Abstract 11335: Does Reduced Parasympathetic Heart Rate Variability Promote Obesity in Children?

Abstract

Introduction: Considering the contribution of the autonomic nervous system (ANS) in regulating both energy expenditure and energy intake, assessment of heart rate variability (HRV) may elucidate the etiology and adaptive processes in the development of obesity. Variations in the cardiac ANS are associated with changes in energy balance and eating behaviours, highlighting the potential key function of the ANS in the etiology of obesity. While it is broadly accepted that obesity impacts HRV, potential impacts of HRV patterns on obesity remain unexplored. We hypothesize that certain HRV patterns increase risk of excess weight in children. Methods: Participants included 406 White youth from the QUALITY cohort (56% boys). Children were considered at risk of CVD due to confirmed parental obesity status. Time- and frequency-domain HRV indices derived from short-term ECG recordings (SDNN, RMSSD, pNN50, LF, HF, and LF/HF ratio) were analyzed at baseline (mean = 9.6 years, SD = 0.9). Adiposity at 2-year follow-up was evaluated through dual-energy X-ray absorptiometry. Total body fat (BF) and BF distribution were captured; central adiposity was estimated using the android-to-gynoid ratio. Prospective associations between HRV at baseline and adiposity at 2-year follow-up were estimated using regression models including weights for well-established confounders (difference in adiposity measures over time, sex, age, sexual maturity, and physical activity). Results: 8-10 year olds with a sympathovagal imbalance described by a sympathetic predominance (LF/HF) presented with higher BF (β = 3.32, p < 0.001) and higher android-to-gynoid ratio (β =0.03, p<0.001) at age 10-12 years. Furthermore, lower levels of parasympathetic indices at age 8-10 years predicted higher BF (RMSSD: β = -0.09, p < 0.01; pNN50: β = -0.13, p < 0.01) and higher android-to-gynoid ratio (RMSSD: β -0.001, p < 0.05; pNN50: β = -0.001, p < 0.01) two years later. Conclusions: Impaired cardiac ANS modulation appears associated with the occurrence of childhood obesity two years later. A sympathetic predominance paired with reduced parasympathetic indices in otherwise healthy children may foreshadow pathophysiological processes that lead to obesity and may help to identify intervention targets.