Oxidatively modified forms of albumin in patients with risk factors of metabolic syndrome

Physical frailty is related to oxidative stress through thiol/disulfide homeostasis parameters

AIM

To evaluate relationship between frailty and oxidative stress through thiol/disulfide homeostasis parameters [Native thiol (NT), total thiol (TT), and disulfide levels (D), disulfide-native thiol (D/NT), disulfide-total thiol (D/TT), native thiol-total thiol (NT/TT) ratios, and ischemia-modified albumin levels (IMA)].

MATERIALS AND METHODS

In total, 139 community-dwelling older adults were included. The frailty status, defined by the FRIED frailty index (FFI) and Clinical Frailty Scale (CFS), and comprehensive geriatric assessment results compared with thiol/disulfide homeostasis parameters and ischemia-modified albumin levels.

RESULTS

NT and TT levels were significantly lower in the frail group (respectively; p = 0.014, p = 0.020). The FFI scores were correlated with the levels of NT, TT, D/NT, D/TT, and NT/TT (respectively; r = - 0.25, r = - 0.24, r = 0.17, r = 0.17, r = - 0.17). The significant correlation could not be retained with the CFS scores. In ROC analysis, the AUC for NT was calculated as 0.639 in diagnosing frailty according to the FFI (95% CI 0.542-0.737), AUC was 0.638 for TT (95% CI 0.540-0.735), and AUC was 0.610 for NT/TT (95% CI 0.511-0.780). The AUC was calculated as 0.610 for both D/NT and D/TT in diagnosing physical frailty (95% CI 0.511-0.708).

CONCLUSION

Thiol/disulfide homeostasis parameters can be a potential biomarker in diagnosing physical frailty. However, further studies are needed for diagnosing frailty defined with cumulative deficit models.

Advanced Oxidation Protein Products Are Strongly Associated with the Serum Levels and Lipid Contents of Lipoprotein Subclasses in Healthy Volunteers and Patients with Metabolic Syndrome

The association between advanced oxidation protein products (AOPPs) and lipoprotein subclasses remains unexplored. Therefore, we performed comprehensive lipoprotein profiling of serum using NMR spectroscopy and examined the associations of lipoprotein subclasses with the serum levels of AOPPs in healthy volunteers (HVs) and patients with metabolic syndrome (MS). The serum levels of AOPPs were significantly positively correlated with the serum levels of very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), and low-density lipoprotein (LDL); however, they were significantly negatively correlated with high-density lipoprotein (HDL). These lipoproteins (and their subclasses) differed markedly regarding the direction of correlations between their lipid contents and AOPPs. The strength of the correlations and the relative contributions of the subclasses to the correlations were different in the HVs and patients with MS. As revealed by orthogonal partial least squares discriminant analyses, the serum levels of IDL were strong determinants of AOPPs in the HVs, whereas the serum levels of VLDL and the lipid content of LDL were strong determinants in both groups. We conclude that IDL, VLDL, and LDL facilitate, whereas HDL diminishes the bioavailability of serum AOPPs. The presence of MS and the lipid contents of the subclasses affect the relationship between lipoproteins and AOPPs.

Evaluation of Ischemic Modified Albumin Levels in Coronavirus Disease 2019-Positive and -Negative Patients with Acute Cardiac Injury

BACKGROUND

The severe acute respiratory syndrome coronavirus 2 is the source of the global pandemic known as coronavirus disease 2019, and the disease prognosis is also linked to the prevalence of cardiac problems. In our study, we aimed to contribute to the early diagnosis and treatment of cardiac complications by evaluating ischemic modified albumin levels in adults with coronavirus disease 2019 disease.

METHODS

Our study was conducted with a total of 176 cases: group 1 (n = 70) with cardiac injury and coronavirus disease 2019 (+), group 2 (n = 57) with cardiac injury and coronavirus disease (-), and group 3 (n = 49) with healthy volunteers. The Mann-Whitney U test, the average, SD, minimum and maximum values, intergroup comparison of the results, and statistical significance were evaluated with the Pearson correlation coefficient.

RESULTS

As a result of the bilateral comparisons, ischemic modified albumin measurements of the coronavirus disease 2019 (+) and coronavirus disease 2019 (-) groups were higher than the control group (P =.006 and P =.006, respectively). There was no statistically significant difference between ischemic modified albumin measurements of coronavirus disease 2019 (+) and coronavirus disease 2019 (-) groups.

CONCLUSION

Ischemic modified albumin measurement accelerates the diagnosis and treatment process in the evaluation of cardiac injuries in coronavirus disease 2019 patients.

Oxidative Stress and Inflammatory Biomarkers in People with Methamphetamine Use Disorder

Objective

This study aimed to investigate the blood serum levels of biomarkers specifying oxidative stress status and systemic inflammation between people using methamphetamine (METH) and the control group (CG). Serum thiol/disulfide balance and ischemia-modified albumin levels were studied to determine oxidative stress, and serum interleukin-6 (IL-6) levels and complete blood count (CBC) were to assess inflammation.

Methods

Fifty patients with METH use disorder (MUD) and 36 CG participants were included in the study. Two tubes of venous blood samples were taken to measure oxidative stress, serum thiol/disulfide balance, ischemia-modified albumin, and IL-6 levels between groups. The correlation of parameters measuring oxidative stress and inflammation between groups with sociodemographic data was investigated.

Results

In this study, serum total thiol, free thiol levels, disulfide/native thiol percentage ratios, and serum ischemia- modified albumin levels of the patients were statistically significantly higher than the healthy controls. No difference was observed between the groups in serum disulfide levels and serum IL-6 levels. Considering the regression analysis, only the duration of substance use was a statistically significant factor in explaining serum IL-6 levels. The parameters showing inflammation in the CBC were significantly higher in the patients than in the CG.

