Serum Total Thiol Levels Research Articles

The investigation of thiol-disulfide homeostasis in patients with diabetic peripheral neuropathy

Objectives: Oxidative stress plays a significant role in the pathogenesis of chronic diabetic complications. Hyperglycemia induced oxidative stress is prominent for the development of diabetic polyneuropathy (PNP). Thiol disulfide homeostasis plays a vital role in antioxidant defense. In this study, we aimed to investigate thiol-disulfide homeostasis, total antioxidant capacity (TAC), and advanced oxidant protein products (AOPP) in patients with PNP. Methods: Eighty patients with T2DM and 19 healthy controls were included in the study. PNP was assessed by using the Michigan Neuropathy Screening Instrument and Electroneuromyography. TAC, AOPP, and total thiols, native thiols and disulfide levels of thiol-disulfide homeostasis parameters were studied with serum samples. The results were compared in patients with/without PNP and control group. Results: Serum HbA1c (9.5 ± 2.0% vs 8.0 ± 1.8%; p = 0.019) and triglyceride levels (204.4 ± 77.0 vs 151.7 ± 58.5 mg/dL, p = 0.014) were significantly higher and serum total thiol levels (540.4 ± 9.9 vs 566.7 ± 2.6 μmol/L, p = 0.038) were significantly lower in patients with PNP. Serum TAC, AOPP, native thiol, and disulfide levels were comparable among patients with/ without PNP. Serum CRP, AOPP, total thiol, and native thiol levels were found to be higher in patients with type 2 DM (p = 0.001, p = 0.002, p = 0.02 and p = 0.03; respectively) compared to the control group. No correlation was observed between serum thiol-disulfide homeostasis parameters and serum glucose and HbA1c levels. Conclusions: Our study reveals that oxidative stress markers such as serum TAC, AOPP, and disulfide levels are closely related to the existence of diabetes. No significant difference was noted among patients with and without diabetic PNP.

Native Thiol, Total Thiol, and Dynamic Disulfide Profile in Patients with Gastrointestinal System Cancer

This study aims to evaluate the use of serum native thiol (NT), total thiol (TT), and dynamic disulfide (DD) levels as biomarkers in patients with gastrointestinal system (GIS) cancer with different cancer types by comparing with healthy controls. A total of 108 subjects consisting of68 patients with GIS cancer and 40 healthy individuals as a control group were included in the study. Serum NT, TT, and DD levels were measured by an automated method developed by Erel. There was a statistically significant difference between NT levels of GIS cancer and the control group (P = 0.001). However, there were no significant differences between male and female patients in terms of serum NT levels (P = 0.08). Similarly, no significant difference was observed when comparing serum NT levels among GIS cancer types (P = 0.886). The serum TT levels were statistically significant difference (P = 0.013) in GIS cancer, 141.82 ± 48.24 μmol/l (12.7-243.9) compare to the control group, 166.03 ± 56.23 μmol/l (12.7-326.8). When the serum TT and DD levels of the patients were compared according to gender, no significant difference was found (P = 0.243 and P = 0.362, respectively). In addition, the TT levels were not significantly difference among GIS malignancies (P = 0.765). When the patient and control groups were compared in terms of DD levels, no statistically significant difference was found (P = 0.378). In conclusion, it was determined that some parameters differ statistically between patients with GIS cancer and healthy controls. Therefore, there is a significant relationship between the thiol/disulfide balance with GIS cancer. This result suggests that oxidative stress may play a role in the development of the GIS cancer, consistent with the findings in this study, but not in terms of DD levels.

Oxidative Stress Level in Patients with Subarachnoid Hemorrhage.

