Oxidative Stress Status in Childhood Obesity: A Potential Risk Predictor

Obesity Is Associated with Oxidative Stress Markers and Antioxidant Enzyme Activity in Mexican Children

The relationship between metabolic disorders and oxidative stress is still controversial in the child population. The present cross-sectional study aimed to analyze the associations between obesity, cardiometabolic traits, serum level of carbonylated proteins (CPs), malondialdehyde (MDA), and the enzyme activity of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in children from Mexico City (normal weight: 120; obesity: 81). Obesity resulted in being positively associated with CAT (β = 0.05 ± 0.01, p = 5.0 × 10-3) and GPx (β = 0.13 ± 0.01, p = 3.7 × 10-19) enzyme activity. A significant interaction between obesity and sex was observed in MDA and SOD enzymatic activity (PMDA = 0.03; PSOD = 0.04). The associations between obesity, MDA level, and SOD enzyme activity were only significant in boys (boys: PMDA = 3.0 × 10-3; PSOD = 7.0 × 10-3; girls: p ≥ 0.79). In both children with normal weight and those with obesity, CP levels were positively associated with SOD enzyme activity (PNormal-weight = 2.2 × 10-3; PObesity = 0.03). In conclusion, in Mexican children, obesity is positively associated with CAT and GPx enzyme activity, and its associations with MDA levels and SOD enzyme activity are sex-specific. Therefore, CP level is positively related to SOD enzyme activity independently of body weight.

The Impact of Paediatric Obesity on Drug Pharmacokinetics: A Virtual Clinical Trials Case Study with Amlodipine

The incidence of paediatric obesity continues to rise worldwide and contributes to a range of diseases including cardiovascular disease. Obesity in children has been shown to impact upon the plasma concentrations of various compounds, including amlodipine. Nonetheless, information on the influence of obesity on amlodipine pharmacokinetics and the need for dose adjustment has not been studied previously. This study applied the physiologically based pharmacokinetic modelling and established a paediatric obesity population to assess the impact of obesity on amlodipine pharmacokinetics in children and explore the possible dose adjustments required to reach the same plasma concentration as non-obese paediatrics. The difference in predicted maximum concentration (Cmax) and area under the curve (AUC) were significant between children with and without obesity across the age group 2 to 18 years old when a fixed-dose regimen was used. On the contrary, a weight-based dose regimen showed no difference in Cmax between obese and non-obese from 2 to 9 years old. Thus, when a fixed-dose regimen is to be administered, a 1.25- to 1.5-fold increase in dose is required in obese children to achieve the same Cmax concentration as non-obese children, specifically for children aged 5 years and above.

Association between biomarkers of redox status and cytokines with different patterns of habitual physical activity in eutrophic and overweight/obese preschoolers: multivariate analysis of a cross-sectional study

BACKGROUND

Although it is well known that obesity is frequently associated with reduced levels of habitual physical activity (HPA), which contributes to determining severe oxidative stress and inflammatory state, this association is however unknown in preschoolers so far. This study aimed to investigate the association between biomarkers of redox status and cytokines with different patterns of HPA according to the adiposity of preschoolers.

METHODS

A cross-sectional study was conducted in 50 preschoolers (25 overweight/obese, OW/OB and 25 eutrophic, EU), matched for age, sex, economic level, and maternal education. Total antioxidant capacity (TAC), superoxide dismutase (SOD) and catalase (CAT) activities, substances reactive to thiobarbituric acid (TBARS), soluble tumor necrosis factor receptors (sTNFRs), and leptin levels were evaluated. HPA levels were evaluated by accelerometry (ActiGraph GT9X accelerometer). Correlation, multiple linear regression, and partial least squares regression analysis were used to determine the association between redox status biomarkers and cytokines with different patterns of HPA (HPA level, bouts of moderate to vigorous physical activity [MVPA], and multivariate pattern of HPA) in EU and OW/OB preschoolers.

RESULTS

OW/OB preschoolers had lower CAT activity, higher levels of TAC, TBARS, and cytokines, and similar levels of HPA to EU preschoolers. In EU preschoolers, SOD activity exhibited a stronger negative association with moderate intensity ranges of HPA (R2 = 0.18), and negative correlation with sTNFRs (r = -0.40 to -0.46). TBARS had a stronger positive association with ranges of light intensity in the multivariate pattern of HPA (R2 = 0.10). In OW/OB preschoolers, the HPA multivariate associative pattern was predominantly from vigorous intensity ranges. Thus, SOD activity had a positive association with the multivariate pattern of HPA (R2 = 0.38) and MVPA bouts (β [95% CI] = 0.457 [0.0026. 0.0576]). TAC had a negative association with the multivariate pattern of HPA (R2 = 0.38) and MVPA bouts (β [95% CI] = -0.718 [-0.0025. -0.0003]). Additionally, leptin levels were lower in OW/OB preschoolers engaged in vigorous physical activity (VPA) (8000-9999 counts/min) for longer periods of time.

CONCLUSION

The results of this study indicate that OW/OB preschoolers have higher levels of oxidative stress biomarkers and pro-inflammatory cytokines compared to EU preschoolers. Moreover, VPA may exert antioxidative and anti-inflammatory effects in OW/OB preschoolers.

Eating Behavior and Factors of Metabolic Health in Primary Schoolchildren: A Cross-Sectional Study in Greek Children

Childhood obesity has been associated with altered blood lipids and bad eating habits. In this cross-sectional study, we assessed cardiorespiratory fitness and metabolic health markers in regard to weight status and dietary habits in schoolchildren. In 134 children (6-11 years), we conducted: (1) Anthropometry, namely z-score BMI (z-BMI), waist-to-height ratio (WHtR), and body composition analysis. (2) Measurements of handgrip strength (HGS), resting metabolic rate (RMR) and VO2max. (3) Quantification of blood lipids and antioxidant vitamins A, E, C. (4) Eating breakfast assessment. About 35% of children were overweight/obese. The z-BMI positively correlated with WHtR (r = 0.637, p < 0.001), and adversely correlated with fat-free mass (r = -0.728, p < 0.001) and vitamin E (r = -0.286, p < 0.001). RMR and VO2max were greater in normal weight children compared to those with overweight/obesity (p < 0.001). HGS did not differ between these groups, but was negatively correlated with dyslipidemia as shown by TG/HDL-C ratio (r = -0.224, p = 0.037). According to regression analysis, eating breakfast routinely at home was positively associated with RMR and adversely associated with z-BMI. Hence, regular breakfast consumption at home may improve RMR in kids. Cardiorespiratory fitness and physical strength are key modulators of metabolic health in Greek children added to a social determinant of health i.e., eating breakfast at home.

