Objective: Sauna bathing is a popular recreational activity and has long since been used to relieve stiff necks and low back pain. Recently, low-temperature sauna has been used to treat congestive heart failure (CHF), coronary artery diseases, chronic fatigue syndrome, and chronic pain. During 1960-1970, thermal stimulation was applied to the patients with renal failure. We could not find the subsequent reports, and the long-term effects are unclear. The purpose of this experiment was to verify the safety of systemic low-temperature sauna treatment (ST) for the 5/6 remnant kidney mouse and to examine the effect of ST on urinary protein excretion. Materials and Methods: The C57BL/6 mice were divided into the following 4 groups; group 1: sham-operated and non-sauna treatment mice (sham+non-ST group: n = 5), group 2: sham-operated and ST mice (sham+ST group: n = 5), group 3: Nx and non-ST mice (Nx+non-ST group: n = 5), and group 4: Nx and ST mice (Nx+ST group: n = 5). Mice received ST at 41°Cfor 15 min and at 32°Cfor 20 min for 12 weeks using a natural convection dry sauna system. Results: After 12 weeks of ST, no differences were observed in creatinine clearance, body weight, fluid intake, urine volume, serum sodium and potassium levels between ST and non-ST groups. Our results showed a significant increase in eNOS mRNA expression in the Nx+ST group compared to that in the Nx+non-ST group. These results suggest the possibility that mild sauna treatment induces thermal vasodilation effects on glomerulus. Systolic blood pressure and urine protein levels in the Nx groups did not change throughout the intervention. Conclusion: There are no clear adverse events associated with low-temperature sauna. Therefore, this study setting is safe in the CKD model mouse. Renal eNOS mRNA expression was increased by the low-temperature sauna. The present results suggest the possibility that ST might provide a renal protective effect by suppressing glomerular hypertension via stimulation of renal NO production in the CKD model mouse.
A foot bath is one of the partial baths which soaks a foot in hot water. The effect makes the blood circulation of the part of the warmed foot better, and is effective for fatigue, edema, poor circulation, and sleep. The purpose in this study is to examine how aging influences the change of the autonomic nerve during a foot bath. The subjects were nine elderly individuals (four men, five women, average age of 73.5 ± 8.4 years old), eight young individuals (all men, average age of 25.5 ± 3.4 years old), and for a 20-minute foot bath, when I touched the lower thigh to the 41°C bath in a seated position for rest ten minutes, performed rest after a foot bath for five minutes. Tympanic temperature with a thermistor, skin blood flow with a laser Doppler flowmeter, and blood pressure and heart rate with an automatic sphygmomanometer were measured. In the younger subjects, tympanic temperature was significantly increased compared to the elderly subjects, and skin blood flow was significantly increased during the foot bath in the lower thigh with both subjects, and the younger subjects were significantly increased compared to the elderly subjects. The femor-skin blood flow significantly increased only in the young subjects. The blood pressure did not change in the young subjects during the foot bath, but the elderly subjects’ pressure dropped. The heart rate increase was shown in the young subjects; however, it was not shown in the elderly subjects. It is thought that an increase of the quantity of fat and decrease of the muscle volume due to aging, a decline in the flexibility of the blood vessel, and attenuation of the sensitivity of the receptor affect the change of these autonomic nerve functions.
Background: A 30-60 min rest after exercising is generally recommended before taking a bath. Although this was considered an appropriate bathing method, effects of pre-bath rest on recovery from exercise fatigue remain unclear. Here, we aimed to examine the effects on fatigue recovery of pre-bath rest after a workload, with the focus on changes in lactic acid levels. Methods and Results: Ten healthy adult men increased their blood lactic acid levels through a treadmill workload performed in accordance with the Bruce method, then took either a 60-min post-workload rest followed by a 10-min full-immersion 38°C bath (Experiment A) or a 10-min full-immersion 38°C bath followed by a 60-min rest (Experiment B). Body temperature, blood pressure, pulse rate, and blood lactic acid level were measured at three time points: before workload (Test 1), after workload (Test 2), and after bathing/resting (Test 3). Decreases and percent decreases in blood lactic acid levels were calculated by comparing Test 3 results with Test 2 results. These calculated values and the measured values in three tests were compared between Experiment A and Experiment B using paired-t test. There were no significant differences in maximum systolic blood pressure, maximum diastolic blood pressure, maximum workload attained, and maximum pulse rate measurements between Experiment A and Experiment B. Differences in systolic blood pressure and diastolic blood pressure measurements in Tests 1, 2, and 3 were not significant. The pulse rates measured at the final measurement (Test 3) were significantly higher in Experiment A than in Experiment B (90.4 ± 18.2 bpm vs 79.6 ± 11.6 bpm, p = 0.04). No significant differences were observed in other measurement timings. The body temperature measurements at the final measurement were slightly higher in Experiment A than in Experiment B (36.4 ± 0.4 vs 36.1 ± 0.3°C, p = 0.05). No significant differences were observed in other measurements. Blood lactic acid levels before workload (Test 1) were significantly higher in Experiment A (6.6 ± 4.7mmol/L) than in Experiment B (2.0 ± 1.4 mmol/L, p = 0.02), but those at other measurement points (Test 2 and Test 3) were similar. Neither decreases nor percentage decreases in blood lactic acid levels differed between Experiment A and Experiment B. Conclusions: Resting before a post-exercise bath did not change the decreases or percent decreases in blood lactic acid levels after bathing at 38°C, suggesting negligible effects of pre-bath resting on recovery from exercise fatigue.
To evaluate the current state of the Onsen-Ryoho-Specialist (Broad Certified Fellow in Balneology, Climatology and Physical Medicine) training system, we surveyed the training facilities designated by the Japanese Society of Balneology, Climatology and Physical medicine (BCPM). Of the 24 facilities targeted by the survey, 21 responded (88%). Currently, the training curriculum for Onsen-Ryoho-Specialists consists of 8 units on diseases and 8 units on therapy methods. As shown in Figs. 1 and 2, it is difficult for a single facility on effectively cover all of these units. The most pressing need is to establish and implement a standardized curriculum across all facilities. Until now, each related academic society has selected training facilities based on its own criteria. Moving forwards, the review/accreditation body of the Japanese Medical Specialist Broad will make site visits to establish and review Onsen-Ryoho-Specialist training facilities. These efforts should lead to the development of fully qualified Onsen-Ryoho-Specialist training facilities.