TABLE VII.G. 2.

Association between nasal obstruction and OSA

Study	Year	LOE	Study design	Study groups	Clinical endpoint	Conclusions
Young et al.69	2001	1b	Prospective population-based cohort study	Population-based sample of individuals enrolled in ongoing Wisconsin Sleep Cohort Study. In-laboratory polysomnography was performed on subset (n = 1032).	Relationship between nasal congestion and snoring.	Chronic severe nasal congestion is an independent risk factor for habitual snoring at baseline and 5-year follow-up (OR 4.9; 95% confidence interval, 2.8–8.8).
An et al.899	2019	1b	Double blind crossover RCT	15 patients with OSA and chronic nasal obstruction without obvious pharyngeal narrowing completed two overnight polysomnograms (randomly applying oxymetazoline or placebo).	Effects of nasal patency on sleep architecture in nasal obstruction- predominant obstructive sleep apnea patients by applying nasal decongestant.	Oxymetazoline resulted in significant increase in REM sleep (p = 0.027) and reduction of stage 1 sleep (p = 0.004). AHI in supine position was significantly reduced (p = 0.001).
Kerr et al.902	1992	1b	Single-blind crossover study	10 patients with OSA receiving oxymetazoline and nasal dilator vs. placebo.	Effect of nasal resistance reduction on OSA and nasal airflow assessed via posterior rhinomanometry and PSG.	Reduction of nasal resistance resulted in no change in AHI but improved subjective sleep quality (p < 0.001).
Stradling et al.533	1991	2b	Cross sectional study	1001 men surveyed regarding sleep quality and underwent polysomnography.	Independent predictors of snoring and obstructive sleep apnea.	Multiple linear regression identified nasal stuffiness as a significant independent predictor of snoring but not OSA.
Vidigal et al.905	2012	2c	Case–control study	47 with moderate/severe OSAS and 20 matched controls.	To evaluate nasal obstruction in patients with OSA compared to controls via questionnaires, physical exam, rhinoscopy, nasal inspiratory peak flow (NIPF), and acoustic rhinometry (AR).	OSA group had a significantly higher score on the nasal symptoms scale (p < 0.01) and higher frequency of nasal alterations including presence of septal deviation (p = 0.01) and inferior nasal turbinate hypertrophy (p < 0.01). NIPF and AR parameters were not significantly different.
McLean et al.903	2005	1b	Single blind crossover RCT	10 patients with nasal obstruction and OSA.	Effect of topical decongestant and external dilator strip on nasal resistance, mouth breathing during sleep, and OSA severity.	While AHI reduced by mean 12 (range 3–22) with treatment, no correlation identified between nasal resistance change and AHI change (r2 = 0.001; p = 0.92).
Clarenbach et al.900	2008	1b	Double blind crossover RCT	12 patients with chronic nasal congestion and OSA treated with nasal xylometazoline or placebo for 1 week.	Effects of topical nasal decongestant on nasal conductance, symptom scores, polysomnography.	While there was a significant decrease in AHI at time of maximal decongestion (p < 0.05), there was no significant change in overall AHI or sleep quality.
Djupesland et al.901	2001	1b	Double blind crossover RCT	18 heavy snorers without severe OSA (mean AHI 9.3) reporting nocturnal nasal obstruction.	Effects of external nasal dilation (Breathe Right) assessed by polysomnography, acoustic rhinometry, and questionnaire.	Nasal dimensions increased significantly (p < 0.001) with active dilator compared to placebo. In habitual snorers (AHI < 10) with severe morning obstruction, no significant reduction in AHI (p = 0.06).
Ishii et al.545	2015	2a	Meta-analysis	10 studies meeting criteria with 320 patients: two RCTs, seven prospective studies, and one retrospective study.	Effect of isolated nasal surgery on OSA.	Isolated nasal surgery for patients with nasal obstruction and OSA improved ESS by 3.53 (95% CI [0.64, 6.23]) and RDI by 11.06 (95% CI [5.92, 16.19]), but had no significant AHI improvement (95% CI [–1.6, 11.62]).
Li et al.906	2011	2a	Meta-analysis	11 prospective noncontrolled clinical trials on outcomes of nasal surgery for OSA.	Effect of nasal surgery on daytime sleepiness, snoring, and polysomnogram.	Mean AHI decreased from 35.2 ± 22.6 to 33.5 ± 23.8 after nasal surgery (p = 0.69). ESS scores decreased from 10.6 ± 3.9 to 7.1 ± 3.7 (p < 0.001). Significant improvement in snoring assessed by questionnaires and visual analog scale (p < 0.05).