Conclusion

CBC can be used to evaluate systemic inflammation in patients with MUD. Parameters measuring thiol/disulfide homeostasis and ischemia-modified albumin can be, also, used to assess oxidative stress.

Association of Inflammatory and Oxidative Status Markers with Metabolic Syndrome and Its Components in 40-to-45-Year-Old Females: A Cross-Sectional Study

Oxidative stress and sterile inflammation play roles in the induction and maintenance of metabolic syndrome (MetS). This study cohort included 170 females aged 40 to 45 years who were categorized according to the presentation of MetS components (e.g., central obesity, insulin resistance, atherogenic dyslipidemia, and elevated systolic blood pressure) as controls not presenting a single component (n = 43), those with pre-MetS displaying one to two components (n = 70), and females manifesting MetS, e.g., ≥3 components (n = 53). We analyzed the trends of seventeen oxidative and nine inflammatory status markers across three clinical categories. A multivariate regression of selected oxidative status and inflammatory markers on the components of MetS was performed. Markers of oxidative damage (malondialdehyde and advanced-glycation-end-products-associated fluorescence of plasma) were similar across the groups. Healthy controls displayed lower uricemia and higher bilirubinemia than females with MetS; and lower leukocyte counts, concentrations of C-reactive protein, interleukine-6, and higher levels of carotenoids/lipids and soluble receptors for advanced glycation end-products than those with pre-MetS and MetS. In multivariate regression models, levels of C-reactive protein, uric acid, and interleukine-6 were consistently associated with MetS components, although the impacts of single markers differed. Our data suggest that a proinflammatory imbalance precedes the manifestation of MetS, while an imbalance of oxidative status accompanies overt MetS. Further studies are needed to elucidate whether determining markers beyond traditional ones could help improve the prognosis of subjects at an early stage of MetS.

Antioxidative Effects of Black Currant and Cornelian Cherry Juices in Different Tissues of an Experimental Model of Metabolic Syndrome in Rats

A Western-style diet, rich in fat and simple sugars, is the main risk factor for a significant number of chronic diseases and disorders, as well as for a progression of metabolic syndrome (MetS). One of the key mechanisms involved in MetS development is increased oxidative stress caused by the accumulation of body fat. Some dietary polyphenols have shown a protective role in preventing oxidative-stress-induced damage. We investigated the difference in the oxidative response of plasma, liver, and visceral adipose tissue in rats fed with a high-fat high-fructose (HFF) diet for ten weeks, and the effectiveness of polyphenol-rich juices (black currant (BC) and cornelian cherry (CC)) in HFF-diet-induced oxidative stress prevention. The most prominent impact of the HFF diet on redox parameters was recorded in the liver, whereas adipose tissue showed the most potent protection mechanisms against oxidative stress. Consumption of both juices decreased advanced oxidation protein product (AOPP) level in plasma, increased paraoxonase1 (PON1) activity in the liver, and significantly decreased total oxidative status (TOS) in adipose tissue. BC exerted stronger antioxidative potential than CC and decreased the superoxide anion radical (O₂^•-) level in the liver. It also reduced TOS, total antioxidative status (TAS), and malondialdehyde (MDA) concentration in adipose tissue. The multiple linear regression analysis has shown that the best predictors of MetS development, estimated through the increase in visceral adiposity, were superoxide dismutase (SOD), AOPP, TOS, and TAS. The consumption of polyphenol-rich juices may provide a convenient approach for the systemic reduction of oxidative stress parameters.

Thiol-Disulfide Homeostasis in Neonatal Patients with Urinary Tract Infection

OBJECTIVE

Urinary tract infection (UTI) is a disease that can cause significant complications in the neonatal period. The thiol-disulfide homeostasis is one of the important antioxidant defense mechanisms. The purpose of this study is to show the relationship between UTI and thiol-disulfide homeostasis in newborns.

STUDY DESIGN

In this prospective study, 40 newborns with UTI and 40 healthy controls were included. Thiol-disulfide tests (disulfide, native thiol, and total thiol levels) and septic screening tests were performed before and after antibiotherapy in UTI group. The control group was selected from healthy newborns who applied to the outpatient clinic.

RESULTS

The C-reactive protein and interleukin-6 levels were higher, while native thiol and native thiol/total thiol ratio were significantly lower in pretreatment group compared with posttreatment and control group. Also, the levels of disulfide, ischemia modified albumin, disulfide/native thiol ratio, and disulfide/total thiol ratio were higher in pretreatment group compared with posttreatment group.

CONCLUSION

The thiol-disulfide homeostasis is an important indicator of oxidative stress during infections. It is valuable to be detected with small amounts of serum in newborns. These molecules can be used to support the diagnosis of UTI in the newborn. Further studies are needed to define the role of thiol-disulfide homeostasis in the UTI of newborn.

KEY POINTS

· The thiol-disulfide homeostasis can be an important indicator of oxidative stress during infections such as UTI.. · The thiol-disulfide homeostasis of newborn is valuable to be detected with small amounts of serum in neonatal period.. · Laboratory tests such as white blood cell count, erythrocyte sedimentation rate, and C-reactive protein are not significantly different in UTIs..

