Positive Airway Pressure Betters Endothelial Dysfunction
CPAP improves endothelial function and myocardial perfusion in obstructive sleep apnea
TUESDAY, July 12 (HealthDay News) -- Continuous positive airway pressure (CPAP) mostly reverses endothelial dysfunction and impaired myocardial perfusion in healthy individuals with obstructive sleep apnea (OSA), according to a study published online July 11 in Hypertension.
Mehmood Butt, M.D., M.B.B.S., from the University of Birmingham Centre for Cardiovascular Sciences in the United Kingdom, and colleagues investigated myocardial perfusion using real-time quantitative myocardial contrast echocardiography with simultaneous assessment of macro and microvascular endothelial dysfunction, and studied the effects of CPAP on OSA. The results were matched between three groups, each with 36 participants: individuals with moderate-to-severe OSA, individuals with hypertension, and healthy controls. Parameters included brachial artery flow-mediated dilation and response to glyceryl trinitrate measured by ultrasound, cutaneous perfusion responses to acetylcholine and sodium nitroprusside measured by laser Doppler, pulse wave velocity, and circulating endothelial and endothelial progenitor cells.
The investigators found that, compared to healthy participants, those in the OSA and hypertension groups had abnormal myocardial perfusion, attenuated brachial artery reactivity, and cutaneous perfusion responses. However, after 26 weeks of CPAP therapy there were significant improvements in these functions in both groups. Significant differences in pulse wave velocity and endothelial cells were not seen across the three groups.
"Concomitant endothelial dysfunction and impaired myocardial perfusion are present in otherwise normal subjects with moderate-to-severe OSA, and effective CPAP treatment reverses many of these macrovascular/microvascular abnormalities," the authors write.
The SonoVue contrast agents used in the study were provided by Bracco Research.