Snoring in a sitting position and neck circumference are predictors of sleep apnea in Chinese patients

BACKGROUND: Snoring is a common symptom among the adult population, and it is the most common complaint in patients with obstructive sleep apnea (OSA) syndrome. Patients who snore in a sitting position while taking a nap or sleeping may have a narrower upper airway. The aim of this study was to evaluate if snoring in a sitting position is a predictor of OSA in patients.

METHOD: We prospectively enrolled 166 SS+ (with a history of snoring in a sitting position) subjects and 139 SS- (who denied having a history of snoring in a sitting position) patients. All of the participants received questionnaires as well as a standard polysomnography thereafter.

RESULT: Patients with self-reported snoring in a sitting position (with a tilt position greater than 70°, SS+ group) had a higher body mass index as well as greater neck, waist, and buttock circumference and scored higher on the Epworth Sleepiness Scale. During the polysomnographic study, the SS+ group had a higher percentage of N1 sleep and lower percentage of N2 sleep. In addition, the SS+ group had a higher apnea-hypopnea index (AHI) as well as higher arousal index and oxygen desaturation index. The sensitivity and specificity of the SS+ group for OSA (defined as AHI ≥ 5) were 0.59 and 0.73, respectively, with a positive predictive value of 0.93. The likelihood ratio was 2.2. On the other hand, the sensitivity and specificity of the SS+ group for moderate to severe OSA (defined as AHI ≥ 15) were 0.82 and 0.48, respectively. Both SS+ and greater neck circumference have a high likelihood ratio for diagnosing OSA.

CONCLUSION: In the present study, the symptoms of self-reported snoring in a sitting position and greater neck circumference can be useful clinical predictors of OSA in Chinese patients.