Childhood obesity and hypertension in pregnancy: a two-sample Mendelian randomization analysis

BACKGROUND

The causal relationship between childhood obesity and hypertension in pregnancy remains unclear. To examine the causal association between childhood obesity and hypertension in pregnancy, two-sample Mendelian randomization analysis was applied.

METHODS

Single-nucleotide polymorphisms (SNPs) associated with childhood obesity were obtained from a published genome-wide association study (GWAS) of 13 848 European individuals. Summary-level data for hypertension in pregnancy were obtained from the FinnGen consortium (11534 cases and 162212 controls). Inverse-variance weighted analysis, weighted-median analysis, and Mendelian randomization-Egger regression were conducted in this Mendelian randomization analysis. Sensitivity analyses were conducted to confirm the accuracy and robustness of our results.

RESULTS

Genetically determined childhood obesity significantly affects hypertension in pregnancy by IVW [odds ratio (OR) = 1.161, 95% confidence interval (CI) 1.086-1.039; P = 9.92 × 10 -6 ] and weighted median (OR = 1.123, 95% CI 1.038-1.214; P  = 0.004). These results were validated by multiple sensitivity analyses.

CONCLUSION

A causal effect between genetically predicted childhood obesity and the risk of hypertension in pregnancy was identified. The prevention of hypertension in pregnancy should be promoted in populations with childhood obesity.

The Relationship Between Vitamin-D Deficiency and Protein Oxidation Among Obese Children

Aim: The aim of the study is to examine the relationship between obesity, Vitamin-D deficiency, and protein oxidation. Methods: Thiol-disulfide homeostasis, Vitamin-D, ischemia modified albumin, insulin, and lipid levels were compared among obese, pre-obese and normal-weight healthy children. Results: A total of 136 children (69 boys and 67 girls) were included in the study. The vitamin-D levels of obese children were lower than those of pre-obese and normal weight (p < 0.05). In the normal weight group, total thiol and native thiol were lower in the pubertal period than in adolescence; were higher in those with sufficient Vitamin-D level than those with insufficient and deficient Vitamin-D (p < 0.05). Vitamin-D level was lower in pre-obese girls than boys (p < 0.05). Those with high triglycerides had high disulfide/total thiol, disulfide, and disulfide/native thiol and low native thiol/total thiol (p < 0.05). Conclusion: Thiol-disulfide homeostasis is negatively affected by low vitamin D levels, pubertal period and high triglyceride levels.

Role of DAMPs and cell death in autoimmune diseases: the example of multiple sclerosis

Multiple sclerosis is a chronic neuroinflammatory demyelinating disease of the central nervous system (CNS) of unknown etiology and still incompletely clarified pathogenesis. The disease is generally considered a disorder resulting from a complex interplay between environmental risk factors and predisposing causal genetic variants. To examine the etiopathogenesis of the disease, two complementary pre-clinical models are currently discussed: the "outside-in" model proposing a peripherally elicited inflammatory/autoimmune attack against degraded myelin as the cause of the disease, and the "inside-out" paradigm implying a primary cytodegenerative process of cells in the CNS that triggers secondary reactive inflammatory/autoimmune responses against myelin debris. In this review, the integrating pathogenetic role of damage-associated molecular patterns (DAMPs) in these two scenario models is examined by focusing on the origin and sources of these molecules, which are known to promote neuroinflammation and, via activation of pattern recognition receptor-bearing antigen-presenting cells, drive and shape autoimmune responses. In particular, environmental factors are discussed that are conceptually defined as agents which produce endogenous DAMPs via induction of regulated cell death (RCD) or act themselves as exogenous DAMPs. Indeed, in the field of autoimmune diseases, including multiple sclerosis, recent research has focused on environmental triggers that cause secondary events in terms of subroutines of RCD, which have been identified as prolific sources of DAMPs. Finally, a model of a DAMP-driven positive feed-forward loop of chronic inflammatory demyelinating processes is proposed, aimed at reconciling the competing "inside-out" and "outside-in" paradigms.

The Current Prevalence of Underweight, Overweight, and Obesity Associated with Demographic Factors among Pakistan School-Aged Children and Adolescents-An Empirical Cross-Sectional Study

Purpose: This study investigated the most recent estimates of underweight, overweight, and obesity prevalence in Pakistani school-aged children and adolescents. Methods: A cross-sectional study was conducted using a convenience random clustered sampling approach with 3,551 Pakistani school children aged 9 to 17 years from 52 schools throughout seven districts in central Punjab province. The CDC US 2000 was used to define underweight (BMI < 5th percentile), overweight (85th ≤ BMI < 95th percentile), and obesity (95th percentile ≤ BMI) for different school grade cohorts (primary, middle, secondary, and higher secondary schools). As a trend test, the Chi-square test was used. A Spearman correlation analysis (r) was used to determine the correlations between demographic variables and weight status. A regression analysis was conducted to explore the predictive power of demographic factors in relation to body weight. Results: In Pakistani school-aged children and adolescents, the prevalence of underweight, normal weight, overweight, and obesity was 21.9%, 66.9%, 5.8%, and 5.4%, respectively. Significant correlations with body weight status were shown for individual demographic parameters (age, gender, school type, and school grade). Children in urban areas were more likely to be underweight, overweight, or obese than those in rural areas. Boys were found to have a lower BMI than girls. Accordingly, more boys than girls were underweight (odds ratio (OR) = 1.57, 95% CI: 1.33-1.85) and more girls had a higher risk of obesity than boys (OR = 1.39, 95% CI: 1.03-1.86). Lower grades showed more underweight (OR = 1.66, 95% CI: 1.39-1.99) whereas higher grades showed a higher risk of obesity (OR = 1.91, 95% CI: 1.41-2.57). Conclusions: In Pakistani school-aged children and adolescents, underweight, overweight, and obesity were prevalent. Compared with studies from 2011, the risk of overweight and obesity in Pakistan has decreased. However, this may also be due to the fact that students in Pakistan have a lower BMI compared to other countries. This issue has also been seen in the present study and is confirmed here by the high number of cases of underweight students. Future research studies should look into additional weight status correlates and factors. To evaluate the association between weight status and behavioral and other health variables, future research should use longitudinal or interventional designs.

