Oxidative Stress In Peripheral Blood And State Of Cognitive Function Of Patients With First-episode Schizophrenia

BackgroundOxidative stress exited in schizophrenia,which is one of most important pathogenesis of schizophrenia.Total antioxidant capacity(T-AOC),total superoxide dismutase(T-SOD),Malondialdehyde(MDA),nitric oxide(NO)and C-reactive protein(CRP)are one of most common oxidative stress biomarkers that reflect indirectly the state of oxidative stress and the capacity of antioxidant.For this reason,the further study of peripheral blood oxidative stress biomarkers of first-episode schizophrenia and the further analysis of relation between oxidative stress and cognitive function of first-episode schizophrenia will provide impotent help for the pathogenesis of schizophrenia.Objective1.Test the expression level of peripheral blood oxidative stress biomarkers of first-episode schizophrenia,clear the probably effects of olanzapine on oxidative stress biomarkers,and analyze the relation between oxidative stress and severity of symptoms of schizophrenia.2.Assessing the cognitive function of first-episode schizophrenia before and after olanzapine monotherapy,and finding the relation between oxidative stress and cognitive impairment of schizophrenia,provide theoretical foundation for anti-oxidative stress therapy for schizophrenia.Methods1.Adopt case-control design,including 34 schizophrenia patients based on diagnostic criteria of DSM-IV about schizophrenia.ALL patients were assessed PANSS,TESS and cognitive function before and after treatment.After the 8-week treatments,only 30 patients finished the research.Olanzapine was the only antipsychotics.Age-,sex-marched individuals were included as healthy controls.2.All the participates were collected blood samples 5ml at morning.The blood samples were centrifugal separation and subpackaged.The expression level of T-AOC,T-SOD,MDA and NO were assessed by colorimetry,and enzyme linked5 immunosorbent assay was conducted to measure the level of CRP of schizophrenia.3.Data analysis was conducted by using SPSS 19.0 for Windows.Enumeration dates of patients were analyzed chi-square test.T test were used when the dates were fitted normal distribution while when not-fit the dates were analyzed non-parametric test.Test results were presented as means ± standard deviations(SD).Pearson correlation analysis and Spearman correlation analysis were conducted as finding the potential relations.Results1.At baseline,the T-SOD expression level of first-episode schizophrenia was significant lower than the levels of healthy controls(Z=-3.674,P<0.01),and the NO level of patients was significant higher than health controls(Z=-2.041,P<0.05).None of the peripheral blood oxidative stress biomarkers of patients got significant improvements after 8-week olanzapine monotherapy(P>0.05).2.At baseline,The patients displayed significantly slower than healthy controls in trailing marking test,and they also expressed impairment in cognitive tasks in the symbolic coding test,attention/vigilance,working memory,verbal learning,visual learning and reasoning and problem solving at baseline(P<0.01,P<0.05).After olanzapine monotherapy,the patients displayed significant faster in trailing marking test(t=3.533,P<0.01)than the performance of baseline,and the profile in symbolic coding(t=-2.569,P<0.05)and working memory(t=-2.911,P<0.01)were significantly elevated compared with theirs at baseline.While the performance in the domain of attention/vigilance,verbal learning,visual learning and reasoning and problem solving got no improvement compared with baseline(P>0.05).3.The positive correlation was found between the levels of NO of patients at baseline and the scores of PANSS(r=0.379,P=0.039);there was positive correlation between the change of T-SOD and the change of score of PANSS(r=0.403,P=0.027),and a positive correlation was also found between the change of T-SOD and the change of the score of PANSS positive symptoms(r=0.379,P=0.028).4.The negative correlation was found between the levels of NO and the performance of verbal learning domain(r=-0.379,P=0.039)at baseline,and a negative correlation was also found between the level of CRP and the score the symbolic coding test(r=-0.547,P=0.002)at baseline;with antipsychotics treatments,there wasfound positive correlation between the level of T-AOC and the performance of CPT-IP(r=0.385,P=0.036);a positive correlation was found between the change of T-AOC and change of performance of symbolic coding test(r=0.488,P=0.006).Conclusion1.Oxidative stress biomarkers levels change were found in first-episode schizophrenia,and the change of decreased T-SOD levels and evaluated NO levels may be one of the importantmechanisms of schizophrenia pathogenesis.2.Cognitive impairments were comprehensive and serious in schizophrenia,and olanzapine could partial improved this deficits.3.There was no significant correlation between oxidative stress biomarkers of first-episode schizophrenia and clinical symptoms.A same tropism was found between expression levels of T-SOD and the score of PANSS and the score of PANSS positive symptoms.4.There was no significant correlation between oxidative stress biomarkers of first-episode schizophrenia and cognitive impairment of the patients.A same tropism was found between expression levels of T-SOD and performance of symbolic coding test of first-episode schizophrenia.