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

Malin Svensson, MD; Karl A. Franklin, PhD; Jenny Theorell-Haglöw, BSc, andEva Lindberg, PhD


CHEST. 2008;134(5):919-924. 

In This Article

Abstract and Introduction


Objectives: The aim was to investigate the significance of snoring and sleep apnea on daytime symptoms in a population-based sample of women.
Method: 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.
Results: 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≥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.
Conclusions: 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.


Approximately 7 to 15% of women snore habitually, and 2 to 2.5% of women have obstructive sleep apnea syndrome (OSAS) with nocturnal apneas and daytime sleepiness.[1,2,3,4,5,6] A frequency of 5 to 15 apneas and hypopneas per hour of sleep is generally considered as mild sleep apnea, and a frequency>15/h indicates moderate-to-severe sleep apnea.[7]

Excessive daytime sleepiness is the main symptom of OSAS, while snoring is often regarded as a harmless sign of the disorder. Other symptoms of sleep apnea in women include fatigue, morning headache, nocturia, and dry mouth at awakening.[1,8,9,10,11] Young and colleagues[1] reported daytime sleepiness in snoring men and women in the general population without sleep apnea, and that a majority of men and women with sleep apnea do not complain of daytime sleepiness. Gottlieb and colleagues[12] reported an increased score in the Epworth sleepiness scale (ESS) score in snoring men and women in different categories of the apnea-hypopnea frequency. Symptoms of sleep apnea are also reported to occur at a lower apnea-hypopnea index (AHI) in women as compared with men.[13] We found no previous study investigating whether typical symptoms of sleep apnea are related to the AHI independent of snoring and vice versa. The aim of this study was to investigate the significance of snoring and nocturnal apneas on daytime symptoms in a population-based sample of women.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.