Oxidant/Antioxidant Status Is Impaired in Sepsis and Is Related to Anti-Apoptotic, Inflammatory, and Innate Immunity Alterations

Oxidative stress is considered pivotal in the pathophysiology of sepsis. Oxidants modulate heat shock proteins (Hsp), interleukins (IL), and cell death pathways, including apoptosis. This multicenter prospective observational study was designed to ascertain whether an oxidant/antioxidant imbalance is an independent sepsis discriminator and mortality predictor in intensive care unit (ICU) patients with sepsis (n = 145), compared to non-infectious critically ill patients (n = 112) and healthy individuals (n = 89). Serum total oxidative status (TOS) and total antioxidant capacity (TAC) were measured by photometric testing. IL-6, -8, -10, -27, Hsp72/90 (ELISA), and selected antioxidant biomolecules (Ζn, glutathione) were correlated with apoptotic mediators (caspase-3, capsase-9) and the central anti-apoptotic survivin protein (ELISA, real-time PCR). A wide scattering of TOS, TAC, and TOS/TAC in all three groups was demonstrated. Septic patients had an elevated TOS/TAC, compared to non-infectious critically ill patients and healthy individuals (p = 0.001). TOS/TAC was associated with severity scores, procalcitonin, IL-6, -10, -27, IFN-γ, Hsp72, Hsp90, survivin protein, and survivin isoforms -2B, -ΔΕx3, -WT (p < 0.001). In a propensity probability (age-sex-adjusted) logistic regression model, only sepsis was independently associated with TOS/TAC (Exp(B) 25.4, p < 0.001). The AUC_TOS/TAC (0.96 (95% CI = 0.93–0.99)) was higher than AUC_TAC (z = 20, p < 0.001) or AUC_TOS (z = 3.1, p = 0.002) in distinguishing sepsis. TOS/TAC, TOS, survivin isoforms -WT and -2B, Hsp90, IL-6, survivin protein, and repressed TAC were strong predictors of mortality (p < 0.01). Oxidant/antioxidant status is impaired in septic compared to critically ill patients with trauma or surgery and is related to anti-apoptotic, inflammatory, and innate immunity alterations. The unpredicted TOS/TAC imbalance might be related to undefined phenotypes in patients and healthy individuals.

Gender-Specific Behaviour in Obesity Stages I-II: Imbalance of Aminothiol Status and Adipomyokine Profile in Subjects with Different Insulin Resistance Severity

The hyperproduction of oxidative stress and inflammatory biomarkers, which is paralleled by decreased levels of antioxidant and anti-inflammatory mediators, is part of cellular mechanisms that contribute to the disruption of metabolic homeostasis in obesity. Whether gender-specific alterations and gender-restricted associations in these biomarkers underlie the increased cardiometabolic risk in men compared to women is unclear. We enrolled 31 women and 29 men, aged ≥50 and ≤70 years and with body mass index ≥ 30 and <40 kg/m². We assessed the concentrations of aminothiols (cysteine, homocysteine, and glutathione), expression of oxidant/antioxidant balance, adipomyokines (leptin, adiponectin, myostatin, and interleukin-6), markers of chronic inflammation, and vitamin D, an index of nutritional state, in plasma and serum samples by using HPLC, ELISA, and chemiluminescent immunoassay methods. We measured insulin resistance (IR) by the homeostasis model assessment (HOMA) index. Despite comparable levels of visceral adiposity, IR, and a similar dietary regimen, men showed, with respect to women, higher oxidant concentrations and lower antioxidant levels, which paralleled IR severity. Myostatin levels correlated with prooxidant aminothiols among men only. Gender-specific alterations in aminothiol status and adipomyokine profile and the gender-restricted association between these biomarkers and metabolic derangement are consistent with an increased cardiometabolic risk in men compared to age-matched women with stage I-II obesity. Strict control of redox and inflammatory status, even addressing gender-specific nutritional targets, may be useful to prevent obesity-related metabolic alterations and comorbidities.

A Review of miRNAs as Biomarkers and Effect of Dietary Modulation in Obesity Associated Cognitive Decline and Neurodegenerative Disorders

There has been a progressive increase in the prevalence of obesity and its comorbidities such as type 2 diabetes and cardiovascular diseases worldwide. Recent studies have suggested that the crosstalk between adipose tissue and central nervous system (CNS), through cellular mediators and signaling pathways, may causally link obesity with cognitive decline and give rise to neurodegenerative disorders. Several mechanisms have been proposed in obesity, including inflammation, oxidative stress, insulin resistance, altered lipid and cholesterol homeostasis, which may result in neuroinflammation, altered brain insulin signaling, amyloid-beta (Aβ) deposition and neuronal cell death. Since obesity is associated with functional and morphological alterations in the adipose tissues, the resulting peripheral immune response augments the development and progression of cognitive decline and increases susceptibility of neurodegenerative disorders, such as Alzheimer's Disease (AD) and Parkinson's Disease (PD). Studies have also elucidated an important role of high fat diet in the exacerbation of these clinical conditions. However, the underlying factors that propel and sustain this obesity associated cognitive decline and neurodegeneration, remains highly elusive. Moreover, the mechanisms linking these phenomena are not well-understood. The cumulative line of evidence have demonstrated an important role of microRNAs (miRNAs), a class of small non-coding RNAs that regulate gene expression and transcriptional changes, as biomarkers of pathophysiological conditions. Despite the lack of utility in current clinical practices, miRNAs have been shown to be highly specific and sensitive to the clinical condition being studied. Based on these observations, this review aims to assess the role of several miRNAs and aim to elucidate underlying mechanisms that link obesity with cognitive decline and neurodegenerative disorders. Furthermore, this review will also provide evidence for the effect of dietary modulation which can potentially ameliorate cognitive decline and neurodegenerative diseases associated with obesity.

