Effect of Waon therapy on oxidative stress in chronic heart failure

Enhanced far infrared emissivity, UV protection and near-infrared shielding of polypropylene composites via incorporation of natural mineral for functional fabric development

Far infrared radiation in the range of 4-20 µm has been showed to have biological and health benefits to the human body. Therefore, incorporating far-infrared emissivity additives into polymers and/or fabrics hold promise for the development of functional textiles. In this study, we incorporated nine types of natural minerals into polypropylene (PP) film and examined their properties to identify potential candidates for functional textiles and apparels. The addition of 2% mineral powders into PP film increased the far-infrared emissivity (5-14 µm) by 7.65%-14.48%. The improvement in far-infrared emissivity within the range of 5-14 µm, which overlaps with the peak range of human skin radiation at 8-14 µm, results in increased absorption efficiency, and have the potential to enhance thermal and biological effects. Moreover, the incorporation of mineral powders in PP films exhibited favorable ultraviolet (UV) protection and near-infrared (NIR) shielding properties. Two films, specifically those containing red ochre and hematite, demonstrated excellent UV protection with a UPF rating of 50+ and blocked 99.92% and 98.73% of UV radiation, respectively. Additionally, they showed 95.2% and 93.2% NIR shielding properties, compared to 54.1% NIR shielding properties of PP blank films. The UV protection and NIR shielding properties offered additional advantages for the utilization of polymer composite with additives in the development of sportswear and other outdoor garments. The incorporation of minerals could absorb near-IR radiation and re-emit them at longer wavelength in the mid-IR region. Furthermore, the incorporation of minerals significantly improved the heat retention of PP films under same heat radiation treatment. Notably, films with red ochre and hematite exhibited a dramatic temperature increase, reaching 2.5 and 3.2 times the temperature increase of PP films under same heat radiation treatment, respectively (46.8 °C and 59.9 °C higher than the temperature increase of 20.9 °C in the PP film). Films with additives also demonstrated lower thermal effusivity than PP blank films, indicating superior heat insulation properties. Therefore, polypropylene films with mineral additives, particularly those containing red ochre and hematite, showed remarkable heat capacity, UV-protection, NIR-shielding properties and enhanced far infrared emissivity, making them promising candidates for the development of functional textiles.

Physical properties and biological effects of ceramic materials emitting infrared radiation for pain, muscular activity, and musculoskeletal conditions

BACKGROUND

Up to 33% of the general population worldwide suffer musculoskeletal conditions, with low back pain being the single leading cause of disability globally. Multimodal therapeutic options are available to relieve the pain associated with muscular disorders, including physical, complementary, and pharmacological therapies. However, existing interventions are not disease modifying and have several limitations.

METHOD

Literature review.

RESULTS

In this context, the use of nonthermal infrared light delivered via patches, fabrics, and garments containing infrared-emitting bioceramic minerals have been investigated. Positive effects on muscular cells, muscular recovery, and reduced inflammation and pain have been reported both in preclinical and clinical studies. There are several hypotheses on how infrared may contribute to musculoskeletal pain relief, however, the full mechanism of action remains unclear. This article provides an overview of the physical characteristics of infrared radiation and its biological effects, focusing on those that could potentially explain the mechanism of action responsible for the relief of musculoskeletal pain.

CONCLUSIONS

Based on the current evidence, the following pathways have been considered: upregulation of endothelial nitric oxide synthase, increase in nitric oxide bioavailability, anti-inflammatory effects, and reduction in oxidative stress.

Infrared sauna as exercise-mimetic? Physiological responses to infrared sauna vs exercise in healthy women: A randomized controlled crossover trial

BACKGROUND

Passive heat therapies have been reported to have similar effects on the cardiovascular system as exercise. Studies supporting these findings in healthy populations have predominantly been done with men using warm water immersions or traditional saunas, rather than newer infrared-based saunas.

