Oxidative Stress In Obese Children Research Articles

Obesity Is Associated with Sustained Symptomatology and Unique Inflammatory Features in Children with Asthma

Obesity complicates the clinical manifestations of asthma in children. However, few studies have examined longitudinal outcomes or markers of systemic inflammation in obese asthmatic children. We hypothesized that obese children with asthma would have: (1) poorer clinical outcomes over 12 months, (2) decreased responsiveness to systemic corticosteroid administration, (3) greater markers of systemic inflammation, and (4) unique amino acid metabolites associated with oxidative stress. Children 6 to 17 years of age (lean, N= 257; overweight, N= 99; obese, N= 138) completed a baseline visit and follow-up visit at 12 months. Outcome measures included asthma control, quality of life, lung function, and exacerbations. A subset received intramuscular triamcinolone and were re-evaluated at 7(+7) days. Leptin, adiponectin, C-reactive protein, total cholesterol, interleukin (IL)-1β, IL-6, IL-17, interferon gamma, tumor necrosis factor alpha, monocyte-chemoattractant protein-1, and amino acid metabolites were also quantified in plasma as potential biomarkers of outcomes in obese children. Obesity was associated with more symptoms, poorer quality life, and more exacerbations that persisted over 1 year despite greater medication requirements. Obese children also had minimal clinical improvement in asthma control and lung function after intramuscular triamcinolone. Leptin, C-reactive protein, and amino acid metabolites associated with glutathione synthesis and oxidative stress differed in obese children. Within the obese group, lower concentrations of arginine-related metabolites also distinguished uncontrolled from controlled asthma at 12 months. Obesity is associated with poorer asthma outcomes and unique systemic inflammatory features that may not be adequately modified with conventional asthma therapies. Novel approaches may be needed given increased symptoms and unique inflammation and oxidative stress in obese children with asthma.

Oxidative stress in obese children and adolescents with and without type 2 diabetes mellitus is not associated with obstructive sleep apnea.

Obesity, obstructive sleep apnea (OSA), and type 2 diabetes mellitus (T2DM) are associated with chronic low-grade inflammation and oxidative stress. In adults, increased lipid peroxidation, a marker of oxidative stress, was found in both metabolic syndrome and OSA. Studies on oxidative stress in children with T2DM and OSA are scarce. Plasma oxidized low-density lipoprotein (Ox-LDL) levels were evaluated in obese children and adolescents with/without T2DM, and the contribution of OSA to oxidative stress was investigated. Ten patients with T2DM, 8 with impaired glucose tolerance (IGT), and 20 body mass index-standard deviation score (BMI-SDS)-matched non-diabetic children (controls) were studied. They all underwent overnight polysomnography. Fasting plasma concentrations of Ox-LDL were measured and compared to the glycemic status and to the presence of OSA. Fourteen patients (36%) were diagnosed with OSA and 21 (55%) with hypertension. There were no significant group differences in plasma Ox-LDL levels or between patients with/without OSA. Plasma Ox-LDL levels were significantly higher among patients with hypertension compared to controls (P = 0.01), while they correlated with homeostasis model assessment (P = 0.02), BMI-SDS (P = 0.049), and systolic blood pressure (P = 0.002). The findings of this pilot study suggest that increased lipid peroxidation is associated with insulin resistance and hypertension in obese children and adolescents, while OSA has most likely minor influence.

Vitamin D supplementation, the metabolic syndrome and oxidative stress in obese children.

Previous studies suggest that vitamin D may play a role in cardiovascular and metabolic health. Oxidative stress has also been implicated in the development of cardiovascular disease. Evidence suggests that vitamin D deficiency may contribute to the occurrence of oxidative stress. This study aimed to determine whether treatment and correction of vitamin D deficiency in obese children led to changes in their metabolic profile, independent of changes in adiposity. In addition, we aimed to determine whether vitamin D deficiency and oxidative stress are causally related in obese children. In the retrospective arm, chart review identified 32 obese children who experienced normalization of vitamin D deficiency or insufficiency with vitamin D supplementation. We then correlated laboratory and anthropometric data with vitamin D levels. In the prospective arm of the study, urinary 8-isoprostane and hydrogen peroxide were measured before and after correction of vitamin D deficiency/insufficiency and correlated to vitamin D levels in seven patients. In our predominantly Hispanic population of obese children in an urban setting, we demonstrated a cause-effect relationship between vitamin D deficiency and oxidative stress. In contrast, we found no association between vitamin D status, adiposity, and markers of insulin sensitivity, nor any effect of vitamin D treatment on the same parameters. These discordant findings suggest a differential effect of vitamin D on cardiovascular risk factors such as oxidative stress and insulin resistance. To confirm these findings, further prospective studies with larger sample size and longer follow-up are warranted.