Redox Imbalance and Methylation Disturbances in Early Childhood Obesity

Obesity is increasing worldwide in prepubertal children, reducing the age of onset of associated comorbidities, including type 2 diabetes. Sulfur-containing amino acids, methionine, cysteine, and their derivatives play important roles in the transmethylation and transsulfuration pathways. Dysregulation of these pathways leads to alterations in the cellular methylation patterns and an imbalanced redox state. Therefore, we tested the hypothesis that one-carbon metabolism is already dysregulated in prepubertal children with obesity. Peripheral blood was collected from 64 children, and the plasma metabolites from transmethylation and transsulfuration pathways were quantified by HPLC. The cohort was stratified by BMI z-scores and HOMA-IR indices into healthy lean (HL), healthy obese (HO), and unhealthy obese (UHO). Fasting insulin levels were higher in the HO group compared to the HL, while the UHO had the highest. All groups presented normal fasting glycemia. Furthermore, high-density lipoprotein (HDL) was lower while triglycerides and lactate levels were higher in the UHO compared to HO subjects. S-adenosylhomocysteine (SAH) and total homocysteine levels were increased in the HO group compared to HL. Additionally, glutathione metabolism was also altered. Free cystine and oxidized glutathione (GSSG) were increased in the HO as compared to HL subjects. Importantly, the adipocyte secretory function was already compromised at this young age. Elevated circulating leptin and decreased adiponectin levels were observed in the UHO as compared to the HO subjects. Some of these alterations were concomitant with alterations in the DNA methylation patterns in the obese group, independent of the impaired insulin levels. In conclusion, our study informs on novel and important metabolic alterations in the transmethylation and the transsulfuration pathways in the early stages of obesity. Moreover, the altered secretory function of the adipocyte very early in life may be relevant in identifying early metabolic markers of disease that may inform on the increased risk for specific future comorbidities in this population.

Cardiovascular Risk Factors in Children with Obesity, Preventive Diagnostics and Possible Interventions

The increasing burden of obesity plays an essential role in increased cardiovascular morbidity and mortality. The effects of obesity on the cardiovascular system have also been demonstrated in childhood, where prevention is even more important. Obesity is associated with hormonal changes and vascular dysfunction, which eventually lead to hypertension, hyperinsulinemia, chronic kidney disease, dyslipidemia and cardiac dysfunction—all associated with increased cardiovascular risk, leading to potential cardiovascular events in early adulthood. Several preventive strategies are being implemented to reduce the cardiovascular burden in children. This paper presents a comprehensive review of obesity-associated cardiovascular morbidity with the preventive diagnostic workup at our hospital and possible interventions in children.

Nutritional Status Influences Oxidative Stress and Insulin Resistance in Preschool Children

Background: Child malnutrition represents a major public health problem with physiological, psychological, and social short- and long-term implications. Objective: To compare the influence of nutritional status on oxidative stress (OS) markers in children aged 3-6 years. Methods: Children were categorized into four groups: underweight, normal weight, overweight, and obesity. Glucose (Glu), cholesterol (Chol), high-density lipoproteins, insulin, triacylglycerols (TG), triacylglycerols/glucose (TyG) index, and the homeostasis model assessment of insulin resistance (HOMA-IR) were analyzed. In addition, OS [malondialdehyde (MDA) and 3-nitrotyrosine (3-NT)] and antioxidant defense markers [superoxide dismutase (SOD), catalase (CAT), and the ratio of reduced/oxidized glutathione (GSH/GSSG)] were quantified. Results: Children with obesity showed significantly higher levels of MDA and 3-NT, and increased SOD activity compared with normal weight children. Glu, Chol, TG levels, TyG indexes, HOMA-IR, MDA, 3-NT, and SOD positively correlated with body mass index (BMI) and Centers for Disease Control and Prevention percentiles (CDC PC). However, CAT concentration and the GSH/GSSG ratio correlated negatively with BMI and CDC PC. In children with underweight, we found a positive correlation of TG levels and TyG indexes with BMI, whereas both markers positively correlated with BMI and CDC PC in children with overweight. MDA negatively correlated with BMI in children with underweight, while a positive association was observed in children with overweight. Finally, SOD, CAT, and GSH/GSSG negatively correlated with both BMI and CDC PC in children with overweight. Conclusions: Malnutrition, especially obesity, is associated with metabolic and OS disturbances in preschool children. It is urgent to design strategies to prevent malnutrition in this age group since this stage of development is crucial to potentially avoid future co-morbidities.

Relation between Inflammation, Oxidative Stress, and Macronutrient Intakes in Normal and Excessive Body Weight Adolescent Girls with Clinical Features of Polycystic Ovary Syndrome

