Obstructive sleep apnea syndrome and gastroesophageal reflux disease: the importance of obesity and gender

It is claimed that gastroesophageal reflux disease (GERD) increases in patients with obstructive sleep apnea syndrome (OSAS). We aimed to evaluate the prevalence of GERD in patients with OSAS and primary snoring and identify OSAS-related risk factors associated with GERD. In this prospective, cross-sectional, multicenter study, in total 1,104 patients were recruited for polysomnography: 147 subjects were in non-OSAS (primary snoring) and 957 patients were in OSAS group. All patients completed a validated GERD questionnaire. Demographic, anthropometric characteristics, and medical history were recorded. The prevalence of GERD was similar in OSAS (38.9 %) and non-OSAS (32.0 %) groups (p = 0.064). There was no difference in terms of major gastroesophageal reflux (GER) symptoms (heartburn/acid regurgitation) between non-OSAS and mild, moderate, and severe OSAS groups. The prevalence of GERD was increased in female OSAS patients (46.6 %) compared to males (35.7 %) (p = 0.002). In OSAS patients with GERD, body mass index was greater (34.0 +/- 7.0 vs. 33.1 +/- 6.8, p = 0.049), waist (115.5 +/- 13.9 vs. 113.1 +/- 13.4, p = 0.007) and hip (117.9 +/- 13.7 vs. 114.2 +/- 12.8, p < 0.0001) circumferences were larger, and Epworth sleepiness scores were higher (10.3 +/- 6.0 vs. 8.8 +/- 5.6, p < 0.0001) than OSAS patients without GERD. Multivariate analysis showed that GERD was significantly associated with female gender, hip circumference, and daytime sleepiness. In this large cohort, the prevalence of GERD was significantly increased in those with primary snoring and OSAS compared to the general population, but severity of OSAS did not influence GERD prevalence. The present results suggest that OSAS was not likely a causative factor but female gender, obesity, and sleepiness were related with prevalence of GERD in OSAS patients.