Abstract
Background: The cold-sensitivity constitution (CSC), known as "Hiesho" in Japanese, is a detriment to the quality of life in young women. While CSC is associated with an imbalance in autonomic nervous activity, reflected by heart rate variability (HRV), foot baths increase parasympathetic nervous activity (PNA) as well as peripheral blood flow and epidermal temperature. In the present study, we investigated the physiological responses of young women with CSC to foot baths.
Methods: We measured the epidermal temperature of the hallux and dorsal hand, as well cutaneous blood flow at the hallux, 15 min before and 15 and 30 min after a 15-minute foot bath. HRV was also calculated.
Results: A total of 32 healthy women, assigned to either the CSC (n = 23) or non-CSC (n = 9) group, were included in the present study. After the foot bath, the epidermal temperature in the hallux increased significantly in both groups. Although the baseline hallux temperature was significantly lower in the CSC than the non-CSC group, there was no difference between the two groups after the foot bath. The baseline dorsal hand temperature was also significantly lower in the CSC than the non-CSC group; however, the foot bath significantly increased dorsal hand temperature in the CSC, but not the non-CSC, group. Cutaneous blood flow to the hallux increased significantly after the foot bath in both groups. Additionally, the PNA in the CSC group was significantly enhanced 30 min post-foot bath.
Conclusion: Foot baths in otherwise healthy young women with CSC increased the epidermal temperatures of the foot and hand. Non-localized effects of foot baths via PNA stimulation may be suggested.
