Snoring Intensity and Excessive Daytime Sleepiness in Subjects Without Obstructive Sleep Apnea

Objectives/Hypothesis: Snoring and excessive daytime sleepiness (EDS) are major obstructive sleep apnea (OSA) symptoms. Snorers with apnea/hypopnea index < 5 are designated "simple snorers" and do not meet OSA criteria. This study aimed to explore a possible association between snoring intensity and EDS defined as Epworth Sleepiness Scale (ESS) scores > 11 in non-OSA subjects. Study Design: Prospective cohort study. Methods: From a total of 2,225 subjects who underwent polysomnography (PSG), 307 simple snorers qualified for the study and were assessed for snoring intensity and ESS score. The correlation between PSG- based snoring intensity measurements and ESS score was evaluated. A prediction model for EDS was derived using multivariate logistic regression. Results: Subjects with EDS tended to be male and of heavier body habitus. Although both genders exhibited similar snoring intensities, men had higher ESS scores than women. A strong linear correlation was demonstrated between the maximal snoring intensity and the ESS score. Maximal snoring sound and male gender were shown to be predictors of EDS, with odds ratios of 1.93 (95% confidence interval [CI]: 1.63-2.26, P < .001) and 3.70 (95% CI: 1.29-12.5, P = .01), respectively. Conclusions: In a population of non-OSA subjects referred to a PSG study, snoring intensity was associated with EDS in both men and women. A positive linear correlation was observed between snoring intensities and ESS scores. Additional studies are needed to further consolidate the evidence regarding the implications of simple snoring for public health.