- Acta Med Okayama. 2010 Apr;64(2):143-7.
The effect of leg hyperthermia using far infrared rays in bedridden subjects with type 2 diabetes mellitus.
Kawaura A, Tanida N, Kamitani M, Akiyama J, Mizutani M, Tsugawa N, Okano T, Takeda E.
Department of Physical Therapy, School of Health Science, KIBI International University, Takahashi, Okayama 716-8508, Japan.
We examined the effect of leg hyperthermia on oxidative stress in bedridden subjects with type 2 diabetes mellitus using 15-min sessions of far infrared rays over a two-week period. Four subjects (male 1, female 3) incapacitated by a stroke were recruited for this study. All patients were admitted to Takahashi Central Hospital and ate the same hospital meals. Fasting plasma glucose, HbA1c, tumor necrosis factor (TNF)alpha, free fatty acid, leptin, adiponectin and plasma 8-epi-prostaglandin F2alpha (8-epi-PGF2alpha) levels as a marker of oxidative stress were measured on admission, just before and 2 weeks after local heating of the leg. Results showed that plasma total 8-epi-PGF2alpha levels were decreased significantly while TNFalpha levels were increased significantly. On the other hand, glucose, HbA1c, free fatty acid, leptin and adiponectin levels were not changed during the study period. These results suggest that repeated leg hyperthermia may protect against oxidative stress.
2. Can Fam Physician. 2009 Jul;55(7):691-6.
Far-infrared saunas for treatment of cardiovascular risk factors: summary of published evidence.
OBJECTIVE: To review the literature about the health benefits of far-infrared sauna (FIRS) use. QUALITY OF EVIDENCE: A search of Web of Science, EBSCO, Ovid MEDLINE, Ovid HealthSTAR, and EMBASE using the terms far-infrared and sauna, refined by limiting the search to studies of humans published in English, yielded 9 relevant papers (level I or level II evidence). MAIN MESSAGE: Far-infrared saunas are approved by the Canadian Standards Association and are sold to the public. The manufacturers claim numerous health benefits; however, the published evidence to substantiate these claims is limited. Four papers support the use of FIRS therapy for those with congestive heart failure and 5 papers support its use for those with coronary risk factors. CONCLUSION: There is limited moderate evidence supporting FIRS efficacy in normalizing blood pressure and treating congestive heart failure; fair evidence, from a single study, supporting FIRS therapy in chronic pain; weak evidence, from a single study, supporting FIRS therapy in chronic fatigue syndrome; weak evidence, from a single study, supporting FIRS therapy for obesity; and consistent fair evidence to refute claims regarding the role of FIRSs in cholesterol reduction.
3. J Cardiol. 2009 Apr;53(2):214-8. Epub 2009 Jan 18.
Waon therapy improves the prognosis of patients with chronic heart failure.
Kihara T, Miyata M, Fukudome T, Ikeda Y, Shinsato T, Kubozono T, Fujita S, Kuwahata S, Hamasaki S, Torii H, Lee S, Toda H, Tei C.
Department of Cardiovascular, Respiratory and Metabolic Medicine, Graduate School of Medicine, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
BACKGROUND: We developed a Waon therapy (soothing warm therapy) and have previously reported that repeated Waon therapy improves hemodynamics, peripheral vascular function, arrhythmias, and clinical symptoms in patients with chronic heart failure (CHF). The aim of this study was to investigate the effect of Waon therapy on the prognosis of CHF patients. PATIENTS AND METHODS: We studied 129 patients with CHF in NYHA functional class III or IV who were admitted to our hospital between January 1999 and March 2001. In the Waon therapy group, 64 patients were treated with a far infrared-ray dry sauna at 60 degrees C for 15min and then kept on bed rest with a blanket for 30min. The patients were treated daily for 5 days during admission, and then at least twice a week after discharge. In the control group, 65 patients, matched for age, gender, and NYHA functional class, were treated with traditional CHF therapy. The follow-up time was scheduled for 5 years. RESULTS: Recent, complete follow-up data on each patient were obtained. The overall survival rate was 84.5% (Kaplan-Meier estimate). Twelve patients died in the control group and 8 patients died in the Waon therapy group at 60 months of follow-up. Cardiac events due to heart failure or cardiac death occurred in 68.7% of the control group but only 31.3% of the Waon therapy group (P<0.01) at 60 months of follow-up. CONCLUSION: Waon therapy reduced cardiac events in patients with CHF. This therapy is a promising non-pharmacological treatment for CHF.