Effects of synbiotic on anthropometry, lipid profile and oxidative stress in obese children.

Recent studies have suggested some beneficial effects of probiotics and/or prebiotics on obesity in adults; such experience is limited in children and adolescents. This study was an open-label, randomised, controlled study including children with primary obesity. The first group was treated with a standard method with a reduced calorie intake and increased physical activity. The second group received add-on daily synbiotic supplementation during one month. The aim of this study was to evaluate potential effects of a synbiotic on anthropometric measurements, lipid profile and oxidative stress parameters. One month of supplementation of the synbiotic resulted in a significant reduction of weight (P<0.001) and body mass index (P<0.01). Changes (% reduction comparing to baseline) in anthropometric measurements, were significantly higher in the children receiving the additional synbiotic supplement (P<0.05). The percentage of children with weight loss was higher in the synbiotic group, but not statistically significant (71.4 vs 64.2%, P>0.05). At the 30(th) day of synbiotic intervention, serum total cholesterol, low density lipoprotein cholesterol and total oxidative stress levels significantly declined (P<0.05). Changes in serum lipid levels were significantly higher in the synbiotic group (P<0.05). Changes in serum total oxidative stress levels before and after the intervention period, were significant in synbiotic group (P<0.01). In our study, changes in weight, body mass index, and triceps skinfold thickness were higher in the group receiving the one month synbiotic supplement thin in the standard method group. The supplement tested also had a beneficial effect on lipid profile and total oxidative stress. To the best of our knowledge, this is the first study showing the effects of synbiotics on oxidative stress in obese patients with an additional effect on weight loss regarding to previous studies.

Urinary Biomarkers of Oxidative Stress and Insulin Resistance in Childhood Obesity

Obesity is a worldwide epidemic and is increasing in children. Obesity can lead to cardiovascular complications and diabetes and is associated with increased oxidative stress. However, characterization of urinary biomarkers of oxidative stress and its correlation to biomarkers of insulin resistance has not been studied in children. Thus, the aim of this study was to correlate biomarkers of oxidative stress to biomarkers of insulin resistance in obese children compared to lean children.Following informed consent, 52 children, 28 lean and 24 obese, were recruited to this study at Texas Children's Hospital. Out of the obese subjects, 48% had metabolic syndrome as defined by the National Cholesterol Education Program.Measures of oxidative stress included 8‐hydroxydeoxyguanosine (8OHdG), 8‐Isoprostane, protein carbonyl, nitrotyrosine, and thiobarbituric acid reactive substances. Assays were performed using enzyme‐linked immunosorbent assays and the coefficient of variation for all assays were &lt;10%. Paired T‐tests were used to compute statistical significance of parametric data and Wilcoxon tests were used for non‐parametric data. Among all the biomarkers of oxidative stress, 8‐OHdG was significantly increased in the obese subjects compared to the control (P‐value &lt;0.01) even when adjusted for BMI. There was a significant correlation of 8‐OHdG with features of the Metabolic syndrome and HOMA‐IR index.Thus, urinary 8‐hydroxyguanosine is a reliable indicator of oxidative stress in obese children and also correlates with insulin sensitivity. Since this marker is measured in urine, it affords a good non‐invasive method to detect children who are at increased cardiovascular risk.

The effect of lifestyle change and metformin therapy on serum arylesterase and paraoxonase activity in obese children

