Diagnostic potential of oxidative stress markers in children and adolescents with type 1 diabetes

Diabetes noninvasive diagnostics and monitoring through volatile biomarkers analysis in the exhaled breath using optical absorption spectroscopy

The review is aimed on the analysis the abilities of noninvasive diagnostics and monitoring of diabetes mellitus (DM) and DM-associated complications through volatile molecular biomarkers detection in the exhaled breath. The specific biochemical reactions in the body of DM patients and their associations with volatile molecular biomarkers in the breath are considered. The applications of optical spectroscopy methods, including UV, IR, and terahertz spectroscopy for DM-associated volatile molecular biomarkers measurements, are described. The applications of similar technique combined with machine learning methods in DM diagnostics using the profile of DM-associated volatile molecular biomarkers in exhaled air or "pattern-recognition" approach are discussed.

Disturbances in the intraventricular conduction system in teenagers with type 1 diabetes. A pilot study

Body Surface Potential Mapping (BSPM) is a multi-electrode synchronous method for examining electrocardiographic records on the patients' body surface that allows the assessment of changes in the heart conduction system. The aim of the study was to visualize and evaluate changes in the intraventricular system in adolescents with T1D.

PATIENTS AND METHODS

Inclusion criteria: age > 12 years, T1D duration >3 years, HbA1c >8%.

EXCLUSION CRITERIA

diagnosis of autonomic neuropathy, heart structural defects, heart failure. BSPM data were processed into map plotting to illustrate differences in ventricular activation time (VAT, isochron lines).

RESULTS

33 teenagers (20 boys), mean age 15.0 ± 2.1 years, T1D from 6.8 ± 4.1 years were included. Mean HbA1c was 9.6 ± 2.0%. In the standard ECG recording abnormalities were not present. The distribution of isolines on the group-mean map plotted for T1D patients only initially resembles the course of isolines on the group-map for normal subjects (N = 30), in whom the electrical impulse stimulating the heart ventricles passes through the atrio-ventricular node, then symmetrically excites the branches of His bundle and finally the Purkinje fibers. In T1D patients, after proper onset of intraventricular stimulation, the isolines reflecting the both ventricles reach higher time values, which indicates problems in the propagation of the ventricular depolarization.

Factors associated with oxidative stress status in pediatric patients with type 1 diabetes mellitus

Background Oxidative stress is implicated in both, the onset and the progression of type 1 diabetes mellitus (T1DM). There is accumulated evidence of increased biomarkers of oxidative stress in newly diagnosed, T1DM patients without complications, and in those with advanced disease. In this cross-sectional study, we investigated factors affecting oxidative stress status in pediatric patients with T1DM. Methods Advanced oxidation protein products (AOPP), prooxidant-antioxidant balance (PAB), total sulfhydryl (SH) groups, and superoxide dismutase (SOD) activity were determined in 170 children and adolescents with T1DM. Principal component analysis was used to investigate clustering of clinical and laboratory variables associated with elevated oxidative stress and reduced antioxidative defense biomarkers. Results Factor analysis extracted five factors, interpreted as (1) "weight status factor" including age, BMI, waist and hip circumferences; (2) "proatherogenic factor" that included LDL-cholesterol, non-HDL-cholesterol, and triglycerides; (3) "metabolic control factor" including glucose and HbA1c; (4) "renal marker factor" with positive loading of urinary albumin excretion rate and negative loading of GFR; and (5) "antiatherogenic factor" that included HDL-cholesterol. High AOPP levels were independently predicted by "proatherogenic" (OR: 2.32; 95% CI: 1.44-3.71; p < 0.001), "metabolic control" (OR: 2.24; 95% CI: 1.35-3.73; p < 0.01), and "renal marker" (OR: 1.65; 95% CI: 1.03-2.65; p < 0.05) factors. "Renal marker factor" was a significant predictor of PAB (OR: 0.52; 95% CI: 0.34-0.81; p < 0.01). Regarding antioxidative defense markers, reduced SH groups were predicted by "proatherogenic factor" (OR: 0.56; 95% CI: 0.34-0.94; p < 0.05), while "weight status factor" predicted lower SOD activity (OR: 1.66; 95% CI: 1.03-2.67; p < 0.05). Conclusions Cardiometabolic risk factors and renal function are associated with oxidative stress in pediatric T1DM patients.

