Simple three-variable screening tool for identification of patients with obstructive sleep apnea-hypopnea syndrome in middle-aged male snorers from Guangxi region: a multi-center study

Abstract

To evaluate the correlation between three variables of neck circumference, body mass index (BMI) and Epworth sleepiness scale (ESS) and obstructive sleep apnea-hypopnea syndrome (OSAHS) and the value of three-variable screening tool among snorers in Guangxi region. From May 2009 to June 2014, 2 955 middle-aged consecutive patients with snoring were recruited from four hospitals of Guangxi Province. All subjects underwent polysomnography (PSG) and physical examinations including neck circumference, BMI and ESS. The diffrences of neck circumference, BMI and ESS were compared between OSAHS and non-OSAHS groups; the correlation between apnea-hypopnea index (AHI) and neck circumference, BMI and ESS were analyzed. The optimal cutoff point of three variables was selected by SPSS's Optimal Binning methods and screening score was assigned according to the Logistic regression coefficient. The recommended cutoff points were neck circumference ≥ 38.5 cm (3 points), BMI ≥ 25.7 kg/m(2) (5 points), ESS ≥ 9 points (1 point) for males and neck circumference ≥ 34.5 cm (5 points), BMI ≥ 24.5 kg/m(2) (2 points), ESS ≥ 7 points (1 points) for females. The best integral value was obtained through the receiver operating characteristic (ROC) curve. A total of 2 803 subjects fulfilled the study criteria. There were 2 366 males and 437 females. The average values of neck circumference, BMI and ESS were (38.7 ± 3.5) cm, (27.3 ± 3.6) kg/m(2) and (8.6 ± 5.4) score respectively. Both males and females had a positive association between AHI and neck circumference, BMI and ESS (r = 0.389, 0.485, 0.293, 0.386, 0.439 and 0.291 respectively, all P < 0.001). For males, at an integral value ≥ 6, the sensitivity was 71.4% in the diagnosis of OSAHS, specificity 65.5% and positive predictive value 91.1%. For females, at an integral value ≥ 3, the sensitivity was 73.3% in the diagnosis of OSAHS, specificity 63.6% and positive predictive value 66.3%. In middle-aged snorers in Guangxi, neck circumference, BMI and ESS are correlated with OSAHS. And a positive association exists between AHI and neck circumference, BMI and ESS. Simple three-variable screening tool is highly valuable for diagnosing OSAHS, especially among male snorers.