OBJECTIVE

To explore short-term thermal and cardiovascular responses in women using an infrared sauna as compared to moderate-intensity exercise.

STUDY DESIGN

Randomized controlled crossover trial with balanced allocations.

SETTING

Brisbane, Australia (August 2019 - March 2020) PARTICIPANTS: Ten healthy women (36 ± 9 years) INTERVENTIONS: 45 min of resting, infrared sauna or indoor bicycling PRIMARY OUTCOME MEASURES: tympanic/skin temperatures; respiratory rate; blood pressure; arterial stiffness; heart rate variability RESULTS: Tympanic temperatures were elevated during infrared sauna as compared to both control (mean diff = +1.05 ^oC ± SEM 0.12 ^oC, 95% C.I.: 0.73 - 1.36, p < 0.0005) and exercise (mean diff = +0.79 ^oC ± SEM 0.12 ^oC, 95% C.I.: 0.49 - 1.08, p < 0.0005). Respiratory rates were higher during exercise as compared to both control (mean diff = +7.66 ± SEM 1.37, 95% C.I.: 4.09 - 11.23, p < 0.0005) and infrared sauna (mean diff = +6.66 ± SEM 1.33, 95% C.I.: 3.20 - 10.11, p < 0.0005). No significant differences in non-invasive measures of blood pressure, arterial stiffness or heart rate variability were detected between any of the interventions.

CONCLUSIONS

These findings suggest the physiological effects of infrared sauna bathing are underpinned by thermoregulatory-induced responses, more so than exercise-mimetic cardiorespiratory or cardiovascular activations.

Sweating as a Preventive Care and Treatment Strategy in Traditional Persian Medicine

Proper and regular sweating plays a significant thermoregulatory role. It is a common perception that, sweating has other important homeostatic functions such as clearance of excessive micronutrients, waste products of metabolic processes, and toxins from the body, which helps to maintain human good health. In addition, sweating, thermotherapy, and sauna are commonly used to treat various diseases such as cardiovascular, respiratory and joint diseases. In traditional Persian medicine (PM) textbooks, sweating is considered a preventive care and treatment strategy as well. In this study, we aim to explain the beneficial effects of sweating in human health and its role in the management of various diseases, as well as introducing the therapeutic applications of some diaphoretic plants from the viewpoint of PM. We reviewed the most famous PM textbooks such as Kamil al-Sinaa al-Tibbiya, Al-Qānūn fī al-Tibb, Zakhireye Kharazmshahi, Kholasat al-Hikmat, Exir-e-Azam, and Hifzos-sihhat-e Naseri. Also, current evidence was searched in PubMed, Web of Science, Scopus, and other relevant databases related to the topic. The results of this study revealed that PM scientists believed proper sweating removes waste products and maintains the body’s health, thus, any disturbances in the excretion of these waste products can cause diseases. They recommended the induction of sweating through hot and dry baths, sun bath, sand bath and also the use of diaphoretic herbs for the management of various diseases. Therefore, further researches are recommended to evaluate the effectiveness of these diaphoretic plants.

The effect of heat therapy on blood pressure and peripheral vascular function: A systematic review and meta-analysis

NEW FINDINGS

What is the topic of this review? We have conducted a systematic review and meta-analysis on the current evidence for the effect of heat therapy on blood pressure and vascular function. What advances does it highlight? We found that heat therapy reduced mean arterial, systolic and diastolic blood pressure. We also observed that heat therapy improved vascular function, as assessed via brachial artery flow-mediated dilatation. Our results suggest that heat therapy is a promising therapeutic tool that should be optimized further, via mode and dose, for the prevention and treatment of cardiovascular disease risk factors.

