Gastroesophageal reflux in patients with morbid obesity: a role of obstructive sleep apnea syndrome?

ABSTRACT

BACKGROUND: Obesity is a risk factor for gastroesophageal reflux disease (GERD) and for obstructive sleep apnea (OSA). Our aim was to evaluate in morbidly obese patients the prevalence of OSA and GERD and their possible relationship. METHODS: Morbidly obese patients [body mass index (BMI) >40 or >35 kg/m(2) in association with comorbidities] selected for bariatric surgery were prospectively included. Every patient underwent a 24-h pH monitoring, esophageal manometry, and nocturnal polysomnographic recording. RESULTS: Sixty-eight patients [59 women and 9 men, age 39.1 +/- 11.1 years; BMI 46.5 +/- 6.4 kg/m(2) (mean +/- SD)] were included. Fifty-six percent of patients had an abnormal Demester score, 44% had abnormal time spent at pH <4, and 80.9% had OSA [apnea hypopnea index (AHI) >10] and 39.7% had both conditions. The lower esophageal sphincter (LES) pressure was lower in patients with GERD (11.6 +/- 3.4 vs 13.4 +/- 3.6 mm Hg, respectively; P = 0.039). There was a relationship between AHI and BMI (r = 0.337; P = 0.005). Patients with OSA were older (40.5 +/- 10.9 vs 33.5 +/- 10.4 years; P = 0.039). GERD tended to be more frequent in patients with OSA (49.1% vs 23.1%, respectively; P = 0.089). There was no significant relationship between pH-metric data and AHI in either the 24-h total recording time or the nocturnal recording time. In multivariate analysis, GERD was significantly associated with a low LES pressure (P = 0.031) and with OSA (P = 0.045) but not with gender, age, and BMI. CONCLUSION: In this population of morbidly obese patients, OSA and GERD were frequent, associated in about 40% of patients. GERD was significantly associated with LES hypotonia and OSA independently of BMI.