The impact of diet on inflammation and oxidative stress (OS) in girls with polycystic ovary syndrome (PCOS) is unknown. Therefore, our study aimed to investigate, in PCOS girls, whether certain macronutrient intakes can be associated with these disturbances. For this purpose, 59 PCOS participants (aged 14-18 years) were recruited to this study and divided into two subgroups: overweight/obese-Ov/Ob group (n = 22) and normal weight-N group (n = 37). Nutrition was assessed using a 3-day food record. The studied markers were total antioxidant capacity (TAC), malondialdehyde (MDA), C-reactive protein (CRP), tumor necrosis factor α (TNF-α), and interleukins 1 and 6 (IL-1 and IL-6). We found plant protein intake inversely correlated with IL-6 (p = 0.007; r = -0.557), TNF-α (p = 0.006; r = -0.564), MDA (p = 0.01; r = -0.539) in the Ov/Ob group and with TAC (p = 0.021; r = -0.38) in the N group. Inverse correlations in the Ov/Ob group were observed between protein intake and IL-6 (p = 0.031; r = -0.461), TNF- α (p = 0.043; r = -0.435); carbohydrates and IL-6 (p = 0.037; r = -0.448), MDA (p = 0.045; r = -0.431); fiber and IL-6 (p = 0.025; r = -0.475). A positive relationship between cholesterol intake and CRP concentration (p = 0.038; r = 0.342) was also found in the N group. These findings revealed that inflammation and OS are increased in Ov/Ob girls with decreased plant protein intake and low carbohydrates in the diet. Moreover, inflammation may be increased by cholesterol intake in slim PCOS girls. On the other hand, decreased intake of fiber and total protein intake increased inflammation. ClinicalTrials.gov Identifier: NCT04738409.

Alterations in glutathione redox homeostasis among adolescents with obesity and anemia

The reduced (GSH)-to-oxidized (GSSG) glutathione ratio represents a dynamic balance between oxidants and antioxidants. However, redox status in adolescents with obesity and anemia has not been investigated. This study investigated the association of erythrocyte GSH redox status (GSH, GSH:GSSG ratio, and glutathione peroxidase [GPx] activity) with anemia and adiposity in adolescents. This case–control study nested in a cross-sectional study enrolled 524 adolescents (268 boys; 256 girls). The prevalence of anemia in overweight and obesity (OWOB) was 5.2% in boys and 11.7% in girls. The GSH:GSSG ratio and GPx activity were significantly higher in girls than in boys (p < 0.001), in anemic than in non-anemic subjects (p < 0.001), and in OWOB than in normal-weight subjects (p < 0.001). Similarly, significantly higher GSH: GSSG level (p < 0.001) and GPx activity (p < 0.001) were found in subjects with 90th percentile waist circumference than in those with < 90th percentile. GPx and GSH:GSSG were positively associated with anemia after adjusting for age, sex, and body mass index (adjusted odds ratio, adjOR [95% confidence interval, CI] 2.18 [1.44–3.29]) or tertiles (adjOR [95% CI], T3 = 2.49 [1.03–6.01]). A similar association was noted for GSH and GPx. A compensatory increased redox defense mechanism exists in anemia and obesity among adolescents without metabolic disturbances.

Effects of Oxidant-Antioxidant and Vitamin D Levels on Clinical and Laboratory Data in Children With Fatty Liver Disease

Background and Aims

Fatty liver increases oxidative stress and may trigger antioxidant mechanisms. We aimed to compare the levels of vitamin D, which has antioxidant properties, as well as total oxidant status (TOS), total antioxidant status (TAS), and catalase between patients with nonalcoholic fatty liver (NAFL) and the control group.

Methods

We compared vitamin D, TOS, TAS, catalase levels, and other biochemical parameters between pediatric patients with ultrasonographically detected NAFL and an age-matched healthy control group.

Results

NAFL patients had a significantly lower vitamin D level (p < 0.001). The patient group also had significantly greater height, weight, body mass index (BMI) Z score, parathyroid hormone, triglyceride, glucose, antioxidant (TAS and catalase), and TOS levels compared to the controls (p ≥ 0.001). There was no significant difference between the obese and non-obese NAFL patients with respect to TAS, TOS, catalase levels, and other biochemical parameters (p < 0.05). There was a positive correlation between height, weight, BMI Z score, and hepatosteatosis grade, and TAS, TOS, and catalase levels, and a negative correlation with vitamin D level. We also found a negative correlation between vitamin D level and TOS and catalase level.

Conclusions

Our study revealed lower levels of vitamin D and higher levels of oxidant-antioxidants including TOS, TAS, and catalase in patients with NAFL.

Iron Metabolism in Obesity and Metabolic Syndrome

Obesity is an excessive adipose tissue accumulation that may have detrimental effects on health. Particularly, childhood obesity has become one of the main public health problems in the 21st century, since its prevalence has widely increased in recent years. Childhood obesity is intimately related to the development of several comorbidities such as nonalcoholic fatty liver disease, dyslipidemia, type 2 diabetes mellitus, non-congenital cardiovascular disease, chronic inflammation and anemia, among others. Within this tangled interplay between these comorbidities and associated pathological conditions, obesity has been closely linked to important perturbations in iron metabolism. Iron is the second most abundant metal on Earth, but its bioavailability is hampered by its ability to form highly insoluble oxides, with iron deficiency being the most common nutritional disorder. Although every living organism requires iron, it may also cause toxic oxygen damage by generating oxygen free radicals through the Fenton reaction. Thus, iron homeostasis and metabolism must be tightly regulated in humans at every level (i.e., absorption, storage, transport, recycling). Dysregulation of any step involved in iron metabolism may lead to iron deficiencies and, eventually, to the anemic state related to obesity. In this review article, we summarize the existent evidence on the role of the most recently described components of iron metabolism and their alterations in obesity.

Antioxidant Enzymes Haplotypes and Polymorphisms Associated with Obesity in Mexican Children

Obesity is a major health problem worldwide and constitutes a sanitary emergency in Mexico, especially childhood obesity. Several studies have proved the relationship between obesity and oxidative stress and the influence of genetic predisposition. This work was aimed to analyze the association of antioxidant enzyme polymorphisms with overweight and obesity in Mexican children and adolescents. A case-control study was performed in 585 children and adolescents aged 3 to 17 years, using two criteria to classify obesity: body mass index (BMI) and body fat percentage (BFP). Anthropometric and biochemical measurements were carried out, and malondialdehyde serum levels were determined. Genotyping was done with the Axiom Genome-Wide LAT microarray, including 68 single nucleotide polymorphisms (SNPs) of the glutathione peroxidase (GPX) and paraoxonase (PON) families. We found six haplotypes associated with obesity—two of them (one in GPX3 and the other in GPX5 and GPX6) in a protective direction when obesity was classified by BMI. The other four haplotypes were associated with obesity when classification was based on BFP—one of them in GPX3 in a protective direction and the others in PON genes conferring obesity risk. In addition, two SNPs, GPX3 rs922429 and GPX4 rs2074451 showed protection against obesity classified by BFP. This study showed genetic susceptibility to oxidative stress in relation to obesity in Mexican children and opens up the possibility that some genetic loci related to obesity are not identified when weight classification is based on BMI.