Yamasaki et al.907	2020	2b	Prospective cohort study	Patients undergoing nasal surgery surveyed through 24 months postoperatively.	Longitudinal snoring symptoms and nasal obstruction after functional nasal surgery for patients with SDB.	OSA patients achieved clinically significant improvement on Snoring Outcome Survey through 24 months (p > 0.05).
Bosco et al.908	2020	2b	Prospective cohort study	34 patients with AHI > 15 and septal deviation treated with nasal surgery.	Effects of nasal surgery on upper airway collapse, assessed using drug-induced sleep endoscopy.	Before nasal surgery, 74% of the patients demonstrated multilevel obstruction. After nasal surgery, 50% patients showed multilevel collapse (p < 0.05) with significant improvement shown in hypopharyngeal collapse.
Li et al.909	2009	2b	Prospective, controlled nonrandomized study	66 patients with OSA (AHI > 5, BMI < 33) and chronic nasal obstruction (surgical, n = 44; control, n = 22).	Effect of septoplasty with inferior turbinate reduction versus medical therapy (steroid or decongestant spray, saline lavage, or oral antihistamine) on snoring, daytime sleepiness, and respiratory adverse events assessed via questionnaire, rhinomanometry, and polysomnogram at baseline and 3 months.	Significantly improved nasal resistance found in the surgical group (p < 0.001). Both groups revealed insignificant changes in polysomnographic parameters. In subgroup analysis, a significant effect of nasal surgery on AHI was found when patients were divided by Friedman tongue position (FTP) into “low” (FTP 1 or 2) and “high” (FTP 3 or 4) (p = 0.007).
Nakata et al.910	2008	2b	Prospective cohort study	49 OSA patients with symptomatic nasal obstruction.	Effect of nasal surgery on nasal resistance, sleep apnea, and sleep quality in patients with OSA assessed via polysomnography before and after surgery.	While there was no significant change in AHI, nasal surgery decreased nasal resistance (p < 0.001), ameliorated sleep-disordered breathing (increased nadir oxygen saturation, p < 0.01; shortened apnea–hypopnea duration, p < 0.05), and improving sleep quality and daytime sleepiness in OSAS (ESS scores, p < 0.001).
Shuaib et al.911	2015	2c	Retrospective cohort study	26 patients with chief complaint of nasal obstruction found to have septal and nasal valve obstruction on examination, who subsequently underwent functional rhinoplasty.	Effect of nasal surgery on nasal resistance, sleep apnea, and sleep quality in patients with OSA assessed via polysomnography before and after functional septorhinoplasty.	Mean AHI preoperatively was 24.7, which dropped to mean postoperative AHI 16, a reduction of 35% (p = 0.013). Among patients with BMI < 30 resulted in 57% mean AHI reduction, from 22.5 to 9.6 (p < 0.01).
Hisamatsu et al.912	2015	2c	Retrospective cohort study	45 patients with moderate or severe OSA and high nasal resistance assessed by rhinomanometry underwent compound nasal surgery (septoplasty, turbinate reduction, and submucosal resection of the posterior nasal nerve).	Effects of nasal surgery on OSA assessed using polysomnography at 3 months, daytime sleepiness, nasal allergy symptoms, and health-related QOL.	Postoperative improvement was demonstrated in at least one polysomnography parameter in 57% and 75% patients with moderate or severe OSA, respectively. Quality of life measures were also significantly improved.
Silvoniemi et al.898	1997	2c	Cross-sectional study	46 patients with severe nasal obstruction due to septal deviation.	Sleep-disordered breathing as assessed by rhinomanometry and whole night sleep recording.	Thirty-one patients (67%) had also heavy disturbing snoring, and apnea periods during sleep were reported by 10 cases.
Lenders et al.913	1991	2c	Case–control study	45 habitual snorers and 22 patients with OSA examined by PSG, rhinomanometry, and acoustic rhinometry.	Association between anatomic nasal obstruction and sleep-disordered breathing.	In 97% of these patients, inferior turbinate hypertrophy was found by acoustic rhinometry, while increased nasal resistance of various degrees was measured in 93% of all patients by active anterior rhinomanometry.