DISCUSSION
PTE is one of the leading causes of death because of its high morbidity and mortality. If untreated, the mortality rate of up to 30% can be reduced to 3-8% as because of early diagnosis and treatment. Despite technological advances in diagnosis, its symptoms, radiological and laboratory findings are not specific [16, 17]. The incidence of pulmonary embolism increases with age [5]. In our study, we found the mean age of the patient group to be 56.87 ± 16.30 years.
Thiols are sulfur analogs of alcohols, which are formed by bonding a sulfur and hydrogen atom to the carbon atom, containing sulfhydryl (-SH) groups. Albumin and other proteins make up the most of the plasma thiol pool, while the remaining small part is low molecular weight thiols such as cysteine, cysteinyl, glycine, glutathione, homocysteine and gamma-glutamylcysteine. Disulphide (RS-SR) bonds are formed when thiols (R-SH) undergo an oxidation reaction by various oxidants. The disulphide bonds formed can be reduced back to the thiol groups, thus maintaining the dynamic thiol / disulphide balance [7]. There are some studies that show that dynamic thiol disulphide balance is affected in many diseases [8-11, 18]. In the study of Parlak et al. investigating the relationship between thiol/disulphide balance status and HDL cholesterol level with pulmonary embolism, it was reported that native thiol, total thiol and HDL-C values were significantly lower in the patient group compared to the control group. It was reported that % disulphide/native thiol was significantly lower in the control group compared to the patient group. It was reported that there was no significant difference in disulphide level between the patient and the control group [19]. Topuz et al. In the study investigating the prognostic significance of thiol disulphide homeostasis in patients with acute pulmonary thromboembolism, it was found that the mean native thiol level was lower in the pulmonary thromboembolism group, the disulphide level and the % disulphide/total thiol ratio was higher than the control group. Among the limitations of this study, it was stated that the patients had some comorbidities such as diabetes mellitus and atherosclerosis, which can change the thiol disulphide balance [20].
There are a few studies investigating thiol/disulphide balance in PTE patients. Determination of dynamic thiol/disulphide status in diseases where oxidative stress plays a major role in pathogenesis would be important. In our study, we found that native thiol, total thiol, native thiol/total thiol levels in the patient group were significantly lower than the control group. We found that the disulphide, disulphide/native thiol, disulphide/total thiol values were significantly higher in the patient group compared to the control group. The result of native thiol, total thiol and disulphide/native thiol in our study is in parallel with the result of both Parlak et al. and Topuz et al. study. However, although Parlak et al. did not find a significant difference in the level of disulphide between the groups, we found significantly higher disulphide levels in the patient group in our study. In addition, although some comorbidities that would change the thiol disulphide balance were not excluded in the study conducted by Topuz et al., it excluded them from our study. The results we got in our study show that there is a significant difference not only between the patient and control groups, but also between the subgroups of the patients.