Obesity is associated with impaired cardiac autonomic modulation in children

Abstract

Objective To examine the cross-sectional association between measurements of obesity and subclinical impairment of cardiac autonomic modulation (CAM) in a population-based sample of children. Methods Data from 616 grade K-5 children randomly selected from Central Pennsylvania were utilized. Obesity was defined using the International Obesity Task Force (IOTF) age and sex specific cut off criteria and classified as normal weight, overweight, and obese. CAM was measured by heart rate variability (HRV) analysis of beat-to-beat RR intervals, including time domain measures i.e., the standard deviation of all RR intervals (SDNN), the square root of the mean of the sum of squares of differences between adjacent RR intervals (RMSSD), and mean heart rate (HR); and frequency domain measures i.e., high frequency power (HF), low frequency power (LF), and LF/HF ratio. Results The prevalence of obesity and overweight in children was 12.3%, and 16.5%, respectively. Age, race, sex, and sleep disorder breathing (SDB) adjusted means (SE) of SDNN were 98(1.24), 90.2(2.58), and 81.9(3.03) milliseconds (ms) in normal weight, overweight, and obese groups, respectively; and that for (log) HF were 6.83(0.04), 6.56(0.08), and 6.35(0.09) ms2, respectively. Comparing the magnitude of effects from BMI, weight, and height percentiles, and waist circumference on HRV indices revealed that body weight was the strongest correlate of HRV indices. Conclusion Childhood obesity is significantly associated with lower HRV, indicative of sympathetic overflow unopposed by parasympathetic modulation. These findings support the need to target childhood-obesity, before traditional “high risk age” for cardiac events.

Short-Term Heart Rate Variability in a Population-Based Sample of 10-Year-Old Children

“…However, while larger BMI was not associated with HRV, larger waist circumference was related to reduced VLF, which is partly consistent with past pediatric findings of greater obesity linked to reduced HRV [16,22,33].…”

Autonomic nervous system balance in children and adolescents with craniopharyngioma and hypothalamic obesity

“…Similar relationships are described in the literature on childhood obesity, with lower HF power on HRV analysis (a parasympathetic marker) in obese children compared with normal-weight children (32,33). A positive correlation between the degree of obesity and the HRV sympathetic markers is found only in the CRHO group.…”

“…A positive correlation between the degree of obesity and the HRV sympathetic markers is found only in the CRHO group. The literature on this topic in children with obesity is conflicting, with studies demonstrating increased (33), reduced (32), or similar (34) levels of sympathetic activity in obese children when compared with normal-weight children.…”

“Broken” autonomic cardiac circadian clock in obese adolescents: evidence and implications

“…Data that were analyzed by adjustments for confounders (specifically age and gender) were compared to those obtained in non-obese children and adolescents. The results expand previous information collected on this topic [3][4][5][6], by showing that the circadian pattern of parasympathetic and sympathetic control of the heart rate signal is altered in these young groups of obese. They also provide evidence that the alterations in vagal modulation of sinus node activity are manifest in both genders, independently of the subject's age and over the whole 24-h period.…”