ABSTRACT

Lifelong sauna exposure is associated with reduced cardiovascular disease risk. Recent studies have investigated the effect of heat therapy on markers of cardiovascular health. We aimed to conduct a systematic review with meta-analysis to determine the effects of heat therapy on blood pressure and indices of vascular function in healthy and clinical populations. Four databases were searched up to September 2020 for studies investigating heat therapy on outcomes including blood pressure and vascular function. Grading of Recommendations, Assessment, Development and Evaluations (GRADE) was used to assess the certainty of evidence. A total of 4522 titles were screened, and 15 studies were included. Healthy and clinical populations were included. Heat exposure was for 30-90 min, over 10-36 sessions. Compared with control conditions, heat therapy reduced mean arterial pressure [n = 4 studies; mean difference (MD): -5.86 mmHg, 95% confidence interval (CI): -8.63, -3.10; P < 0.0001], systolic blood pressure (n = 10; MD: -3.94 mmHg, 95% CI: -7.22, -0.67; P = 0.02) and diastolic blood pressure (n = 9; MD: -3.88 mmHg, 95% CI: -6.13, -1.63; P = 0.0007) and improved flow-mediated dilatation (n = 5; MD: 1.95%, 95% CI: 0.14, 3.76; P = 0.03). Resting heart rate was unchanged (n = 10; MD: -1.25 beats/min; 95% CI: -3.20, 0.70; P = 0.21). Early evidence also suggests benefits for arterial stiffness and cutaneous microvascular function. The certainty of evidence was moderate for the effect of heat therapy on systolic and diastolic blood pressure and heart rate and low for the effect of heat therapy on mean arterial pressure and flow-mediated dilatation. Heat therapy is an effective therapeutic tool to reduce blood pressure and improve macrovascular function. Future research should aim to optimize heat therapy, including the mode and dose, for the prevention and management of cardiovascular disease.

Impact of whole body passive heat stress and arterial shear rate modification on radial artery function in young men

We sought to determine how whole body heating acutely influences radial artery function, characterized using flow-mediated dilation (FMD) and low-flow-mediated constriction (L-FMC), and the mechanistic role of shear rate modification on radial artery functional characteristics during heating. Eleven young healthy men underwent whole body heating (water-perfused suit) sufficient to raise the core temperature by +1°C. Trials were repeated with (heat + WC) and without (heat) the application of a wrist cuff located distal to the radial artery examined, known to prevent increases in mean and anterograde shear rates but increase retrograde shear rate. Radial artery characteristics were assessed throughout each trial, with FMD and L-FMC assessed before and upon reaching the target core temperature. Heat markedly increased radial artery mean and anterograde shear rates, along with radial artery diameter and blood flow (P < 0.05). Heat + WC abolished the heat-induced increase in mean and anterograde shear rates (P > 0.05) but markedly increased retrograde shear rate (P < 0.05). Concomitantly, increases in radial artery diameter and blood flow were decreased (heat + WC vs. heat, P < 0.05). Heat attenuated FMD (8.6 ± 1.2% vs. 2.2 ± 1.4%, P < 0.05), whereas no change in FMD was observed in heat + WC (7.8 ± 1.2% vs. 10.8 ± 1.2%, P > 0.05). In contrast, L-FMC was not different in either trial (P > 0.05). In summary, acute whole body heating markedly elevates radial artery shear rate, diameter, and blood flow and diminishes FMD. However, marked radial artery vasodilation and diminished FMD are absent when these shear rate changes are prevented. Shear rate modifications underpin the radial artery response to acute whole body heat stress, but further endothelium-dependent vasodilation (FMD) is attenuated likely as the vasodilatory range limit is approached.NEW & NOTEWORTHY We observed that acute whole body heating elevates radial artery shear rate, diameter, and blood flow. This results in a diminished flow-meditated dilatation (FMD) but does not change low-flow-mediated constriction (L-FMC). Preventing shear rate changes during whole body heating reduces radial artery vasodilation and reverses FMD reductions but has no effect on L-FMC. These findings indicate that shear rate changes underpin conduit artery responses to acute whole body heat stress, but further endothelium-dependent flow-mediated vasodilation is attenuated as the vasodilatory range limit is approached.

