Table 4.

Partial Spearman’s Rank Order Correlation Results Controlling for Age, BMI, ESS

	Enlarged PVS
	r	P
MMSE	−0.141	0.152
AHI	0.565	<0.001
LSaO2	−0.635	0.001
TS90%	0.525	<0.001
ODI	0.618	<0.001
SE	−0.319	0.001
AI	0.273	0.005
N1%	0.101	0.310
N2%	0.532	<0.001
N3%	−0.403	<0.001
REM%	−0.478	<0.001

Note: Differences of P<0.05 indicated statistical significance.

Abbreviations: PVS, perivascular space; BMI, body mass index; MMSE, Mini Mental State Scale; ESS, Epworth Sleepiness Scale; AHI, apnea hypopnea index; SE, sleep efficiency; LSaO2, the lowest blood oxygen saturation; TS90%, percentage of sleep time spent with an oxygen saturation < 90%; ODI, oxygen desaturation index; N1%, percentage of non-rapid eye movement sleep N1 stage; N2%, percentage of non-rapid eye movement sleep N2 stage; N3%, percentage of non-rapid eye movement sleep N3 stage; REM%, percentage of rapid eye movement sleep; AI, arousal index.