In women, habitual snoring may be an independent cause of excessive daytime sleepiness and daytime fatigue, regardless of sleep apnea occurrences. Researchers from Sweden performed polysomnography on 400 randomly selected women, aged 20 to 70 years. The apnea-hypopnea index (AHI) was calculated, and women who acknowledged snoring loudly and either disturbingly often or very often were considered habitual snorers. Habitual snoring was independently related to excessive daytime sleepiness, falling asleep involuntarily during the day, waking up unrefreshed, daytime fatigue, and dry mouth on awakening, even after adjusting for AHI, age, BMI, smoking, total sleep time, percentage of slow-wave sleep, and percentage of rapid eye movement sleep. Researchers conclude that snoring is an independent cause of excessive daytime sleepiness and not merely a proxy for sleep apnea. This study is published in the November issue of the journal CHEST.


Carbon monoxide (CO) levels in a patient's blood may determine the severity of a patient's obstructive sleep apnea (OSA). Researchers from Japan determined the CO levels in 35 patients with OSA and 17 agematched healthy control subjects, both before and after polysomnography. Although there was no difference in CO levels between the two groups prior to sleep, the postsleep circulating CO levels were significantly higher in patients with OSA compared with control subjects. Furthermore, the change in CO level, which was defined as a gap between the presleep and postsleep CO levels, correlated with the apnea-hypopnea index and hypoxia duration as a percentage of total sleep time. This showed that the higher the CO level, the more severe the OSA. Treatment with continuous positive airway pressure (CPAP) resulted in normalization of the postsleep CO level. Researchers speculate that because patients with OSA have an increased risk for cardiovascular morbidity and CO levels are a marker for cardiovascular risk, using CPAP to reduce CO levels could, ultimately, reduce a patient's risk for cardiovascular morbidity. This study is published in the November issue of the journal CHEST.

Article adapted by Medical News Today from original press release.

Source: Jennifer Stawarz
American College of Chest Physicians