Oxidative stress and adipokine levels were significantly correlated in diabetic patients with hyperglycemic crises

BACKGROUND

To investigate the relationship between blood adipokine level and oxidative stress in diabetic patients with hyperglycemic crises before and after treatment.

METHODS

We measured superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, total antioxidant capacity (TAC), and levels of 8-iso-prostaglandin F2α (8-iso-PGF2α), adiponectin, leptin, and resistin in 63 diabetic patients with hyperglycemic crises.

RESULTS

Prior to treatment, patients with hyperglycemic crises had significantly lower serum SOD activity, TAC, and adiponectin and leptin levels, and higher serum levels of MDA, 8-iso-PGF2α, and resistin compared with the healthy control individuals (all at P < 0.05). After treatment, SOD, TAC, adiponectin, and leptin levels increased significantly, while MDA, 8-iso-PGF2α, and resistin levels decreased significantly (all at P < 0.05) in the patients.

CONCLUSIONS

Diabetic patients with hyperglycemic crises have increased oxidative stress, which is associated with serum adipokine abnormalities; improved oxidative stress after treatment suggests that oxidative stress may serve as target and/or indicator for the treatment of hyperglycemic crises.

Leptin concentration and oxidative stress in diabetic ketoacidosis

BACKGROUND

Diabetes is a common metabolic state during ageing, and one in five elderly individuals suffers from diabetes. However, few studies have been performed in elderly diabetic patients, and large randomized clinical trials in this population are rare. The purpose of this study was to investigate changes in serum leptin levels in elderly patients with diabetic ketoacidosis (DKA) before and after treatment and assess its relationship with oxidative stress parameters.

MATERIALS AND METHODS

Serum leptin levels, plasma superoxide dismutase (SOD) activity, plasma malondialdehyde (MDA) levels, plasma total antioxidant capacity (TAC) and plasma 8-iso-prostaglandin F_2α (8-iso-PGF_2α ) levels were measured in elderly patients aged 81.76 ± 9.42 years with DKA before and after treatment.

RESULTS

Plasma SOD activity, TAC and serum leptins before treatment were significantly lower in elderly patients with DKA compared with the control group (P < 0.05), whereas plasma MDA and 8-iso-PGF_2α levels before treatment were significantly higher in elderly patients with DKA (P < 0.05). Plasma SOD activity, TAC and serum leptin levels in elderly patients with DKA were significantly elevated after treatment, whereas their plasma MDA and 8-iso-PGF_2α levels were significantly reduced (P < 0.05). Leptin levels negatively correlated with plasma 8-iso-PGF2α after treatment in elderly DKA patients (r = -0.36, P < 0.05). Stepwise multiple regression analysis showed that 8-iso-PGF_2α was a significant factor affecting serum leptin levels.

CONCLUSIONS

Serum leptin levels in the elderly patients with DKA were significantly reduced after treatment, which was associated with oxidative stress.

Effect of Antioxidant Supplementation on Total Antioxidant Status in Indian Children with Type 1 Diabetes

Hyperglycemia results in the overproduction of free oxygen radicals that impair the endogenous antioxidant defenses. A randomized controlled trial was conducted to compare the effect of 3 months of antioxidant supplementation in the form of foods rich in micronutrients with pharmacological supplement on total antioxidant status of Indian children with type 1 diabetes. Ninety children with diabetes (mean age 11.5 ± 3.6 yrs, 37 boys) were randomly allocated to three groups: Group 1 (n = 31) = DM controls; Group 2 (n = 30) = multimicronutrient syrup; and Group 3 (n = 29) = dietary supplements (nine snack recipes rich in micronutrients). They received intervention for 3 months. Healthy controls were enrolled from local schools. Fasting blood was tested for total antioxidant status (TAS) and glycosylated hemoglobin (HbA1C). Children with diabetes had lower TAS (0.70 ± 0.2 vs. 1 ± 0.24 mmol/l, p = .0001) compared to healthy controls. Anthropometric and biochemical parameters were similar at baseline for all groups of diabetic children. Group 1 showed significant deterioration in TAS at endline (0.72 ± 0.16 vs. 0.60 ± 0.17 mmol/l, p = .008). Increase in TAS recorded in Group 2 was from 0.66 ± 0.21 to 0.70 ± 0.16 mmol/l and in Group 3 was from 0.68 to 0.73 mmol/l. There was a significant difference between Group 1 and Group 3 for percentage change in TAS (-13% vs. 16%, p = .035). Postsupplementation there was an increase in TAS values in children with diabetes, but they were still lower than in healthy controls. Indian diabetic children have compromised antioxidant status, which may be improved by incorporation of multimicronutrient-rich recipes in their diets.