4. J Cardiol. 2008 Oct;52(2):79-85. Epub 2008 Aug 27.
Beneficial effects of Waon therapy on patients with chronic heart failure: Results of a prospective multicenter study.
Miyata M, Kihara T, Kubozono T, Ikeda Y, Shinsato T, Izumi T, Matsuzaki M, Yamaguchi T, Kasanuki H, Daida H, Nagayama M, Nishigami K, Hirata K, Kihara K, Tei C.
Department of Cardiovascular, Respiratory and Metabolic Medicine, Graduated School of Medicine, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
BACKGROUND: We conducted a prospective multicenter case-control study to confirm the clinical efficacy and safety of Waon therapy on chronic heart failure (CHF). METHODS: Patients (n=188) with CHF were treated with standard therapy for at least 1 week, and then were randomized to Waon therapy (n=112) or a control group (n=76). All patients continued conventional treatment for an additional 2 weeks. The Waon therapy group was treated daily with a far infrared-ray dry sauna at 60 degrees C for 15min and then kept on bed rest with a blanket for 30min for 2 weeks. Chest radiography, echocardiography, and plasma levels of brain natriuretic peptide (BNP) were measured before and 2 weeks after treatment. RESULTS: NYHA functional class significantly decreased after 2 weeks of treatment in both groups. Chest radiography also showed a significant decrease of the cardiothoracic ratio in both groups (Waon therapy: 57.2+/-8.0% to 55.2+/-8.0%, p<0.0001; control: 57.0+/-7.7% to 56.0+/-7.1%, p<0.05). Echocardiography demonstrated that left ventricular diastolic dimension (LVDd), left atrial dimension (LAD), and ejection fraction (EF) significantly improved in the Waon therapy group (LVDd: 60.6+/-7.6 to 59.1+/-8.4mm, p<0.0001; LAD: 45.4+/-9.3mm to 44.1+/-9.4mm, p<0.05; EF: 31.6+/-10.4% to 34.6+/-10.6%, p<0.0001), but not in the control group (LVDd: 58.4+/-10.3mm to 57.9+/-10.4mm; LAD: 46.3+/-9.7mm to 46.2+/-10.1mm; EF: 36.6+/-14.1% to 37.3+/-14.0%). The plasma concentration of BNP significantly decreased with Waon therapy, but not in the control group (Waon: 542+/-508pg/ml to 394+/-410pg/ml, p<0.001; control: 440+/-377pg/ml to 358+/-382pg/ml). CONCLUSION: Waon therapy is safe, improves clinical symptoms and cardiac function, and decreases cardiac size in CHF patients. Waon therapy is an innovative and promising therapy for patients with CHF.
5. J Cardiol. 2008 Apr;51(2):106-13.
Repeated waon therapy improves pulmonary hypertension during exercise in patients with severe chronic obstructive pulmonary disease.
Umehara M, Yamaguchi A, Itakura S, Suenaga M, Sakaki Y, Nakashiki K, Miyata M, Tei C.
Department of Cardiovascular, Respiratory and Metabolic Medicine, Graduated School of Medicine, Kagoshima University, Sakuragaoka 8-35-1, Kagoshima 890-8520, Japan.
OBJECTIVES: Repeated Waon therapy, which uses a far infrared-ray dry sauna system, improved the vascular endothelial function and the cardiac function in patients with chronic heart failure. In patients with chronic obstructive pulmonary disease (COPD), pulmonary hypertension (PH) is associated with a poor prognosis. We investigated whether repeated Waon therapy improves PH, cardiac function, exercise tolerance, and the quality of life (QOL) in patients with COPD. METHODS: Consecutive 13 patients with COPD, who met the Global Initiative for Chronic Obstructive Lung Disease criteria and had breathlessness despite receiving conventional treatments, were recruited for this study. They underwent Waon therapy at 60 degrees C in sauna for 15 min following 30 min warmth with blankets outside of the sauna room. This therapy was performed once a day, for 4 weeks. Cardiac function, exercise tolerance, and St. George’s Respiratory Questionnaire (SGRQ) were assessed before and 4 weeks after Waon therapy. RESULTS: Right ventricular positive dP/dt at rest elevated significantly from 397 +/- 266 to 512 +/- 320 mmHg/s (p = 0.024) after the therapy. While the PH at rest did not significantly decrease, the PH during exercise decreased significantly from 64 +/- 18 to 51 +/- 13 mmHg (p = 0.028) after Waon therapy. Furthermore, the therapy prolonged the mean exercise time of the constant load of cycle ergometer exercise test from 360 +/- 107 to 392 +/- 97 s (p = 0.032). The total scores of SGRQ improved from 59.7 +/- 16.9 to 55.3 +/- 17.2 (p = 0.002). In addition, no adverse effects were observed related to Waon therapy. CONCLUSIONS: Repeated Waon therapy improved right ventricular positive dP/dt, PH during exercise, exercise tolerance and the QOL in patients with severe COPD.