One of the antioxidant mechanisms is the dynamic balance between thiol and disulfide, which, in subarachnoid hemorrhage and other chronic diseases, is disrupted in favor of the latter. The two most commonly used oxidative stress (OS) biochemical markers are the oxidative stress index (OSI) value, which indicates the total oxidant status (TOS) and total antioxidant status (TAS) balance, and the thiol-disulfide (TDS) value, which indicates the total thiol (TT) and native thiol (NT) balance. High OS levels require further investigations. We aimed to investigate the OS level in aneurysmal SAH (aSAH) patients. In this clinical prospective study, blood samples were collected from 50 consecutively treated patients with aSAH and 50 volunteers. Serum TOS, TAS, TT, and NT levels were measured using Erel's method via a spectrophotometer. The Glasgow Coma Scale (GCS) scores, Fisher grades, length of hospital stay (LOS), and the Glasgow Outcome Scale (GOS) scores were recorded. Consequently, the OSI and TDS values were calculated in all participants. A statistically significant difference was observed in the TAS, TOS, OSI, and TDS values between the aSAH patients and the controls. The TT and NT values were significantly lower in aSAH patients than in the controls. A correlation was identified between the OSI values and the GCS scores. Although a correlation was observed between the TDS values and the LOS, no correlation was found between the OSI and the TDS values. The OSI and TDS, which are OS indicators, might serve as the additional objective nominal data to evaluate the treatment efficacy and follow-up for SAH patients. Moreover, decreasing the OSI values and increasing the TT values can be used as improvement indicators in the treated aSAH patients. If we can reduce the OS at the early stage of SAH, it could improve the prognosis by reducing both the morbidity and mortality rates. Further randomized investigations are required to prove the findings in this prospective study.

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

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

Analysis of thiol/disulphide homeostasis and oxidant-antioxidant status as a result of exposure to radio-frequency electromagnetic fields

ABSTRACT The aim of the current study is to investigate the effect of daily long-term radio-frequency electromagnetic field (RF-EMFs) exposure on thiol/disulphide homeostasis and oxidant-antioxidant status in the serum of rats. Fourteen male Sprague Dawley rats were divided into two equal groups (n = 7). They were grouped as group 1 (sham-control) and group 2 (2100 MHz exposed). Group 2 rats were exposed to GSM-like signals for 5 h/day, 7 days per week for 14 days. In serum of blood samples, the native, total and native/total thiol levels and antioxidant-oxidant parameters were analyzed. The study revealed that the mean serum total thiol levels of GSM exposure group was rather higher than sham-control group (p = 0,219); the mean serum native thiol levels of GSM exposure group was rather higher than sham-control group (p = 0,416), and the mean serum disulphide levels of GSM exposure group was rather higher than sham-control group (p = 0,566). On the other hand, the mean serum total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI) of GSM exposure group were higher than sham-control group. There are no data in the literature, that examine the effects of RF-EMFs on thiol/disulphide homeostasis. The results of this study, indicate that RF-EMFs did not cause oxidative stress and statistically changes in thiol/disulphide homeostasis. More sample sizes and longer-term exposures are needed to confirm the results of this study.

Dynamics of serum total thiol levels at the treatment of laryngeal cancer patients

Thiol groups of the intra and extracellular molecules are antioxidant and protect cells from damage caused by free radicals, but dynamics data of serum total thiol (sTT) levels in patients at laryngeal cancer are almost absent. Purpose of the study: Determination and comparison the serum total thiol levels at different stages of special treatment methods in laryngeal cancer patients. Material and methods: In twenty-eight laryngeal cancer (T2-3 NX M0 category) patients’ examination of the thiol status dynamics was carried out before, during and after the combined treatment with “ELISA” diagnostics test system. Results: Almost a twofold decrease in sTT content indicators was noted but no identified statistically significant differences between T2 and T3 categories tumors. There was an increase in sTT levels in patients in the postoperative and during radiation therapy period, which, however, were below the control values. At the same time, when the combined treatment was completed, a significant decrease in the level of sTT was noted, which emphasizes the need for long-term antioxidant therapy. Higher sTT levels have been associated with a reduced risk of laryngeal cancer recurrence. Conclusions: In laryngeal cancer patients, the level of serum total thiol was lower than in patients of the control group. There were no statistically significant differences in sTT levels in patients with T2 and T3 tumors. Low levels of the serum total thiol are related with predict a poor outcome for patients.