Administration of Selenium Decreases Lipid Peroxidation and Increases Vascular Endothelial Growth Factor in Streptozotocin Induced Diabetes Mellitus

Objective

The imbalance in oxidant/antioxidant status plays a pivotal role in diabetes mellitus (DM). Selenium is a integral component of the antioxidant enzyme glutathione peroxidase. Se treatment induces angiogenesis and improves endothelial function through increased expression of vascular endothelial growth factor (VEGF). The aim of this study is to investigate the effect of selenium on oxidative stress, VEGF, and endothelin 1 (ET1) in a DM rat model.

Materials and Methods

We performed an experimental animal study with 64 adult male Wistar-Albino rats. Rats were divided into the following groups (n=8): control (C)7, C21, C+sodium selenite (Se)7, and C+Se21 (control rats), and DM7, DM21, DM+Se7, and DM+Se21 (diabetic rats). Diabetes was induced by 2-deoxy-2-(3-methyl-3-nitrosoureido)- D-glucopyranose [streptozotocin (STZ)]. Three weeks after STZ, DM+Se7 rats received intraperitoneal (i.p.) injections of 0.4 mg/kg Se for 7 days. The DM+Se21 rats received these injections for 21 days. The same dose/duration of Se was administered to the C+Se7 and C+Se21 groups. The remaining rats (C7, C21, DM7, DM21) received physi- ologic saline injections for 7 or 21 days. Ferric reducing antioxidant power (FRAP), malon- dialdehyde (MDA), advanced oxidation protein products (AOPP), and endothelial function markers (VEGF and ET1) in plasma samples were measured.

Results

Diabetic rats (DM7 and DM21) had significantly increased plasma FRAP (P=0.002, P=0.001), AOPP (P=0.024, P=0.01), MDA (P=0.004, P=0.001), and ET1 (P=0.028, P=0.003) levels compared with C7 and C21 control rats. VEGF (P=0.02, P=0.01) significantly decreased in DM7 and DM21 diabetic rats compared with their controls (C7, C21). Se administration reversed the increased MDA and decreased VEGF levels, and lowered plasma glucose levels in the DM+Se7 and DM+Se21 diabetic groups compared with diabetic rats (DM7, DM21). We observed positive correlations between FRAP-AOPP (r=0.460), FRAP-ET1 (r=0.510), AOPP-MDA (r=0.270), and AOPP-ET1 (r=0.407), and a negative correlation between MDA-VEGF (r=-0.314).

Conclusion

We observed accentuated oxidative stress and impaired endothelial function in diabetes. Se treatment reduced lipid peroxidation and hyperglycemia. Se probably improved endothelial dysfunction in diabetic rats because of the increased VEGF levels.

Optimisation of an Advanced Oxidation Protein Products Assay: Its Application to Studies of Oxidative Stress in Diabetes Mellitus

Advanced oxidation protein products (AOPP) are reportedly elevated in the plasma of patients with a number of diseases, including diabetes mellitus, that involve oxidative stress. However, the accurate measurement of AOPP in human plasma is hampered by the formation of a precipitate following the addition of potassium iodide and glacial acetic acid according to the published assay procedure. Here we describe a modification of the AOPP assay which eliminates interference by precipitation and provides a robust, reliable, and reproducible protocol for the measurement of iodide oxidising capacity in plasma samples (intra-assay CV 1.7–5.3%, interassay CV 5.3–10.5%). The improved method revealed a significant association of AOPP levels with age (p < 0.05) and hypertension (p = 0.01) in EDTA-anticoagulated plasma samples from 52 patients with diabetes and 38 nondiabetic control subjects, suggesting a possible link between plasma oxidising capacity and endothelial and/or vascular dysfunction. There was no significant difference between AOPP concentrations in diabetic (74.8 ± 7.2 μM chloramine T equivalents) and nondiabetic (75.5 ± 7.0 μM chloramine T equivalents) individuals.