6. Photodermatol Photoimmunol Photomed. 2006 Apr;22(2):78-86.
Biological effect of far-infrared therapy on increasing skin microcirculation in rats.
Yu SY, Chiu JH, Yang SD, Hsu YC, Lui WY, Wu CW.
Institute of Molecular and Cellular Biology, Department of Life Science, National Tsing-Hua University, Hsinchu, and Division of General Surgery, Department of Surgery, Veterans General Hospital, Taipei, Taiwan.
BACKGROUND/PURPOSE: Insufficient microcirculation of skin leads to acute and chronic tissue ischemia in cases of trauma, reconstructive surgery, diabetes mellitus and peripheral arterial occlusive disease. The autonomic nervous system and nitric oxide (NO) play important roles in maintaining blood perfusion of the skin. Far-infrared (FIR) therapy provides low energy of light emitted from an artificial radiator and has been used to treat many vascular-related disorders. Nevertheless, the mechanisms through which FIR works remain unclear. The present study aims to test the hypothesis that the effect of FIR is through increasing skin microcirculation by a mechanism other than its thermal effect. METHODS: Sixty rats were used in the present study. A WS TY301 FIR emitter was placed 20 cm above the rats. Skin temperature and blood flow were continuously measured by a K-type thermocouple. Under laboratory control, the abdominal skin temperature steadily increased from 38-39 degrees C, and was kept at constant temperature. Skin microcirculation was measured with a continuous laser Doppler flowmeter. RESULTS: There was no significant change of skin blood flow during FIR treatment. Skin blood flow increased significantly soon after the removal of the FIR emitter. The stimulating effect on skin blood flow was more significant in the rats treated with FIR for 45 min and could be sustained as long as 60 min. These findings suggested a non-thermic biological effect of FIR on skin microcirculation. The promotive effect of FIR on increasing skin blood flow was not influenced by pretreatment of APP (atropine, propranolol and phentolamine), but was suppressed by pretreatment with NG-nitro-L-arginine methyl ester (an endothelial nitric oxide synthase inhibitor). CONCLUSION: In conclusion, FIR therapy exerts a NO-related biological effect to increase skin microcirculation in rats. This might bring into perspective the clinical application of FIR to treat ischemic disease by augmenting L-arginine/NO pathway.
7. Circ J. 2006 Apr;70(4):463-70.
Repeated thermal therapy up-regulates endothelial nitric oxide synthase and augments angiogenesis in a mouse model of hindlimb ischemia.
Akasaki Y, Miyata M, Eto H, Shirasawa T, Hamada N, Ikeda Y, Biro S, Otsuji Y, Tei C.
Department of Cardiovascular, Respiratory and Metabolic Medicine, Graduate School of Medicine, Kagoshima University, Sakuragaoka, Japan.
BACKGROUND: Nitric oxide (NO), constitutively produced by endothelial NO synthase (eNOS), plays roles in angiogenesis. Having reported that thermal therapy up-regulated the expression of arterial eNOS in hamsters, we investigated whether this therapy increased angiogenesis in mice with hindlimb ischemia. METHODS AND RESULTS: Unilateral hindlimb ischemia was induced in apolipoprotein E-deficient mice, which were divided into control and thermal therapy groups. The latter mice were placed in a far-infrared dry sauna at 41 degrees C for 15 min and then at 34 degrees C for 20 min once daily for 5 weeks. Laser Doppler perfusion imaging demonstrated that the ischemic limb/normal side blood perfusion ratio in the thermal therapy group was significantly increased beyond that in controls (0.79+/-0.04 vs 0.54+/-0.08, p<0.001). Significantly greater capillary density was seen in thermal therapy group (757+/-123 /mm2 vs 416+/-20 /mm2, p<0.01). Western blotting showed thermal therapy markedly increased hindlimb eNOS expression. To study possible involvement of eNOS in thermally induced angiogenesis, thermal therapy was given to mice with hindlimb ischemia with or without N(G)-nitro-L-arginine methyl ester (L-NAME) administration for 5 weeks. L-NAME treatment eliminated angiogenesis induced using thermal therapy. Thermal therapy did not increase angiogenesis in eNOS-deficient mice. CONCLUSION: Angiogenesis was induced via eNOS using thermal therapy in mice with hindlimb ischemia.
