Positional Sleep Apnea Among Regional and Remote Australian Population and Simulated Positional Treatment Effects

Abstract

Purpose

To assess the prevalence of positional sleep apnea (POSA) and its predictors in patients diagnosed to have obstructive sleep apnea (OSA) in the regional and remote population of the Northern Territory of Australia over a two-year study period (2018 and 2019).

Patients and Methods

Of the total 1463 adult patients who underwent a diagnostic polysomnography (PSG), 946 patients were eligible to be included in the study, of them, 810 consecutive patients with OSA (Apnea-Hypopnea Index (AHI) ≥ 5) who slept >4 h and had ≥30 min sleep in both supine and lateral positions were assessed. Patients were considered to have POSA if supine AHI to lateral AHI ratio ≥2. The likely comparative impact of use of continuous positive airway therapy (CPAP) or positional therapy (PT) on disease severity was evaluated using model simulation.

Results

A total of 495/810 (61%) patients had POSA, the majority were males (68% vs 60%, p=0.013) and non-Indigenous Australians (93% vs 87%, p=0.004). POSA patients were younger (mean difference 2.23 years (95% CI 0.27, 4.19)), less obese (BMI mean difference 3.06 (95% CI 2.11, 4.01)), demonstrated less severe OSA (p < 0.001) and a greater proportion reported alcohol consumption (72% vs 62%, p=0.001) as compared to those with non-POSA. Using the simulation model, if patients with POSA use PT two-thirds (323/495, 65%) would obtain significant improvement of their OSA severity, with one in five (92/495, 19%) displaying complete resolution. Comparing this to simulated CPAP therapy, where the majority (444/495, 90%) will show significant improvement, and one-third (162/495, 33%) will display complete resolution.

Conclusion

POSA needs to be routinely recognised and positional therapy integrated in practice especially in the remote regions and in the developing world when effective methods are in place to monitor positional therapy.

Keywords:

• adherence: apnea hypopnea index
• body mass index
• continuous positive airway pressure
• obstructive sleep apnea
• positional therapy

Abbreviations

AHI, Apnea-Hypopnea Index; ASA, Australian Sleep Association; ATSI, Aboriginal and/or Torres Strait Islander; BMI, body mass index; CI, confidence interval; CPAP, continuous positive airway therapy; DPH, Darwin Private Hospital; DRSH, Darwin Respiratory and Sleep Health; ESS, Epworth Sleepiness Scale; HREC, Human Research Ethics Committee; IQRs, interquartile ranges; NATA, National Association of Testing Authorities; NT, Northern Territory; ORs, odds ratios; OSA, obstructive sleep apnea; POSA, positional sleep apnea; PPs, positional patients; PSG, polysomnography; PT, positional therapy; RA, Regional Australia; RDH, Royal Darwin Hospital; REM, rapid eye movement; NREM, non rapid eye movement; TEHS, Top End Health Service.

Summary

Sleep apnea is a global epidemic that is being increasingly recognised around the world, including among various socioeconomic groups and people living in remote and regional areas of Australia. Currently, the major treatment modality for sleep apnea has been the use of continuous positive airway therapy device and the applicability/monitoring of which poses many logistic challenges to those who have lesser access to health-care services. A phenotypic variant of sleep apnea is “positional sleep apnea”, where the apneas are predominantly noted during certain body positions. Altering the body position during sleep may help in alleviating the apnoeic episodes. However, there is sparse evidence in the literature regarding the prevalence or the effects of positional therapy in the regional and remote Australian population. Our study has demonstrated that positional sleep apnea is highly prevalent in the regional and remote adult Australian population and more commonly noted among males, younger adults, individuals who consume alcohol and in those with a lower body mass index and patients who display lesser overall severity of sleep apnea. Moreover, the model simulation of positional treatment effect in our study shows that positional treatment may be a promising alternate effective therapeutic modality that could help in the treatment paradigm for sleep apnea among vulnerable and underprivileged populations around the world.

Acknowledgments

We extend our sincere gratitude to the administrative staff Ms Tiziana Buysman, Mrs. Elisha Gamorot and sleep technologist Ms. Charmain Atos, Ms. Ara Perez, Mr. Jessie Crespo, Mr. Mark Ramirez and Ms. Bianca Al-Dossary at Darwin Respiratory and sleep health for their contribution towards this study. We also thank Dr David Cunnington, Respiratory and Sleep specialist from the Melbourne Sleep Disorders Centre, Victoria Pde, East Melbourne VIC, Australia for his expert opinion and advice.

Institution where work was performed: Department of Respiratory and Sleep Medicine, Royal Darwin Hospital, Darwin, Northern Territory, Australia and Darwin Respiratory and Sleep Health, Darwin Private Hospital, Darwin, Northern Territory, Australia. 0810.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

All authors declare no conflicts of interest.