Endothelial Dysfunction and Ischemia-Modified Albumin Levels in Males with Diabetic and Nondiabetic Erectile Dysfunction

In this study, we aimed to determine endothelial dysfunction and ischemia-modified albumin (IMA) levels in patients diagnosed with erectile dysfunction (ED) and to examine the relationship between these and diabetes disease. 86 male patients (46 patients with diabetes, age: $51.5\pm 9.2$ and 40 patients with nondiabetes (control group), age: $54.78\pm 12.2$ ) were included in the study. IMA, a new indicator of tissue ischemia and oxidative stress, was checked. Superoxide dismutase (SOD) activity, another oxidative stress indicator, was examined. Endothelin-1 (ET-1), one of the parameters of endothelial dysfunction, was measured. Additionally, endothelial function was evaluated with flow-mediated vasodilatation (FMD). Student’s $t$ -test was used for statistical evaluation. $p$ values less than 0.05 were considered statistically significant. SOD activity was significantly lower in the diabetic group than in the control group, and ET-1 was significantly higher ( $p<0.001$ ). IMA was found to be significantly higher in the diabetic group than the control group ( $p<0.001$ ). FMD was significantly lower in diabetic group compared to the control group ( $p<0.002$ ). According to our findings, the co-occurrence of erectile dysfunction and diabetes demonstrates a complex condition that includes endothelial dysfunction, oxidative stress, and tissue ischemia. When the correlation of indicators, which are markers, was examined, the severity of the co-occurrence of diabetes and erectile dysfunction was again demonstrated.

Data-Driven Cluster Analysis of Oxidative Stress Indexes in relation to Vitamin D Level, Age, and Metabolic Control in Patients with Type 2 Diabetes on Metformin Therapy

Recent advances in vitamin D research indicate that patients with type 2 diabetes mellitus (T2DM) are suffering from vitamin D deficiency and increased oxidative stress to a variable extent, which could produce different health impacts for each individual. The novel multivariate statistical method applied in the present study allows metabolic phenotyping of T2DM individuals based on vitamin D status, metabolic control, and oxidative stress status in order to identify effectively different subtypes in our type 2 DM study population. Data-driven statistical cluster analysis was performed with 95 patients with T2DM, treated with metformin. Clusters were based on 12 variables-age, disease duration, vitamin D level, insulin, fasting glycemia (FG), glycated hemoglobin (HbA1c), high-density and low-density lipoprotein, total cholesterol (TC), triglycerides (TG), body mass index (BMI), and triglycerides/glucose index (TYG). The analysis revealed four unique clusters which differed significantly in terms of vitamin D status, with a mean 25 (OH) D level in cluster 1 (57.84 ± 11.46 nmol/L) and cluster 4 (53.78 ± 22.36 nmol/L), falling within the insufficiency range. Cluster 2 had the highest mean level of 25 (OH) D (84.55 ± 22.66 nmol/L), indicative of vitamin D sufficiency. Cluster 3 had a mean vitamin D level below 50 nmol/L (49.27 ± 16.95), which is considered deficient. Patients in the vitamin D sufficient cluster had a significantly better glycemic and metabolic control as well as a lower level of lipid peroxidation compared to other clusters. The patients from the vitamin D sufficient cluster also had a significantly higher level of vitamin D/MPO, vitamin D/XO, vitamin D/MDA, vitamin D/CAT, and vitamin D/TRC than that in the vitamin deficient and insufficient clusters. The vitamin D deficient cluster included significantly younger patients and had a significantly lower level of AOPP/TRC and albumin/TRC than the vitamin D sufficient cluster. The evidence from our cluster analysis in the context of separated T2DM demonstrates beneficial effects of optimal vitamin D status on metabolic control and oxidative stress in T2DM patients. Older T2DM patients require higher vitamin D levels in order to achieve good metabolic control and favorable antioxidant protection. Since protein damage is more pronounced in these patients, adding water-soluble antioxidant in addition to higher doses of vitamin D should be considered.

Thiol-disulfide homeostasis and ischemia-modified albumin as a marker of oxidative stress in patients with sarcopenia

AIM

Sarcopenia is characterized by progressive and generalized loss of skeletal muscle mass and strength. Chronic inflammatory conditions and increased oxidative stress are in the pathogenesis of sarcopenia. Our aim was to evaluate the relationship between sarcopenia and thiol-disulfide homeostasis and ischemia-modified albumin levels as an oxidative stress marker.

METHODS

Patients aged ≥65 years were recruited in this study. Sarcopenia was diagnosed according to the European Working Group on Sarcopenia in Older People criterion. Total thiol, native thiol, disulfide and ischemia-modified albumin levels were measures according to clinical and laboratory features. Patients were divided into two groups according to their sarcopenia presence; thiol-disulfide homeostasis and ischemia-modified albumin levels were evaluated between these groups.

RESULTS

Overall, 94 patients were analyzed. The mean age was 75.0 ± 6.71 years. A total of 39% of the patients were diagnosed as probable sarcopenia, 3.2% had sarcopenia, 6.4% had severe sarcopenia and 51.1% were diagnosed as normal. The levels of native thiol, total thiol, disulfide level and disulfide-native thiol, native thiol-total thiol and disulfide-total thiol ratios were similar in patients with sarcopenia when compared with the control group. In addition, there were no differences between albumin and ischemia-modified albumin levels. In univariate regression analysis, handgrip strength was found to be an independent predictor of native thiol and total thiol, and disulfide levels.

CONCLUSION

This is the first study in the literature that evaluates the thiol-disulfide homeostasis and ischemia-modified albumin levels in sarcopenic older patients. Long-term studies are warranted to confirm the relationship between oxidative stress markers and sarcopenia. Geriatr Gerontol Int 2021; 21: 584-589.

Study of ischemia modified albumin (IMA) as a biomarker in hypertensive retinopathy

Background

Hypertension (HTN) is one of the leading causes of morbidity and mortality worldwide. A prompt diagnosis and treatment of hypertensive retinopathy (HR), the leading complication of HTN is pivotal for a better visual outcome. Increased blood pressure on its own cannot fully clarify the development of retinal alterations, therefore an additional pathogenetic mechanism, such as oxidative stress, might be inquired.

The aim of the study was to evaluate the changes in the level of ischemia modified albumin (IMA) in the serum and tears of HR patients in order to establish the predictive value of IMA for the HR progression.

