected (uncorrected) b
Aβ42 [pg/mL]	38.43 (7.76)	40.08 (7.37)	1.65 (0.84 to 2.47)	4.84 (2.68 to 7)	16.81 (1, 37)	0.002 (0.0002)
Aβ40 [ng/mL]	0.29 (0.05)	0.30 (0.05)	0.01 (0.006 to 0.02)	4.24 (2.15–6.32)	16.05 (1, 37)	0.002 (0.0003)
Aβ42/40	0.14 (0.03)	0.14 (0.03)	0.001 (-0.002 to 0.001)	0.65 (-0.70 to 1.10)	0.79 (1, 37)	1 (0.38)
P-tau217 [pg/mL]	0.37 (0.16)	0.36 (0.16)	-0.01 (-0.01 to 0.03)	-0.56 (-7.13 to 6.01)	0.95 (1, 37)	1 (0.34)
P-tau231 [pg/mL]	6.88 (3.05)	6.67 (3)	-0.22 (-0.52 to 0.95)	2.48 (-8.86 to 13.83)	0.35 (1, 35) c	1 (0.55)
P-tau181 [pg/mL]	10.61 (4.89)	9.94 (4.43)	-0.71 (-0.76 to 2.10)	-0.15 (-11.75 to 11.46)	0.90 (1, 37)	1 (0.35)
GFAP [pg/mL]	0.11 (0.07)	0.10 (0.05)	-0.01 (-0.004 to 0.02)	-1.81 (-10.03 to 6.40)	2.04 (1, 37)	1 (0.16)
NfL [ng/mL]	3.83 (2.10)	3.42 (1.47)	-0.41 (-0.12 to 0.94)	-3.96 (-11.75 to 3.82)	2.46 (1, 37)	1 (0.13)

Data shown as mean (SD) or mean (95%CI) unless specified otherwise. Abbreviations: Aβ, amyloid beta; GFAP, glial fibrillary acidic protein; NfL, neurofilament light; P-tau, phosphorylated tau

^a Main effects of sampling time from repeated measures two-way ANOVA

^bP-values were corrected for multiple comparison using the Bonferroni-Dunn method

^c Data was missing for 2 participants