Repeated Dry Sauna Therapy Improves Quality of Life in Obese Korean People

Background

Dry sauna treatments improve the quality of life for chronic pain, congestive heart failure, and type 2 diabetes patients. This study aimed to determine whether dry sauna therapy improved the quality of life of obese people.

Methods

A total of 38 consecutive participants aged over 20 years with a body mass index of ≥25 kg/m² were recruited for the study. The participants were treated with a 90°C dry sauna for 15 minutes, twice daily for 4 consecutive days. To assess the quality of life, all participants completed the 5 level EQ-5D questionnaires and the EQ-Visual Analog Scale. Study parameters were measured on the same day prior to commencing the sauna sessions in a fasted state and 2 days after the last sauna session.

Results

The average age was 62.3±9.5 years; 84.2% of the participants were female. The mean body mass index was 28.5±2.4 kg/m². Dry sauna significantly improved the mean 5 level EQ-5D index scores from 0.83±0.12 to 0.89±0.11 and increased the mean EQ-Visual Analog Scale from 79.0±15.2 to 91.1±9.7. However, there were no significant changes in body mass index, blood pressure, heart rate, or body composition before and after the 8-session sauna therapy.

Conclusion

Dry sauna improved the health-related quality of life of obese patients without adverse events. Further clinical studies in larger study populations are needed to verify these findings and provide concrete evidence for obesity treatment.

Can heat therapy help patients with heart failure?

To review and analyze the clinical outcomes of thermal therapy (≤1.4°C increase in core body temperature) in patients with heart failure (HF). A systematic review and meta-analysis regarding the effects of thermal therapy on HF was done by searching PubMed, Ovid Medline, Ovid Embase, Scopus, and internal databases up to date (2019). Improvement in the New York Heart Association (NYHA) class: Ten studies with 310 patients showed significant improvement in NYHA class. Only 7 among 40 patients remained in Class IV and 99 patients in Class III from 155 patients. Increased patients in lower classes indicate that more patients showed improvement. Sixteen studies on 506 patients showed an overall improvement of 4.4% of left ventricular ejection fraction (LVEF). Four studies reported improved endothelial dysfunction by 1.7% increase in flow-mediated dilation (FMD) on 130 patients. Reduction in blood pressure: Thermal therapy reduced both systolic blood pressure (SBP) and diastolic blood pressure by 3.1% and 5.31%, respectively, in 431 patients of 15 studies. Decrease in cardiothoracic ratio (CTR): Eight studies reported an average of 5.55% reduction of CTR in a total of 347 patients. Improvement in oxidative stress markers: Plasma brain natriuretic peptide (BNP) levels significantly decreased (mean difference of 14.8 pg/dL) in 303 patients of 9 studies. Improvement of quality of life: Among 65 patients, thermal therapy reduced cardiac death and rehospitalization by 31.3%. A slight increase in core body temperature is a promising, noninvasive, effective, and complementary therapy for patients with HF. Further clinical studies are recommended.

Acute and short-term efficacy of sauna treatment on cardiovascular function: A meta-analysis

OBJECTIVE

The role of sauna bathing in cardiovascular function treatment has been increasingly explored, but insufficient attention has been paid to its efficacy. We performed a meta-analysis to provide more evidence for the efficacy of sauna treatment in cardiovascular nursing.

METHODS

Sixteen peer-reviewed journal articles were screened to summarize the efficacy of the sauna on cardiovascular function. Both acute (0-30 min after the sauna) and short-term (2-4 weeks following the sauna treatment) efficacies were investigated.

