Metabolic syndrome (MetS) is associated with systemic inflammation, oxidative stress, and hypovitaminosis D. Our aim was to determine whether vitamin D mediates inflammation and oxidative stress, assessed through selected biomarkers, in children with obesity and/or MetS. Eighty children with normal weight, overweight, or obesity were analyzed for serum vitamin D, C-reactive protein, leukocytes, adiponectin, monocyte chemoattractant protein-1, myeloperoxidase, interferon-inducible T-cell alpha chemoattractant (I-TAC/CXCL11), superoxide dismutase-1, fasting lipid and glucose levels, ultrasound-measured abdominal fat thickness, waist circumference, body mass index and blood pressure. Children with obesity or overweight had lower vitamin D levels, increased blood pressure, visceral and subcutaneous fat thickness, and higher leukocytes, C-reactive protein, and myeloperoxidase levels. Those with MetS also had lower adiponectin levels. Vitamin D levels are negatively correlated with body mass index, waist circumference, and visceral and subcutaneous fat thickness. Correlation, mediation, and regression analyses showed no link between vitamin D and inflammatory/oxidative stress variables. The novel biomarker I-TAC did not correlate with obesity or vitamin D status. Our results indicate that vitamin D does not significantly mediate inflammation or oxidative stress in children and adolescents with obesity and/or MetS. Selected inflammation/oxidative stress biomarkers appear to be altered primarily due to obesity rather than vitamin D status.

Background: Systemic inflammation and oxidative stress are fundamental contributors to the onset of conditions related to childhood obesity, such as cardiovascular (CV) diseases. We aimed to assess CV risk in childhood obesity by examining sex differences in adiposity indices, cardiometabolic profiles, inflammation, and oxidative stress biomarkers. We also aimed to assess the potential of the interferon-inducible T-cell alpha chemoattractant (I-TAC/CXCL11) as a novel biomarker. Methods: Eighty children (36 girls) aged 5–18 years with overweight, obesity, or normal weight were analyzed. Fasting blood samples were obtained to assess C-reactive protein (CRP), leukocytes, myeloperoxidase (MPO), adiponectin, monocyte chemoattractant protein-1, superoxide dismutase-1, I-TAC/CXCL11, and a comprehensive cardiometabolic profile, including glucose, lipid, renal, liver, and thyroid function markers. Adiposity indices were determined using bioelectrical impedance analysis (BIA) and anthropometric measures, including BMI, waist-to-hip and waist-to-height ratios, and visceral and subcutaneous fat thickness. Blood pressure (BP) and pulse wave velocity were also evaluated. Results: Girls had less central obesity and fewer CV risk factors than boys, despite having similar total fat mass. Both girls and boys with overweight or obesity showed higher CRP levels. Girls with excess weight had increased leukocyte counts, while boys had elevated MPO levels, which correlated positively with adiposity indices, systolic BP, and homocysteine, and negatively with HDL. I-TAC/CXCL11 levels were similar across groups. Conclusions: Adiposity indices are essential for evaluating CV risk in children and adolescents, with sex differences underscoring the need for tailored approaches. MPO correlated significantly with CV risk markers, supporting its inclusion in routine assessments. I-TAC/CXCL11 warrants further study in childhood obesity.

Background/Objectives: Oxidative stress and systemic inflammation are significant contributors to the development and progression of cardiovascular disease, causing adverse effects on vascular health and atherosclerosis from an early age. Patients with established cardiovascular risk factors commonly exhibit markers indicating heightened oxidative stress and inflammation. Our study sought to assess the levels of interleukin-2 receptor, which could serve as an early indicator of cardiovascular damage due to oxidative stress and inflammation in at-risk children. Methods: The study comprised 46 paediatric patients with chronic kidney disease, 50 paediatric patients with hypertension, and 33 healthy controls. Anthropometric measurements, pulse wave velocity, body composition, routine laboratory tests, and measurements of interleukin-2 receptor levels were conducted for all participants. Results: Interleukin-2 receptor levels were notably lower in patients with hypertension (p < 0.001) and those with overweight/obesity (p < 0.001) with several associated measures. Interleukin-2 receptor levels exhibited significant negative correlations with various anthropometric measurements, body composition, and liver damage and a positive correlation with kidney function tests. Conclusions: Children diagnosed with hypertension or obesity exhibited notably lower interleukin-2 receptor levels.