Daytime Sleepiness Relates to Snoring Independent of the Apnea-Hypopnea Index in Women From the General Population

Abstract

The aim was to investigate the significance of snoring and sleep apnea on daytime symptoms in a population-based sample of women. From the general population, 400 women aged 20 to 70 years were randomly selected, with oversampling of habitually snoring women. The women were investigated using full-night polysomnography and a questionnaire. The apnea-hypopnea index (AHI) was calculated, and women who acknowledged snoring loudly and disturbingly often or very often were considered habitual snorers. Habitual snoring was independently related to excessive daytime sleepiness (odds ratio [OR], 2.28; 95% confidence interval [CI], 1.31 to 3.99), to falling asleep involuntarily during the day (OR, 2.11; 95% CI, 1.06 to 4.21), to waking up unrefreshed (OR, 2.14; 95% CI, 1.30 to 3.52), to daytime fatigue (OR, 2.77; 95% CI, 1.54 to 4.99), and to a dry mouth on awakening (OR, 2.00; 95% CI, 1.22 to 3.27) after adjustment for AHI, age, body mass index (BMI), smoking, total sleep time, percentage of slow-wave sleep, and percentage of rapid eye movement (REM) sleep. An AHI > or = 15/h was only related to a dry mouth on awakening after adjustment for snoring, age, BMI, smoking, total sleep time, percentage of slow-wave sleep, and percentage of REM sleep (OR, 2.24; 95% CI, 1.14 to 4.40). An AHI of 5 to 15/h was not related to any daytime symptom. Excessive daytime sleepiness and daytime fatigue are related to habitual snoring independent of the apnea-hypopnea frequency, age, obesity, smoking, and sleep parameters in a population-based sample of women, but not to the AHI. This indicates that snoring is an independent cause of excess daytime sleepiness and not merely a proxy for sleep apnea.