Environmental Health and Preventive Medicine

, 6:149

Obesity and cardiac autonomic nerve activity in healthy children: Results of the toyama birth cohort study

Authors

    • Department of Welfare Promotion and Epidemiology, Faculty of MedicineToyama Medical and Pharmaceutical University
  • Ichiro Izumi
    • Department of Welfare Promotion and Epidemiology, Faculty of MedicineToyama Medical and Pharmaceutical University
  • Takashi Yamagami
    • Department of Welfare Promotion and Epidemiology, Faculty of MedicineToyama Medical and Pharmaceutical University
  • Sadanobu Kagamimori
    • Department of Welfare Promotion and Epidemiology, Faculty of MedicineToyama Medical and Pharmaceutical University
Original Article

DOI: 10.1007/BF02897962

Cite this article as:
Sekine, M., Izumi, I., Yamagami, T. et al. Environ Health Prev Med (2001) 6: 149. doi:10.1007/BF02897962

Abstract

Objectives

To determine the relationship between obesity and cardiac autonomic nerve activity in healthy children.

Methods

16 healthy male children comprising of 9 nonobese and 7 obese subjects (body mass index > 19.1 kg/m2) aged 8–9 years were selected. Electrocardiograms were measured for 10 min. under controlled ventilation (0.25 Hz) in the supine position. Consecutive 256-second RR interval data were transformed by the Fast Fourier Transform method into power spectral data. Very low frequency (VLF; 0.003–0.04 Hz), low frequency (LF; 0.04–0.15Hz), high frequency (HF; 0.15–0.40Hz), and total power (TP; 0.003–0.40Hz) were calculated and transformed into a natural logarithm (In). Normalized units (nu) were also calculated as follows: LFnu=LF/(TP-VLF)x100. HFnu=HF/(TP-VLF)x100. Low/high-frequency ratio (LHR) was calculated as LF divided by HF. Unpaired t test was performed to compare the 2 groups.

Results

TP In and HFnu, reflecting cardiac parasympathetic nerve activity, in obese children were significantly lower than those in nonobese children. In contrast, LFnu and LHF, reflecting cardiac sympathetic nerve activity, in obese children were significantly higher than those in nonobese children.

Conclusions

These findings suggest that obese children have higher sympathetic nerve activity and lower parasympathetic nerve activity than nonobese children.

Key words

obesitychildrenautonomic nerve activityheart rate variabilitythe Toyama Birth Cohort Study
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Copyright information

© Japanese Society of Hygiene 2001