Obesity is known to be associated with many diseases in the long and short terms. Elevated oxidative stress contributes to the development of such obesity-related diseases as dyslipidemia, diabetes mellitus and hypertension. Levels of the endogenous antioxidants paraoxonase and arylesterase have been shown to decrease in such diseases. The purpose of this study was to investigate whether or not changes in lifestyle and metformin therapy would affect serum paraoxonase and arylesterase levels. The study was performed with 25 overweight, 26 obese and 25 morbidly obese patients aged 6-15 years as well as 27 healthy children. Serum paraoxonase (PON1) and arylesterase (ARE) activity levels and total cholesterol, triglyceride, low-density protein, high-density protein, very low-density protein, glucose, aspartate amino transferase and alanine amino transferase levels were measured. Enrolled patients were assessed at initial presentation and again at 6 months. No procedure was performed in the control group, while the overweight, obese and morbidly obese groups were recommended diet and exercise and given metformin therapy (insulin-resistant subjects only). Serum PON1 activity levels in patients with metabolic syndrome were significantly lower than those in individuals without metabolic syndrome (p<0.05), while lipid concentrations were significantly higher (p<0.05). Metabolic syndrome patients had higher serum glucose, total cholesterol, low-density protein, very low-density protein and triglyceride values compared to those of the control group but significantly lower high-density protein values (p<0.05). No difference was determined between the groups in terms of PON1 and ARE levels following diet and exercise and metformin therapy. Measurement of PON1 and ARE enzyme levels may be useful in monitoring the effectiveness of treatment aimed at reducing oxidative stress in obese children.

Markers of bone turnover in obese children. Relationship to the nutritional status and oxidative stress level.

Recent data showed that some bone related markers correlate with BMI in the pediatric population. Moreover, obesity in childhood increase the risk of atherosclerosis development by induced oxidative stress. The aim of this study was to determine the relationship between bone turnover markers, nutritional status and oxidative stress in obese children comparing to the lean controls. Bone turnover markers (osteocalcin (OC), N-terminal telopeptide of type I collagen (NTx), sRANKL), oxidative stress markers (TAC – total antioxidative capacity, glutathione peroxidase, oxy-LDL) and leptin were determined in 50 obese and 79 healthy children. BMI and body composition (fat mass (FAT), fat-free mass (FMM), predicted muscle mass (PMM) and total body water (TBW)) were evaluated in all children. OC was significantly lower in obese children and correlated significantly (negatively p

Evaluation of oxidant-antioxidant status in overweight and morbidly obese Saudi children.

To evaluate the antioxidant enzymes and oxidative products in overweight and obese Saudi children before the onset of metabolic complications. The study was carried out on 231 Saudi children. They were classified into three groups: uncomplicated overweight, uncomplicated morbid obesity, and the matched age group as control. All subjects underwent anthropometric measurements and activities of superoxide dismutase, catalase, glutathione peroxidase (GSH-Px), glutathione reductase, the concentrations of reduced GSH, malondialdehyde (MDA) oxidized low-density lipoprotein (ox-LDL) and advanced oxidation protein products (AOPPs) were measured in the blood of these groups. Overweight and obese children had a significantly higher body mass index, while obese children only had a significantly higher waist-to-hip ratio compared to that of the control group. The enzyme activities under study were significantly elevated in the overweight group, although they were significantly reduced among obese children. The concentration of GSH was reduced in both the overweight and obese groups. The mean values of ox-LDL, MDA and AOPP were non-significantly increased in overweight children, while they were significantly elevated in obese children compared to that of normal weight children. A significant disturbance of oxidant-antioxidant status was observed in severely morbid children. The increase of oxidative stress in obese children is associated with the increase in AOPPs and MDA which reflects an imbalance between reactive oxygen species production and antioxidant defense.

Markers of bone turnover in obese children: relationship to the nutritional status and oxidative stress level

Recent data showed that some bone related markers correlate with BMI in the pediatric population. Moreover, obesity in childhood increase the risk of atherosclerosis development by induced oxidative stress. The aim of this study was to determine the relationship between bone turnover markers, nutritional status and oxidative stress in obese children comparing to the lean controls. Bone turnover markers (osteocalcin (OC), N-terminal telopeptide of type I collagen (NTx), sRANKL), oxidative stress markers (TAC – total antioxidative capacity, glutathione peroxidase, oxy-LDL) and leptin were determined in 50 obese and 79 healthy children. BMI and body composition (fat mass (FAT), fat-free mass (FMM), predicted muscle mass (PMM) and total body water (TBW)) were evaluated in all children. OC was significantly lower in obese children and correlated significantly (negatively p

Urinary Biomarker of Vitamin E Status Is Negatively Correlated with Biomarkers of Oxidative Stress in Obese Children

Urinary Biomarker of Vitamin E Status Is Negatively Correlated with Biomarkers of Oxidative Stress in Obese Children