Antioxidants and Oxidative Stress in Children: Influence of Puberty and Metabolically Unhealthy Status

Oxidative stress could help explain the relationship between childhood obesity and a metabolically unhealthy (MU) status. Moreover, puberty could also influence this relationship, since it entails physiological cardiometabolic changes. We aimed to evaluate plasma antioxidants and oxidative stress biomarkers in MU and metabolically healthy (MH) prepubertal and pubertal children and their associations with pro-inflammatory and endothelial damage biomarkers, taking puberty into account. A total of 1444 Spanish children aged 3-17 years (48.9% males, 66% prepubertal, 47.1% with obesity) were recruited. Blood pressure, anthropometric and biochemical parameters were measured, and children were categorized as having a MU or MH status according to risk factors. Retinol, carotenes, tocopherols, total antioxidant capacity (TAC), oxidized low-density lipoprotein and selected pro-inflammatory and endothelial damage biomarkers were analyzed. General linear models adjusted for age, sex, recruitment center and body mass index, partial correlations and stepwise linear regressions were performed. Lower carotenes and tocopherols levels were found in MU than in MH children. Plasma TAC was lower in prepubertal and higher in pubertal children with obesity compared to normal-weight children. Antioxidants and oxidative stress biomarkers showed novel associations with several pro-inflammatory and endothelial damage biomarkers, with pubertal differences, supporting the importance of considering both the antioxidant and oxidative stress status and puberty in the prevention of metabolic diseases in childhood.

Unhealthy lifestyle and oxidative damage in childhood obesity

PURPOSE

Oxidized LDL cholesterol (oxLDL) has been considered as a sensor of oxidative stress (OS) in childhood obesity. We integrated and related our oxLDL existing results previously assessed in overweight/obese children to lifestyle variables to investigate OS-related lifestyle variables.

METHODS

178 Caucasian children/adolescents have been evaluated and according to BMI percentiles have been classified as normal weight (BMI < 75th); overweight (BMI 75-97th) and obese (BMI > 97th). Serum oxLDL levels have been measured. The dietary habits and physical activity have been also assessed.

RESULTS

No differences between normal weight and overweight/obese children were detected according to the total score of dietary habits section. Normal weight subjects reported a higher total physical activity score (p = 0.001) compared to overweight/ obese children. No correlation between oxLDL and total dietary habits and physical activity scores was noted. Increased oxLDL in subjects drinking < 1 L/day of water (p = 0.022) and in daily consumers of chocolate drinks at breakfast (p = 0.029) was observed, while a decreased oxLDL was reported in subjects consuming a breakfast based mainly on fruits (p = 0.004). Moreover, "high-fat diet" and "always eating a dessert at the end of the meal" were correlated with increased oxLDL with a trend towards significance. As regards physical activity, no correlations were observed.

CONCLUSIONS

Diet and physical activity may not have an immediate impact on OS response in children with or without obesity. Unhealthy lifestyle, including increased fat, simple sugar intake, poor water intake, emerged as external exposome predictors of OS, that may be monitored to improve health status.

LEVEL OF EVIDENCE

Level III, case-control analytic studies.

Systemic anti-oxidant capacity is inversely correlated with systolic blood pressure and pulse pressure in children with obesity

BACKGROUND AND AIMS

Oxidative stress leading to endothelial dysfunction is a candidate driver of obesity-related hypertension. We aimed to assess whether the total anti-oxidant capacity (TAC) was associated with blood pressure in children/adolescents with obesity.

METHODS AND RESULTS

One hundred and fifty-two children/adolescents with obesity (79 boys; age 11.9+/-2.5 years) underwent blood drawing for the assessment of TAC, lipids and HOMA-IR. Blood pressure was measured and classified according to the latest American Academy of Pediatrics Guidelines. Serum TAC was measured by a commercial kit (Sigma-Aldrich). The average TAC was 1.11+/-0.4 mMol/Trolox equivalents. Systolic blood pressure was predicted by TAC (B = -5.8, p = 0.003), z-BMI (B = 2.39, p = 0.008), height [cm] (B = 0.38, p < 0.001) and diastolic blood pressure (B = 0.56, p < 0.001). Diastolic blood pressure was predicted by age [years] (B = 0.58, p = 0.001), log-HOMA-IR (B = 3.0, p = 0.002), and systolic blood pressure (B = 0.26, p < 0.001), but not by TAC. The pulse pressure was predicted only by TAC (B = - 6.6, p = 0.002), and height [cm] (B = 0.42, p < 0.001). Overall "elevated blood pressure + hypertension" or hypertension alone were not associated with TAC. However, systolic "elevated blood pressure + hypertension" was associated with TAC (OR = 0.4 [0.1-0.9], p = 0.037), and z-BMI (OR = 2.1 [1.3-3.6], p = 0.004).

CONCLUSION

The systemic anti-oxidant capacity is inversely associated with systolic blood pressure and pulse pressure in children and adolescents with obesity.

