Relationship between oxidative stress and endothelial cell apoptosis in patients with obstructive sleep apnea-hypoventilation syndrome

Abstract

Objective To study the relationship between oxidative stress and endothelial cell apoptosis in patients with obstructive sleep apnea-hypoventilation syndrome (OSAHS). Methods Sixth-seven patients definitely diagnosed by potysomnography (PSG) as OSAHS were divided into three groups according to their apnea-hypoventilation index (AHI), 14 in mild group (5 < AHI≤20), 21 in moderate group (20 < AHI≤40) and 32 in severe group (AHI 40). And, 18 healthy persons (AHI <5) were recruited as controls. Blood samples were obtained form all of them after PSG performance for measuring apoptotic endothelial cells (CD146AnnV+) and serum levels of superoxide dismutase (SOD) and malondialdehyde (MDA). Results Serum level of MDA and CD146AnnV+ in moderate and severe OSAHS group were significantly higher than those in control group (all P < 0.05). Serum level of SOD in moderate and severe OSAHS group was significantly lower than that in control group (P < 0.05). CD146AnnV+ correlated positively with AHI, the longest apnea time (LAT) and oxygen desaturation index (ODI) (r = 0.778, 0.609 and 0.689, respectively, all P < 0.05) and correlated reversely with saturation of arterial blood oxygen at night (SaO2min) (r =-0.635, P < 0.01). CD146AAnnV+ correlated positively with serum level of MDA (r = 0. 698, P < 0.01), and correlated reversely with serum level of SOD (r =-0.705, P < 0.01). Results of linear multivariate regression analysis showed that AHI, serum levels of SOD and MDA were independent risk factors for endothelial cells apoptosis in patients with OSAHS. Conclusions There existed oxidative stress due to intermittent hypoxia in patients with OSAHS, which could be one of the major causes in exacerbating endothelial damage. Key words: Sleep apnea-hypopnea, obstructive; Vascular endothelial cell; Apoptosis; Oxidative stress