8. Circ J. 2005 Jun;69(6):722-9.
Repeated sauna therapy increases arterial endothelial nitric oxide synthase expression and nitric oxide production in cardiomyopathic hamsters.
Ikeda Y, Biro S, Kamogawa Y, Yoshifuku S, Eto H, Orihara K, Yu B, Kihara T, Miyata M, Hamasaki S, Otsuji Y, Minagoe S, Tei C.
Department of Cardiovascular, Respiratory and Metabolic Medicine, Graduate School of Medicine, Kagoshima University, Kogoshima, Japan.
BACKGROUND: Vascular endothelial dysfunction is involved in the pathophysiology of chronic heart failure (CHF). It has been reported that sauna therapy, which allows thermal vasodilation, improves vascular endothelial dysfunction in patients with CHF. The present study investigates the mechanisms through which sauna therapy improves endothelial dysfunction induced by CHF. METHODS AND RESULTS: Normal control and male TO-2 cardiomyopathic hamsters were used. Thirty-week-old TO-2 hamsters were treated daily with an experimental far infrared-ray dry sauna system for 15 min at 39 degrees C followed by 20 min at 30 degrees C. This procedure raised the rectal temperatures by about 1 degrees C. Arterial endothelial nitric oxide (NO) synthase (eNOS) mRNA and protein expressions were examined, and serum concentrations of nitrate were measured. The expression of eNOS mRNA in the aortas of normal controls did not change, whereas those of the TO-2 hamsters decreased with age. Four weeks of sauna therapy significantly increased eNOS mRNA expression in the aortas of TO-2 hamsters compared with those that did not undergo sauna therapy. Sauna therapy also upregulated aortic eNOS protein expression. Serum nitrate concentrations of the TO-2 hamsters were increased by 4 weeks of sauna therapy compared with those that did not undergo sauna. CONCLUSION: Repeated sauna therapy increases eNOS expression and NO production in cardiomyopathic hamsters with heart failure.
9. Circ J. 2004 Dec;68(12):1146-51.
Effects of repeated sauna treatment on ventricular arrhythmias in patients with chronic heart failure.
Kihara T, Biro S, Ikeda Y, Fukudome T, Shinsato T, Masuda A, Miyata M, Hamasaki S, Otsuji Y, Minagoe S, Akiba S, Tei C.
Department of Cardiovascular, Graduate School of Medicine, Kagoshima University, Sakuragaoka, Kagoshima, Japan.
BACKGROUND: The aim of the present study was to determine whether repeated 60 degrees C sauna treatment improves cardiac arrhythmias in chronic heart failure (CHF) patients, because ventricular arrhythmias are an important therapeutic target in CHF. METHODS AND RESULTS: Thirty patients (59+/-3 years) with New York Heart Association functional class II or III CHF and at least 200 premature ventricular contractions (PVCs)/24 h assessed by 24-h Holter recordings were studied. They were randomized into sauna-treated (n=20) or non-treated (n=10) groups. The sauna-treated group underwent a 2-week program of a daily 60 degrees C far infrared-ray dry sauna for 15 min, followed by 30 min bed rest with blankets, for 5 days per week. Patients in the non-treated group had bed rest in a temperature-controlled room (24 degrees C) for 45 min. The total numbers of PVCs/24 h in the sauna-treated group decreased compared with the non-treated group [848+/-415 vs 3,097+/-1,033/24 h, p<0.01]. Heart rate variability (SDNN, standard deviation of normal-to-normal beat interval) increased [142+/-10 (n=16) vs 112+/-11 ms (n=8), p<0.05] and plasma brain natriuretic peptide concentrations decreased [229+/-54 vs 419+/-110 pg/ml, p<0.05] in the sauna-treated group compared with the non-treated group. CONCLUSION: Repeated sauna treatment improves ventricular arrhythmias in patients with CHF.
10. Jpn Heart J. 2004 Mar;45(2):297-303.
Repeated sauna therapy reduces urinary 8-epi-prostaglandin F(2alpha).
Masuda A, Miyata M, Kihara T, Minagoe S, Tei C.
Department of Cardiology, Respiratory and Metabolic Medicine, Kagoshima University, Kagoshima, Japan.
