Study On The Correlation Between Serum Catalase,Glutathione Peroxidase,Lipid Peroxidation Levels And OSAHS,OSAHS Associated Hypertension

Objectives: To investigate the serum catalase (CAT),glutathione peroxidase(GSH-PX),lipid peroxidation(LPO) levels in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) without complications and in those with obsturctive sleep apnea-hypopnea syndrome associated hypertension (OSAHS+HT). The concentration of malonaldehyde(MDA) represent the LPO level. To evaluate the relationship between the three biochemical parameters and OSAHS and OSAHS+HT in order to explore the change of oxidant stress in patients with OSAHS and OSAHS+HT. To study the role of serum CAT, GSH-PX, LPO levels in the pathogenesis and progress of OSAHS and OSAHS+HT.Methods: 45 males with OSAHS were included randomly in the study , who were made a diagnosis by using polysomnography (PSG) ,the standard of diagnosis according to diagnostic standard formulated by group of sleep-breath disease to chinese medical association.All patients with OSAHS were divided into two subgroups: 24 OSAHS patients without complications (age=45.17±7.05,BMI=28.36±2.82kg/m2)and 21 OSAHS+HT patients(age=49.95±9.08,BMI=28.76±3.55 kg/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 are 23 males in control subjects (age=47.00±10.98,BMI=27.15±2.67 kg/m2),who were excluded OSAHS and HT, there are no significant differences in ages and BMI among control, OSAHS and OSAHS+HT subjects. Smoking, drinking, diets, drugs and other disturbance factors were excluded in this study. All observed subjects in this study were excluded infection ,Liver and nephridium disease ,rheumatic disease,cerebrovacular,malignancy diabetes mellitus,coronary heart disease and other diseases which can affect the serum catalase, glutathione peroxidase, lipid peroxidation levels .Fasting venous blood were obtained from all observed subjects after sleep-breathing monitoring within the following 5 minutes in the next morning. The serum catalase level were measured by visible radiation method , the serum GSH-PX level were detected by colorimetric method, The MDA were detected by thibabituric acid, respectively.and record the sleep-breathing parameters ,including apnea hypopnea index (AHI) , percentage of sleep time below 90% oxygen saturation (SaO2﹤90%), percentage of sleep time the total duration of apnea/hypopnea,the lowest SaO2 ,average lowest SaO2 and the longest duration of apnea/hypopnea.Differences in serum catalase,glutathione peroxidase,malonaldehyde 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 catalase,glutathione peroxidase,malonaldehyde levels:1.1 the serum catalase level:in control subjects were 62.33±7.28U/ml, in patients with OSAHS were 53.13±5.54 U/ml ,in patients with OSAHS+HT were 47.61±6.58 U/ml.1.2 the serum GSH-PX level: in control subjects were118.82±24.47U, in patients with OSAHS were 98.73±20.58U,in patients with OSAHS+HT were 84.86±14.58 U.1.3 the MDA concentration: in control subjects were 4.13±0.44 nmol/L, in patients with OSAHS were 5.66±0.87 nmol/L,in patients with OSAHS+HT were 6.22±0.82 nmol/L.The serum CAT,GSH-PX level were lower, serum MDA concentrations were higher in patients with OSAHS compared with those in control subjects. There were statistical significances. There were similar results in patients with OSAHS+HT compared with those in control subjects and in patients with OSAHS+HT compared with OSAHS patients(p<0.01, respectively).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=3.4,2.32,2.26;p <0.01,p<0.05,p<0.05), both the lowest SaO2 and average the lowest SaO2 were lower in OSAHS+HT patients (t=2.38,2.21;p<0.05,p<0.05). But there were no differences in the longest duration of apnea/hypopnea between two groups(t=1.36 ,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: The serum MDA levels were correlated positively with AHI,percentage of sleep time SaO2<90%,percentage of sleep time the total duration of apnea/hyponea both in OSAHS and OSAHS+HT patients ,were correlated negatively with the lowest SaO2 and average the lowest SaO2. The correlations were not found between the longest dutation of apnea/hypopnea and MDA. The correlations between serum CAT,GSH-PX and sleep-breathing parameters were not as same as those of MDA evels , were correlated negatively with AHI,percentage of sleep time SaO2<90%,percentage of sleep time the total duration of apnea/hyponea both in OSAHS and OSAHS+HT patients, were correlated positively with the lowest SaO2 and average the lowest SaO2. And there were no correlations with the longest dutation of apnea/hypopnea.Conclusions: 1. Despite controlling for age, BMI and excluding disturbance factors such as smoking, drinking, diets and drugs, the resum MDA concentrations in patients with OSAHS and OSAHS+HT were higher than those in control subjects. Both the rusum CAT,GSH-PX levels in patients with OSAHS and OSAHS+HT were lower than those in control subjects,which indicated that there are oxidative stress and oxidative damage in OSAHS patients no matter with or without hypertension, and oxidative damage happened independent of , and possibly prior to hypertension.2. The serum CAT and GSH-PX levels in patients with OSAHS+HT was lower than those in patients with OSAHS. The serum MDA contents in patients with OSAHS+HT was higher than those in patients with OSAHS. The damage caused by the imbalance of oxidative /anti- oxidative was more obvious in patients with OSAHS+HT,oxidative stress may be one of the reasons caused hypertension in OSAHS patients.3. compared with sleep-breathing parameters, the severity and degree of hypoxemia in patients with OSAHS+HT were more seriously than OSAHS patients.4. The resum MDA levels were correlated positively to both AHI , percentage of sleep time SaO2<90% and percentage of sleep time the total duration of apnea/hyponea . The resum MDA level were correlated negatively to both the lowest SaO2 and average the lowest SaO2 . which showed a strong correlation between MDA increasing with the degree of hypoxemia. And indicated that there was a strong correlation between the change of MDA and the severity of OSAHS and OSAHS+HT.CAT,GSH-PX levels were correlated negatively to AHI and SaO2<90% and percentage of sleep time the total duration of apnea/hyponea ,the resum CAT,GSH-PX levels correlated positively to the lowest SaO2 and average the lowest SaO2 , which showed a strong correlation between CAT,GSH-PX reducing and the degree of hypoxemia. And the severity of OSAHS and OSAHS+HT.Our study demonstrated the change of oxidative /anti- oxidative imbalance in patients with OSAHS and OSHAS+HT,and it is more obvious in patients with OSHAS+HT.The information of the severity of sleep disordered breathing and the degree of oxidative stress can be obtained by measuring the change of the three biochemical parameters, which has important value to advice the early treatment and to improve the prognosis.