Relationship Among Plasma Vascular Endothelial Growth Factor, Plasma Nitric Oxide And Obstructive Sleep Apnea-hypopnea Syndrome

Objective To investigate the role of vascular endothelial growth factor(VEGF) and nitric oxide(NO) in physiopathologic process of obstructive sleep apnea-hypopnea syndrome(OSAHS).Methods All subjects underwent overnight polysomnography. In Experiment 1, plasma concentrations of VEGF were measured by a quantitative enzyme-linked immunoassay technique and plasma levels of NO were measured as plasma nitrites and nitrates in 46 patients with OSAHS(including 26 OSAHS patients with cardiovascular or cerebrovascular diseases, and 20 OSAHS patients without cardiovascular or cerebrovascular diseases) and 30 healthy adults. In Experiment2, 26 OSAHS patients with cardiovascular or cerebrovascular diseases were divided two subgroups, which were classified:"nCPAP acceptors"including patients who accepted nasal continuous positive airway pressure treatment (nCPAP)(n=15)and"nCPAP nonacceptors"including patients who did not accept nCPAP(n=11). VEGF and NO concentrations were compared in each subgroup before and after half-year nCPAP treatment.Results Experiment 1: (1)VEGF concentrations were found to be significantly high in OSAHS patients compared with healthy adults(171.2±65.3 vs 115.0±54.1 pg/ml,P <0.01),and exhibited linear correlations with AHI(r= 0.873, P <0.01),the duration of nocturnal hypoxia( r= 0.504, P <0.01),and the lowest nocturnal oxygen saturation (r=-0.818, P <0.01). Plasma NO levels were lower in OSAHS patients than healthy adults(63.4±23.1 vs 86.3±45.0μmol/L, P <0.05), also exhibited linear correlations both AHI(r= -0.605, P <0.01)and the duration of nocturnal hypoxia( r= -0.388, P <0.01). (2)OSAHS with cardiovascular or cerebrovascular diseases had higher VEGF levels and lower NO levels than those without cardiovascular or cerebrovascular diseases. Experiment 2: A significant decrease in VEGF concentrations and a significant increase...