0883 Examination of Changes in Arterial Stiffness with Exercise in Overweight or Obese Patients with and without Obstructive Sleep Apnea

Abstract

Introduction: Increased arterial stiffness is a precursor of atherosclerosis and is observed in obstructive sleep apnea (OSA) patients without overt cardiovascular disease. Exercise confers cardioprotection by mitigating arterial stiffness. Regular exercise is recommended as a lifestyle treatment option in clinical guidelines for OSA. We hypothesized that improvements in arterial stiffness typically seen with exercise would be attenuated in overweight/obese adults with more severe OSA compared to those without OSA. Method(s): Participants underwent overnight polysomnography to determine the presence of OSA. Tertile-based cut-off points were used to categorize nocturnal O2 saturation (meanSpO2) and apnea hypopnea index (AHI). Total body fat was measured using dual energy X-ray absorptiometry. Arterial stiffness and wave reflection (AIx), were derived from a standard brachial cuff before and upon completion of a 6-week (3 sessions/week, 1 hour/session) exercise- training program. Result(s): Thirty-two (age: 51 +- 8 years; BMI: 33.0 +- 4.6 kg/ m2; 19 men: 13 women) adults with and without OSA completed the study. At baseline, AIx was significantly higher among those in the lowest tertile of meanSpO2 compared to those in the highest tertile (44 +- 7 % vs. 28 +- 11 %, p<0.05). No significant differences in AIx were observed across tertiles of AHI or total body fat. Spearman's correlation analysis revealed a negative relation between AIx and meanSpO2 (rho=-0.53, p<0.05), but not with AHI (rho=0.13, p=0.46). Exercise training did not alter AIx of the cohort (Baseline: 39 +- 12 % vs. Follow up: 37 +- 12 %, p=0.21). Moreover, no significant changes in AIx or total body fat were observed with exercise within tertiles of meanSpO2. Conclusion(s): Our data indicate that sleep-related hypoxemia (based on meanSpO2), but not sleep fragmentation, may be a more influential factor for increasing arterial stiffness. However, our exercise intervention did not alter AIx, suggesting no adverse or beneficial affect on arterial stiffness. The implication of exercise programs of longer duration on the vascular health of overweight/obese patients with and without OSA should be comprehensively examined.