Is disulphide/thiol ratio related to blood pressure in masked hypertension?

Differential Modulation of Markers of Oxidative Stress and DNA Damage in Arterial Hypertension

Patients with arterial hypertension have an increased risk of developing tumors, particularly renal cell carcinoma. Arterial hypertension is linked to DNA damage via the generation of oxidative stress, in which an upregulated renin-angiotensin-aldosterone system plays a crucial role. The current study investigated surrogates of oxidative stress and DNA damage in a group of hypertensive patients (HypAll, n = 64) and subgroups of well (HypWell, n = 36) and poorly (HypPoor, n = 28) controlled hypertensive patients compared to healthy controls (n = 8). In addition, a longitudinal analysis was performed with some of the hypertensive patients. Markers for oxidative stress in plasma (SHp, D-ROM, and 3-nitrotyrosine) and urine (8-oxodG, 15-F2t-isoprostane, and malondialdehyde) and markers for DNA damage in lymphocytes (γ-H2AX and micronuclei) were measured. In HypAll, all markers of oxidative stress except malondialdehyde were increased compared to the controls. After adjustment for age, this association was maintained for the protein stress markers SHp and 3-nitrotyrosine. With regard to the markers for DNA damage, there was no difference between HypAll and the controls. Further, no significant differences became apparent in the levels of both oxidative stress and DNA damage between HypWell and HypPoor. Finally, a positive correlation between the development of blood pressure and oxidative stress was observed in the longitudinal study based on the changes in D-ROM and systolic blood pressure. In conclusion, we found increased oxidative stress in extensively treated hypertensive patients correlating with the level of blood-pressure control but no association with DNA damage.

The relationship between adjuvant chemotherapy and thiol-disulfide compounds

Aim

Thiols are the organic compounds of the antioxidant system. There is limited data in the literature concerning chemotherapy (CT) in cancer and thiol balance. In this study, we aimed to evaluate the possible changes of thiol/disulfide levels with the recurrent CT cycles and type of cancer.

Materials and Methods

The 40 healthy individuals and 40 patients who had been newly diagnosed with early-stage breast, ovary and endometrium cancer receiving adjuvant CT. Blood samples were taken from all patients three times as basal and after the first and second CT sessions.

Results

We compared preadjuvant treatment levels of thiol and disulfide parameters in the patients group with the control group. The median of native thiol and total thiol was found to be higher in the control group than in the study group (P < 0.001). In addition, disulfide/native thiol and disulfide/total thiol rates were found to be higher in the patient group (P = 0.001). When we look at the comparison before and after CT in the patient group, disulfide/native thiol and disulfide/total thiol rates, which represent increased oxidative stress (OS) levels were found to be higher after CT than before CT measurement (P < 0.016).

Discussion

This is the first study, which has researched the relationship between cancer type and thiol compounds and changes of thiol compounds during CT therapy, by using the method designed by Erel and Neşelioğlu. In this study, we found that pre-CT thiol disulfide balance in cancer patients shifted toward disulfide direction and OS levels may increase after repetitive CT sessions.

Dynamic thiol/disulphide balance in patients undergoing hypotensive anesthesia in elective septoplasties

OBJECTIVE

We aimed to investigate the effects of hypotensive anaesthesia on oxidative stress with serum thiol/disulphide balance in patients undergoing elective septoplasty procedures under general anaesthesia.

METHODS

Seventy-two patients between the ages of 18-60, with a physical condition I -II, according to the American Society of Anesthesiologists, were included in this prospective observational study. Septoplasty was chosen for standard surgical stress. According to the maintenance of anaesthesia, patients were divided into the groups as Hypotensive Anaesthesia (n = 40) and Normotensive Anaesthesia (n = 32). Serum thiol/disulphide levels were measured by the method developed by Erel & Neşelioğlu.

RESULTS

The native thiol and total thiol values of both groups measured at the 60th min intraoperatively were significantly lower than the preoperative values (both P < .01). Intraoperatively, at the 60th min, there was no significant difference in terms of post-native thiol and post-total thiol levels between hypotensive and normotensive anaesthesia groups (P = .68 and .81, respectively). Age >40 years and female gender were found to have a significant effect on dynamic oxidative stress (P = .002 and .001, respectively).

CONCLUSION

This pilot study has found that hypotensive anaesthesia had no adverse effect on dynamic thiol/disulphide balance in elective surgeries.

The association of dynamic thiol-disulphide balance with white-coat hypertension

OBJECTIVE

Dynamic thiol-disulphide homeostasis is an indicator of the antioxidant system that interacts early with the oxidative environment. This study aimed to assess the dynamic thiol/disulphide balance in individuals with white-coat hypertension (WCH).