Increased serum levels of ischemia-modified albumin and C-reactive protein in type 1 diabetes patients with ketoacidosis

Ischemia-modified albumin (IMA) levels have been advocated as a biomarker for evaluating the oxidative stress status. No data are showed on the potential role of IMA in type 1 diabetes (T1D). We aimed to establish the correlation among serum levels of IMA, C-reactive protein (CRP), and diabetic ketoacidosis (DKA) in patients with T1D. Fifty-seven patients with T1D, 27 patients with DKA, and 40 controls were enrolled. Serum IMA and CRP levels were measured and evaluated to distinguish from DKA. CRP and IMA levels were significantly elevated in patients with DKA at admission to the hospital compared to non-DKA and control subjects. CRP and IMA levels were higher in non-DKA patients than in controls. CRP, plasma glucose, and IMA levels were reduced after insulin treatment. Serum IMA levels were an independent risk marker for DKA (OR = 1.225, p = 0.002, 95 % CI: 1.076-1.394). Receiver operating characteristic curve analyses showed no difference in the areas under curve for serum IMA and CRP values. This study indicates that IMA and CRP levels were significantly correlated with DKA diagnosis. IMA can act as a biomarker that reflects the presence of DKA.

Evidence for augmented oxidative stress in the subjects with type 1 diabetes and their siblings: a possible preventive role for antioxidants

BACKGROUND/OBJECTIVES

Oxidative stress (OS) is thought to be involved in both development of type 1 diabetes (T1D) and its further complications. In this study, certain biomarkers of OS were compared among the subjects with T1D, their non-diabetic siblings and unrelated healthy controls.

SUBJECTS/METHODS

Known cases of T1D from both sexes aged 5-25 years were enrolled in a case-control study (n(1)=60). There were two control groups; non-diabetic siblings (n(2)=60) and unrelated apparently healthy subjects (n(3)=60). Anthropometric, dietary and laboratory assessments were done.

RESULTS

There was no significant difference in dietary data among the groups. Total antioxidant capacity was significantly lower in T1D than both related and unrelated controls (1.6 ± 0.05, 1.7 ± 0.05 and 1.8 ± 0.06 mmol BSA equivalent/l, respectively, P=0.044). Both T1D subjects and their siblings showed lower glutathione peroxidase (GSH-px) levels (median (interquartile range): 22.2 (28.6), 29.9 (23) and 41.8 (73.6) U/ml, respectively, P=0.006). On the contrary, superoxide dismutase concentrations were significantly higher in T1D group and the siblings than unrelated healthy controls (243 (45.3), 157.8 (176.9) and 27.9 (8.7) U/l, respectively, P<0.001). Serum concentrations of GSH correlated with energy intake in the siblings (r=0.521, P<0.001) and unrelated controls (r=0.268, P=0.042) but not in T1D group. The associations remained significant after controlling for blood glucose (r=0.437, P=0.001 and r=0.420, P=0.011, respectively) in both the groups.

CONCLUSION

Augmented OS in the siblings may indicate an increased requirement for antioxidants in genetically diabetes-prone subjects.

Elevated advanced oxidation protein products (AOPPs) indicate metabolic risk in severely obese children

BACKGROUND AND AIMS

The assessment of oxidative stress may aid in the identification of subsequent metabolic risk in obese children. The objective of this study was to determine whether the plasma level of advanced oxidation protein products, analyzed with a recently proposed modified assay that involves a delipidation step (mAOPPs), was related to metabolic risk factors (MRFs) in severely obese children.

