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 testing on 400 randomly selected women, aged 20 to 70 years. 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, falling asleep involuntarily during the day, waking up unrefreshed, daytime fatigue, and to a dry mouth on awakening, even after adjusting for AHI, age, body mass index (BMI), smoking, total sleep time, percentage of slow-wave sleep, and percentage of rapid eye movement (REM) sleep. Researchers conclude that snoring is an independent cause of excess daytime sleepiness and not merely a proxy for sleep apnea.
CARBON MONOXIDE LEVELS MAY PINPOINT SLEEP APNEA SEVERITY
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 patents with OSA and 17 age-matched healthy controls, both before and after polysomnography testing. Although there was no difference in CO levels between the two groups prior to sleep, the postsleep circulating CO levels were significantly higher in OSA patients compared with the controls. Furthermore, the change in CO level, which was defined as a gap between the presleep and postsleep CO levels, correlated with apnea-hypopnea index and hypoxia duration as a percentage of total sleep time, which 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.
|Contact: Jennifer Stawarz|
American College of Chest Physicians