RESULTS

For pooled acute efficacy, body temperature and heart rate significantly (p<0.001) grew by 0.94℃ and 17.86 beats/min, respectively; reductions of 5.55 mmHg (p<0.001) and 6.50 mmHg (p<0.001) were also observed in systolic blood pressure and diastole blood pressure, respectively. For combined short-term efficacy, left ventricular ejection fraction (LVEF), 6-min walk distance, and flow-mediated dilation (p<0.001) increased by 3.27%, 48.11 m, and 1.71%, respectively; greater amelioration in LVEF was observed in participants with lower LVEF. The proportion of patients with New York Heart Association class III and IV decreased by 10.9% and 12.2%, respectively. Systolic blood pressure, diastolic blood pressure, brain natriuretic peptide concentration, left ventricular end-diastolic dimension, cardiothoracic ratio, and left atrial dimension reduced by 5.26 mmHg (p<0.001), 4.14 mmHg (p<0.001), 116.66 pg/mL (p<0.001), 2.79 mm (p<0.001), 2.628% (p<0.05), and 1.88 mm (p<0.05), respectively, while the concentration of norepinephrine in the plasma remained unchanged.

CONCLUSION

Sauna treatment was found to play a positive role in improving cardiovascular function and physical activity levels, especially in patients with low cardiovascular function. These findings reveal that thermal intervention may be a promising means for cardiovascular nursing.

Dry sauna therapy is beneficial for patients with low back pain

Background

Dry sauna has been very popular as an alternative therapy for promoting health among people who want to improve their health condition without relying on pharmaceuticals. The aim of this study was to investigate whether dry sauna therapy improved quality of life and reduced pain in participants with low back pain.

Methods

Study participants comprised a total of 37 consecutive patients who were over 20 years of age with low back pain. Dry sauna therapy was performed twice per day for 5 consecutive days over the course of 1 week, thus comprising a total of 10 sessions each of 15 min of exposure to a 90°C dry sauna.

Results

The verbal numerical rating scale (VNRS) and Oswestry disability index (ODI) scores were significantly reduced after dry sauna therapy (P < 0.001 for both). VNRS pain scores had a median (range) of 5 (2–8) before dry sauna therapy and 3 (0–8) after dry sauna therapy. ODI scores had a median (range) of 12 (2–24) before dry sauna therapy and 8 (1–17) after dry sauna therapy. The proportion of participants who reported successful treatment (excellent + good) was 70%. No adverse effects were observed related to dry sauna therapy.

Conclusions

Our results suggest that dry sauna therapy may be useful to improve quality of life and reduce pain in patients with low back pain. Therefore, pain physicians can recommend dry sauna therapy as an alternative and complimentary therapy for patients with low back pain.

Sauna bathing is associated with reduced cardiovascular mortality and improves risk prediction in men and women: a prospective cohort study

BACKGROUND

Previous evidence indicates that sauna bathing is related to a reduced risk of fatal cardiovascular disease (CVD) events in men. The aim of this study was to investigate the relationship between sauna habits and CVD mortality in men and women, and whether adding information on sauna habits to conventional cardiovascular risk factors is associated with improvement in prediction of CVD mortality risk.

METHODS

Sauna bathing habits were assessed at baseline in a sample of 1688 participants (mean age 63; range 53-74 years), of whom 51.4% were women. Multivariable-adjusted hazard ratios (HRs) were calculated to investigate the relationships of frequency and duration of sauna use with CVD mortality.

RESULTS

A total of 181 fatal CVD events occurred during a median follow-up of 15.0 years (interquartile range, 14.1-15.9). The risk of CVD mortality decreased linearly with increasing sauna sessions per week with no threshold effect. In age- and sex-adjusted analysis, compared with participants who had one sauna bathing session per week, HRs (95% CIs) for CVD mortality were 0.71 (0.52 to 0.98) and 0.30 (0.14 to 0.64) for participants with two to three and four to seven sauna sessions per week, respectively. After adjustment for established CVD risk factors, potential confounders including physical activity, socioeconomic status, and incident coronary heart disease, the corresponding HRs (95% CIs) were 0.75 (0.52 to 1.08) and 0.23 (0.08 to 0.65), respectively. The duration of sauna use (minutes per week) was inversely associated with CVD mortality in a continuous manner. Addition of information on sauna bathing frequency to a CVD mortality risk prediction model containing established risk factors was associated with a C-index change (0.0091; P = 0.010), difference in - 2 log likelihood (P = 0.019), and categorical net reclassification improvement (4.14%; P = 0.004).

