TABLE VII.H.

Association between OSA and GERD

Study	Year	LOE	Study design	Study groups	Clinical endpoint	Conclusion
Teklu et al.935	2020	2c	Cross-sectional study	101 adult patients who underwent polysomnogram	Relationship between reported reflux symptoms and OSA	Patients with OSA have worse symptoms of laryngopharyngeal reflux based on RSI (p = 0.003).
Morse et al.931	2004	2b	Cross sectional study	136 patients referred for polysomnogram	Relationship between OSA and GERD in a large group of patients with OSA	Subjective reports of sleep quality were affected by GERD severity, but no significant correlation between OSA and GERD.
Sundar et al.934	2010	2b	Cross sectional study	75 patients with isolated chronic cough	Rates of OSA among patients with chronic cough	37% of patients with chronic cough had a diagnosis of GERD. 44% were found to have OSA. 93% of the patients that had interventions to optimize their sleep-disordered breathing reported improvement in cough.
Chan et al.925	2010	2b	Cross sectional study	108 consecutive patients referred for evaluation of SDB	Prevalence and severity of chronic cough in patients with sleep-disordered breathing	33% of patients with SDB reported a chronic cough. Patients with SDB and chronic cough were predominantly females (p < 0.001), reported nocturnal heartburn (p = 0.03), and rhinitis (p = 0.02) compared to those without SDB.
Caparroz et al.937	2019	2b	Cross sectional study	56 patients with moderate or severe OSA	Prevalence of laryngopharyngeal reflux in patients with moderate and severe OSA by reflux symptom index questionnaire and indirect videolaryngoscopy	64.3% of patients with moderate or severe OSA had laryngopharyngeal reflux (positive RSI and/or positive endolaryngeal reflux finding score). BMI was a predictor of reflux presence. In patients with positive score for endoscopic findings and reflux symptom index, there was a trend toward significance for a higher mean AHI and a percentage of sleep time with oxyhemoglobin saturation below 90% (p = 0.05).
Lee et al.929	2018	3b	Case–control study	19 OSA patients with unilevel complete obstruction and 69 OSA patients with multilevel complete obstruction on drug-induced sleep endoscopy (DISE)	Relationship between level of obstruction determined by DISE, and laryngopharyngeal reflux (LPR)-related clinical parameters	No significant correlation between OSA severity and LPR-related symptoms. Multilevel complete obstruction on DISE did not affect the LPR-related clinical parameters (p > 0.05).
Kim et al.928	2017	2b	Cross sectional study	73 patients who underwent multilevel surgery for OSA	Effect of multilevel surgery for OSA on symptoms of laryngopharyngeal reflux (LPR) and polysomnogram	Treatment for OSA using multilevel surgery reduced symptoms of LPR; mean RSI score decreased from 11.48 ± 7.95 to 4.95 ± 6.19 after surgery (p < 0.001).
Altintas et al.923	2017	2b	Cross sectional study	62 patients with AHI > 5	Relationship between presence of LPR and level of depression and anxiety in patients with OSA assessed via questionnaire and laryngeal examination	There were significantly higher levels of depression and anxiety in patients with LPR and OSA (p =0.016). A positive correlation was found between RSI and AHI scores (r = 0.338; p = 0.007).
Elhennawi et al.926	2016	2b	Cross sectional study	62 patients with OSA	Relationship between OSA and LPR assessed with ambulatory 24-h pH monitoring	LPR is common in patients with OSA (66%). Patients with severe OSA have significantly higher nocturnal LPR (p < 0.05). Number of reflux episodes and total duration of reflux during sleep are significantly correlated to degree of OSA (p < 0.05). Daytime reflux was not related to degree of OSA (p > 0.05).
Qu et al.932	2015	2b	Case–control study	36 OSA patients and 10 healthy controls underwent 24-h double-probed combined esophageal multichannel intraluminal impedance and pH monitoring simultaneously with polysomnography	Esophageal functional changes observed in OSA	63.9% of patients had both OSA and LPR by pH monitoring and polysomnogram. Significant differences were found in the onset velocity of liquid swallows (p = 0.029) and percent relaxation of the lower esophageal sphincter (LES) during viscous swallows (p = 0.049) between patients with OSA versus healthy controls.
