Treatment of Obstructive Sleep Apnea in Young and Middle‐Aged Adults: Effects of Positive Airway Pressure and Compliance on Arterial Stiffness, Endothelial Function, and Cardiac Hemodynamics

Abstract

BackgroundThe cardiovascular effects of positive airway pressure (PAP) therapy in obstructive sleep apnea (OSA) patients are not clear because of confounding by comorbid conditions.Methods and ResultsProspective interventional study of PAP therapy and withdrawal. Apnea Hypopnea Index (AHI; events/hour of sleep) was determined from polysomnography. Central aortic blood pressures (BPs), Aortic Augmentation Index (AAIx), and central (PWV c‐f) and peripheral pulse wave (PWV c‐r) velocities were determined by applanation tonometry. Echocardiography and brachial artery reactivity testing were performed at baseline, after 4 and 12 weeks of PAP therapy, and 1 week after PAP withdrawal. The 84 participants were mean (SD) 41.1 (7.6) years old and had 39.8 (24.5) AHI events/hour. After 4 weeks post‐PAP initiation and sustained after 12 weeks, subjects experienced decreases in central systolic BP (P=0.008), diastolic BP, mean BP, AAIx, and PWV c‐r, and brachial artery dilation (all P<0.001), as well as improvements in left ventricular diastolic function and systemic and pulmonary vascular resistance. In adjusted models, PAP use (hours/night) predicted reductions in diastolic BP (β=−0.65 [SE, 0.32] mm Hg/hour; P=0.045), AAIx (β=−0.53 [0.27] %/hour; P=0.049) and PWV c‐r (β=−0.13 [0.05] m·s−1/hour; P=0.007), and improved brachial artery flow‐mediated dilation (β=0.31 [0.14] %/hour use; P=0.015). After 1 week of PAP withdrawal, brachial diameter, diastolic BP, mean BP, AAIx, and heart rate increased (P≤0.05).Conclusions PAP therapy reduces arterial tone and improves endothelial and diastolic function in young to middle‐aged adults. This positive effect is observed after 4 weeks and depends on hours of use, but reverts quickly with PAP withdrawal.Clinical Trial RegistrationURL: https://clinicaltrials.gov/. Unique identifier: NCT01317329.

Cardiovascular Events in Moderately to Severely Obese Obstructive Sleep Apnea Patients on Positive Airway Pressure Therapy

“…In severely obese patients, CPAP treatment improved but did not normalize pulse wave analysis [36,37] . Other positive short-term effects of CPAP on pulse wave analysis were recently reported by Korcarz et al [38] in a younger and less obese population compared to our patients. In our cohort, patients with events during follow-up showed a trend for higher PWV at diagnosis, although the difference did not reach significance, probably owing to an insufficient sample size.…”

Cardiorespiratory interaction with continuous positive airway pressure

“…Indeed, an improvement in vascular stiffness evaluated by pulse wave analysis early in the morning after CPAP therapy has been described, when compared with the same measurements in the afternoon (63). Another study concluded that CPAP improves vascular function even after short-term treatment (64), but also that there is a rapid reversal following CPAP withdrawal (65).…”

Vascular responses to hypoxia are not impaired in obstructive sleep apnoea patients free of overt cardiovascular disease

“…elevated diastolic blood pressure and heart rate) can begin to return within 48–72 h (Kohler et al., ; Turnbull et al., ). Moreover, blood pressure and heart rate continue to increase during 1–2 weeks of CPAP withdrawal (Kohler et al., ; Korcarz, Benca, Barnet, & Stein, ). For patients in the oxygen group, their OSA was not treated (i.e.…”

“…Air: OSA patients randomized to receive no OSA treatment for two weeks (n = 26). 2011; Korcarz, Benca, Barnet, & Stein, 2016). For patients in the oxygen group, their OSA was not treated (i.e.…”