Anatomically based treatments for obstructive sleep apnoea (OSA) such as CPAP and mandibular advancement splints (MAS) often do not completely resolve OSA or are poorly tolerated with non-compliance in a significant proportion of patients. In the case of CPAP, the gold standard of OSA treatment, 46-83% of patients have been reported to not adhere to treatment [1]. Compliance from MAS is higher but reduction of AHI is less and side effects including craniofacial changes can occur [2-4].
This has resulted in interest in treatments that address physiological traits that are found to contribute to instability of breathing control during night time breathing such as hypersensitivity of the chemoreflex (loop gain), poor responsiveness of upper airway dilating muscles and low arousal threshold during sleep [5, 6].
Breathing retraining that improves efficiency and control of daytime breathing might also impact on breathing and airway stability at night and influence some or all of the physiological traits known to contribute to sleep apnoea, particularly in the case of patients with minimal anatomical risk factors.
There can be a bi-directional relationship between daytime and night time breathing. Individuals with severe daytime dysfunctional breathing can maintain abnormal breathing control at night [7]. There is also evidence that some individual with OSA who have unstable ventilatory control at night maintain unstable breathing when awake [8].
Breathing exercises and activities that involve high levels of breathing control can improve daytime breathing control and functionality, and might also improve night time breathing and sleep apnea. Research has shown that a diverse variety of breathing retraining approaches improve sleep apnoea measures or clinically significant symptoms e.g. Buteyko method, inspiratory resistance training and diaphragmatic breathing. There is also a reduced incidence of sleep apnea with intensive and regular participation in activities that require high levels of breath control e.g. singing and playing wind instruments.
The research suggests that improvements are due to a range of factors such as improved muscle tone of the upper airway, better respiratory muscle strength, improved neuroplasticity of breathing control, increased nightime oxygen levels, correction of hyperventilation/dysfunctional breathing and improved autonomic nervous system function.
Good results are dependent on patient selection and appropriately targeted and individualised treatment.
References
- Weaver, T.E. and R.R. Grunstein, Adherence to continuous positive airway pressure therapy: the challenge to effective treatment. Proceedings of the American Thoracic Society, 2008. 5(2): p. 173-178.
- Doff, M.H., et al., Oral appliance versus continuous positive airway pressure in obstructive sleep apnea syndrome: a 2-year follow-up. Sleep, 2013. 36(9): p. 1289-96.
- Tsuda, H., et al., Craniofacial changes after 2 years of nasal continuous positive airway pressure use in patients with obstructive sleep apnea. Chest, 2010. 138(4): p. 870-4.
- Battagel, J.M. and B. Kotecha, Dental side-effects of mandibular advancement splint wear in patients who snore. Clin Otolaryngol, 2005. 30(2): p. 149-56.
- Eckert, D.J., Phenotypic approaches to obstructive sleep apnoea–new pathways for targeted therapy. Sleep medicine reviews, 2016.
- Edwards, B.A., et al., Acetazolamide improves loop gain but not the other physiological traits causing obstructive sleep apnoea. J Physiol, 2012. 590(5): p. 1199-211.
- Lowe, S., et al., Idiopathic hyperventilation (IHV) during wakefulness and sleepAm Rev Respir Crit Care Med, 2001.
- Messineo, L., et al., Breath-holding as a means to estimate the loop gain contribution to obstructive sleep apnoea. J Physiol, 2018.