Evaluation of thiol disulphide levels in patients with pulmonary embolism

Abstract Objectives Maintaining the thiol-disulphide balance is essential for antioxidant defense and apoptosis. The study aimed to evaluate of thiol-disulphide levels in patients with pulmonary embolism (PE). Methods The study included a total of 97 participants: 48 patients and 49 healthy individuals. Serum native thiol (NT), total thiol (TT) and disulphide (DS) levels (µmol/L) were measured using the novel spectrophotometric method. Results We found significantly lower levels of NT (195.44±83.3 μmol/L), DS (20.42±9.20 μmol/L) and TT (236.26±90.66 μmol/L) in patients with PE compared with the healthy controls (304.42±62.13, 24.33±8.09 and 353.07±63.58 μmol/L respectively). Patients with PE had lower serum albumin levels (3.11±1.03 g/dL) and higher ischaemia modified albumin (IMA) levels (0.82±0.16 g/dL) compared with the controls (3.89±0.52 and 0.67±0.15 g/dL, respectively). Serum albumin levels in patients were strongly correlated with plasma IMA (r=−0.737; p&lt;0.001), NT (r=0.786; p&lt;0.001) and TT levels (r=0.841; p&lt;0.001). Serum NT levels were strongly correlated with serum TT levels (r=0.981; p&lt;0.001) in patients. Conclusions This study found lower TT, NT and DS levels in patients with PE than in the control group. Our study revealed that thiol-disulphide homeostasis could be altered during PE and further studies are needed to be used as prognostic markers for hospital mortality.

Dynamic thiol/disulphide homeostasis in patients with hypertrophic cardiomyopathy.

In addition to the genetic complexity of hypertrophic cardiomyopathy (HCM), there must be other disease-modifying factors that contribute to its highly variable clinical and phenotypic expression. The authors aimed to investigate serum thiol/disulphide homeostasis as aproxy for oxidative stress using anovel automated assay in patients with HCM. This cross-sectional study was conducted on 119 patients with HCM and 52 without HCM. The methods used to measure dynamic thiol/disulphide homeostasis as calorimetric and duplex quantities were developed in 2014. Median serum native thiol levels were significantly lower in patients with HCM than in those without (312.5 μmol/L [285-370 μmol/L] vs 421 μmol/L [349-469.5 μmol/L]; p < 0.001). Serum total thiol levels and disulphide levels were considerably lower than those in the control group ([844.68 ± 195.99 μmol/L vs 1158.92 ± 243.97 μmol/L; p < 0.001], [259.13 ± 65.66 μmol/L vs 375.02 ± 79.99 μmol/L; p < 0.001], respectively). Serum disulphide/native thiol ratios and disulphide/total thiol ratios were significantly lower in HCM patients than in controls (0.80 ± 0.09 vs 0.92 ± 0.05; p < 0.001 and 0.31 [0.30-0.32] vs 0.32 [0.32-0.33]; p < 0.001). Finally, reduced thiol ratios were higher and oxidized thiol ratios were significantly lower in patients with HCM than in controls. Despite the fact that antioxidant capacity was impaired, the extracellular environment remained in areducing state by keeping serum disulphide/native thiol ratios low. Therefore, the authors speculate that HCM may behave similarly to tumours with respect to serum thiol-disulphide levels.

Dynamic Thiol/Disulfide Homeostasis in Predicting Adverse Neonatal Outcomes in Fetal Growth Restriction

Aim: The main aim of this study was to investigate thiol/disulfide homeostasis associated with fetal growth restriction (FGR) and to evaluate whether alterations are predictive for adverse neonatal outcomes. Methods: 273 pregnant women (77 with FGR and 196 with normal fetal growth) were enrolled in this prospective case–control study. Results: Native thiol and total thiol were decreased in FGR compared to the control group (p < .001; p < .001). Decreased levels of maternal serum native and total thiol were significantly associated with adverse neonatal outcomes in FGR (OR: 0.983, 95% CI 0.976–0.991, p < .001; OR: 0.983, 95% CI 0.976–0.991, p < .001). Decreased maternal serum total thiol levels were the only significantly associated risk factor with adverse neonatal outcomes in FGR (OR: 0.981, 95% CI 0.963–1.000, p = .046). Conclusion: The decrease in the antioxidants of thiol/disulfide mechanism may be related to the development of both FGR and adverse neonatal outcome in FGR.