METHODS

This cross-sectional study included a total of 117 individuals who presented to our outpatient cardiology clinic. Seventy patients were diagnosed with WCH. All blood samples were obtained from the patients after a minimum of 8 h of fasting, centrifuged immediately, stored in Eppendorf tubes, and protected at -80°C.

RESULTS

The two groups were well-balanced in terms of age, gender, and BMI. Native thiol and total thiol levels were lower in the WCH group than in normotensive individuals. However, disulphide levels were higher in the former. Serum disulphide concentration positively correlated with 24-h SBP, and 24-h DBP. In backward stepwise logistic regression analysis, serum disulphide [odds ratio (OR) = 1.165 (1.089-1.245), 95% confidence interval (CI), P < 0.001] and serum total thiol levels [OR = 0.992 (0.984-1.000), 95% CI, P = 0.050] were independently associated with WCH.

CONCLUSION

We demonstrated that dynamic thiol/disulphide balance shifted strongly towards disulphide formation due to thiol oxidation in patients with WCH.

Altered thiol/disulfide homeostasis and ischemia-modified albumin levels in children with irritable bowel syndrome

BACKGROUND

In this study, we assessed thiol/disulfide homeostasis (TDH) parameters and ischemia-modified albumin (IMA) levels in children with irritable bowel syndrome (IBS) compared with healthy children.

METHODS

Fifty-six children with IBS and 53 healthy children were included in the study after assessment of inclusion and exclusion criteria. Plasma thiol/disulfide and IMA levels were compared between children with and without IBS.

RESULTS

The mean values of native thiol, total thiol, and disulfide were 343.779 ± 138.654 μmol/L, 365.398 ± 140.148 μmol/L, and 23.190 ± 4.978 μmol/L, respectively, in the IBS group and 409.908 ± 69.288 μmol/L, 433.481 ± 76.891 μmol/L, and 20.090 ± 4.252 μmol/L, respectively, in the control group. Native thiol and total thiol values were significantly reduced in the IBS group compared with the control group. The mean IMA values were 0.835 ± 0.083 (g/L) and 0.778 ± 0.072 in the IBS and control groups, respectively. The IMA value was significantly increased in the IBS group.

CONCLUSION

Impaired thiol/disulfide homeostasis and increased IMA levels can be considered etiological factors in children with IBS.

Thiol-disulfide homeostasis: an integrated approach with biochemical and clinical aspects

Dynamic thiol-disulfide homeostasis (TDH) is a new area has begun to attract more scrutiny. Dynamic TDH is reversal of thiol oxidation in proteins and represents the status of thiols (-SH) and disulfides (-S-S-). Organic compounds containing the sulfhydryl group is called thiol, composed of sulfur and hydrogen atoms. Disulfides are the most important class of dynamic, redox responsive covalent bonds build in between two thiol groups. For many years, thiol levels were analyzed by several methods. During last years, measurements of disulfide levels have been analyzed by a novel automated method, developed by Erel and Neselioglu. In this method, addition to thiol (termed as native thiol) levels, disulfide levels were also measured and sum of native thiol and disulfide levels were termed as total thiol. Therefore, TDH was begun to be understood in organism. In healthy humans, TDH is maintained within a certain range. Dysregulated dynamic TDH has been implicated several disorders with unknown etiology. A growing body of evidence has demonstrated that the thiol-disulfide homeostasis is involved in variety diseases, such as diabetes mellitus, hypertension, nonsmall cell lung cancer, familial Mediterranean fever (FMF), inflammatory bowel diseases, occupational diseases, gestational diabetes mellitus and preeclampsia. These results may elucidate some pathogenic mechanism or may be a predictor indicating diagnostic clue, prognostic marker or therapeutic sign. In conclusion, protection of the thiol-disulfide homeostasis is of great importance for the human being. Evidence achieved so far has proposed that thiol-disulfide homeostasis is an important issue needs to elucidate wholly.

Relationship between elevated bilirubin level and subclinical atherosclerosis as well as oxidative stress in Gilbert syndrome

Aim:

This study aimed to determine oxidant status and left ventricular mass index (LVMI) and their relationship with mild hyperbilirubinemia in patients with Gilbert syndrome (GS).

Background:

Gilbert syndrome (GS) presents with mild indirect hyperbilirubinemia, normal liver function tests, and normal hepatic histology.

Methods:

A total of 84 patients, including 41 (48.8%) patients with GS and 43 (51.2%) patients without GS, were included in the study. Total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were examined for oxidant status.

