Cardiac autonomic dysfunction in children and adolescents with obesity: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the association between excess weight and cardiac autonomic modulation in children and adolescents. DATA SOURCE: PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched from inception to April 2, 2026 for observational studies comparing short-term resting heart rate variability between children and adolescents with excess weight and normal-weight controls. The protocol was registered in PROSPERO (CRD420251005501). DATA SYNTHESIS: Eighteen studies comprising 1,590 participants were included. Random-effects meta-analyses using standardized mean differences showed lower root mean square of successive differences of RR intervals (RMSSD -1.00; 95% confidence interval [95%CI] -1.68 to -0.31), lower percentage of successive normal-to-normal intervals differing by more than 50 ms (pNN50 -0.48; 95%CI -0.68 to -0.28), and higher low-frequency/high-frequency ratio (LF/HF 0.70; 95%CI 0.30 to 1.10) in the excess weight group. No significant differences were observed for the standard deviation or mean of normal-to-normal intervals. Leave-one-out analyses supported directional robustness, and between-group body mass index difference significantly moderated LF/HF (β=-0.15; p=0.045), but not RMSSD. CONCLUSIONS: Pediatric excess weight appears to be associated with impaired cardiac autonomic modulation, mainly characterized by lower parasympathetic-related heart rate variability indices. Among the evaluated parameters, pNN50 showed the most consistent reduction, whereas RMSSD showed the largest pooled effect.