The Effect of the 50 g Glucose Challenge Test on The Thiol/Disulfide Homeostasis in Pregnancy

The role of protein oxidation in the development of diabetic microvascular complications

OBJECTIVE

The role of protein oxidation in the development of diabetic microvascular complications was investigated.

METHODS

In total, 266 participants were split into five groups: Group 1; diabetes mellitus for at least 10 years without any complications, Group 2; diabetic nephropathy, Group 3; diabetic neuropathy, Group 4; diabetic retinopathy, and Group 5; control group. Thiol, disulfide, ferroxidase, and ischemia-modified albumin (IMA) levels were analyzed in the serum.

RESULTS

Native thiol, total thiol, and native thiol/total thiol were lower in Group 4 than Groups 1, 3, and 5 (p<0.001). However, disulfide/native thiol and disulfide/total thiol were higher in Group 4 than all other groups (p<0.001). IMA was higher in Groups 3 and 4 than all other groups (p<0.001). Ferroxidase was lower in Groups 3 and 4 than Group 2 (p<0.001).

CONCLUSION

Thiol-disulfide homeostasis impairment in favor of disulfide may have a function in the progress of diabetic retinopathy. Furthermore, the disruptions of IMA and ferroxidase levels involve in the development of diabetic retinopathy and neuropathy.

Dynamic thiol/disulfide homeostasis as oxidative stress marker in diabetic ketoacidosis

Background/aim

The aim of present study was to investigate the dynamic thiol/disulfide homeostasis as oxidative stress marker in diabetic ketoacidosis (DKA).

Materials and methods

A total of 77 participants consisting of 32 patients with DKA and 45 healthy volunteers were included in the study. Thiol/disulfide homeostasis (TDH) [total thiol-native thiol/disulfide changes] were measured in both groups (patient group and control group) using a brand new method developed by Erel and Neselioglu. Half of the difference between total thiol and native thiol concentrations gives the amount of disulfide bond. 


Results

Total thiol, native thiol, and disulfide levels in blood were found to be low. The levels of total thiol (P < 0.001) and native thiol (P < 0.001 ) were significantly lower in patients with DKA than in the control group. At the same time, the level of disulfide was nonsignificantly lower in the patient group than the control group (P = 0.388). The level of IMA was higher in the patient group than in the control group (P < 0.001).

Conclusion

The total thiol, native thiol, and disulfide levels in DKA decrease in favor of oxidative stress.

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.

Thiols and ceruloplasmin levels in serum of children with attention deficit hyperactivity disorder: A cross-sectional study

Attention deficit hyperactivity disorder (ADHD) is a childhood onset disorder with well-known findings that include impulsivity, hyperactivity, and inattention. This study aims to explore the relationship between the levels of ceruloplasmin, native thiol, total thiol, and disulfide and ADHD by comparing case and control groups. The study case group comprised 50 children aged 6-16 years who had been diagnosed with ADHD. The control group included 47 healthy children. Clinical interviews were conducted and the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version Turkish Adaptation and the Conners Parent Rating Scale were administered. Additionally, blood samples were taken and native thiol, total thiol, disulfide, and ceruloplasmin levels measured. In the ADHD group, the mean native thiol, total thiol, and disulfide levels were significantly lower than the control group. There was no significant difference between the ADHD and control groups in ceruloplasmin levels. Total thiol and native thiol levels were inversely correlated with scores on the Conners Inattention and Hyperactivity subscales; total thiol was negatively correlated with the ADHD index. Thiol-disulfide homeostasis was impaired in ADHD children and was related to symptom severity. Oxidative stress balance may play a role in ADHD.

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.

Evaluation of thiol/disulfide homeostasis in patients with gestational diabetes mellitus

This study aimed to study the dynamic thiol/disulfide homeostasis in pregnant women with gestational diabetes mellitus (GDM). Forty-five pregnant women with GDM and 45 age-matched healthy pregnancies were included in this study. Thiol/disulfide homeostasis was measured using a commercial kit (Rel Assay Diagnostics). The patients with GDM had significantly higher disulfide concentrations than healthy pregnant patients (p = .001). Besides, the GDM group had significantly higher disulfide/total thiol, disüplhide/native thiol, and native thiol/total thiol ratio than healthy pregnant patients (p = .001, p = .001 and p = .001, respectively). The significantly higher concentrations of disulfide, disulfide/total thiol, disüplhide/native thiol, and native thiol/total thiol ratio in women with GDM could be considered as the increased oxidative stress.

