Association of Cellular Adhesion Molecules and Oxidative Stress with Endothelial Function in Obstructive Sleep Apnea

Objective To evaluate the impact of oxidative stress and cellular adhesion molecules on ischemic reactive hyperemia (IRH) in patients with OSA. Materials and Methods Consecutive patients treated at a sleep laboratory and whose polysomnography showed an apnea hypopnea index (AHI) >= 5 were included in the study. Patients with acute illness receiving vasoactive medications were excluded. Based on their oxygen desaturation index (ODI), subjects were assigned to the mild-moderate (ODI <= 30) or the severe desaturation group (ODI > 30). Then IRH and oxidative stress markers [malondialdehyde (MDA)] and proinflammatory markers (ICAM-1 and P-selectin) were measured. Results Sixty-eight subjects with OSA were included, 31 in the mild-moderate desaturation group and 37 in the severe group. No differences by age, gender and body mass index were observed. The severe desaturation group showed significantly higher values in the AHI, MDA, ICAM-1 and P-selectin (p< 0.005), as well as a worsening of IRH (p= 0.001). Only ICAM-1 (p= 0.019) and P-selectin (p= 0.033) were independently associated with IRH in a multiple-linear regression model. Conclusion Patients with OSA and greater intermittent hypoxia showed worse endothelial function, and higher levels of MDA, ICAM-1 and P-selectin. Nevertheless, ICAM-1 and P-selectin rather than MDA were independently associated with IRH.