Rodrigues et al.933	2014	2b	Cross sectional study	A total of OSA patients divided into obese group (n = 39) and non-obese patients (n = 66)	Relationship between obesity on LPR and OSA	In the obese group, mean RSI was 6.7 in patients with mild OSA and 11.53 in patients with moderate to severe OSA (p < 0.05). No correlation between OSA severity and RSI in non-obese group.
Xavier et al.936	2019	1b	Cross sectional study	27 adults with LPR confirmed by two validated instruments (RSI ≥ 13 and reflux finding score ≥ 7) and OSA underwent full polysomnography with concomitant multichannel intraluminal impedance-pH esophageal monitoring	Temporal correlation between reflux episodes and respiratory events in patients with LPR and OSA	Among patients with well-established laryngopharyngeal reflux and OSA, there is no temporal association between reflux and obstructive respiratory events.
Eryılmaz et al.927	2012	1b	Prospective cohort study	44 patients underwent double probed 24 h pH monitoring simultaneously with polysomnography due to the complaints of SDB and reflux, at 0 and 3 months	Effect of OSA therapy on LPR parameters	OSA and LPR coexist frequently. LPR treatment did not improve the polysomnographic parameters, but significantly reduced ESS (p = 0.02) and snoring (p = 0.007). Although CPAP treatment significantly improved subjective parameters of reflux, such as RSI and RFS (p = 0.016 for both), there was no significant improvement in objective parameters of 24-h pH monitoring.
Magliulo et al.930	2018	2a	Meta-analysis	10 papers studying LPR in OSA were included with 870 identified OSA patients	Incidence of LPR in OSA patients	There is a high incidence of LPR (45.2%) among OSA patients. AHI severity did not correlate with presence of laryngopharyngeal reflux (p = 0.3). OSA patients with LPR had higher BMI compared with LPR patients (p = 0.001).
Caparroz et al.924	2019	2b	Cross sectional study	70 patients with moderate or severe OSA underwent validated questionnaires, laryngoscopy to calculate the Reflux Finding Score (RFS), and fiber-optic endoscopic evaluation of swallowing (FEES)	Association between presence of dysphagia with signs and symptoms suggestive of LPR in patients with moderate and severe OSA	Although 17.9% of patients presented with findings suggestive of concomitant LPR and dysphagia, there was no statistically significant association between these two conditions.
Kim et al.939	2018	1b	Cross sectional study	216 patients underwent both PSG and EGD	Relationship between OSA and GERD	Endoscopically proven GERD was associated with more severe OSA (p = 0.01). GERD symptoms were also associated with worse sleep quality (p = 0.03).
Rassamee- hiran et al.940	2016	2a	Meta-analysis	2 randomized trials and 4 prospective cohort studies on the effect of treatment for GERD on OSA	Association between PPI treatment for GERD and improvement in OSA	No differences in AHI before and after treatment with PPIs (SMD 0.21; 95% CI [−0.11, 0.54]).
Gilani et al.938	2016	2b	Retrospective study	Adults with OSA and GERD and potentially confounding conditions were identified in the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey	Association between GERD and OSA controlling for concurrent confounders in a national database	Significant positive association between GERD and OSA was observed, which persisted after adjustment for age, sex, race/ethnicity, sino-nasal obstruction, inflammatory disorders, obesity, asthma, and lung disorders (OR 1.94, 95% CI [1.07–3.54], p = 0.030).
Shepherd et al.941	2016	1b	Prospective cohort study	20 obese individuals (BMI > 30), nine non-obese individuals (BMI < 30) with moderate-to-severe OSA, and 17 obese control subjects (BMI > 30) underwent high-resolution esophageal manometry, 24-h esophageal pH-impedance monitoring, and in-laboratory polysomnography	Effect of OSA on GERD independent of obesity	The two obese groups did not show any significant differences in the total number of acidic reflux events (41 ± 20 vs. 28 ± 16); however, the obese OSA group had a greater number of acidic reflux events compared to the non-obese OSA group (22 ± 12 events, p < 0.05). In multivariate analysis, BMI significantly predicted number of acidic reflux events (r(2) = 0.16, p = 0.01). However, AHI showed no significant association with GERD severity.
Xavier et al.942	2013	2c	Cross-sectional study	74 patients with OSA	Prevalence of symptoms of reflux in OSA patients assessed with questionnaire	98% of the subjects with suspected OSA had symptoms suggestive of LPR; prevalence was significantly higher among obese individuals (p = 0.002).