Comparison of Thermogenic Sympathetic Response to Food Intake between Obese and Non-obese Young Women

Authors

  • Tamaki Matsumoto,

    1. Laboratory of Applied Physiology, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
    2. International Buddhist University, Osaka, Japan
    Search for more papers by this author
  • Chiemi Miyawaki,

    1. Laboratory of Applied Physiology, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
    Search for more papers by this author
  • Hidetoshi Ue,

    1. Laboratory of Applied Physiology, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
    Search for more papers by this author
  • Tomo Kanda,

    1. Laboratory of Applied Physiology, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
    Search for more papers by this author
  • Yasuhide Yoshitake,

    1. Department of Human Health Sciences, Waseda University, Tokorozawa, Japan
    Search for more papers by this author
  • Dr. Toshio Moritani

    Corresponding author
    1. Laboratory of Applied Physiology, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
      Laboratory of Applied Physiology, Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku, Kyoto 606, Japan. E-mail: moritani@virgo.jinkan.kyoto-u.ac.jp
    Search for more papers by this author

Laboratory of Applied Physiology, Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku, Kyoto 606, Japan. E-mail: moritani@virgo.jinkan.kyoto-u.ac.jp

Abstract

Objective: Sympathetic nervous system abnormality in humans is still a matter of debate. The present study was designed to examine diet-induced autonomic nervous system activity and metabolic change in obese and non-obese young women.

Research Methods and Procedures: Sixteen age- and height-matched obese and non-obese young women participated in this study. Sympathovagal activities were assessed by means of our newly developed spectral analysis procedure of heart-rate variability during the resting condition and after mixed-food ingestion (480 kcal). Energy expenditure was also measured under these two conditions.

Results: There was no significant difference in any of the parameters of the heart-rate variability between the obese group and control group during the resting condition. In the control group, both absolute values (221.5 ± 54.5 vs. 363.8 ± 43.7 ms2, p < 0.05) and relative values (0.23 ± 0.03 to 0.36 ± 0.02, p < 0.05) of a very-low-frequency component and global sympathetic nervous system index (1.46 ± 0.19 vs. 3.26 ± 0.61, p < 0.05) were significantly increased after mixed-food ingestion compared with the values obtained after resting condition. However, no such sympathetic response was found in the obese group. Energy expenditure increased in the two groups after the meal, but the magnitude of the increase above the preprandial resting condition was significantly greater in the control group than in the obese group (11.2 ± 2.3 vs. 6.7 ± 0.8%, p < 0.05).

Discussion: Our data suggest that despite identical sympathovagal activities at the resting condition, obese young women may possess a reduced sympathetic response to physiological perturbation such as mixed food intake, which might be related to lowered capacity of thermogenesis and the state of obesity.

Ancillary