We investigated the effects of hot spring water drinking in Kawayu on blood glucose levels and insulin secretions. Kawayu hot spring water is characterized “acid alum vitriol hydrogensulfide” with a pH of 1.98. First, a glucose tolerance test (GTT) was performed on eight non-diabetic people and nine diabetic patients after drinking of tap water or Kawayu hot spring water at a one-week interval. Plasma glucose levels after pre-drinking spring water showed significantly (p=0.05) decreasing compared with those after pre-drinking tap water. Serum immunoreactive insulin (IRI) levels after predrinking hot spring water were tend to be higher at the early phase of GTT than those after pre-drinking tap water. And, we confirmed the correlation between the total decreasing of blood glucose levels and the reactions of insulin secretion at early phase of GTT after spring water drinking. Second, GTT was performed on seven diabetic patients before and after four-week drinking of Kawayu hot spring water. The results showed that hemoglobin A1c levels and total cholesterol levels ware decreased significantly (p<0.05). Total blood glucose levels of tested GTT were, however, almost similar before and after drinking treatment. These findings suggest that drinking of Kawayu hot spring water is beneficial for diabetic patients.

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Spa could have direct effects for physical and mental health but also non-daily pleasure with a visit to spa itself and surroundings. Therefore, the visit should be strongly related with quality of life (QOL) as well as general health status. First of all, this study was conducted to clarify these relationships. Secondly, the QOL was investigated as a confounding factor to health effects of spa. Subjects of this study are about all 6, 000 citizens older than 40 years of age living in Japanese J-town. Self-administrated questionnaires were distributed to the subjects at once and collected for the analysis (Response rate; 94.5%). With regard to the spa visit, (1) no visit at all recently in two or three years, (2) once a year, (3) twice or three times a year and (4) once a month, (5) twice or three times a month were classified.
With regard to QOL (Quality of Life), a questionnaire of WHO-QOL was used. The present study demonstrated the visitors to spa have significantly higher WHO-QOL for each subcategory; physical health, psychological status, social relationship, and environment status compared with non-visitors. Therefore, the visitors have had higher total scores of WHO-QOL compared with non-visters. With regard to past history of fracture, the visitors have had significantly lower it's prevalence compared with non-visitors. However, the significance of prevalence was cancelled in adjusting the WHO-QOL. WHO-QOL relating to the frequency of spa visit as well as the prevalence of fracture was identified as a confounding factor to health effects of spa.

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Purpose It has been reported that the excretion of urinary uric acid is increased by the ingestion of bicarbonated salt spring water or bathing in radioactive spring water. Furthermore, uric acid is considered to play an important role in diminishing oxidative stresses. We therefore investigated the influence of bathing water on the excretion of uric acid from the aspect of urinary oxidation-reduction potential (ORP).
Methods 1. Nine volunteers (three males and six females) aged 22 to 26 were divided into three bathing groups: in sulphur spring water, in bicarbonated salt spring water, and in tap water. Urine specimens were taken six times from 0600 to 1600 while repeating bathing and taking meals alternatively at intervals of 2 hours. ORP, pH, and the concentrations of uric acid and creatinine in urine specimens were measured.
2. ORP, pH, and the concentrations of uric acid and creatinine were measured in the urine specimens taken from the seven subjects in the bicarbonated salt spring and sulphur spring bathing groups early in the morning everyday during the stay at the spa. In addition, serum uric acid levels were measured at the beginning and the end of the stay.
Results 1. The average ORP was 527mV in tap water, 407mV in bicarbonated salt spring, and 145mV in sulphur spring bathing. The urinary ORP increased obviously after bathing in tap water and decreased after bathing in sulfur spring water. The average urinary ORP was 257mV after bathing in tap water, 220mV after bathing in bicarbonated salt spring water, and 216mV after bathing in sulfur spring water. Urinary uric acid/creatinine ratio showed a significant and negative correlation with urinary ORP in all three kinds of water. Urinary pH after bathing varied randomly. Urinary uric acid/creatinine ratio exhibited a significant positive correlation with the urinary pH in all three kinds of water.
2. While serum uric acid elevated after a short stay at the spa of less than 10 days, it decreased after a long stay of more than 2 weeks.
Discussion and Conclusions Urinary ORP immediately reflected the ORP of bathing water. The urinary uric acid/creatinine ratio possessed a negative correlation with urinary ORP. Because the ORP of spring water is commonly lower than that of tap water, bathing in spring water may increase the excretion of uric acid and as a result, may lower the serum uric acid levels after the long stay at the spa. The urinary uric acid/creatinine ratio exhibited a significant positive correlation with urinary pH. The results suggest that if the urinary pH gradually becomes alkaline after a long period of ingestion of alkaline spring water, the excretion of uric acid will be promoted, resulting in a lowered serum uric acid.