Methods

Serum and tear samples for the measurement of IMA were collected from 90 patients detected primarily with HR, who were not taking any antihypertensive or other drug that could influence the results of the study, divided according to the Keith-Wagener classification into GI – 36 patients with HR grade I, GII – 35 with HR grade II and GIII – 19 with HR grade III. Serum and tear IMA levels were assessed using the Co²⁺ binding method and expressed as median and interquartile range. Kruskal-Wallis and Mann-Whitney nonparametric tests were used to compare the groups and the Spearman correlation coefficient was calculated (SPSS 23.0), with p<0.05 being statistically significant.

Results

The groups showed a statistically significant difference in serum IMA (p=0.006), the values increasing in parallel with the progression of HR. The serum IMA level in GII increased compared to GI (+3%; 239.06 μM/L (IQR 75.58) vs 231.77 μM/L (IQR 104.09), p=1.00), as well as in GIII patients compared to GII (+17%; 277.67 μM/L (IQR 88.72) vs 239.06 μM/L (IQR 75.58), p=0.04). There were no differences in IMA content (p=0.160), between groups in the tears. No correlations were found between serum and tear IMA levels (p=0.134), but serum IMA showed a significant moderate strength, positive correlation with the degree of HR (r=0.307, p=0.003).

Conclusion

A progressive enhancement in serum IMA level as HR advanced was identified. Thereby, the results suggest the potential relevance of serum IMA as a sensitive and early biomarker useful for grading and optimal treatment of the patients with HR.

Correlation IMA with TIMI frame count in slow coronary flow: can it be a guide for treatment?

AIM

Coronary slow flow (CSF) is defined as late opacification in epicardial coronary arteries with no significant stenosis. The aim of this study is to evaluate the relationship between ischemia-modified albumin (IMA) by using Spectrophotometer in CSF.

METHODS

Level of IMA was measured by spectrophotometer. CSF patients were chosen for the determination of IMA level. All obtained data were compared with control groups.

RESULTS

Serum IMA levels increased in the CSF group. It was observed that there was a significant increase in IMA levels in patients with CSF when compared to controls (p < 0.05).

CONCLUSION

IMA may play a role in the pathogenesis of CSF. IMA levels in the serum can be considered as a marker to predict coronary slow flow. IMA level can be used as a guide for coronary slow flow. Also, as increases number square frame, value IMA Increases similarly. It was found that the severity of impotence was correlated with CSF. Therefore, the IMA level may be predictive of the course of treatment. This study is the first one to show the relationships of IMA in CSF. In addition, further studies should be performed on IMA in CSF patients.

The relationship of ischemia-modified albumin levels to disease activity scores and HLA-B27 in patients with ankylosing spondylitis

OBJECTIVE:

Recent studies have implicated increased oxidative stress in the pathogenesis of Ankylosing spondylitis (AS). Ischemia-modified albumin (IMA), an altered form of albumin, increases oxidative stress. This study aimed to investigate the relationship between IMA levels and other indicators of disease severity in AS.

METHODS:

This study included 63 AS patients and 48 healthy controls. Patients were examined for serum lipid profile, C-reactive protein (CRP), complete blood count, Bath Ankylosing Spondylitis Disease Activity Index, human leukocyte antigen (HLA) B27, and treatment regimen. They were categorized based on disease activity, HLA-B27 status, and the drug treatment and compared for IMA levels.

RESULTS:

The patients had significantly higher IMA levels than controls (p=0.020); among patients, the levels were higher in those with active disease (p=0.001) and positively correlated with the CRP levels. No significant difference was found between the IMA levels of the patients with different HLA-B27 status or treatment method.

CONCLUSION:

The IMA levels were higher in patients than controls and further increased in patients with active AS. IMA was associated with disease activity and can be used as an inflammatory marker in AS. More comprehensive future studies with a larger sample size may help understand the relationship in greater detail.

Increased ischemia-modified albumin levels in children with steroid-sensitive nephrotic syndrome

Objective:

Growing evidence shows that oxidative stress plays an important role in the development and progression of nephrotic syndrome (NS). In this study, we aimed to examine serum IMA levels as an indicator of oxidative stress in children with steroid-sensitive NS (SSNS) in remission and relapse.

Methods:

This cross-sectional study was carried out at the Pediatric Nephrology Unit of Sanliurfa Training and Research Hospital, Sanliurfa, Turkey, from April 2019 to December 2019. In this study Serum IMA and albumin levels were determined in 70 children with SSNS and 45 healthy controls. Among the children with SSNS, 50 were in remission and 20 were in relapse. Then, adjusted IMA levels were calculated from the IMA/albumin ratio.

Results:

IMA and adjusted IMA levels significantly increased and albumin significantly decreased in children with SSNS in relapse and remission compared with those of the healthy controls. Moreover, these alterations were more prominent in the relapse group than in the remission group. IMA was inversely correlated with albumin in children with SSNS (r= −0.881, p= <0.001).

Conclusions:

Our findings demonstrated that elevated IMA and adjusted IMA levels observed in patients with SSNS were associated with increased oxidative stress and could indirectly reflect the degree of oxidative damage in glomerular structures.

The Role of microRNAs in Metabolic Syndrome-Related Oxidative Stress

Oxidative stress (OxS) is the cause and the consequence of metabolic syndrome (MetS), the incidence and economic burden of which is increasing each year. OxS triggers the dysregulation of signaling pathways associated with metabolism and epigenetics, including microRNAs, which are biomarkers of metabolic disorders. In this review, we aimed to summarize the current knowledge regarding the interplay between microRNAs and OxS in MetS and its components. We searched PubMed and Google Scholar to summarize the most relevant studies. Collected data suggested that different sources of OxS (e.g., hyperglycemia, insulin resistance (IR), hyperlipidemia, obesity, proinflammatory cytokines) change the expression of numerous microRNAs in organs involved in the regulation of glucose and lipid metabolism and endothelium. Dysregulated microRNAs either directly or indirectly affect the expression and/or activity of molecules of antioxidative signaling pathways (SIRT1, FOXOs, Keap1/Nrf2) along with effector enzymes (e.g., GPx-1, SOD1/2, HO-1), ROS producers (e.g., NOX4/5), as well as genes of numerous signaling pathways connected with inflammation, insulin sensitivity, and lipid metabolism, thus promoting the progression of metabolic imbalance. MicroRNAs appear to be important epigenetic modifiers in managing the delicate redox balance, mediating either pro- or antioxidant biological impacts. Summarizing, microRNAs may be promising therapeutic targets in ameliorating the repercussions of OxS in MetS.

