Physiological Mechanism of Hiesho

―Evaluation by Cardiovascular and Autonomic Dynamics―

Abstract

　According to previous studies, up to 50% of women in Japan suffer from“hiesho,”a common condition characterized by persistent coldness in the extremities ; however, the pathophysiology of hiesho remains unclear. The purpose of this study is to clarify the physiological mechanism of hiesho by measuring circulatory and autonomic nervous activities between individuals reporting hiesho versus those that do not. 20 apparently healthy women, 12 reporting hiesho and 8 without, were including in this prospective study from October 2012 to January 2013. Physiological parameters measured included heart rate (HR), blood pressure, skin surface temperature, skin blood flow, tympanic membrane temperature, thermography, and plethysmography. Autonomic nervous activity was measured via frequency of heart rate variability, with 0.04-0.15 Hz defined as low frequency (LF) and 0.15-0.5Hz defined as high frequency (HF). HF is an index of parasympathetic nerve activity, while LF/HF is an index of sympathetic nerve activity. Compared to controls (mean age, 20.1±0.5), the hiesho group (mean age, 22.0±0.8) had significantly different skin blood flow (6.3±0.7 vs 9.3±1.0 ; P=0.019). HR (64.9±2.7 vs 58.8±1.2 ; P=0.06), LF/HF (1.2±0.2 vs 0.7±0.1 ; P=0.076), and HF variability (1224.2±310.9 vs 1678.0±852.1 ; n.s.) showed a trend toward difference. Hiesho individuals have lower parasympathetic nervous activity and higher sympathetic nervous activity, as well as decreased blood flow and lower skin temperature in peripheral circulation, compared to controls. Our data suggest that hiesho may result from both decreased parasympathetic nervous activity and peripheral circulation due to chronic vasoconstriction from increased sympathetic nervous system activity.