Exercise tolerance in obstructive sleep apnea-hypopnea (OSAH), before and after CPAP treatment: Effects of autonomic dysfunction improvement

Cardiovascular Performance Following Continuous Positive Airway Pressure in Patients with Severe Obstructive Sleep Apnea

“…This study also demonstrated improvement in HRR in severe OSA patients after 180 days of CPAP therapy, which agrees with the majority of other studies (Maeder et al, 2009;Quadri et al, 2017). CPAP therapy is effective in suppressing sympathetic nerve activity (Santamit et al, 2015) and improved chronotropic control during exercise (Quadri et al, 2017).…”

“…This disagreement may be due to the fact that their studies were done in patients with mild to moderate OSA, while this study was carried out in patients with severe OSA. Sleep fragmentation and hypoxia cause autonomic dysfunction and ventricular dysfunction (Kaleth et al, 2007), both of which induce exercise tolerance limitation and early occurrence of dyspnea and limb muscle fatigue, and therefore the lower V'O 2max found in the present study (Przybylowski et al, 2007;Quadri et al, 2017). One potential consequence is that β-adrenergic receptors are down regulated, resulting in an inability to elevate HR sufficiently to quickly meet the physiological demands imposed by exercise, and finally an increase in HR reserve (Kaleth et al, 2007).…”

“…Previous studies have demonstrated that CPAP treatment for 60 to 180 days improved exercise capacity, as reflected by an increase in V'O 2max and maximum workload (Lin et al, 2004;Maeder et al, 2009;Quadri et al, 2017). However, another study found no evidence of increased V'O 2max following CPAP treatment for 90 days (Pendharkar et al, 2011).…”

“…This study found significant improvements in V'O 2max of approximately 4% after treatment with CPAP therapy for 180 days. Moreover, it is likely that CPAP therapy improves CO (Quadri et al, 2017) and metabolism in mitochondria of muscle cells (Kline et al, 2013). Longitudinal research is needed to evaluate the effect of CPAP on V'O 2max and cardiovascular adaptation in OSA patients.…”

“…HR reserve improvement resulting from CPAP therapy is an effective treatment for sympathetic overactivity (Quadri et al, 2017;Santamit et al, 2015) and oxidative stress (Tichanon et al, 2016). CPAP therapy is also effective in increasing HR at maximal exercise.…”