Predictive value of Kushida index and acoustic pharyngometry for the evaluation of upper airway in subjects with or without obstructive sleep apnea.

Acoustic pharyngometry is a relatively new noninvasive method that quantifies geometrically complexed pharyngeal dimensions. Our study aimed to investigate the predictability and usefulness of acoustic pharyngometry in diagnosis of obstructive sleep apnea (OSA), and we developed a prospective clinical trial in 16 subjects without apnea and 54 subjects with apnea. All seventy subjects received polysomnography (PSG) to assess the sleep architecture, including breathing and the degree of apnea hypopnea index. Acoustic pharyngometry was performed in four body positions (sitting, supine, right and left lateral) while awake with tidal breathing in addition to morphometric measurements (Kushida index) of oral cavity. This study shows that the cross-sectional area and volume of the upper airway is smaller in the supine position than any other positions. As well, the oropharyngeal junction area of the supine position is the most predictive parameter to discriminate between subjects with or without OSA. Acoustic pharyngometry can be a clinically useful tool for localizing the narrowed portion of the upper airway and predicting obstructive sleep apnea.

The short-term effects of high-dose testosterone on sleep, breathing, and function in older men.

Androgen therapy may precipitate obstructive sleep apnea in men. Despite increasing androgen use in older men, few studies have examined sleep and breathing. Randomized, double-blind, placebo-controlled studies examining effects of testosterone simultaneously on sleep, breathing, and function in older men are not available. Seventeen community-dwelling healthy men over the age of 60 yr were randomized to receive three injections of im testosterone esters at weekly intervals (500 mg, 250 mg, and 250 mg) or matching oil-based placebo and then crossed over to the other treatment after 8 wk of washout. Polysomnography, anthropometry, and physical, mental, and metabolic function were assessed at baseline and after each treatment period. Testosterone treatment reduced total time slept ( approximately 1 h), increased the duration of hypoxemia ( approximately 5 min/night), and disrupted breathing during sleep (total and non-rapid eye movement respiratory disturbance indices both increased by approximately seven events per hour) (all P < 0.05). Despite expected effects on body composition (increase in total and lean mass, reduction in fat mass, P < 0.05, bioimpedance method), upper airway dimensions did not change (acoustic reflectometry). Driving ability (computer simulation), physical activity (accelerometry, Physical Activity Scale in the Elderly), quality of life (SF36, Functional Outcomes of Sleep Questionnaire), mood (Profile of Mood States Questionnaire), sleepiness (Epworth, Stanford scales), and insulin resistance (homeostasis model) also were not changed by treatment. Short-term administration of high-dose testosterone shortens sleep and worsens sleep apnea in older men but did not alter physical, mental, or metabolic function. These changes did not appear to be due to upper airway narrowing. Further study of longer-term lower-dose androgen therapy on sleep and breathing is needed to evaluate its safety in older men.