【作者】 高爱武；

【导师】 平芬；

【作者基本信息】 河北医科大学 ， 内科学， 2008， 硕士

【摘要】 目的:了解阻塞性睡眠呼吸暂停低通气综合征(obstructive sleep apnea-hypopnea syndrome,OSAHS)及阻塞性睡眠呼吸暂停低通气综合征合并高血压病(obstructive sleep apnea-hypopnea associated hypertension,OSAHS+HT)患者血清8-羟基脱氧鸟苷酸(8-hydroxy-2’-deoxyguanosine, 8-OHdG )和锰超氧化物歧化酶( manganese superoxide dismutase,MnSOD)水平的变化。研究两者与OSAHS及OSAHS+HT的关系,旨在探讨OSAHS及OSAHS+HT患者体内氧化损伤及抗氧化情况,以及8-OHdG和MnSOD在OSAHS+HT的病因、发病机制和病情进展中的作用。方法:随机选择OSAHS患者40例(均为男性),所有患者均有夜间睡眠中打鼾、呼吸暂停及白天嗜睡病史,并经多导睡眠图(polysomnography, PSG)监测确诊,OSAHS的诊断依据中华医学会呼吸病学分会睡眠呼吸疾病学组制定的诊断标准[1],即睡眠呼吸暂停低通气指数(apnea hypopnea index AHI,平均每小时睡眠中的呼吸暂停加上低通气次数)≥5次/h。呼吸暂停指睡眠过程中口鼻呼吸气流均停止10s以上,低通气指睡眠过程中呼吸气流强度较基础水平降低50%以上并伴有血氧饱和度较基础水平下降≥4%。其中无并发症的OSAHS患者20例,年龄29～68(49.40±9.31)岁,体重指数23.11～34.29(29.81±3.38)kg/m2。OSAHS+HT患者20例(均为男性),年龄25～61(43.95±9.17)岁,体重指数22.72～34.60(28.49±3.18)kg/m2,符合OSAHS诊断标准,并达到《中国高血压防治指南》[2]高血压诊断标准,高血压发生晚于OSAHS,且排除肾源性、内分泌性等因素引起的继发性高血压;对照组20例(均为男性),年龄29～67岁(47.55±11.18),体重指数24.02～34.91(28.62±3.27)kg/m2,经询问病史及行Stardust便携式睡眠监测仪初筛检查,排除OSAHS。三组间年龄和体重指数无显著性差异(均p>0.05),并除外吸烟、饮酒、饮食及药物等干扰因素。所有入选者在睡眠呼吸监测结束,晨醒5分钟内抽取空腹静脉血6ml,应用酶联免疫吸附试验检测血清8-OHdG水平,黄嘌呤氧化酶法检测血清MnSOD水平。并记录有关的监测指标,包括睡眠呼吸暂停低通气指数(apnea hypopnea index,AHI)、血氧饱和度(SaO2)<90%占总睡眠时间百分比、睡眠呼吸障碍事件总时间占总睡眠时间百分比、睡眠呼吸障碍事件时最低SaO2及平均最低SaO2、睡眠呼吸障碍事件最长时间。比较正常对照、OSAHS、OSAHS合并HT三组间8-OHdG,MnSOD水平,同时比较OSAHS与OSAHS+HT患者的睡眠呼吸监测指标,三组间8-OHdG,MnSOD比较采用方差分析,两两比较采用q检验。OSAHS与OSAHS+HT患者的睡眠呼吸监测指标比较采用t检验,并将OSAHS、OSAHS+HT患者血清8-OHdG,MnSOD水平与睡眠呼吸监测指标进行直线相关分析。结果:1.血清8-OHdG,MnSOD水平:正常对照组分别为1.50±1.33ng/ml、12.45±5.15U/ml,OSAHS患者组分别为2.69±2.11ng/ml、10.49±6.60U/ml,OSAHS+HT患者组分别为3.16±2.54ng/ml、7.18±4.34U/ml。OSAHS患者与对照组比较,血清8-OHdG水平升高,血清MnSOD水平降低,均有统计学差异(q分别为7.405,3.934;p<0.01,p<0.01)。OSAHS+HT患者与对照组比较血清8-OHdG升高,血清MnSOD水平降低,差异均有显著性(q分别为10.290,10.579;p<0.01,p<0.01)。OSAHS+HT患者组与OSAHS患者组比较,血清8-OHdG升高,血清MnSOD水平降低,差异均有显著性(q分别为2.885,6.644;p<0.01,p<0.01)。2.与OSAHS患者比较,OSAHS+HT患者的睡眠呼吸监测指标AHI升高、SaO2<90%占总睡眠时间百分比,睡眠呼吸障碍事件总时间占睡眠时间百分比升高,均有统计学差异(t分别为2.95,2.18,2.24;p<0.01,p<0.05,p<0.05),睡眠呼吸障碍事件时最低SaO2降低,平均最低SaO2也降低,且差异有显著性(t分别为2.96,2.33,p<0.05,p<0.05);而睡眠呼吸障碍最长时间在两组间无统计学差异(均为p>0.05)。3. OSAHS及OSAHS+HT患者睡眠呼吸各项指标与血清8-OHdG,MnSOD直线相关分析显示:①血清8-OHdG水平与OSAHS、OSAHS+HT患者AHI呈正相关(r=0.974,p<0.01;r=0.765,p<0.01),与SaO2<90%占总睡眠时间百分比呈正相关(r=0.739,p<0.01;r=0.702,p<0.01),与睡眠呼吸障碍事件总时间占睡眠时间百分比呈正相关(r=0.829,p<0.01;r=0.583,p<0.01),与睡眠呼吸障碍事件时最低SaO2呈负相关(r=-0.751,p<0.01;r=-0.560,p<0.05),与平均最低SaO2呈负相关(r=-0.718,p<0.01;r=-0.808,p<0.01)。而与睡眠呼吸障碍最长时间无相关性(r=0.185,p>0.05;r=0.023,p>0.05)。②血清MnSOD水平与OSAHS、OSAHS+HT患者AHI呈负相关(r=-0.806,p<0.01;r=-0.929,p<0.01)。与SaO2<90%占总睡眠时间百分比呈负相关(r=-0.567,p<0.01;r=-0.758,p<0.01),与睡眠呼吸障碍事件总时间占睡眠时间百分比呈负相关(r=-0.738,p<0.01;r=-0.809,p<0.01),与睡眠呼吸障碍事件时最低SaO2正相关(r=0.612,p<0.01;r=0.567,p<0.01),与平均最低SaO2正相关(r=0.518,p<0.05;r=0.742,p<0.01),而与睡眠呼吸障碍最长时间无相关性(r=-0.210,p>0.05;r=-0.099,p>0.05)。结论:1.除外年龄、体重指数等相关因素的影响,并排除吸烟、饮酒、饮食及药物等干扰因素,OSAHS及OSAHS+HT患者血清8-OHdG较正常对照组水平均升高,其升高的水平与AHI及SaO2<90%占总睡眠时间的百分比呈正相关,与睡眠呼吸障碍事件时最低SaO2、平均最低SaO2呈负相关。