Adiposity and cardiac autonomic function in children with a family history of obesity

Abstract

Purpose Data on associations between adiposity and heart rate variability (HRV) in pre-pubertal children are limited. We examined the associations between adiposity indices and HRV, independent of lifestyle behaviors, comparing multiple indicators of adiposity, and explored differences between boys and girls. Methods Data stem from 469 participants of the QUALITY cohort (630 children aged 8-10 yrs with a parental history of obesity). Adiposity indices included waist-to-height ratio, body mass index (BMI) percentiles and categories (overweight, obesity), dual-energy x-ray absorptiometry (DEXA) defined fat mass percentage and android/gynoid ratio. HRV indices in the frequency and the spectral domain were derived from a daytime 3-hr Holter recording. Multivariable linear regression models were adjusted for age, sex, Tanner stage, physical activity, screen time, and fitness. Interactions between sex and adiposity were tested. Results Greater adiposity was associated with decreased parasympathetic modulation and increased sympathetic dominance. Waist-to-height ratio was associated with lower parasympathetic activity: RMSSD (B=-23.32 [-42.42, -4.22]), pNN50 (B=-16.93 [-28.58, -5.27]), LF/HF ratio (B=1.83 [0.97, 2.70]). Patterns of association were similar for android/gynoid ratio. Overweight was not associated with altered HRV. Obesity was negatively associated with RMSSD and pNN50 and positively with LF/HF ratio. Greater fat mass percentage was associated with lower RMSSD, pNN50 and HF, and increased LF/HF ratio. There were no differences between boys and girls. Conclusion Specific markers of adiposity relate to altered HRV in childhood, with waist-to-height ratio being potentially a more relevant marker of HRV than BMI and more pragmatic than percent body fat. NCT03356262, November 11, 2017.