We have reported that repeated sauna therapy improves impaired vascular endothelial function in a patient with coronary risk factors. We hypothesized that sauna therapy decreases urinary 8-epi-prostaglandin F(2alpha) (PGF(2alpha)) levels as a marker of oxidative stress and conducted a randomized, controlled study. Twenty-eight patients with at least one coronary risk factor were divided into a sauna group (n = 14) and non-sauna group (n = 14). Sauna therapy was performed with a 60 degrees C far infrared-ray dry sauna for 15 minutes and then bed rest with a blanket for 30 minutes once a day for two weeks. Systolic blood pressure and increased urinary 8-epi-PGF(2alpha) levels in the sauna group were significantly lower than those in the non-sauna group at two weeks after admission (110 +/- 15 mmHg vs 122 +/- 13 mmHg, P < 0.05, 230 +/- 67 pg/mg x creatinine vs 380 +/- 101 pg/mg x creatinine, P < 0.0001, respectively). These results suggest that repeated sauna therapy may protect against oxidative stress, which leads to the prevention of atherosclerosis.
11. J Am Coll Cardiol. 2001 Oct;38(4):1083-8.
Repeated thermal therapy improves impaired vascular endothelial function in patients with coronary risk factors.
Imamura M, Biro S, Kihara T, Yoshifuku S, Takasaki K, Otsuji Y, Minagoe S, Toyama Y, Tei C.
First Department of Internal Medicine, Faculty of Medicine, Kagoshima University, Sakuragaoka, Kagoshima, Japan.
OBJECTIVES: We sought to determine whether sauna therapy, a thermal vasodilation therapy, improves endothelial function in patients with coronary risk factors such as hypercholesterolemia, hypertension, diabetes mellitus and smoking. BACKGROUND: Exposure to heat is widely used as a traditional therapy in many different cultures. We have recently found that repeated sauna therapy improves endothelial and cardiac function in patients with chronic heart failure. METHODS: Twenty-five men with at least one coronary risk factor (risk group: 38 +/- 7 years) and 10 healthy men without coronary risk factors (control group: 35 +/- 8 years) were enrolled. Patients in the risk group were treated with a 60 degrees C far infrared-ray dry sauna bath for 15 min and then kept in a bed covered with blankets for 30 min once a day for two weeks. To assess endothelial function, brachial artery diameter was measured at rest, during reactive hyperemia (flow-mediated endothelium-dependent dilation [%FMD]), again at rest and after sublingual nitroglycerin administration (endothelium-independent vasodilation [%NTG]) using high-resolution ultrasound. RESULTS: The %FMD was significantly impaired in the risk group compared with the control group (4.0 +/- 1.7% vs. 8.2 +/- 2.7%, p < 0.0001), while %NTG was similar (18.7 +/- 4.2% vs. 20.4 +/- 5.1%). Two weeks of sauna therapy significantly improved %FMD in the risk group (4.0 +/- 1.7% to 5.8 +/- 1.3%, p < 0.001). In contrast, %NTG did not change after two weeks of sauna therapy (18.7 +/- 4.2% to 18.1 +/- 4.1%). CONCLUSIONS: Repeated sauna treatment improves impaired vascular endothelial function in the setting of coronary risk factors, suggesting a therapeutic role for sauna treatment in patients with risk factors for atherosclerosis.
12. Jpn Circ J. 2001 May;65(5):434-8.
Repeated thermal therapy upregulates arterial endothelial nitric oxide synthase expression in Syrian golden hamsters.
Ikeda Y, Biro S, Kamogawa Y, Yoshifuku S, Eto H, Orihara K, Kihara T, Tei C.
The First Department of Internal Medicine, Faculty of Medicine, Kagoshima University, Japan.
It has been previously reported that sauna therapy, a thermal therapy, improves the hemodynamics and clinical symptoms in patients with chronic heart failure and also improves endothelial function, which is impaired in such patients. The present study investigated whether the improvements observed with sauna therapy are through modulation of arterial endothelial nitric oxide synthase (eNOS) expression. Eight male Syrian golden hamsters underwent sauna therapy, using an experimental far infrared-ray dry sauna system, at 39 degrees C for 15 min followed by 30 degrees C for 20 min daily for 4 weeks. Control group hamsters were placed in the sauna system switched off at room temperature of 24 degrees C for 35 min. Immunohistochemistry found greater amounts of the immunoreactive products of eNOS in the endothelial cells of the aorta and carotid, femoral and coronary arteries in the sauna group than in the control group. Western blot analysis also revealed that 4-week sauna therapy significantly increased eNOS expression in aortas by 50% in 4 series of independent experiments with an identical protocol (p<0.01). In reverse transcription polymerase chain reaction assay, the eNOS mRNA in aortas was greater in the sauna group than in controls, with a peak at 1-week of sauna therapy (approximately 40-fold increase). In conclusion, repeated thermal therapy upregulates eNOS expression in arterial endothelium.