Objective:

To evaluate oxidative DNA damage and circulating mitochondrial DNA integrity in children with different obesity phenotypes as indicators of metabolic risk.

Approach:

• Study Design: A retrospective, cross-sectional study involving 103 children aged 6–12 years classified into normal-weight controls, preclinical obesity (pOb), and clinical obesity (cOb) using the 2025-OCF criteria.
• Biomarker Assessment: Oxidative DNA damage was quantified using 8-hydroxy-2′-deoxyguanosine (8-OH-dG), and c-mtDNA integrity was evaluated by long-range PCR.
• Lipid Metabolism Markers: Lipid metabolism markers including triglycerides, HDL cholesterol, and the triglyceride-to-HDL cholesterol ratio were measured.
• Cytokine Measurement: Plasma cytokine levels were quantified using flow cytometry.

Key Findings:

• Both pOb and cOb groups showed significantly higher 8-OH-dG levels and reduced c-mtDNA integrity compared to controls (p < 0.0001).
• 8-OH-dG levels positively correlated with triglycerides, TG/HDL-C ratio, and TyG index.
• c-mtDNA integrity exhibited inverse correlations with lipid-related markers and positive correlation with HDL-C levels.
• Waist circumference percentile was independently associated with both 8-OH-dG and c-mtDNA integrity after adjustments.

Interpretation:

Oxidative DNA damage and reduced c-mtDNA integrity were observed in both preclinical and clinical obesity groups, indicating mitochondrial and oxidative alterations associated with excess adiposity.

Limitations:

• The study is cross-sectional, limiting causal inferences.
• Sample size may restrict the generalizability of findings.

Conclusion:

c-mtDNA integrity and 8-OH-dG may serve as biomarkers associated with excess adiposity and metabolic risk in pediatric obesity.

Sources:

• ClinicalTrials.gov