Serum total thiol levels and the risk of lung, colorectal, breast and prostate cancer: A prospective case-cohort study.

Free thiol groups of intra and extracellular molecules are considered to be antioxidative and to protect cells from damage caused by free radicals. However, the associations of serum total thiol levels (TTL) with the incidences of the four most frequent cancer sites have not yet been investigated in a large population-based, prospective study. TTL was measured in case-cohort design in a sample from the population-based, Norwegian Tromsø 3 study (cancer cases: n = 941; random subcohort: n = 1,000) and was repeatedly measured at Tromsø 5. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated by weighted multivariable-adjusted Cox regression with time-dependent modeling of TTL for incident lung, colorectal, breast and prostate cancer. High serum TTL were associated with a reduced risk of all four major cancers. The associations with lung (top vs. bottom tertile: HR, 0.64; 95% CI, 0.41, 0.99) and breast cancer (top vs. bottom tertile: HR, 0.64; 95% CI, 0.42, 0.96) were statistically significant, whereas associations with colorectal (top vs. bottom tertile: HR, 0.79; 95% CI, 0.54, 1.16) and prostate cancer (top vs. bottom tertile: HR, 0.79; 95% CI, 0.53, 1.17) were not statistically significant but pointed in the same protective direction. These findings from a large, prospective Norwegian cohort study suggest a preventive role of thiols against the development of the four most frequent cancers. Whereas associations with breast and lung cancer could be shown with statistical significance, larger studies are needed to corroborate potential associations of TTL with colorectal and prostate cancer.

The prognostic and predictive significance of serum thiols and disulfide levels in advanced non-small cell lung cancer

Serum Total Thiol (TT), Native Thiol (NT), and Disulfide (SS) levels were found significantly lower in benign proliferative pathologies and cancer disease compared to healthy subjects. We conducted this prospective study to investigate the possible predictive and prognostic significance of these markers in non-small cell lung cancer (NSCLC), which is one of the most associated cancers with oxidative stress. This was a non-randomized, prospective, and case-control study of 120 subjects, including 60 patients with metastatic or inoperable NSCLC at the time of diagnosis and 60 demographically-matched controls. Morning fasting venous blood serum samples from both NSCLC and control group were stored at −80 °C for equal periods and then TT, NT, and SS levels were measured spectrophotometrically. Serum TT, NT, and SS levels were compared between groups and their relationships with demographic features and survival of NSCLC patients were analyzed. In results, Serum TT, NT, and SS levels were significantly lower in NSCLC patients than those in control group, with a low SS level being an independent indicator of poor survival.

Evaluation of thiol-disulphide homeostasis in radiation workers

Purpose: To evaluate thiol-disulphide homeostasis – a novel, easily calculated, readily available, and relatively cheap oxidative stress marker – in radiation workers and compare the results with healthy controls.Materials and methods: A total of 108 participants were enrolled in the study including 63 hospital workers occupationally exposed to ionizing radiation in the units of interventional radiology, interventional cardiology and nuclear medicine. A control group consisted of 45 individuals staff in the same hospital. Serum thiol-disulphide homeostasis measurement was investigated via the spectrophotometric method newly described by Erel and Neşelioğlu.Results: The mean serum native thiol levels of radiation workers (528.96 ± 86.42 μmol/l) was significantly lower than control subjects (561.05 ± 104.83 μmol/l) (p = .045). The mean serum total thiol levels of radiation workers (547.70 ± 91.50 μmol/l) was lower than control subjects (580.36 ± 112.24 μmol/l). Nevertheless, there was no significant difference between total thiol of exposed workers and controls.Conclusions: The results show that long-term low dose ionizing radiation may lead to oxidative stress and have side-effects in antioxidant thiol groups. We may suggest supporting radiation workers by safe antioxidant nutritional formulations and following up via both physical dosimetry and biodosimetric methods.

Evaluation of thiol levels, thiol/disulfide homeostasis and their relation with inflammation in cardiac syndrome X.

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. 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. 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). 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.

The association of thiol/disulphide homeostasis and lipid accumulation index with cardiovascular risk factors in overweight adolescents with polycystic ovary syndrome.