Long non-coding RNA HCP5 serves as a ceRNA sponging miR-17-5p and miR-27a/b to regulate the pathogenesis of childhood obesity via the MAPK signaling pathway

Background This study aimed to investigate the completing endogenous RNA (ceRNA) network involved in childhood obesity. Methods The microarray dataset GSE9624 was downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed long non-coding RNAs (lncRNAs) (DELs) and messenger RNAs (DEMs) were isolated between the childhood obesity and non-obesity tissue samples. Then, Gene Ontology (GO) functional and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of isolated DEMs were performed. DELs and DEMs targeted miRNAs were predicted to construct a ceRNA regulatory network. Finally, critical lncRNAs were validated in another dataset. Results A total of 1257 differentially expressed RNAs were screened, including 28 lncRNAs and 1229 mRNAs. In addition, these RNAs were mainly involved in defense response, cell cycle, mitogen-activated protein kinase (MAPK) signaling pathway, apoptosis, etc. Three lncRNAs (human leukocyte antigen complex 5 [HCP5], long intergenic non-protein coding RNA 839 [LINC00839] and receptor activity modifying protein 2 [RAMP2-AS1]) and two related miRNAs (hsa-miR-17-5p and hsa-miR-27a/b-3p) were identified as key RNAs in childhood obesity. Specifically, lncRNA HCP5 interacted with miR-17-5p and miR-27a/b to regulate nemo-like kinase (NLK) and Ras-related protein 2 (RRAS2) via the MAPK signaling pathway. Finally, four genes (RRAS2, NLK, bcl2/adenovirus E1B protein-interacting protein 3 [BNIP3] and phorbol-12-myristate-13-acetate-induced protein 1 [PMAIP1]) targeted by miRNAs were predicted as critical genes and might be novel diagnostic biomarkers of childhood obesity. Conclusions lncRNA HCP5 could serve as a ceRNA sponging miR-17-5p and miR-27a/b to regulate the pathogenesis of childhood obesity via NLK and RRAS2 in the MAPK signaling pathway.

Association between inflammation, oxidative stress, vitamin D, copper and zinc with pre-obesity and obesity in school children from the city of Podgorica, Montenegro

Background Childhood obesity is a serious health condition with increasing rates worldwide. The aim of this study was to investigate the association between inflammation, oxidative stress, vitamin D, copper and zinc in pre-obese and obese children compared to controls. Methods The study involved 202 children aged 7-15 years (63.9% boys), randomly chosen from 10 elementary schools in Podgorica, Montenegro. Participants were divided into three groups according to their nutritional status (International Obesity Task Force [IOTF] criteria): normal-weight (42.1%), pre-obese (40.6%) and obese (17.3%). Serum biochemical analyses were performed (C-reactive protein [CRP], retinol-binding protein [RBP], total antioxidant status [TAS], total vitamin D [VD], copper and zinc). Results Serum TAS and CRP concentrations were higher in pre-obese and obese children compared to controls (p < 0.001). Serum VD concentrations were lower in pre-obese and obese children compared to their normal-weight peers (p = 0.027 and p = 0.054, respectively). Copper, zinc and RBP concentrations did not differ significantly among the groups (p > 0.05). In pre-obese and obese children, a positive correlation was found between CRP and copper (r = 0.305, p = 0.011 and r = 0.440, p = 0.013, respectively), and TAS and RBP (r = 0.528, p < 0.001 and r = 0.434, p = 0.015, respectively). Standard regression analyses showed that CRP and TAS increase (p < 0.001) whereas VD decreases (p = 0.011) with the body mass index (BMI). Conclusions We show that pre-obesity and obesity in childhood are positively associated with oxidative stress and inflammation, and inversely associated with VD status. Copper and zinc concentrations were not associated with excess fat in children.

Body Habitus and Risk of Mortality in Pediatric Sepsis and Septic Shock: A Retrospective Cohort Study

OBJECTIVE

To investigate the association between body habitus and mortality in critically ill children with sepsis or septic shock.

STUDY DESIGN

This was a retrospective cohort study of prospectively collected data of children admitted to US pediatric intensive care units (PICUs) with a primary or secondary diagnosis of sepsis or septic shock. We separated body habitus into underweight, normal weight, overweight, and obese. Outcomes were mortality (primary), treatment with invasive mechanical ventilation (secondary), and time to PICU discharge for survivors (secondary). Multivariable analyses using mixed-effects logistic regression and shared frailty models clustered by unit and adjusted for confounding variables were used to assess the association between body habitus and outcomes.

RESULTS

There were 7038 children with sepsis or septic shock. Mortality was 10.1% (n = 714) and 52.9% (n = 3720) required invasive mechanical ventilation. Body habitus was not associated with mortality after controlling for hospital level effects and confounding variables. Children who were overweight and obese had greater odds of invasive mechanical ventilation (overweight OR 1.23 [95% CI 1.05-1.45], P = .011 and obese OR 1.57 [95% CI 1.37-1.80], P < .001) compared with children of normal weight. In survivors treated with invasive mechanical ventilation, children who were obese had a longer time to PICU discharge than children of normal weight (obese hazard ratio for discharge 0.84 [95% CI, 0.77-0.92], P < .0001).

CONCLUSIONS

There was no association between body habitus and mortality in critically ill children with sepsis. Children who were overweight and obese were more likely to receive invasive mechanical ventilation and mechanically ventilated survivors who were obsese had a longer time to PICU discharge.

The Asti Study: The Induction of Oxidative Stress in A Population of Children According to Their Body Composition and Passive Tobacco Smoking Exposure

Obesity and exposure to second-hand tobacco smoking (SHS) may influence oxidative stress (OS) levels, especially in children. This study investigated body composition and SHS influence on OS induction in the paediatric population. The first purpose was identifying an appropriate BMI standard for adiposity assessment in OS investigations. Secondly, SHS and obesity were analysed as inductors of OS. The epidemiologic sample involved 330 children. Three BMI (body mass index) references (IOTF, CDC, and WHO) and an impedentiometric scale supplied body-composition measurements. Partecipants filled out a questionnaire and provided urinary samples for biomarker quantifications: isoprostane (15-F2t IsoP) and cotinine as OS and SHS biomarker, respectively. Obesity prevalence changed over different BMI references (14%, 21%, and 34% for IOTF, CDC, and WHO, respectively). Obese children, by IOTF, showed an increase of 56% in 15-F2t IsoP compared to those normal weight (p = 0.020). Children belonging to the third and the fourth cotinine quartile compared to those of the first quartile had higher 15-F2t IsoP (1.45 ng/mg, 95% CI: 1.06⁻1.97, p = 0.020 and 2.04 ng/mg, 95% CI: 1.55⁻2.69, p < 0.0001, respectively). Obesity assessment in children requires appropriate BMI reference depending on research field. Both SHS exposure and obesity may increase OS in children.

