Relationships of Cardiac Autonomic Function With Metabolic Abnormalities in Childhood Obesity

Abstract

KAUFMAN, CHRISTOPHER L., DANIEL R. KAISER, JULIA STEINBERGER, AARON S. KELLY, AND DONALD R. DENGEL. Relationships of cardiac autonomic function with metabolic abnormalities in childhood obesity. Obesity. 2007;15:1164 -1171. Objective: The objective was to examine cardiovascular autonomic (cANS) function and its potential relationships with leptin resistance, insulin resistance, oxidative stress, and inflammation in a pediatric sample with varying levels of obesity. Research Methods and Procedures: Participants were normal-weight (NW; BMI Ͻ85th percentile, 6 male, 4 female), overweight (OW; 85th percentile Ͻ BMI Ͻ95th percentile, 6 male, 4 female), and obese children (OB; BMI Ͼ95th percentile, 6 male, 10 female) who had cANS function assessed via heart rate variability (HRV) methods during resting conditions. Standard time-domain and frequencydomain measures [high-frequency normalized units (HFnu; measure of parasympathetic nervous system activity) and low frequency:high-frequency ratio (LF:HF; overall sympathovagal balance)] of HRV were calculated. Fasting blood samples were drawn for measurement of glucose, insulin, lipids, 8-isoprostane, leptin, soluble leptin-receptor (sOB-R), C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-␣ (TNF-␣). Results were reported as mean Ϯ standard error of the mean. Results: OB had significantly elevated LF:HF and decreased HFnu when compared with NW (p Ͻ 0.05), but no differences between OW and NW were observed. Measures of HRV were significantly related to leptin, insulin resistance, 8-isoprostane, and CRP (p Ͻ 0.05), but these relationships were not significant after adjustment for fat mass. Discussion: When compared with NW, OB but not OW children are characterized by cANS dysfunction and increased leptin, insulin resistance, oxidative stress, and inflammation (CRP). The relationships between these factors seem to be dependent on quantity of fat mass and/or other factors associated with being obese.

Índices geométricos de variabilidade da frequência cardíaca em crianças obesas e eutróficas

“…Sekine et al 18 , analyzing HRV indexes in the frequency domain, suggest that they have more sympathetic activity and less parasympathetic activity as compared with eutrophic children, while Nagai et al 19 and Nagai & Moritani 20 observed both sympathetic and parasympathetic activities decreased in obese children. Yakinci et al 21 , using autonomic function tests, observed normal sympathetic activity and parasympathetic underactivity, and more recently, Kaufman et al 16 observed increase in LF/HF ratio and decreased HF index. Pascoal et al 22 found higher cardiac tone in the standing position when compared obese children with eutrophic children.…”

“…Studies have shown that obesity causes changes in the function of the autonomic nervous system in children and adolescents 16,17 . Such a condition of imbalance may represent a major negative factor since the autonomic function controls some of the internal functions of the body and, accordingly, deserves attention.…”

Chaotic global parameters correlation with heart rate variability in obese children

“…Studies have shown that obesity produces abnormalities of the autonomic nervous system in children and young adults 21,22 . Autonomic behavior is assessed through Heart Rate Variability (HRV) a simple, non-invasive tool for the detection and study of cardiac irregularities in many conditions.…”

Associations of Metabolic Variables with Electrocardiographic Measures of Sympathovagal Balance in Healthy Young Adults

“…www.intechopen.com The metabolism of food produces a shift in sympathovagal balance toward greater sympathetic modulation, similar to that associated with postural changes (Piccirillo et al 1998;Paolisso et al 2000;Martini et al, 2001;Rabbia et al, 2003;Guizar et al, 2005;Kaufman et al, 2007a;Kaufman et al, 2007b;Nagai and Moritani, 2004). Higher body mass index is associated www.intechopen.com with greater sympathetic responsiveness to postural changes, higher plasma leptin levels (Paolisso et al, 2000) and greater lipolytic activity of adipocytes (Berlan et al, 2002;Tentolouris et al, 2008).…”