Ischemia-Modified Albumin Levels and Thiol-Disulphide Homeostasis in Diabetic Macular Edema in Patients with Diabetes Mellitus Type 2

PURPOSE

It was aimed to assess the role of thiol-disulphide homeostasis and ischemia-modified albumin (IMA) level in the development of diabetic macular edema (DME) in patients with diabetes mellitus type 2 (T2DM).

MATERIALS AND METHODS

Sixty-six study patients were divided into two groups. Group I included 43 patients with T2DM and DME, and Group 2 included 23 patients with T2DM without eye involvement. A novel colorimetric method was used to assess thiol-disulphide homeostasis. Between the two groups IMA, total anti-oxidant, and total oxidant levels were measured and compared.

RESULTS

In Group 1, total and native thiol levels and disulphide levels were lower compared to Group 2 (p = .025, p < .001 and p = .013, respectively). Disulphide/native thiol, disulphide/total thiol ratios and native thiol/total thiol were similar between the groups. Total anti-oxidant level (TAL) reduced whereas total oxidant level (TOL) increased in Group 1 compared to Group 2 (p = .001, p = .002, respectively). Albumin level decreased, whereas IMA level increased in Group 1 compared to Group 2 (p < .001 for both).

CONCLUSIONS

The disruption in thiol/disulphide homeostasis, increased IMA and oxidative stress have an impact on the development of diabetic macular edema.

The evaluation of thiol-disulfıte balance, ischemıa albumın modıfıcation and seruloplazmine as a new oxidatıve stress in mild cognitive impairment and early stage alzheimer's disease patients

BACKGROUND

Alzheimer's Disease (AD) is the most common form of dementia seen in advanced age. It is characterized by progressive deterioration in cognitive functions. The prevalence of Alzheimer's disease increasing day by day due to the increase in the share of the elderly population in the general population due to developing health and living conditions, is limited and early diagnosis and effective treatment possibilities are very limited. From this point of view, a specific biomarker for AD is very important. As a new oxidative stress biomarker, the levels of thiol-disulfide balance, ischemia-modified albumin and seroloplazminin were evaluated. The aim of this study was to determine the serum levels of oxidative stress biomarkers in the early stages of the disease and to compare these oxidative stress markers with patients with mild cognitive impairment as a precursor form of Alzheimer's disease and to determine whether these markers develop at an earlier stage.

METHODS

30 volunteers with early stage AD according to NINCDS-ARDRA criteria, 19 volunteers with Midl Cognitive İmpairment according to PCA criteria and 30 volunteers with defined criteria were selected from the subjects aged between 55 and 88 who applied to Gazi University Health Research. Statistical analysis of the data showed that there was a significant difference between the endgroups and biomarkers for the early diagnosis of Alzheimer's disease, but this complicated matter has to be investigated in more comprehensive and detailed studie.

RESULTS

In the present study, we investigated oxidative stress parameters, thiol-disulphide balance, ischemia modified abumin and seruloplasmin in parallel with the impairment in cognitive dysfunction from control group to Mild Cognitive Impairment (MCD) and AD group by using a newly-developed method.

CONCLUSIONS

This is the first study in literature comparing Early Stages Alzheimer Disease (ESAD), MCD and healthy volunteer groups. Our study has revealed that these newly developed tests may be candidates as oxidative stress biomarkers in pathgenesis of AD. However it was concluded that more comprehensive and detailed studies are required to enlighten this issue.

Parameters of Oxidative and Inflammatory Status in a Three-Month Observation of Patients with Acute Myocardial Infarction Undergoing Coronary Angioplasty-A Preliminary Study

Background and Objectives: Patients with acute myocardial infarction (MI) are usually treated with percutaneous transluminal coronary angioplasty (PTCA), which is burdened with a risk of postoperative complications, often accompanied by biochemical disturbances. The aim of our study was to evaluate a set of selected parameters of oxidative and inflammatory status, which could be useful in the management of post-procedural care in MI patients after PTCA. Materials and Methods: In this preliminary study, ischemia modified albumin (IMA), advanced oxidation protein products (AOPP), thiol groups (SH), total antioxidant status (TAS), insulin growth factor-1 (IGF-1), presepsin (PSP), and trimethylamine N-oxide (TMAO) were chosen as candidate biomarkers, and were determined in patients with MI who underwent PTCA at two time points: During cardiac episodes (at admission to the hospital, T0) and 3 months later (T3). Results: Most of the examined parameters were significantly different between patients and control subjects (except for IMA and TAS), but only hsCRP changed significantly during the time of observation (T0 vs. T3). Discriminant analysis created a model composed of AOPP, hsCRP, PSP, and TMAO, which differentiated male subjects into a group with MI and a control (without cardiovascular diseases). Conclusion: This set of parameters seems useful in evaluating inflammatory and oxidative status in MI patients after PTCA.

Nitric Oxide Products are not Associated with Metabolic Syndrome

Background

Nitric oxide (NO) is oxidative stress biomarker which is regarded as one of the key determinants of energy metabolism and vascular tone. Considering the controversial reports on the association between nitric oxide products (NOx) and metabolic syndrome (MetS), the aim of the current study was to examine that potential relationship. Additionally, we aimed to evaluate a broad spectrum of other oxidative stress biomarkers [i.e., malondialdehyde (MDA), advanced oxidation protein products (AOPP), xanthine oxidoreductase (XOD), xanthine oxidase (XO) xanthine dehydrogenase (XDH)] in relation with MetS.