DNA damage in obesity: Initiator, promoter and predictor of cancer

Epidemiological evidence linking obesity with increased risk of cancer is steadily growing, although the causative aspects underpinning this association are only partially understood. Obesity leads to a physiological imbalance in the regulation of adipose tissue and its normal functioning, resulting in hyperglycaemia, dyslipidaemia and inflammation. These states promote the generation of oxidative stress, which is exacerbated in obesity by a decline in anti-oxidant defence systems. Oxidative stress can have a marked impact on DNA, producing mutagenic lesions that could prove carcinogenic. Here we review the current evidence for genomic instability, sustained DNA damage and accelerated genome ageing in obesity. We explore the notion of genotoxicity, ensuing from systemic oxidative stress, as a key oncogenic factor in obesity. Finally, we advocate for early, pre-malignant assessment of genome integrity and stability to inform surveillance strategies and interventions.

Obesity induced alterations in redox homeostasis and oxidative stress are present from an early age

Objectives

Oxidative stress and inflammation have been postulated as underlying mechanisms for the development of obesity-related insulin resistance. This association however, remains elusive especially in childhood. We sought to investigate this relation by measuring oxidative stress and antioxidant response biomarkers, before and during an oral glucose tolerance test (OGTT), in different biological samples from obese children.

Subjects

24 children were recruited for the study, (18 obese and 6 controls). After OGTT, the obese group was subdivided in two, according to whether or not carbohydrate metabolic impairment (Ob.IR+, Ob.IR-; respectively) was found. Different biomarkers were analyzed after fasting (T = 0) and during an OGTT (T = 60 and 120 min). Lipoperoxides were measured in plasma, erythrocytes, and urine; while advanced glycation end products were determined in plasma, and redox status (GSH/GSSG ratio) in erythrocytes.

Results

We found marked differences in the characterization of the oxidative status in urine and erythrocytes, and in the dynamics of the antioxidant response during OGTT. Specifically, Ob.IR+ children show increased oxidative stress, deficient antioxidant response and a significant imbalance in redox status, in comparison to controls and Ob.IR- children.

Conclusion

Obese children with insulin resistance show increased levels of oxidative stress biomarkers, and a stunted antioxidant response to an OGTT leading to increased oxidative stress after a single glucose load, as detected in erythrocytes, but not in plasma. We propose erythrocytes as sensors of early and acute changes in oxidative stress associated with insulin resistance in childhood obesity. This is a pilot study, performed with a limited sample size, so data should be interpreted with caution until reproduced.

Total Oxidant and Antioxidant Status in Prepubertal Children with Obesity

Aims

Obesity is accompanied by the formation of oxygen free radicals, whose intensified activity without effective defense mechanisms can lead to oxidative stress and related complications. We evaluated the presence of oxidative stress in obese prepubertal children.

Methods

The study included 83 healthy children aged 2–10 years (62 with obesity and 21 nonobese controls). Total oxidant capacity (TOC), total antioxidant capacity (TAC), oxidized low-density lipoprotein (ox-LDL), lipid parameters, glucose, and C-reactive protein (CRP) were measured in serum. Oxidative stress index (OSI) was calculated.

Results

Serum TOC concentration was significantly higher (p < 0.05) and TAC concentration was lower (p < 0.05) in obese children. OSI was higher (p < 0.01) in obese subjects compared with controls. CRP levels were normal in all children, but median CRP value was higher (p < 0.01) and HDL cholesterol levels were lower (p < 0.05) in the obese group. We found a significant negative correlation between TAC and ox-LDL concentrations (r = −0.27, p < 0.05) in obese children. Furthermore, obesity duration was positively correlated with TOC level (r = 0.32, p < 0.05) in this group.

Conclusions

Obesity-related oxidative stress already occurs in prepubescence. Early obesity diagnosis and the necessary therapeutic activity implementation is a vital strategy for the prophylaxis of free radical damage and related multiorgan complications.

One-year follow-up of clinical, metabolic and oxidative stress profile of morbid obese patients after laparoscopic sleeve gastrectomy. 8-oxo-dG as a clinical marker

Obesity has grown worldwide over the last few decades. In its different degrees, obesity is accompanied by many clinical and biochemical alterations reflecting the pathological condition of various body tissues. Among the mechanisms underlying the pathogenesis of obesity and associated complications, oxidative stress (OS) may be playing an important role. In the present study, we have characterized at systemic level the degree of OS status in a group of morbid obese patients (BMI>40kg/m²) at basal sate and its modulation during one year after bariatric surgery using the laparoscopic sleeve gastrectomy (LSG) technique. As compared with normal weight subjects matched in age, peripheral blood mononuclear cells (PBMc) of obese patients present a significant reduction of the antioxidant enzyme activities superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) as well as a significant increase of the oxidized/reduced glutathione ratio (GSSG/GSH) in these cells. Lipid peroxidation is significantly increased in the patient group as shown by the increased levels of malondialdehyde (MDA) in PBMc and the amount of F2-Isoprostanes (F2-IsoPs) released in urine. In addition, the DNA damage product 8-oxo-7,8-2'-deoxyguanosine (8-oxo-dG) was also observed to be increased in serum and urine of morbid obese patients as compared with the control group. After LSG, an improvement of their ponderal and metabolic profile was accompanied by a progressive recovery of antioxidant enzyme activities and the decline of oxidative byproducts both in PBMc and biological fluids. The observed changes of urinary 8-oxo-dG levels correlate positively with its serum concentration, the lipid peroxidation products MDA and F2-IsoPs, triglycerides, glucose, insulin, HOMA index and body weight and negatively with the percentage of weight and BMI loss and antioxidant activities. We conclude that the analysis of urinary 8-oxo-dG could be validated as a useful marker for the monitoring of ponderal and metabolic status of morbid obese patients.