Table 5.

CRF attenuates the adverse effect of poor sleep on CSF biomarkers

CSF Biomarker	SPI × VO2 peak§		SPI (Low VO2 peak)†		SPI (High VO2 peak)‡
	β (SE)	p	β (SE)	p	β (SE)	p
Aβ42	−6.05 (5.93)	.313	-	-	-	-
t-tau	−7.94 (3.20)	.016	83.08 (39.84)	.042	−66.43 (51.44)	.203
p-tau	−1.12 (.41)	.008	14.39 (5.06)	.007	−6.62 (6.54)	.316
t-tau/Aβ42	-.02 (.01)	.061	.21 (.09)	.028	−.06 (.12)	.629
p-tau/Aβ42	−.01 (.01)	.041	.04 (.01)	.009	−.01 (.01)	.740

^§The regression estimates and associated p values are for the SPI × VO₂ peak interactive term in each CSF biomarker’s model. This term assesses whether VO₂ peak modifies the effect of sleep on the examined CSF biomarkers.

^†The regression estimates and associated p values are for the simple main effect for the influence of sleep problems on each CSF biomarker within the Low VO₂ peak group.

^‡The regression estimates and associated p values are for the simple main effect for the influence of sleep problems on each CSF biomarker within the High VO₂ peak group.

Variables included in the model were age at GXT, sex, APOE ε4 status, time interval between GXT and sleep assessment, time interval between sleep and CSF assessments, SPI score, VO₂ peak, and a SPI × VO₂ peak interaction, with the SPI × VO₂ peak interaction term being the effect of primary interest.

CRF=cardiorespiratory fitness; CSF=cerebrospinal fluid; SPI=Sleep Problems Index I; VO₂ peak=peak volume of oxygen consumed during graded exercise test; β=regression estimate; SE=standard error; Aβ₄₂=amyloid-beta 42; t-tau=total tau; p-tau=phosphorylated tau; GXT=graded exercise test; APOE ε4=the ε4 allele of the apolipoprotein E gene