表明8-OHdG随OSAHS及OSAHS+HT患者的病情加重而增加。血清MnSOD水平在两组患者较正常对照组均降低,降低的水平均与AHI及SaO2<90%占总睡眠时间的百分比呈负相关,与睡眠呼吸障碍事件时最低SaO2及平均最低SaO2呈正相关,表明MnSOD随OSAHS及OSAHS+HT患者的病情加重而降低。表明其随缺氧的加重而降低。2. MnSOD是线粒体中能催化超氧阴离子发生歧化反应的抗氧化酶,其功能主要是清除氧自由基,保护细胞不受损害。MnSOD水平的稳定对于维持细胞的正常生理功能起着重要作用。8-OHdG是活性氧自由基氧化损伤细胞核DNA或线粒体DNA后形成的产物。MnSOD水平在OSAHS+HT患者较OSAHS患者明显降低,而OSAHS+HT患者较OSAHS患者降低更明显。血清8-OHdG水平明显增高,而OSAHS+HT患者较OSAHS患者升高更明显。说明OSAHS患者无论是否合并高血压,均存在氧化应激及氧化损伤。这种氧化应激所造成的损伤在OSAHS+HT患者中更明显。OSAHS患者已经存在氧化失衡,说明OSAHS患者的氧化应激的发生是独立于或先于高血压的发生而发展的,可能为OSAHS患者发生高血压的原因之一。而多项研究表明氧化应激与多种疾病互为因果。而氧化应激的存在可使自由基增多,也可造成内皮损伤,血管收缩,从而引起高血压病的发生。8-OHdG、MnSOD在阻塞性睡眠呼吸暂停低通气综合征患者血中含量的变化可反映病情的严重程度,了解氧化应激的程度,可指导OSAHS的早期治疗及改善其预后。更多还原

【Abstract】 Objectives: To investigate the serum 8-OHdG and serum MnSOD concentrations in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) without complications and in those with obsturctive sleep apnea-hypopnea associated hypertension (OSAHS+HT). To evaluate the relationship between three biochemical parameters and OSAHS and OSAHS+HT in order to explore the change of oxidant stress and oxidative DNA damage in patients with OSAHS and OSAHS+HT. To study the role of serum 8-OHdG and serum MnSOD in the pathogenesis and progress of OSAHS+HT.Methods: Forty males with OSAHS were included randomly in the study and twenty age-matched and body mass index (BMI) -matched healthy men served as control subjects. OSAHS patients with nocturnal snoring, apnea and excessive daytime sleepiness syndrome and control subjetcs without those syndromes underwent overnight polysomnography (PSG) and portal sleep apnea monitoring, respectively. Inclusion criteria for the present study were apnea-hypopnea index (AHI)≥5/h for OSAHS patients and AHI<5/h for control subjects. Apnea was defined as an absence of airflow for≥10s, and hypopnea was defined as a reduction of airflow associated with a reduction of oxygen saturation by 4% from baseline. The AHI was defined as the average of apneic and hypopneic events per sleep hour. All patients with OSAHS were divided into two subgroups:20 OSAHS patients without complications (age= 49.40±9.31, BMI=29.81±3.38kg/m2) and 20 OSAHS+HT patients (age =43.95±9.17, BMI=28.49±3.18kg/m2). Occurrence of hypertension was later than that of OSAHS in patients with OSAHS+HT. Other secondary hypertension (such as renovascular and endocrinic hypertension) were excluded in OSAHS+HT patients. There were no significant differences in age and BMI among control subjects (age=47.55±11.18, BMI=28.62±3.27kg/m2), OSAHS and OSAHS+HT subjects. Smoking, drinking, diets, drugs and other disturbance factors were excluded in this study. Fasting venous blood were obtained from all observed subjects after sleep-breathing monitoring within the following 5 minutes in the next morning. The serum 8-OHdG concentrations were measured by ELISA, the serum MnSOD