Methods

A total of 109 volunteers (46.8% of them with MetS) were included in this cross-sectional study. Biohemical and anthropometric parameters, as well as blood pressure, were obtained. The MetS was diagnosed according to the International Diabetes Federation criteria.

Results

Multivariate logistic regression analysis showed that XOD (OR=1.011; 95% CI 1.002-1.019; p=0.016), XO (OR=1.014; 95% CI 1.003-1.026; p=0.016), MDA (OR=1.113; 95% CI 1.038-1.192; p=0.003) and AOPP (OR=1.022; 95% CI 1.005-1.039; p=0.012) were the independent predictors of MetS, whereas no association between NOx and MetS was found. As XOD rose for 1 U/L, XO for 1 U/L, MDA for 1 μmol/L and AOPP for 1 T/L, probability for MetS rose for 1.1%, 1.4%, 11.3% and 2.2%, respectively. Adjusted R² for the Model was 0.531, which means that 53.1% of variation in MetS could be explained with this Model.

Conclusion

Unlike XOD, MDA and AOPP, NOx is not associated with MetS.

Ischemia modified albumin in experimental ovarian torsion with and without controlled reperfusion

Purpose: Ovarian torsion, being a gynecological emergency, requires to be rapidly diagnosed and treated with minimal consequences on ovarian function after the removal of torsion. As ischemia modified albumin (IMA) is considered a good biomarker in diverse ischemic diseases, the aim of our study was to determine the effect of different ovarian torsion/detorsion models on serum and ovarian homogenates levels of IMA in an experimental study.

Methods: IMA was measured in the serum and ovarian homogenates of 7 groups of female rats (10 animals in each group): 1 - control (no intervention); 2 - sham (only laparotomy); 3 - ischemia group: 3 hours ovarian torsion (OT); 4 - 3 hours OT (ischemia), 1 hour simple reperfusion; 5 - 3 hours ischemia, 1 hour controlled reperfusion that was assured during the first two minutes by opening and closing the clips on the ovarian pedicles in 10 seconds intervals, followed by simple reperfusion; 6 - 3 hours ischemia, 24 hours simple reperfusion; 7 - 3 hours OT, 24 hours controlled reperfusion. The results were analyzed by Welch’s ANOVA and Spearman correlation.

Results: Ischemia increases the IMA in both serum and ovarian homogenates compared to control and sham groups. The controlled reperfusion groups had a statistically significant lower IMA in serum compared to simple reperfusion groups. IMA was found to be higher in the ovarian homogenates of simple reperfusion compared to controlled reperfusion groups.

Conclusion: Our results suggest that controlled reperfusion prevent the processes that increase the IMA in ovarian torsion.

Ischemia-modified albumin: Crosstalk between fatty acid and cobalt binding

Myocardial ischemia is difficult to diagnose effectively with still few well-defined biochemical markers for identification in advance, or in the absence of myocardial necrosis. "Ischemia-modified albumin" (IMA), a form of albumin displaying reduced cobalt-binding affinity, is significantly elevated in ischemic patients, and the albumin cobalt-binding (ACB) assay can measure its level indirectly. Elucidating the molecular mechanism underlying the identity of IMA and the ACB assay hinges on understanding metal-binding properties of albumin. Albumin binds most metal ions and harbours four primary metal binding sites: site A, site B, the N-terminal site (NTS), and the free thiol at Cys34. Previous efforts to clarify the identity of IMA and the causes for its reduced cobalt-binding capacity were focused on the NTS site, but the degree of N-terminal modification could not be correlated to the presence of ischemia. More recent work suggested that Co2+ ions as used in the ACB assay bind preferentially to site B, then to site A, and finally to the NTS. This insight paved the way for a new consistent molecular basis of the ACB assay: albumin is also the main plasma carrier for free fatty acids (FFAs), and binding of a fatty acid to the high-affinity site FA2 results in conformational changes in albumin which prevent metal binding at site A and partially at site B. Thus, this review advances the hypothesis that high IMA levels in myocardial ischemia and many other conditions originate from high plasma FFA levels hampering the binding of Co2+ to sites A and/or B. This is supported by biophysical studies and the co-association of a range of pathological conditions with positive ACB assays and high plasma FFA levels.

Metabolic syndrome components are associated with oxidative stress in overweight and obese patients

OBJECTIVE

The aim of this study is to evaluate the influence of the body mass index (BMI) and the metabolic syndrome (MetS) parameters on oxidative and nitrosative stress in overweight and obese subjects.

SUBJECTS AND METHODS

Individuals were divided into three groups: the control group (G1, n = 131) with a BMI between 20 and 24.9 kg/m2, the overweight group (G2, n = 120) with a BMI between 25 and 29.9 kg/m2 and the obese group (G3, n = 79) with a BMI ≥ 30 kg/m2.

RESULTS

G3 presented higher advanced oxidation protein products (AOPPs) in relation to G1 and G2 (p = 0.001 and p = 0.011, respectively) whereas G2 and G3 had lower levels of nitric oxide (NO) (p = 0.009 and p = 0.048, respectively) compared to G1. Adjusted for the presence of MetS to evaluate its influence, the levels of AOPPs did not differ between the groups, whereas NO remained significantly lower. Data adjusted by the BMI showed that subjects with higher triacylglycerol levels had higher AOPPs (p = 0.001) and decreased total radical-trapping antioxidant parameter/uric Acid (p = 0.036). Subjects with lower high-density lipoprotein (HDL) levels and patients with higher blood pressure showed increased AOPPs (p = 0.001 and p = 0.034, respectively) and lower NO levels (p = 0.017 and p = 0.043, respectively). Subjects who presented insulin resistance had higher AOPPs (p = 0.024).

