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Tanabe Tsuyoshi

Affiliate Master Yamaguchi University

山口医学 Volume 63 Issue 1 pp. 5 - 10
published_at 2014-02-01
Creators : Tanabe Tsuyoshi Publishers : 山口大学医学会
Creators : Ishimaru Yasutaka Mahbub MH Yamaguchi Natsu Hase Ryosuke Nakagami Yuki Takahashi Hidekazu Watanabe Rie Saito Hiroyuki Shimokawa Junki Yamamoto Hiroshi Kikuchi Shinya Tanabe Tsuyoshi Publishers : Yamaguchi University School of Medicine
Abstract Purpose: The purpose of this study was to investigate the effects of two different postures (sitting and standing) and three different ambient temperatures (10℃, 20℃, and 30℃) on heart rate variability (HRV) among healthy young adults. Methods: Twelve young adult volunteers (males 6, females 6) were recruited. Following acclimatization to any the room temperature (10℃, 20℃ or 30℃), 5-min measurements of HRV were conducted in sitting and standing postures of the subjects. Results: Compared to the sitting posture, measurements obtained in the standing posture revealed a significant decrease in high-frequency power/HF, root mean square of successive differences between RR intervals, standard deviation of Poincaré plot perpendicular to the line-of-identity or SD1 and SD1/standard deviation of Poincaré plot along the line-of-identity or SD2, and a significant increase in lowfrequency power/LF and LF/HF under all experimental conditions (p<0.05 to 0.005). Majority of HRV parameters showed significant differences while the values obtained under 10℃ were compared with 20℃ and 30℃ conditions, respectively (p<0.05 to 0.001). Conclusions: Our findings suggest the predominance of sympathetic tone in the standing compared with sitting posture. Furthermore, colder conditions caused a predominance of the parasympathetic activity in both sitting and standing postures, and such effects of ambient temperature on the sympathovagal balance were stronger in the latter posture.
Creators : Wada Sunao Mahbub MH Nakagami Yuki Hase Ryosuke Yamaguchi Natsu Takahashi Hidekazu Saito Hiroyuki Shimokawa Junki Watanabe Rie Harada Noriaki Tanabe Tsuyoshi Publishers : Yamaguchi University School of Medicine