Results:

TAS was found to be higher in the GS patients compared to the non-GS patients (1.7±0.1 vs. 1.5±0.2; p=0.002); there was no significant difference between the groups in terms of mean TOS and mean OSI (p>0.05). No significant difference was observed either between the GS and non-GS patients in terms of mean left ventricular volume and mean LVMI (p>0.05). However, subgroup analysis based on sex revealed that GS patients had a lower LVMI for both sexes. In GS patients, TAS level had a positive correlation with albumin (r=0.319; p=0.042), triglyceride (r=0.392; p=0.011), total bilirubin (r=0.420; p=0.006), direct bilirubin (r=0.361; p=0.020), and indirect bilirubin (r=0.338; p=0.0311) levels; no correlation was found between TAS level and other laboratory findings (p>0.05). The regression model indicated that risk factors of direct bilirubin (β±SE=0.13±0.03; p<0.001), uric acid (β±SE=0.04±0.01; p=0.001), and albumin (β±SE=0.17±0.04; p<0.001) were independent predictors of TAS level.

Conclusion:

This study revealed a relationship between mild hyperbilirubinemia and antioxidant balance in GS. Although statistical significance was not reached, LVMI was found to be lower in the GS group compared to the non-GS group for both sexes.

Thiol/disulfide homeostasis and ischemia modified albumin levels in autoimmune gastritis and their relations with gastric emptying

Background/aim

Autoimmune gastritis is an autoimmune and inflammatory disorder. The aim of this study is to examine dynamic thiol/disulfide homeostasis and ischemia modified albumin levels, and to analyze the association between thiol/disulfide homeostasis and gastric emptying time in autoimmune gastritis.

Materials and methods

Thiol/disulfide homeostasis tests and ischemia modified albumin levels were determined in 50 autoimmune gastritis patients and 53 healthy subjects. Patients with delayed and normal gastric emptying were compared by thiol/disulfide homeostasis tests.

Results

The results showed that native thiol (μmol/L), total thiol (μmol/L), and native thiol/total thiol ratio (%) of the patients with autoimmune gastritis decreased compared to the control group (177.7 ± 34.18 vs. 245.25 ± 33.83, P = 0.001, 227.25 ± 36.78 vs. 284.20 ± 27.19, P = 0.03, and 8.84 ± 1.1 vs. 7.74% ± 1.3%, P = 0.001). In addition, native thiol (μmol/L), total thiol (μmol/L), and native thiol/ total thiol ratio (%) were found to be lower in patients with delayed gastric emptying (198.65 ± 24.27 vs. 167.12 ± 20.51, 241.81 ± 27.14 vs. 213.92 ± 26.35, 8.34 ± 1.29 vs. 7.20 ± 1.83, P = 0.001). Disulfide level, disulfide/native thiol, disulfide/total thiol (P = 0.001) ratios, and ischemia modified albumin levels (ABSU, 0.71 ± 0.08 vs. 0.83 ± 0.07) were found to be higher in autoimmune gastritis patients with delayed gastric emptying (P = 0.001).

Conclusion

The results showed that thiol/disulfide homeostasis in patients with autoimmune gastritis caused an increase in ischemia modified albumin and disulfide whereas a decrease in thiols. An altered thiol/disulfide balance was also observed in patients with delayed gastric emptying. These results suggest that the oxidative process is involved in patients with autoimmune gastritis.

The effect of newly initiated exercise training on dynamic thiol / disulphide homeostasis in sedentary obese adults

We studied dynamic thiol/disulphide homeostasis, an indicator of oxidative stress, to investigate the effects of newly initiated exercise training on sedentary obese adults. Seventeen sedentary obese adults and 15 normal-weight controls were included in the sample for this study. The obese adults were given a physical exercise training program that lasted twelve weeks. Before and after the exercise training program, blood samples were collected, and serum thiol/disulphide parameters were measured by using a novel technique. Before the start of the exercise training, it was observed that thiol/disulphide homeostasis was impaired, and this impairment was positively correlated with body mass index in sedentary obese adults because of the higher reactive oxygen species production in adipose tissue. However, while the obese participants' body mass index significantly decreased, the thiol/disulphide homeostasis parameters in the obese adults did not change over time as calculated at the baseline and compared to the calculation after the twelve weeks of exercise training. Despite a decrease in body mass index that occurred after the twelve weeks of exercise training, there was a lack of improvement in the obesity-induced impairment of thiol/disulphide homeostasis, which suggests that a newly initiated exercise training program may lead to oxidative stress.