CONCLUSIONS

Nitrosative stress was related to BMI, and protein oxidation and nitrosative stress were related to metabolic changes and hypertension. MetS components were essential participants in oxidative and nitrosative stress in overweight and obese subjects.

The higher mortality associated with low serum albumin is dependent on systemic inflammation in end-stage kidney disease

BACKGROUND

The correlation of low serum albumin with mortality in patients with chronic kidney disease (CKD) is partly linked to its association with systemic inflammation. However, it is not clear to what extent albumin's correlation with mortality depends on concomitant systemic inflammation. Here we addressed this question in patients with CKD stage 5.

METHODS

Serum albumin (S-Alb), systemic inflammation (high-sensitive C-reactive protein, hsCRP), cardiovascular disease (CVD) and nutritional status (subjective global assessment, SGA) were assessed at baseline in 822 patients: 523 incident dialysis patients, 212 prevalent hemodialysis (HD) and 87 prevalent peritoneal dialysis (PD) patients. Patients were divided into four groups according to hsCRP and S-Alb in each cohort: Group 1 -normal S-Alb and normal hsCRP (reference); Group 2 -low S-Alb and normal hsCRP; Group 3-normal S-Alb and high hsCRP; Group 4-low S-Alb and high hsCRP. Survival over 60 months was analyzed.

RESULTS

In Cox analysis, Group 4 had an increased mortality risk (adjusted Hazard ratio (95% confidence interval): 1.62 (1.06-2.47); p = 0.02) whereas the augmented mortality risks for Groups 2 and 3 in univariate analyses were not significant after adjustments for age, gender, blood pressure, diabetes mellitus, smoking, SGA, renal function and renal replacement technique.

CONCLUSIONS

Whereas mortality risk was increased in CKD stage 5 patients with low S-Alb and high CRP, it was not increased in patients with low S-Alb and normal CRP. Our observation suggests that inflammatory status should be taken into account when using S-albumin for risk assessment in CKD stage 5 patients.

MG53 and disordered metabolism in striated muscle

MG53 is a member of tripartite motif family (TRIM) that expressed most abundantly in striated muscle. Using rodent models, many studies have demonstrated the MG53 not only facilitates membrane repair after ischemia reperfusion injury, but also contributes to the protective effects of both pre- and post-conditioning. Recently, however, it has been shown that MG53 participates in the regulation of many metabolic processes, especially insulin signaling pathway. Thus, sustained overexpression of MG53 may contribute to the development of various metabolic disorders in striated muscle. In this review, using cardiac muscle as an example, we will discuss muscle metabolic disturbances associated with diabetes and the current understanding of the underlying molecular mechanisms; in particular, the pathogenesis of diabetic cardiomyopathy. We will focus on the pathways that MG53 regulates and how the dysregulation of MG53 leads to metabolic disorders, thereby establishing a causal relationship between sustained upregulation of MG53 and the development of muscle insulin resistance and metabolic disorders. This article is part of a Special issue entitled Cardiac adaptations to obesity, diabetes and insulin resistance, edited by Professors Jan F.C. Glatz, Jason R.B. Dyck and Christine Des Rosiers.

A meta-analysis of the association of serum ischaemia-modified albumin levels with human hypothyroidism and hyperthyroidism

Serum levels of ischaemia-modified albumin (IMA) have been studied as a novel and simple measure of oxidative stress (OXS) in different thyroid pathologies. However, results of available studies in the literature were not consistent. This meta-analysis was attempted to quantify the overall effect size for serum IMA levels in human hypothyroidism (HT) and hyperthyroidism (HYT) and to study its associations with the thyroid profile. Databases of PubMed/Medline, EMBASE, Google Scholar, Web of Science and Science Direct were searched for articles. Data on serum IMA levels in HT, HYT patients and euthyroid controls were extracted to compute standardized mean differences (SMD) by the random-effects model. The associations between IMA and thyroid profile were computed by the meta-analysis of correlation coefficients. IMA levels in HT patients (SMD=1.12; Z=2.76; P=0.006) and HYT patients (SMD=1.64; Z=2.57; P=0.01) were significantly higher than in euthyroid controls and the thyroid treatment showed a favourble effect on serum IMA levels. There were strong and significant correlations between IMA and hormonal status in HT and HYT groups. This meta-analysis showing increased IMA level in both HT and HYT patients and its association with thyroid profile suggests that serum IMA could be used as a simple measure of increased OXS in thyroid dysfunction.

Oxidative Stress and Advanced Glycation End Products in Hashimoto's Thyroiditis

BACKGROUND

Oxidative stress, which occurs as a result of an imbalance between free-radical production and antioxidant defense mechanisms, has been implicated in the pathogenesis of several autoimmune disorders, including thyroid diseases. Importantly, it has been correlated to thyroid dysfunction. This study investigated the changes in oxidative balance in euthyroid Hashimoto's thyroiditis (HT) by means of specific serum tests, such as derived reactive oxygen metabolites (d-ROMs) and the biological antioxidant potential (BAP) test. In addition, advanced glycation end products (AGEs) and advanced oxidation protein products (AOPPs)--compounds formed by the transformation of proteins--were evaluated as potential new markers of oxidative stress in this disease.

METHODS

This study included 134 euthyroid subject: 71 newly diagnosed HT patients (63 females; M age = 38 ± 13 years) and 63 age and sex-matched healthy controls. None of them were on thyroxine therapy.

