Obstructive sleep apnea (OSA) is the most common form of sleep-disordered breathing, affecting 5-15% of the population. There are intermittent episodes of partial or complete obstruction of the upper airway during sleep that disrupt normal ventilation and sleep architecture.  OSA is typically associated with excessive daytime sleepiness, snoring, and witnessed apneas. Patients are 8 times more likely to have auto accidents, and they may suffer hypertension, coronary artery disease, stroke, congestive heart failure, pulmonary hypertension, and cardiac arrhythmias. Of these, the association between OSA and hypertension is the most convincing. Although the exact mechanism has not been understood, there is some evidence that OSA is associated with frequent apneas causing mechanical effects on intrathoracic pressure, cardiac function, and intermittent hypoxemia, which may in turn cause endothelial dysfunction and increase in sympathetic drive.

Therapy with continuous positive airway pressure has been demonstrated to improve cardiopulmonary hemodynamics in patients with OSA and may reverse the endothelial cell dysfunction.  Compliance with CPAP has been a problem.  Simpler treatment alternatives, ranging from surgical (tonsillectomy and adenoidectomy; uvula surgery), medical and dental therapies, are being used, although none have matched the efficacy of continuous positive airway pressure.  Randomized studies are needed.

Patients with severe OSAS had significantly narrower cross-sectional area at the level of uvula in expiration, more inferiorly positioned hyoid bone, and thicker soft palate compared with patients with mild/moderate OSAS (P < .05) and the control group (P < .05). In addition, severe OSAS patients had bigger neck circumference than those in the control group (P < .05)(Am J Neuroradiol 2005 Nov;26(10):2624-9).

Sleep Apnea in 11% Chinese Women Over 39: In a study of Chinese women over age 39, 34.3% of 1336 admitted various degree of snoring. Selected one had sleep studies. The estimated prevalence of AHI 5,10,15/h and OSAHS was 41%, 24%, 17% and 11%, respectively. Sleep choking, xerostomia or pharyngoxerosis in the morning was more common with OSAHS. Follicle-stimulating hormone and BMI were predictors of AHI. Epidemic survey of the middle and aged women related obstructive sleep apnea hypopnea syndrome in Beijing. Ye JY, et al. Capital University, Beijing, China. . Zhonghua Er Bi Yen Hou Tou Jing Wai Ke Za Zhi. 2005 Aug;40(8):611-7

The Epworth Sleepiness Scale

The scale assesses the presence of pathological sleepiness but does not indicate likely causes. The upper limit of a normal score is 9. Ask the patient to rate his or her chances of falling asleep in the following situations as 0 = never, 1 = possibly, 2 = probably, and 3 = almost certainly:

	Sitting and reading
	Watching television
	Sitting inactive in a public place (such as a cinema or theatre)
	As a passenger in a car for an hour without a break
	Lying down to rest in the afternoon
	Sitting and talking to someone
	Sitting quietly after a lunch without alcohol
	In a car, while stopped for a few minutes in traffic (not necessarily when the patient is the driver)