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We investigated the difference between muscle-EAT and nerve-EAT basically and clinically. A basic study was performed on healthy adult males. The skin blood flow, deep-tissue temperature, deep hemodynamics, heart rate, and deep-pain threshold were adopted as indexes, and they were compared for a total of three groups: the muscle stimulation-EA group, nerve stimulation-EA group and control group (no stimulation). An acupuncture needle was inserted into the gastrocnemius muscle for muscle stimulation-EA and another needle into the tibial nerve in the femoral region for nerve stimulation-EA. Electric current was then applied at 1Hz for 15 minutes after the flexibility of the foot joint was conformed. Each index was measured after it became stable and was recorded from 10 minutes before starting stimulation until 20 minutes after ending stimulation.
A clinical study was performed on 41 patients with cervical radiculopathy. Muscle-EAT was applied to the patients as the first choice. Cases graded five points or less in pain score (10-point method) after one month were included in the muscle-EAT group. Cases graded six points or more were subjected to nerve-EAT and were included in the nerve-EAT group. The therapeutic results in these two groups were examined for a period of three months at intervals of one month based on the pain score and the evaluation criteria for the results of treatment of cervical radiculopathy.
As a result, we found that the skin blood flow significantly increased on the stimulated side in both the muscle stimulation-EA and nerve stimulation-EA group. The increase was greater in the nerve stimulation group than in the muscle stimulation group. The deep-tissue temperature rose significantly on the stimulated side in the nerve stimulation-EA group. Regarding the deep hemodynamics, deoxy Hb decreased significantly in the nerve stimulation-EA group. No difference was found in heart rate between the two groups. The deep-pain threshold was significantly raised by nerve stimulation.
Patients with cervical radiculopathy who did not respond to continuous muscle-EAT for one month were subjected to nerve-EAT. After three months (two months after changing to nerve-EAT), similar improvements were found in both groups. Significant improvement of paresthesia was obtained with nerve-EAT.
These results suggested that the nerve-EAT influences the peripheral circulation and the deep pain threshold more effectively, enhancing the clinical efficacy.

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Footbath is a safe and easy thermal therapy, however, it may cause stress on our body depending on the temperature. Temperature dependent changes of stress biomarkers in the saliva or urine, and of R-R variability by footbath were studied, and mechanism of effects and side effects were discussed.
Subjects were 14 healthy adult females (32±6 yeas old). The experiments started after permission of the Ethical Committee of International Research Center for Traditional Medicine. They took footbath at 38, 40, 42°C and control study after providing informed consents. They took footbath after 10min rest in a sitting position. Each footbath was 30min long, followed by 10min rest. The same subject participated in the studies four times at the same time of day before lunch. These experiments were in a random order four days apart each other except menstruation periods. Their ECG R-R variability and their concentration of salivary IgA and urinary 8 (OH) dG/creatinin were measured before and after footbath. The autonomic nervous balance was estimated from FFT analysis of the R-R variability; LF (0.04-0.15Hz) and HF (0.15-0.40Hz).
The results indicated that at 40 and 42°C their autonomic nervous balance estimated from LF/HF or HF power changed to sympathetic predominance. At 38, 40 and 42°C, salivary IgA increased significantly, and at 40 and 42°C, urinary 8 (OH) dG/creatinin increased significantly, while no significant change occurred in the control study.
These results indicated footbath for 30min at 40 and 42°C induced sympathetic predominance and caused oxidative stress. It was reported that oxidative stress induced activation of platelet aggregation. The oxidative stress as well as sympathetic activation may be related with the causes of the accidents during hot bathing as well as with the effects of thermal therapy. Further investigations are worth being performed.

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We studied temperature-dependent effects of the footbath on heart rate variability, EEG (F3, F4, P3, P4 of 10/20 international method), cerebral circulation, and subjective comfort, using electrocardiography (ECG), electroencephalography (EEG), near-infrared spectroscopy (NIRS), transcranial Doppler (TCD) and face scale. Subjects were 14 healthy adult women (32±6 years old) who took 3 types of footbath (10cm below the knee at 38°C, 40°C, and 42°C) and the control sitting position without footbath in a randomized sequence after providing written informed consent. Their ECG, EEG, NIRS on the forehead, and TCD findings for the middle cerebral artery were monitored for 50min including a 30min footbath. Subjective changes were monitored every 5min using the face scale. LF (low frequency; 0.04-0.15Hz) and HF (high frequency; 0.15-0.4Hz) components and Lorenz plots parameters were obtained from ECG R-R variability. EEG power and EEG right-left coherence were also calculated.
At 42°C footbath, total hemoglobin (Hb) concentration of the forehead, LF/HF ratio, Pulsatility Index (PI: a marker of intracranial circulation and intracranial pressure obtained from TCD), and parietal β₁ wave power increased significantly. HF power and EEG coherence of θ and α₁ wave of the parietal and frontal leads decreased significantly with decline of comfort. At 40°C, cerebral circulation, LF/HF and PI changed less, but EEG power of the frontal α₁ and α₂, and parietal β₁ waves increased significantly after the cessation of footbath with simultaneous increase of comfort. At 38°C, transient but significant decrease of PI value after footbath was associated with significant increase of EEG power of the frontal θ and parietal α₂ waves after footbath. Parameters having statistically significant correlation with subjective comfort were HF power, Lorenz plots parameters, EEG power and coherence, and frontal Oxy Hb (r=0.150-0.231, p<0.0001 by Spearman's method). The EEG power of frontal α₁ waves had the largest correlation coefficient with subjective comfort (r=0.231, p<0.0001).
It was assumed that temperature-dependent changes of autonomic nervous activity and cerebral circulation caused changes of EEG and comfort during footbath. It was indicated that frontal α₁ wave power of EEG and Lorenz plots parameters obtained from R-R variability may be usable as indices of comfort in hot bathing.

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