RESULTS

Serum d-ROMs were elevated, and BAP decreased in HT patients compared with controls (p < 0.001), and the two parameters were inversely correlated (r = -0.211; p = 0.027), clearly indicating an enhanced oxidative stress. Furthermore, AGE levels were higher in HT patients (M = 223.18 AU/g prot) than in controls (M = 189.636 AU/g prot; p = 0.020) and inversely correlated with BAP levels (r = -0.196; p = 0.037). In uni- and multivariate analysis, serum antithyroperoxidase antibodies were the main predictors for d-ROMs (p = 0.006), BAP (p < 0.001), and AGEs (p = 0.014), irrespective of thyrotropin and/or free thyroxine values. No differences in AOPPs levels were found between patients and controls (p = 0.923).

CONCLUSIONS

Oxidants are increased and antioxidants decreased in euthyroid HT patients. As a result, the oxidative/antioxidative balance is shifted toward the oxidative side. Moreover, this study reports on a possible significant involvement of AGEs in HT, thus contributing to a better definition of the redox homoeostasis dysregulation in HT.

Metabolic syndrome increases oxidative stress but does not influence disability and short-time outcome in acute ischemic stroke patients

Oxidative stress has been implicated in the pathophysiology of cardiovascular disease and MetS and it may be one of molecular mechanisms involved in stroke. The aims of the present study were to verify differences in oxidative stress markers in acute ischemic stroke patients with and without MetS and to verify whether MetS influences disability and short time outcome of the patients. 148 patients with acute ischemic stroke were divided in two groups: with MetS (n = 92) and without MetS (n = 56). The modified Rankin Scale (mRS) was used for measuring the functional disability after 3-month follow-up. The study assessed the metabolic profile and oxidative stress markers. Stroke patients with MetS had higher levels of lipid hydroperoxides (p < 0.0001) and advanced oxidation protein products (AOPP, p = 0.0302) than those without MetS. Hydroperoxides were directly and independently associated with MetS (OR: 1.000, 95 % IC = 1.000-1.000, p = 0.005). Linear regression demonstrated that AOPP levels (R(2) = 0.281, p < 0.0001) and oxidative stress index (OSI, R(2) = 0.223, p < 0.0001) were directly associated with triglycerides levels and hydroperoxides levels was also directly associated with glucose levels (R(2) = 0.080, p = 0.013. The mRS and short-come outcome did not differ after 3 months in both groups. In conclusion, an increase in oxidative stress markers was shown in acute ischemic stroke patients with MetS and this elevation seems to be involved mainly with changes in lipid profile, but the presence of MetS did not influence short-time disability and survival of the acute ischemic stroke patients.

Ischemia-modified albumin levels in overt and subclinical hypothyroidism

BACKGROUND

Free radical-mediated oxidative stress (OS) has been implicated in the pathogenesis of thyroid disorders. The ischemia-modified albumin (IMA) has been proposed as a marker of protein oxidative damage, which has been found to reflect hypoxic stress.

AIM

Our aim was to evaluate IMA, malondialdehyde (MDA), and reduced glutathione (GSH) levels in patients with overt hypothyroidism (OHT) and subclinical hypothyroidism (SHT) in comparison to euthyroid controls.

SUBJECTS AND METHODS

Albumin, IMA, IMA/albumin ratio, MDA, GSH, total cholesterol (TC), triglycerides (TG), HDL-Cholesterol were assessed in 105 subjects grouped into OHT, SHT patients, and euthyroid controls with 35 subjects in each group.

RESULTS

MDA and IMA levels were significantly elevated while the GSH concentrations were significantly lower in OHT and SHT patients compared to controls (p < 0.01). When IMA values were normalized for albumin concentrations, the IMA/albumin ratio was also significantly elevated in both patient groups compared to controls (p < 0.01). These changes were more pronounced in the OHT group when compared to SHT group. In OHT group, thyroid-stimulating hormone (TSH) levels showed significant positive correlation with MDA (r = 0.470, p = 0.004), IMA (r = 0.530, p = 0.001), and IMA/albumin ratio (r = 0.525, p = 0.001). Both IMA (r = -0.342, p = 0.041), IMA/albumin ratio (r = -0.378, p = 0.023) showed significant negative correlation with GSH in OHT patients. No significant correlation between variables was, however, observed in SHT group.

CONCLUSIONS

Increase of MDA and IMA levels with decreased antioxidant status indicate the presence of OS in hypothyroid patients, which was more pronounced in OHT patients. Elevated levels of IMA can be a clinically useful marker of protein oxidative damage and OS in hypothyroidism.

Association between advanced oxidation protein products and 5-year mortality risk among amazon riparian elderly population

Proteins are important targets of several modifications caused by oxidative stress, leading to structural changes and consequently partial or total loss of their functions. The oxidized proteins include advanced oxidation protein products (AOPP) derived from oxidation-modified albumin, as well as fibrinogen and lipoproteins. An increase in AOPP levels indicates an oxidative stress state and the presence of coexisting inflammation. Several investigations have also suggested an association between high AOPP levels and aging-related diseases. However, the link between elevated AOPP levels and elderly mortality risk has not yet been investigated. Here, we report on a 5-year longitudinal study that investigated the potential association between AOPP levels and mortality using a population-based representative sample of riparian elders living in Brazilian Amazon region (Maués-AM). Age, sex, socioeconomic and cultural conditions, chronic morbidities, polypharmacy, and previous morbidities were also tested as potential confounders. The AOPP levels were measured in 540 (84.78%) individuals, all of whom were followed over a 5-year period in order to establish the mortality rate. Within this study period, 74 (13.7%) elders died and 466 (86.3%) survived. The AOPP levels were higher among the elders who died within the 5-year period (46.27 ± 40.6 mmol/L) compared with those who survived (36.79 ± 20.84 mmol/L) (p = 0.002). The analysis confirmed the link between high AOPP levels and mortality risk, independent of other intervenient factors. These results suggest that elevated AOPP levels could be used to predict mortality risk in elderly patients.