Oxidative stress in obese children and its relation with insulin resistance

In obese populations, oxidative stress plays a major role in the pathogenesis of serious diseases such as diabetes, coronary heart disease, and atherosclerosis. In this study, we investigated the status of oxidative stress in obese children as to nitrite/nitrate and glutathione peroxidase levels, and their relation with insulin resistance (IR). A total of 63 obese children were enrolled in the study. Each was relegated to one of three groups: 20 obese children without IR (11 adolescents, 9 prepubertal; mean age 10.27 +/- 2.36 years; 10 males, 10 females), 22 obese children with IR (13 adolescents, 9 prepubertal; mean age 11.26 +/- 2.52 years; 10 males, 12 females), and a control group of 21 children (14 adolescents, 7 prepubertal; mean age 11.41 +/- 2.00 years; 10 males, 11 females). Glutathione peroxidase levels were lower in the obese group with IR than in either the control group or the obese group without IR (0.032 +/- 0.01 vs. 0.048 +/- 0.01 and 0.042 +/- 0.01, respectively). Nitrite/nitrate levels were higher in the obese group with IR than in the control group or the obese group without IR (89.83 +/- 25.00 vs. 66.00 +/- 21.75, and 68.65 +/- 28.98, respectively) and compared by pubertal status, adolescents' results were similar. However, in prepubertal children, nitrite/nitrate and glutathione peroxidase levels were not significantly different between groups. Multiple regression analysis revealed that nitrite/nitrate levels were positively correlated with the homeostasis model assessment of IR (HOMA-IR) independent of body mass index, age, gender, serum lipids, and pubertal stages, and that glutathione peroxidase levels were negatively correlated with body mass index and HOMA-IR independent of age, gender, pubertal status, and serum lipids. This study demonstrates that oxidative stress exists even in populations of obese children, and that oxidative stress markers have a relation with the HOMA-IR, which was used as a surrogate marker of IR.

Endothelial dysfunction, inflammation, and oxidative stress in obese children and adolescents: markers and effect of lifestyle intervention

With an increasing prevalence, pediatric obesity is often a prelude to adulthood obesity, and represents a major public health issue. Comorbidities are very common and severe in obese adults, justifying the search for earlier markers or risk factors for cardiovascular diseases in obese children. Endothelial dysfunction has been found to be present in the early stages of atherosclerosis, and can be non-invasively assessed with widely accepted and well-standardized techniques at the macrocirculation level. Endothelial dysfunction at the microcirculation level is less documented in obese children. Obesity in children has been repeatedly and independently correlated to endothelial dysfunction, inflammation and oxidative stress markers, although the relationship between these factors remains to be investigated. However, this would not only allow substantial improvements in risk stratification, but also provide essential data regarding the evolution of endothelial dysfunction in childhood obesity, especially during puberty when pro-inflammatory and pro-oxidative changes, with relative insulin resistance, occur. Therapeutic strategies such as lifestyle interventions in early childhood obesity appear all the more necessary, optimally including both exercise and diet because of their known effects on inflammatory and oxidative stress markers, potentially reversing endothelial dysfunction.

Postprandial Endothelial Function, Inflammation, and Oxidative Stress in Obese Children and Adolescents

Most studies in adults suggest that acute glucose consumption induces a transient impairment in endothelial function. We hypothesized that obese youth would demonstrate reduced endothelial function and increased inflammation and oxidative stress following acute glucose ingestion and that transient elevations in plasma glucose would correlate with endothelial dysfunction, inflammation, and oxidative stress. Thirty-four obese (BMI ≥ 95th percentile) children and adolescents (age 12.4 ± 2.6 years; BMI = 37.9 ± 6.7 kg/m2; 50% females) underwent measurement of endothelial function (reactive hyperemic index (RHI)), glucose, insulin, C-reactive protein (CRP), interleukin-6 (IL-6), circulating oxidized low-density lipoprotein (oxLDL), and myeloperoxidase (MPO) in a fasting state and at 1- and 2-h following glucose ingestion. Repeated measures ANOVA with Tukey post-tests and Pearson correlations were performed. Glucose and insulin levels significantly increased at 1- and 2-h (all P values < 0.001). Compared to baseline, there were no statistically significant differences in 1- and 2-h RHI, CRP, IL-6, and oxLDL. However, MPO significantly decreased at the 1- (P < 0.05) and 2-h (P < 0.001) time points. At the 1-h time point, glucose level was significantly inversely correlated with RHI (r = -0.40, P < 0.05) and at the 2-h time point, glucose level was positively correlated with MPO (r = 0.40, P < 0.05). An acute oral glucose load does not reduce endothelial function or increase levels of inflammation or oxidative stress in obese youth. However, associations of postprandial hyperglycemia with endothelial function and oxidative stress may have implications for individuals with impaired glucose tolerance or frank type 2 diabetes.