The effect of thiol-disulfide homeostasis in patients undergoing on-pump coronary artery bypass grafting

Background

In this study, we aimed to investigate the effects of thiol-disulfide homeostasis in patients undergoing on-pump coronary artery bypass grafting.

Methods

Between January 2018 and October 2018, a total of 51 patients (43 males, 8 females; mean age 61.8±8.7 years; range, 38 to 78 years) who underwent isolated on-pump coronary artery bypass grafting were included. Thiol-disulfide homeostasis parameters were studied in the preoperative period (T1), 30 min after the removal of cross-clamp (T2), and postoperative sixth h (T3). Hemodynamic parameters such as atrial fibrillation and inotropic support requirement of the patients were evaluated in the postoperative period.

Results

There were significant differences in the measured thiol-disulfide homeostasis parameters at different time points of surgery (p<0.001). Binary logistic regression analysis showed that T2-disulfide/native thiol ratio was an independent predictor of the development of postoperative atrial fibrillation (p=0.042). There were positive and significant correlations between the T2-disulfide levels and cross-clamp time (r:0.307, p=0.029).

Conclusion

Thiol-disulfide homeostasis in patients undergoing on-pump coronary artery bypass grafting changes toward to disulfide. Disulfide levels increase in parallel with prolonged ischemia time. Decreased native thiol and increased disulfide levels during ischemic period may be predictive of postoperative atrial fibrillation.

Is otitis media with effusion associated with oxidative stress? Evaluation of thiol/disulfide homeostasis

BACKGROUND

We evaluated the relationship between otitis media with effusion and thiol/disulfide homeostasis using a novel marker of oxidative stress.

METHODS

The study group consisted of 30 patients (mean age 8.33 ± 3.30 years) with bilateral otitis media with effusion admitted to our hospital. The control group consisted of 35 (mean age 7.40 ± 3.97 years) age-, sex-, and body mass index-matched healthy subjects. Thiol/disulfide homeostasis was measured using a newly developed method.

RESULTS

Native and total thiol levels were lower in the study than the control group (native thiols 421.37 ± 72 μmol/L vs. 464.46 ± 46.42 μmol/L, p < 0.05; total thiols 468.42 ± 77.89 μmol/L vs. 501.32 ± 50.30 μmol/L, respectively). Disulfide levels and the disulfide/native thiol and disulfide/total thiol ratios were higher in the study group (disulfides 23.56 ± 4.68 μmol/L vs. 18.43 ± 4.94 μmol/L; disulfide/native thiol ratio 5.65 ± 1.05 vs. 3.97 ± 1.03%; disulfide/total thiol ratio 5.06 ± 0.83 vs. 3.66 ± 0.88%, respectively).

CONCLUSION

Oxidative stress may be the major cause of the increase in oxidized thiols in patients with bilateral otitis media with effusion, however, this relationship requires further investigation.

Thiol/Disulfide Balance in Patients with Familial Hypercholesterolemia

OBJECTIVE

Herein, we investigated the balance of thiol/disulfide, with the hypothesis that the balance between disulfides and thiols, which are natural antioxidants, might be disrupted in patients with familial hypercholesterolemia, which eventually leads to endothelial damage.

METHODS

In this study, we evaluated 51 patients diagnosed with familial hypercholesterolemia and 81 healthy subjects. Blood samples were taken from the patients after a minimum of 12 hours of fasting; samples were immediately centrifuged, stored in Eppendorf tubes, and preserved at -80°C.

RESULTS

This study found that thiol levels are significantly lower in patients with familial hypercholesterolemia, whereas disulfide levels are higher (independent of age, gender, and body mass index). This means that in such patients, the thiol/disulfide balance changes in favour of disulfide.

CONCLUSIONS

In this study, we found that the thiol/disulfide balance in patients with familial hypercholesterolemia is disrupted in favour of disulfide.

Thiol/disulphide homeostasis in thoracic aortic aneurysm and acute aortic syndrome

AIM

The aim of this study was to evaluate whether ranging values of thiol and disulphide herald a dilatation or impending acute aortic syndrome at thoracic aorta. Results/methodology: Study population consisted of patients with aortic aneurysm (n = 58), with acute aortic syndrome (n = 32) and without aortic aneurysm (control group; n = 61). A spectrophotometric method was used to determine thiol and disulphide. Native and total thiol levels were moderately correlated with maximal aortic diameter. At the end of 6 months, there was statistically significant increase in native, total thiol levels and decrease in disulfide and disulphide/native thiol ratio in operated group.