METHODS AND RESULTS

The plasma levels of mAOPPs were determined by spectrophotometry in 54 severely obese and 44 healthy children. We also measured lipid peroxidation biomarkers (thiobarbituric acid-reactive substances, malondialdehyde, and 8-isoprotane F(2α)) and sulfhydryl groups, a marker of antioxidant defense. Protein oxidation and lipid peroxidation markers were higher and sulfhydryl levels were lower in obese children compared with controls. Taking metabolic risk into account, obese children were subdivided according to the cutoff point (53.2 μmol/L) obtained for their mAOPPs values from the ROC curve. Anthropometric measures and the existence of hypertension did not differ between groups. The presence of dyslipidemia and insulin resistance was significantly higher in the group with higher mAOPPs levels. The highest levels of mAOPPs were found in the children with ≥3 MRFs. The level of mAOPPs was positively correlated with triglycerides and negatively correlated with high-density lipoprotein cholesterol. There was no correlation of this marker of protein oxidation with biomarkers of lipid peroxidation.

CONCLUSION

The determination of mAOPPs in delipidated plasma is an easy way to evaluate protein oxidation. It may be useful in severely obese children for better cardiovascular risk assessment.

Damage of DNA and proteins by major lipid peroxidation products in genome stability

Oxidative stress and lipid peroxidation (LPO) accompanying infections and chronic inflammation may induce several human cancers. LPO products are characterized by carbohydrate chains of different length, reactive aldehyde groups and double bonds, which make these molecules reactive to nucleic acids, proteins and cellular thiols. LPO-derived adducts to DNA bases form etheno-type and propano-type exocyclic rings, which have profound mutagenic potential, and are elevated in several cancer-prone diseases. Adducts of long chain LPO products to DNA bases inhibit transcription. Elimination from DNA of LPO-induced lesions is executed by several repair systems: base excision repair (BER), direct reversal by AlkB family proteins, nucleotide excision repair (NER) and recombination. Modifications of proteins with LPO products may regulate cellular processes like apoptosis, cell signalling and senescence. This review summarizes consequences of LPO products' presence in cell, particularly 4-hydroxy-2-nonenal, in terms of genomic stability.

A quantitative evaluation of total antioxidant status and oxidative stress markers in preeclampsia and gestational diabetic patients in 24-36 weeks of gestation

OBJECTIVE

To assess the plasma and serum maternal total antioxidant status, circulating levels of lipid peroxidation breakdown products (MDA), protein oxidation markers (AOPPs), myeloperoxidase (MPO) and lipid hydroperoxide (LHP) in preeclampsia, gestational diabetes mellitus (GDM) patients and compare them with noncomplicated normal pregnancies between 24 and 36 weeks of gestation.

STUDY DESIGN

27 GDM, 27 preeclampsia and 29 noncomplicated singleton pregnancies were included. The blood samples were taken at the diagnosis of disease.

RESULTS

TAS was decreased in GDM and preeclampsia when compared to normal pregnancies. MDA levels were higher only in GDM group than normal pregnancies. AOPP levels were increased but MPO and LHP levels were not changed both in GDM and preeclampsia when compared to normal pregnancies.

CONCLUSIONS

We concluded that increased oxidative stress and reduction in antioxidant defense mechanisms may contribute to disease processes both in GDM and preeclampsia.

Advanced oxidation protein products (AOPPs) in juvenile overweight and obesity prior to and following weight reduction

OBJECTIVES

To evaluate the formation of advanced oxidation protein products (AOPPs) in juvenile overweight/obesity and obesity-related disorders and to investigate the effect of weight reduction on AOPPs.

DESIGN AND METHODS

AOPPs were determined in 114 overweight/obese children and adolescents without/with insulin resistance and metabolic syndrome and compared with 53 lean controls. Measurements were repeated following weight reduction program (diet/exercise, bran-enriched diet/exercise, and diet/exercise plus metformin).

RESULTS

Overweight/obese subjects had higher AOPPs than lean controls, more elevated in patients with co-occurring metabolic syndrome. AOPPs positively correlated with central obesity, triglycerides, lipid peroxidation and insulin, and negatively with glucose to insulin ratio. AOPPs decreased following obesity intervention and DeltaAOPPs correlated with DeltaBMI%. AOPPs reduction was more pronounced in subjects on bran-enriched diet. Baseline AOPPs were a better predictor of clinically significant weight reduction than BMI%.

CONCLUSIONS

Juvenile overweight/obesity was associated with AOPPs accumulation, more pronounced in metabolic syndrome. Body mass reduction decreased oxidative stress, with bran-enriched diet being more effective than diet/exercise alone.