Weight status, heart rate variability and quality-of-life in children with obstructive sleep apnea

Pediatric obstructive sleep apnea (OSA) is associated with autonomic dysfunction and impaired quality-of-life (QoL). This study investigated whether weight status modifies the impact of OSA severity on heart rate variability (HRV) and disease-specific QoL. This retrospective cohort study included 115 children with OSA who underwent overnight polysomnography and HRV assessment. Participants were categorized by body mass index z-score into normal-weight, overweight, and obesity groups. Hierarchical multiple regression tested the moderating effect of weight status on the relationship between the apnea-hypopnea index (AHI) and both the low-frequency/high-frequency (LF/HF) ratio and total OSA-18 score. Compared to normal-weight peers (56.5%), children with overweight (21.7%) and obesity (21.7%) exhibited significantly higher AHI and impaired autonomic regulation, including elevated LF/HF ratios ( q < 0.05). Hierarchical regression revealed that both overweight ( p = 0.02) and obesity ( p = 0.02) significantly modified the impact of AHI on the LF/HF ratio, indicating exacerbated sympathetic dominance. However, weight status did not interact with AHI to affect QoL. While AHI uniformly correlates the subjective QoL burden regardless of adiposity, weight status fundamentally modifies the autonomic response. Heavier children exhibit heightened cardiovascular vulnerability to sleep-disordered breathing, underscoring the need for targeted weight management to mitigate cardiometabolic risk in pediatric OSA. Overweight and obesity significantly exacerbate autonomic dysfunction in children with obstructive sleep apnea (OSA), driving a reduction in total heart rate variability (HRV) and a marked increase in the low-frequency/high-frequency ratio, even when disease-specific quality-of-life scores remain comparable across weight groups. This study is among the first to demonstrate that weight status structurally modifies the autonomic response to sleep-disordered breathing, amplifying sympathetic predominance in response to respiratory severity. HRV analysis may serve as a critical, non-invasive tool to stratify cardiovascular risk in pediatric OSA, guiding clinicians toward more targeted, individualized interventions and early weight management.