DISCUSSION/CONCLUSION

Lower thiol levels may be associated with the higher risk of aortic aneurysm development and may increase after surgical therapy.

The change in serum Thiol/Disulphide homeostasis after transrectal ultrasound guided prostate biopsy

Objectives

The aim of this prospective clinical study was to investigate variations in a novel oxidative stress marker (thiol/disulphide homeostasis) in men who underwent transrectal ultrasound guided prostate biopsy (TRUSB).

Materials and Methods

A total of 22 men undergoing TRUSB of the prostate were enrolled in the study. Patients with abnormal digital rectal examination and/or total prostate specific antigen (PSA) over 4ng/mL underwent TRUSB with 12 cores. Serum samples were obtained before and just after the procedure to evaluate the possible changes in thiol/disulphide homeostasis. Mean age, total PSA and free PSA, prostate volume and histopathological data were also recorded.

Results

Mean age of the study population was 65.05±8.89 years. Significant decreases in native and total thiol levels were documented after the biopsy procedure. However, serum disulphide levels and disulphide/native thiol, disulphide/total thiol and native/total thiol ratios did not significantly change after TRUSB. No correlation was observed between oxidative parameters and total PSA and free PSA levels, prostate volume and histopathology of the prostate. However, mean patient age was significantly correlated with mean native and total thiol levels.

Conclusion

Significant decreases in serum native and total thiol levels related to the prostate biopsy procedure suggest that TRUSB causes acute oxidative stress in the human body. Since our trial is the first in the current literature to investigate these oxidative stress markers in urology practice, additional studies are warranted.

Thiol/disulphide homeostasis in celiac disease

AIM

To determine dynamic thiol/disulphide homeostasis in celiac disease and to examine the associate with celiac autoantibodies and gluten-free diet.

METHODS

Seventy three patients with celiac disease and 73 healthy volunteers were enrolled in the study. In both groups, thiol/disulphide homeostasis was examined with a new colorimetric method recently developed by Erel and Neselioglu.

RESULTS

In patients with celiac disease, native thiol (P = 0.027) and total thiol (P = 0.031) levels were lower, while disulphide (P < 0.001) level, disulphide/native thiol (P < 0.001) and disulphide/total thiol (P < 0.001) ratios were higher compared to the control group. In patients who do not comply with a gluten-free diet, disulphide/native thiol ratio was found higher compared to the patients who comply with the diet (P < 0.001). In patients with any autoantibody-positive, disulphide/native thiol ratio was observed higher compared to the patients with autoantibody-negative (P < 0.05). It is found that there is a negative correlation between celiac autoantibodies, and native thiol, total thiol levels and native thiol/total thiol ratio, while a positive correlation is observed between disulphide, disulphide/native thiol and disulphide/total thiol levels.

CONCLUSION

This study is first in the literature which found that the patients with celiac disease the dynamic thiol/disulphide balance shifts through disulphide form compared to the control group.

A novel method for determining the relation between nasal polyposis and oxidative stress: the thiol/disulphide homeostasis

CONCLUSION

It is thought that oxidative stress may be the major cause of the increase in the oxide thiol form in the study group. The relationship between oxidative stress status and dynamic thiol/disulphide in nasal polyposis now needs to be investigated.

OBJECTIVES

The purpose of this study was to evaluate the relation between nasal polyposis and thiol/disulphide homeostasis, used as a marker of oxidative stress, by measuring that exchange using a novel technique.

MATERIALS AND METHODS

The study group consisted of 40 patients (mean age = 46.75 ± 13.92 years) with bilateral nasal polyposis patients admitted to the hospital. The control group consisted of 31 (mean age = 43.20 ± 5.68 years) age, sex, and body mass index matched healthy subjects. Thiol/disulphide homeostasis concentrations were measured using a newly-developed method (Erel & Neselioglu).

RESULTS

Native thiol and total thiol levels were lower in the study group compared to the control group (native thiol = 415.8 ± 69.1 μmol/L vs 448.7 ± 37.5 μmol/L, p < 0.05; total thiol = 449.02 ± 72.0 μmol/L vs 477.28 ± 44.5 μmol/L, p < 0.05, respectively). Disulphide level and the disulphide/native thiol and disulphide/total thiol ratios were higher in the study group compared to the control group (disulphide = 16.58 ± 5.04 μmol/L vs 14.28 ± 5.3 μmol/L, p < 0.05; disulphide/native thiol ratio = 4.07 ± 1.52% vs 3.14 ± 1.04%, p < 0.05, disulphide/total thiol ratio = 3.73 ± 1.23% vs 2.94 ± 0.92%, p < 0.05, respectively).