contents were detected by xanthine oxidase method, respectively. Differences in serum 8-OHdG and MnSOD among three groups were assessed by using one-way analysis of variance and further multiple comparisons were performed with SNK-q test. Sleep-breathing parameters of patients with OSAHS without complications were compared with those of patients with OSAHS+HT by using student’s two- tailed t test. Furthermore, linear correlations were performed between three biochemical parameters and sleep-breathing parameters of patients with OSAHS and OSAHS+HT, respectively.Results: 1. the serum 8-OHdG and serum MnSOD concentrations were 1.50±1.33ng/ml、12.45±5.15U/ml in control subjects, were 2.69±2.11ng/ml、10.49±6.60U/ml,in patients with OSAHS and 3.16±2.54ng/ml、7.18±4.34 U/ml in patients with OSAHS+HT, respectively. The serum 8-OHdG concentrations were higher, serum MnSOD concentrations were lower in patients with OSAHS compared with those in control subjects. There were statistical significances (q=7.405, 3.934, respectively; p<0.01). There were similar results in patients with OSAHS+HT compared with those in control subjects and significant differences were found (q=10.290, 10.579, respectively; p<0.01). Compared with OSAHS patients, there was a decreased trend of serum MnSOD concentrations in the patients with OSAHS+HT, but this difference reached statistical significance (q=2.885, 6.644, respectively; p<0.01). 2. Compared with OSAHS patients, both AHI and percentage of sleep time below 90% oxygen saturation (SaO2<90%) and percentage of sleep time the total duration of apnea/hyponea were higher in OSAHS+HT patients (t=2.95, 2.18, 2.24, repectively; p<0.01), both the lowest SaO2 and average the lowest SaO2 were lower in OSAHS+HT patients (t=2.96, p<0.05; t=2.33, p<0.05). But there were no differences in the longest duration of apnea/hypopnea between two subgroups(p>0.05). 3. The linear correlations were found between three biochemical parameters and sleep-breathing parameters in patients with OSAHS and OSAHS+HT as follows:①The serum 8-OHdG levels were correlated positively with AHI both in OSAHS and OSAHS+HT patients (r=0.974, p<0.01; r=0.765, p<0.01), were correlated positively with SaO2<90% (r=0.739, p<0.01; r=0.702, p<0.01), were correlated positively with percentage of sleep time the total duration of apnea/hyponea (r=0.829, p<0.01; r=0.583, p<0.01), were correlated negatively with the lowest SaO2 (r=-0.751, p<0.01; r=-0.560, p<0.05) and were correlated negatively with average the lowest SaO2 (r=-0.718, p<0.01; r=-0.808, p<0.01). The correlations were not found between the longest dutation of apnea/hypopnea and levels of three biochemical parameters in patients with OSAHS and OSAHS+HT. (r=0.185, p>0.05; r=0.023, p>0.05).