Comparison of the Physio-phycho-biochemical Effects of Carbon Dioxide-enriched and Plain Water Footbath / 日本温泉気候物理医学会雑誌

ABSTRACT

Carbon dioxide (CO₂)-enriched water, one of the Japanese pharmacopeias, has been used as an alternative thermotherapy to treat the intractable diabetic skin diseases. However, few scientific researches on the physiological effects of CO₂-enriched footbath have been reported. Fifteen males (aged 22-52, 31±10) took part in this study after providing their written informed consents. They took three kinds of footbath (plain water, CO₂-enriched water and control without water) at 38°C for 30min in random sequence. Their core temperature from oral and tympanic membrane, cutaneous blood flow, tissue hemoglobin concentration at the cerebral frontal cortex and trapezoid muscle, systemic blood pressure, heart rate variability, salivary IgA, comfortable feeling with face scale were measured before, during and after footbath. CO₂-enriched footbath showed significant physiological effects on the systemic and peripheral circulation. Local (under water) cutaneous blood flow, and tissue blood flow of the frontal cortex were significantly higher than in the plain water footbath. The systolic and diastolic blood pressure and heart rate in CO₂-enriched footbath were also lower than those in the plain water footbath. Heart rate variability of CO₂-enriched footbath showed an decrease of LF/HF ratio and more HF/(LF+HF) ratio than that of plain water footbath. These parameters indicated lesser stress for the heart in CO₂-enriced footbath than in the plain water footbath. The relaxing effect of CO₂-enriched footbath was also indicated from the results of face scale and salivary IgA concentration. All of these results supported that the CO₂-enriched footbath was less stressful and more relaxing, and had more physiological effects on the local systemic and cerebral circulatory system and autonomic nervous system than plain water footbath.