Oxidative markers in children with severe obesity following low‐calorie diets supplemented with mandarin juice

To evaluate the effect of supplementing a hypocaloric diet with mandarin juice, a food with a high content of antioxidants (vitamin C, flavonoids and carotenoids), on biomarkers of oxidant/antioxidant status of severe obese children. Forty obese children were randomized into two groups pair-wise in a 4-week controlled intervention study. Both groups followed a hypocaloric diet. One group received additionally a supplementation of 500mL of 100% mandarin juice daily. Clinical data, anthropometry, dietary intake and fasting blood samples were collected at baseline and after the intervention. Lipid peroxidation was assessed by circulating levels of malondialdehyde, and protein oxidation was determined by the concentration of plasma carbonyl groups. The antioxidant defence was evaluated by red cell-reduced glutathione and plasma levels of α-tocopherol and vitamin C. The supplemented group experienced a decrease in the levels of malondialdehyde (-9.6%, p =0.014) and carbonyl groups (-36.1%, p =0.006) and an increase in antioxidants (α-tocopherol +16.1%, p=0.006, glutathione +36.1%, p < 0.0001, and vitamin C + 94.6%, p < 0.0001). The mandarin juice consumption with a reduced calorie diet positively affects the antioxidant defence and produces a decrease in biomarkers of oxidative stress in obese children.

Is obesity associated with oxidative stress in children?

We evaluated the presence of oxidative stress in obese children without co-morbidities. The study population included 68 children (30 girls, 38 boys), between 6 and 14 years of age. The levels of markers of oxidative damage (malondialdehyde [MDA], and plasma carbonyl groups [CG]) and measures of antioxidant defense, such as the enzyme glutathione peroxidase (GPx) and low molecular scavengers (erythrocyte-reduced glutathione [GSH], alpha-tocopherol and beta-carotene) were determined. Children were categorized in groups by the standard deviation score of body mass index (SDS-BMI). Twenty children were non-obese (SDS-BMI< or =1.33), and the 48 obese children (SDS-BMI> or =2) were further divided into two groups: SDS-BMI> or =3 (22 children) and > or =2 SDS-BMI<3 (26 children). The levels of MDA and CG were significantly higher (p<0.05) in children with SDS-BMI> or =3. The GPx activity was increased, while the GSH concentration was lower in obese children compared with non-obese children (p<0.01). There were no differences in serum alpha-tocopherol and beta-carotene levels between groups. MDA was the sole marker of oxidative damage that was positively correlated with SDS-BMI, (r=0.35, p=0.015), and negatively with high-density lipoprotein cholesterol (HDL-C) (r=- 0.32, p=0.027). GPx was inversely related to total cholesterol (r=- 0.34, p=0.019). In multiple regression analysis, we confirmed that SDS-BMI and HDL-C were determinants of MDA. Severe childhood obesity is associated with oxidative stress. Thus, providing foods with high antioxidant capacity in addition to a hypocaloric diet is crucial for the treatment of obese children.

The relationship between obesity and markers of oxidative stress in dogs

Obesity, a serious epidemic affecting much of our pet population, increases the risk of developing numerous diseases. It has been demonstrated that obesity increases oxidative stress in obese children, cats and other species. Oxidative stress can result in DNA damage with subsequent alterations in gene expression, cell signaling, mutations, cell death or cell transformation. These effects of oxidative damage predispose animals and humans to numerous disease processes and cancer. The objective of the study was to demonstrate that obese dogs are under oxidative stress resulting in DNA damage and decreased endogenous antioxidant protection measured by serum glutathione levels and the ratio of reduced (GSH) to oxidized (GSSG) glutathione. In this case–control study, 10 obese dogs were compared with aged-matched healthy control dogs. Dogs with BCS of 7 or greater (9 pt scale) were considered obese. Dogs were evaluated by history, physical exam, body condition score, CBC, serum biochemical analysis and total T4, with both groups showing no significant differences in CBC, serum biochemical or T4 analysis. Single-cell gel electrophoresis (Comet assay) was used to measure DNA damage, and high performance liquid chromatography was used to measure serum glutathione. Reduced glutathione levels were significantly higher in the obese group (p = 0.012). The results of this pilot study suggest that obesity is associated with an increase in antioxidant potential, therefore justifying a larger study with antioxidant supplementation to determine how antioxidants in weight loss diets effects endogenous antioxidant capabilities.