To assess thiol/disulphide homeostasis and lipid accumulation product index, and to determine whether they are associated with increased cardiovascular disease (CVD) risk or not in overweight adolescents with polycystic ovary syndrome (PCOS). Case-control study. Education and Research Hospital. Group 1: 43 overweight+PCOS, Group 2: 45 normal weight+PCOS, Group 3: 27 overweight adolescents and Group 4: 96 age-matched, normal weight healthy controls. Serum lipid profiles, hormonal parameters and thiol/disulphide homeostasis were measured. Lipid accumulation index (LAP index) and homeostasis model assessment (HOMA-IR) were calculated. The relation between thiol/disulphide homeostasis and LAP index, and increased CVD risk were evaluated in overweight adolescents with PCOS. Native and total thiol levels were significantly lower in overweight+PCOS adolescents when compared with both normal weight PCOS and control adolescents (P = 0·002). LAP index values were significantly higher in Group 1 when compared separately with the rest of the three groups (P < 0·001). Multivariable logistic regression analysis revealed serum total thiol levels of lower than 405·45 μmol/l were independently associated with increased risk of CVD in overweight PCOS adolescents (OR: 1·019, 95% CI: 1·001-1·036). In addition, a LAP index greater than 21·54 was also associated with increased CVD risk in overweight PCOS adolescents (OR: 1·270, 95% CI: 1·174-1·374). In conclusion, we suggest that increased LAP index and decreased total thiol levels may contribute to the increased CVD risk in overweight adolescents with PCOS.

Lipid Peroxidation and Antioxidant Status in Nonobese Type 2 Diabetes Mellitus

The aim of the study was to investigate the association between lipid peroxidation and antioxidant status in nonobese type 2 diabetes mellitus (T2DM) and further to correlate whether their significant association is putatively associated with the pathogenesis of T2DM. A number of 102 nonobese T2DM subjects and 95 nondiabetic subjects as healthy controls were enrolled in this cross-sectional study. Serum samples were collected in cryovials for malondialdehyde (MDA) and thiol assays. Total thiol or sulfhydryl (–SH) groups in peripheral blood mononuclear cells (PBMCs) and sera, as well as level of MDA, a marker for lipid peroxidation in serum, were measured spectrophotometrically. Serum MDA level was found significantly higher whereas serum and PBMC total thiol levels were diminished significantly among nonobese T2DM subjects compared to HC subjects. Moreover, serum MDA level is found to have a significant inverse correlation with serum total thiol and PBMC thiol levels among DM subjects, but no significant correlation was observed in HC individuals. A significant inverse correlation between serum MDA and serum total thiol levels among nonobese T2DM subjects suggests a close association of increased oxidative stress with decreased antioxidant status in nonobese T2DM.

The Association between Diabetic Retinopathy and Levels of Ischemia-Modified Albumin, Total Thiol, Total Antioxidant Capacity, and Total Oxidative Stress in Serum and Aqueous Humor.

Purpose. To investigate the oxidant and antioxidant status of patients with type 2 diabetes mellitus and nonproliferative diabetic retinopathy (DRP). Methods. Forty-four patients who had cataract surgery were enrolled in the study. We included 22 patients with DRP in one group and 22 patients in the control group. Samples of aqueous humor and serum were taken from all patients. Serum and aqueous ischemia-modified albumin (IMA), total thiol, total antioxidant capacity (TAC), and total oxidative stress (TOS) levels were compared in two groups. Results. Median serum IMA levels were 44.80 absorbance units in the DRP group and 40.15 absorbance units in the control group (P = 0.031). Median serum total thiol levels in the DRP group were significantly less than those in the control group (3051.13 and 3910.12, resp., P = 0.004). Mean TOS levels in the serum were 2.93 ± 0.19 in the DRP group and 2.61 ± 0.26 in the control group (P = 0.039). The differences in mean total thiol, TAC, and TOS levels in the aqueous humor and mean TAC levels in the serum were not statistically significant. Conclusion. IMA, total thiol, and TOS levels in the serum might be useful markers in monitoring the risk of DRP development.

