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 (P_MDA = 0.03; P_SOD = 0.04). The associations between obesity, MDA level, and SOD enzyme activity were only significant in boys (boys: P_MDA = 3.0 × 10⁻³; P_SOD = 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 (P_{Normal-weight} = 2.2 × 10⁻³; P_Obesity = 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.

Background: Childhood obesity is a growing health concern and added sugar intake has been associated with increased obesity risk. Emerging evidence suggests that miR-143-5p and miR-223-3p are involved in metabolic regulation. Therefore, this study evaluated their plasma expression according to added sugar intake and their association with cardiometabolic risk parameters. Methods: This cross-sectional study included 91 children aged 6–12 years, comprising 44 with normal weight and 47 with overweight/obesity. Anthropometric measurements, clinical characteristics, and dietary added sugar intake were assessed. Plasma expression of miR-143-5p and miR-223-3p was quantified by RT-qPCR. Results: Compared with low added sugar intake, high added sugar intake was associated with lower plasma miR-143-5p expression and higher miR-223-3p expression. Both miR-143-5p and miR-223-3p expression levels were higher in children with overweight/obesity and insulin resistance than in their respective counterparts. In adjusted analyses, neither miRNA was associated with cardiometabolic risk parameters. However, added sugar intake was positively associated with miR-223-3p expression (β = 0.188, 95% CI: 0.022, 0.354) and glucose levels (β = 1.944, 95% CI: 0.133, 3.755). Conclusions: These findings suggest that higher added sugar intake is associated with altered circulating miRNA expression and higher fasting glucose concentrations in school-aged children.

Background: Childhood obesity is a growing health concern and added sugar intake has been associated with increased obesity risk. Emerging evidence suggests that miR-143-5p and miR-223-3p are involved in metabolic regulation. Therefore, this study evaluated their plasma expression according to added sugar intake and their association with cardiometabolic risk parameters. Methods: In this cross-sectional study, 91 children aged 6 to 12 years were included (44 normal weight and 47 with overweight/obesity). Anthropometric, and clinical parameters, and dietary added sugar consumption were analyzed. RT-qPCR was performed to assess the expression of miR-143-5p and miR-223-3p in plasma. Results: Compared with low added sugar intake, high added sugar intake was associated with lower plasma miR-143-5p expression and higher miR-223-3p expression. Both miR-143-5p and miR-223-3p expression levels were higher in children with overweight/obesity and insulin resistance than in their respective counterparts. In adjusted analyses, neither miRNA was associated with cardiometabolic risk parameters. However, added sugar intake was positively associated with miR-223-3p expression (β = 0.188, 95% CI: 0.022, 0.354) and glucose levels (β = 1.944, 95% CI: 0.133, 3.755). Conclusions: High added sugar intake was associated with lower miR-143-5p expression, higher miR-223-3p expression, and increased fasting glucose concentrations in school-aged children, suggesting early alterations in metabolic regulation.