Thiol/Disulfide Homeostasis and Ischemia-Modified Albumin Levels in 61 Patients with Hypercapnia: A Case-Control Study

Abstract

Background: Hypercapnia is abnormally high arterial partial pressure of carbon dioxide (CO2). CO2 can affect redox signaling mechanisms, leading to production of oxidative derivatives. Thiol is formed by attaching a sulfhydryl group to a carbon atom. Under oxidative stress, it forms covalent bonds called thiol disulphide bonds. Serum albumin is modified to ischemia-modified albumin (IMA) by exposure to free radicals. This case-control study aimed to evaluate thiol/disulphide homeostasis and IMA levels in 61 patients with hypercapnia. Material/Methods: We studied 61 patients with hypercapnia and 61 normocapnic volunteers in the control group, between May 2018 and January 2019; 56 of these patients were diagnosed with chronic obstructive pulmonary disease and 5 of them were diagnosed with obstructive sleep apnea syndrome. Arterial blood samples analyzed by using the Ellman reagent for thiol/disulphide data. A colorometric assay was used for detection of IMA levels. Results: Native thiol and total thiol values in the hypercapnic group were significantly lower than in the control group (P=0.024, P=0.006 respectively), as IMA values were significantly higher (P<0.001). There was no statistically significant difference between the hypercapnic and control groups in terms of disulphide, disulphide/native thiol, disulphide/total thiol, and native thiol/total thiol values (P>0.05). Conclusions: In hypercapnic patients, there are changes in thiol/disulphide homeostasis and IMA levels. All significant differences in this study support that changes in thiol disulphide homeostasis and IMA in hypercapnic patients are indicators of oxidative stress.