Protein and lipid oxidative damage in healthy students during and after exam stress

Oxidative damage at cellular level is thought to be one of the mechanisms in the pathogenesis of psychological stress (anxiety). The aim of this study was to investigate lipid and protein oxidative damage in exam anxiety conditions. Blood samples were collected in two stages (during the exam period and post vacation) from 51 healthy female students after responding to Beck Anxiety Inventory (BAI) and test anxiety questionnaire. Protein carbonyl, total thiol and malondialdehyde (MDA) levels were determined in serum. Participants reported significantly higher levels of subjective anxiety during the exam period than post vacation. Also the level of total thiol was significantly lower during the exam period compared with post vacation (p<0.001). Meanwhile, protein carbonyl and MDA levels during the exams were significantly higher than those in post-exam period (p<0.01). During the exam period, there was a negative correlation between serum total thiol levels and the severity of anxiety (r=−0.45, p<0.01). A significant positive correlation between the changes in serum protein carbonyl and MDA levels, also between those markers and anxiety score was found during the exam period. The high level of protein carbonyl and MDA, also low level of total thiol during the exam period demonstrated an oxidative damage to proteins and lipids in stress conditions. Our results suggest that oxidative damage to cellular compounds may be one of the mechanisms involved in the pathogenesis of anxiety.

Investigation of oxidative and antioxidative status in patients with diabetic cataracts

To investigate the oxidative and antioxidative status in diabetic patients with cataracts and nondiabetic patients with cataracts as compared to controls. Materials and methods: There were 149 subjects included in the present study. Blood was collected from type 2 diabetic patients suffering from cataracts (diabetic cataract; n = 42), senile nondiabetic patients suffering from cataracts (nondiabetic cataracts; n = 60), and healthy subjects of a control group (n = 47). Serum levels of total oxidant status (TOS), total antioxidant status (TAS), total thiol levels (TTLs), and paraoxonase 1 (PON1) were investigated in the samples. Results: TTLs were significantly reduced in diabetic cataract patients (444.8 µmol/L) compared with both nondiabetic cataract patients (525.1 µmol/L) and the control group (569.9 µmol/L). Plasma PON1 levels also were significantly reduced in diabetic cataract patients (241.9 U/L) relative to the control group (178.3 U/L). There were no statistically significant differences between TAS and TOS levels among groups. Conclusion: The present study demonstrates a significant reduction in serum TTLs and serum PON1 activities in diabetic cataract patients compared with controls. These findings represent a failure in the antioxidant system, which may be related to the cataractogenic process.

Evaluation of serum oxidative and antioxidative status in patients with erectile dysfunction

We evaluated and compared serum oxidative and antioxidative parameters of patients with erectile dysfunction (ED) and control subjects. Twenty married male patients with ED for at least 12 months (Group 1) and 20 volunteer healthy, sexually active, married and age-matched men (Group 2) were included in the study. Group 1 and 2 were compared concerning serum mean total antioxidant capacity (TAC), total oxidant status (TOS), paraoxonase1 (PON1), arylesterase, total thiol and oxidative stress index (OSI). Mean patient age was 47.9 ± 8.1 and 44.4 ± 10.6, respectively, in Group 1 and 2. Serum TAC levels were 1.7 ± 0.5 and 2.3 ± 0.3, respectively, in Group 1 and 2 (P = 0.002). Serum TOS levels were 21.8 ± 20.5 and 11.7 ± 2.2, respectively, in Group 1 and 2 (P = 0.035). Serum PON1 levels were 69.8 ± 13.1 and 164.9 ± 56.5, respectively, in Group 1 and 2 (P < 0.001). Serum arylesterase levels were 336 ± 12 and 370.4 ± 47.9, respectively, in Group 1 and 2 (P = 0.003). Serum total thiol levels were 733.1 ± 253 and 885.5 ± 95.3, respectively, in Group 1 and 2 (P = 0.016). Serum OSI was 0.14 ± 0.17 and 0.05 ± 0.11, respectively, in Group 1 and 2 (P = 0.021). Mean blood platelet count was significantly higher in Group 1 (P = 0.001). A positive correlation between platelets and oxidative state and a negative correlation between platelets and antioxidative state were found. Oxidative stress was detected to be increased, whereas antioxidative parameters were detected to be decreased in patients with ED.