Table 3.

Associations between self-reported daytime sleepiness with MRI metrics

	β	SE	p
Total brain volume, % ICV
Continuous ESS scores	0.328	0.137	.017
Excessive daytime sleepiness (ESS > 10)	0.606	0.221	.006
Cortical gray matter volume, % ICV
Continuous ESS scores	0.254	0.119	.033
Excessive daytime sleepiness (ESS > 10)	0.484	0.193	.013
Subcortical gray matter volume, % ICV
Continuous ESS scores	−0.009	0.023	.696
Excessive daytime sleepiness (ESS > 10)	−0.019	0.037	.613
White matter hyperintensities volume, % ICV
Continuous ESS scores	0.005	0.070	.942
Excessive daytime sleepiness (ESS > 10)	−0.054	0.110	.626
	OR	95% CI	p
Covert brain infarcts, (presence/absence)
Continuous ESS scores	0.579	0.358-0.937	.026
Excessive daytime sleepiness (ESS > 10)	0.677	0.285-1.609	.378

A natural log transformation was applied to ESS and white matter hyperintensities volume. Dichotomous ESS scores was cutoff at >10, representing excessive daytime sleepiness compared to those without. Bold values represent significant associations. MRI metrics are presented as a percentage of intracranial volume, except for covert brain infarcts. Models were adjusted for age, age squared, sex, and time between ESS and MRI assessments, APOE ε4 allele carriers, body mass index, sleeping medications, depression, and revised Framingham Stroke Risk Profile score. CI, confidence interval; ESS, Epworth Sleepiness Scale; ICV, intracranial volume; MRI, magnetic resonance imaging; OR, Odds ratio; SE, standard error.