title: Evaluation of thiol levels, thiol/disulfide homeostasis and their relation with inflammation in cardiac syndrome X.
abstract: OBJECTIVE
  Cardiac syndrome X (CSX) is characterized by the presence of myocardial ischemia in the absence of coronary artery stenosis on angiograms. Its relation to oxidative stress and inflammation is well known. There are no data on thiols and their relation with inflammation in CSX. The aim of this study was to investigate thiol levels and thiol/disulfide homeostasis in CSX patients.
  
  
  METHODS
  Fifty consecutive patients who had documented myocardial ischemia and normal coronary angiogram (CSX group), and 45 age-matched and sex-matched consecutive patients who had normal coronary angiogram without myocardial ischemia (control group) were enrolled in this study. C-reactive protein (CRP), neutrophil/lymphocyte ratio (NLR), native thiol, total thiol, and disulfide levels were measured and disulfide/thiol ratios were calculated in all patients.
  
  
  RESULTS
  Demographic, clinical, basic laboratory, and echocardiographic characteristics were similar in the two groups (P>0.05). Serum total thiol, native thiol, and disulfide levels decreased significantly in the CSX group compared with the control group (P<0.001). CRP and NLR increased significantly in the CSX group compared with the control group (P<0.001). Although disulfide/native thiol levels increased in the CSX group, this reduction did not reach statistical significance (5.8 vs. 5.5, P>0.05). The reduction of thiols was correlated negatively with CRP and NLR (P<0.001). Although univariate logistic regression analyses showed that serum total and native thiol levels, CRP and NLR were independent predictors for CSX estimation, stepwise multivariate logistic regression analysis showed only total thiol levels as an independent predictor for CSX (odds ratio=0.966, 95% confidence interval: 0.950-0.982, P<0.001). Also, receiver operating characteristic curve analysis showed that serum total thiol values of 338.4 or below could predict the CSX with 86% sensitivity and 84% specificity (area under curve=0.903; 95% confidence interval: 0.842-0.965).
  
  
  CONCLUSIONS
  Serum total thiol levels decreased significantly in CSX and this reduction independently predicted CSX with strong sensitivity and specificity. This suggests that the reduction in thiols along with increased inflammation may play a pathophysiological role in the development of CSX.
authors.affiliation: Departments of aCardiology bBiochemistry, Faculty of Medicine, Harran University cDepartment of Cardiology, Mehmet Akif Inan Training and Research Hospital, Sanliurfa dMus State Hospital, Cardiology Clinic, Mus eDepartment of Biochemistry, Faculty of Medicine, Yildirim Beyazit University, Ankara, Turkey.
authors.forename: Ibrahim H
authors.initials: IH
authors.lastname: Altiparmak
authors.forename: Muslihittin E
authors.initials: ME
authors.lastname: Erkus
authors.forename: Hatice
authors.initials: H
authors.lastname: Sezen
authors.forename: Recep
authors.initials: R
authors.lastname: Demirbag
authors.forename: Zekeriya
authors.initials: Z
authors.lastname: Kaya
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Sezen
authors.forename: Ozgur
authors.initials: O
authors.lastname: Gunebakmaz
authors.forename: Ramazan
authors.initials: R
authors.lastname: Asoglu
authors.forename: Feyzullah
authors.initials: F
authors.lastname: Besli
authors.forename: Salim
authors.initials: S
authors.lastname: Neselioglu
authors.forename: Ozcan
authors.initials: O
authors.lastname: Erel
mesh_terms: D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D017023:Coronary Angiography; D004220:Disulfides / Q000097:blood*; D004452:Echocardiography; D005080:Exercise Test; D005260:Female; D006706:Homeostasis; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000175:diagnosis; D016015:Logistic Models; D008297:Male; D017566:Microvascular Angina / Q000097:blood* / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008875:Middle Aged; D015999:Multivariate Analysis; D055414:Myocardial Perfusion Imaging; D016017:Odds Ratio; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D013438:Sulfhydryl Compounds / Q000097:blood*
chemical_list: D015415:Biomarkers; D004220:Disulfides; D013438:Sulfhydryl Compounds