②The correlations between serum MnSOD and sleep-breathing parameters were not as same as those of 8-OHdG. MnSOD levels levels were correlated negatively with AHI both in OSAHS and OSAHS+HT patients (r=-0.806, p<0.01; r=-0.929, p<0.01), were correlated negatively with SaO2<90% both in OSAHS and OSAHS+HT patients (r=-0.567, p<0.01; r=-0.758, p<0.01), were correlated negatively with percentage of sleep time the total duration of apnea/hyponea (r=-0.738, p<0.01; r=-0.809, p<0.01), were correlated positively with the lowest SaO2 (r=0.612, p<0.01; r=0.567, p<0.01), and were correlated positively with average the lowest SaO2 (r=0.518, p<0.05; r=0.742, p<0.01). And there were no correlations with the longest dutation of apnea/hypopnea (r=-0.210, p > 0.05; r=-0.099, p>0.05).Conclusions: 1. Despite controlling for age, BMI and excluding disturbance factors such as smoking, drinking, diets and drugs, the resum 8-OHdG concentrations in patients with OSAHS and OSAHS+HT were higher than those in control subjects. The resum 8-OHdG levels were correlated positively to both AHI and SaO2<90% and were correlated negatively to both the lowest SaO2 and average the lowest SaO2 . which showed a strong correlation between 8-OHdG increasing with the degree of hypoxemia. Both the MnSOD levels in patients with OSAHS and OSAHS+HT were lower than those in control subjects. MnSOD levels were correlated negatively to AHI and SaO2<90% and correlated positively to the lowest SaO2 and average the lowest SaO2 , which showed a strong correlation between MnSOD reducing with the degree of hypoxemia. 2. MnSOD,as an important antioxidant enzyme in mitochondria,which can catalyze the dismutation of superoxide ion,and protect the cells from oxidative damage.It is important that the stable level of MnSOD maitaining the normal physiology function of the cells. The content of 8-hydroxydeoxyguanosine (8-OHdG) by which the cellular DNA damage caused by active oxygen species. The serum MnSOD contents in patients with OSAHS+HT was lower than those in patients with OSAHS. The serum 8-OHdG contents in patients with OSAHS+HT was higher than those in patients with OSAHS.Our study demonstrated the change of oxidative /anti- oxidative imbalance between oxidative stress and oxidative DNA damage in patients with OSAHS no matter with or without hypertension. The imbalance of oxidative /anti- oxidative was more obvious in patients with OSAHS+HT. Our study documents the existence of oxidative damage in OSAHS, which suggests that important oxidative stress of OSAHS occur independent of , and possibly prior to, the development of systemic hypertension. Several studies showed oxidative stress was significantly correlated with many of disease. The information of the severity of sleep disordered breathing and the degree of oxidative stress can be obtained by measuring the change of two biochemical parameters, which has important value to advice the early treatment and to improve the prognosis.更多还原