الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 158 |  |  |
| | | from | 158 | | |
Abstract
Background: OSA is a chronic disorder that leads to many CVD including hypertension, arrhythmias and CHF. PSG is the gold method for detection of OSA, even though up to 93% of women and 82% of men with moderate-severe OSA still remain undiagnosed due to delayed recognition of OSAS symptoms by general practitioners. CPET has been conventionally used for evaluation of CAD and rehabilitation of the cardiac patients. Modern systems analyze gas exchange at rest, during exertion, and recovery and also yield measures of VO2, VCO2, and VE together with heart rate, blood pressure, electrocardiography findings, and symptoms. This may have clinical utility if used with the available screening tools used to diagnose OSA.
Aim of study: To assess altered ventilatory response and HRR in exercise in subjects with obstructive sleep apnoea and their correlation with severity.
Methods: Case control study was enrolled including 30 patients with obstructive sleep apnoea divided according to its severity (5 mild, 8 moderate and 17 severe) and 15 control healthy overweight with sedentary lifestyle individuals. The two groups underwent cardiopulmonary exercise testing and different pulmonary and circulatory parameters were calculated.
Results:
• STOPBANG questionnaire and ESS are considered good tools for OSA screening.
• Increased OSA severity mostly combined with lower minimal O2 saturation and more cardiovascular system complications.
• OSA, results in impaired ventilatory efficacy to graded exercise testing, reflected by significantly greater VE, VE/VCO2, and VE/VO2 measures across submaximal exercise and peak exercise.
• Exaggerated VE/VCO2 slope and its relation to OSA severity is a marker of chemoreflex sensitivity and is a potent predictor of poor prognosis for OSA complications.
• Subjects with OSA had reduced maximal exercise capacity, BR and VO2 at AT compared with control healthy sedentary overweight individuals.
• Subjects with OSA have an autonomic dysfunction expressed as delayed HRR and weaker CR.
• Peak O2 pulse is an indicative measure of stroke volume and a low O2 pulse in subjects with OSA indicates the limited ability to increase stroke volume during exercise.
• Elevated BP response present in subjects with OSA is due to elevated sympathetic tone and reduced NO release from endothelium as a consequence of repeated obstructive events present in subjects with OSA.
According to above results, CPET could be used as a clinical utility for early detection of OSA outcomes.