Nocturnal gastro-esophageal reflux and respiratory symptoms in patients with obstructive sleep apnea, before and after CPAP treatment, compared to the general population - The Icelandic Sleep Apnea Cohort (ISAC) study

Introduction: To estimate the prevalence of reported nocturnal gastro-esophageal reflux (nGER) and respiratory symptoms in obstructive sleep apnea (OSA) subjects compared to the general population. Also change in nGER with CPAP treatment. Methods: 826 OSA patients referred for CPAP treatment. 623 subjects have had a 2 year follow-up visit (n=412 CPAP users, n=211 nonusers). The control group consisted of 939 subjects randomly selected from the general population (81% response rate). Both groups answered the same questionnaires on nGER, sleep, respiratory symptoms, general health and quality of life measured by SF-12. Results: Altogether 18.6% of OSA females and 13.6% of males (p=0.07) compared to 7.5% of controls (p Conclusion: nGER is a common clinical symptom of OSA and often related to respiratory symptoms. Prevalence of nGER decreases with CPAP treatment in a majority of OSA patients.