Thiol/Disulfide Homeostasis in Patients with Molar Pregnancies

Introduction: We aimed to investigate serum dynamic thiol and disulfide levels in patients with molar pregnancy (MP), and compare these concentrations with those of healthy pregnant women. Materials and Methods: Forty-one patients who were diagnosed with MP and 41 gestational age-matched healthy pregnant women were included in this prospective study. MP cases were separated in two groups as complete hydatidiform mole (CHM) and partial hydatidiform mole (PHM). Demographic features and thiol/disulfide homeostasis were recorded for each woman. Results: There was a significant correlation between the decrease in the total thiol and native thiol levels in MP patients. However, no significant difference was observed between CHM and PHM groups in terms of serum disulfide levels. Conclusion: OS is increased in MPs both in complete and partial moles, as determined by thiol/disulfide analysis.

The effect of hyperglycemic peak induced by oral glucose tolerance test on the oxidant and antioxidant levels

Background/aim

The possibility of adverse effects of the oral glucose tolerance test (OGTT) carried out for the screening of gestational diabetes among pregnant women and fetuses is a frequently discussed topic. The purpose of this study was to investigate the effects of the hyperglycemia peak during OGTT on the levels of oxidants and antioxidants in the body.

Materials and methods

Eighty individuals who applied to the Outpatient Clinic with suspected diabetes and OGTT indication were included in the study. Glucose, total oxidant capacity status (TOS), total antioxidant capacity (TAS), superoxide dismutase (SOD), and lipid hydroperoxide (LOOH) levels were tested on blood samples collected from these individuals at 0, 60, and 120 min during the OGTT carried out with 75 g of glucose. Oxidative stress index (OSI) was calculated as the ratio of TOS to TAS.

Results

While the oxidative parameters TOS and LOOH were significantly increased at 60. min of OGTT, only LOOH was significantly increased at 120. min of OGTT. Significant decreases in antioxidative parameters (TAS, SOD) were observed at 60. and 120. min of the OGTT and OSI was significantly increased at 60. and 120. min of the OGTT.

Conclusion

Oxidative stress parameters were increased and antioxidative parameters were decreased during the OGTT. However, more extended studies are required to determine the effects of the increased oxidative stress on pregnant women and fetuses.

Thiol-Disulfide Homeostasis, Serum Ferroxidase Activity, and Serum Ischemia Modified Albumin Levels in Childhood Iron Deficiency Anemia

Aim: The aim is to compare the markers of oxidative stress in iron deficient children to that of non-anemic children. Method: Serum thiol-disulfide level, ferroxidase activity and ischemia-modified albumin (IMA) levels were compared between iron deficiency anemia (IDA) and non-anemic children. Results: A total of 117 children, 66 with IDA and 51 non-anemic children were included in the study. Disulfide, disulfide/native thiol, and disulfide/total thiol levels were significantly higher in the IDA group (p: 0.001). Serum ferroxidase levels were significantly lower in the IDA group (p: 0.04); but there was no significant difference between the two groups regarding serum IMA levels (p: 0.42). There was a weak negative correlation between disulfide and serum hemoglobin (p: 0.004), iron (p: 0.041), and ferritin (p: 0.023) levels while there was a weak positive correlation between ferroxidase activity and these parameters. Conclusion: There is an increased protein oxidation in children with IDA compared with non-anemic controls.

Thiol-Disulfide Homeostasis, Serum Ferroxidase Activity, and Serum Ischemia Modified Albumin Levels in Neonatal Jaundice

AIM

Hyperbilirubinemia causes oxidative stress.

METHOD

We evaluated three oxidative stress markers in hyperbilirubinemic neonates (native/total thiol levels, serum ferroxidase activity and ischemia modified albumin (IMA), comparing these levels to levels in a control group to determine which indicators were the most sensitive.

RESULTS

Serum from 124 term infants (67 with pathologic jaundice and 57 controls) were evaluated. Native/total thiol ratio was significantly lower (p:0.021) while disulfide levels were significantly higher (p:0.001) in the jaundiced group. There was no significant difference in ferroxidase (p:0.603) or IMA (p:0.251) levels.

CONCLUSION

Altered thiol/disulfide homeostasis in the favor of disulfide indicates augmented oxidative stress in jaundiced term infants. The lack of alteration in ferroxidase or IMA levels suggests these latter alterations take more time or more severe oxidative stress to become altered or are not as sensitive as the thiol/disulfide ratio to detect oxidative stress states.