CONCLUSIONS

Higher frequency and duration of sauna bathing are each strongly, inversely, and independently associated with fatal CVD events in middle-aged to elderly males and females. The frequency of sauna bathing improves the prediction of the long-term risk for CVD mortality.

Effects of sauna bath on heart failure: A systematic review and meta-analysis

BACKGROUND

Sauna bath has potential as a lifestyle treatment modality for heart failure (HF). It is important to analyze the current evidence to help suggest paths of future study and potential for clinical application.

HYPOTHESIS

Sauna bath has a positive effect on HF patients.

METHODS

PubMed, Cochrane Library, and CINAHL databases were searched to identify randomized and nonrandomized controlled studies to compare effects of sauna bath with no sauna bath. Studies were searched for both infrared sauna bath and Finnish sauna bath. The strength of evidence was rated using a modified GRADE approach. Out of 1444 studies, nine met the inclusion criteria and were included in this review. Seven of these nine studies were included in the meta-analysis. Only studies with infrared sauna bath met the inclusion criteria.

RESULTS

In the meta-analysis, exposure to an infrared sauna bath in 60°C for 15 minutes, followed by a 30-minute rest in warm environment, five times a week for 2 to 4 weeks, was associated with a significant reduction in B-type natriuretic peptide, cardiothoracic ratio, and an improvement in left-ventricular ejection fraction. There was no significant effect on left-ventricular end-diastolic diameter, left atrial diameter, systolic blood pressure, or diastolic blood pressure. The strength of evidence varied from moderate to insufficient.

CONCLUSION

Infrared sauna bath was associated with short-term improvement in cardiac function. More evidence is needed about long-term effects of sauna bath and the effects of a Finnish sauna on cardiovascular health among patients with HF or other cardiovascular diseases.

Potential mechanisms for the effects of far-infrared on the cardiovascular system - a review

Far-infrared (FIR) is a form of thermal radiation, which may have beneficial effects on cardiovascular health. Clinical studies suggest that FIR irradiation may have therapeutic effects in heart failure, myocardial ischaemia and may improve flow and survival of arteriovenous fistula. Animal studies have suggested a wide range of potential mechanisms involving endothelial nitric oxide synthase and nitric oxide bioavailability, oxidative stress, heat shock proteins and endothelial precursor cells. However, the exact cellular and molecular mechanism of FIR on the cardiovascular system remains elusive. The purpose of this review is to discuss the current literature, focusing on mechanistic studies involving the cardiovascular system, and with a view to highlighting areas for future investigation.

Evaluation of the Role of Balneotherapy in Rehabilitation Medicine

Balneotherapy is a treatment with healing waters, which includes bathing and physiotherapy in thermal water, therapeutic drinks, medical massage, and water jet massage. It is based on the buoyancy, physical properties, temperature, and chemical effects of mineral water. Throughout European and Japanese medical institutions, balneology and hot spring therapy is very much a part of routine medical treatment. The mechanism of balneotherapy is not yet completely understood. Balneotherapeutic procedures are mainly performed for the prevention, treatment, and rehabilitation of musculoskeletal diseases, but they have also proven useful for various other indications such as for the treatment or rehabilitation of dermatological diseases, immuno-inflammatory diseases, chronic pain syndromes, chronic cardiac diseases, and metabolic syndromes or neurological diseases as well as in the rehabilitation of patients with psychiatric conditions. Balneotherapy works well in the case of muscle tension, as it is relieving and relaxing, and it may be associated with improvement of various diseases. However, further investigations are necessary to determine the effectiveness, safety, standard procedures, and potential side effects of balneotherapy.

Longitudinal associations of sauna bathing with inflammation and oxidative stress: the KIHD prospective cohort study

PURPOSE

We sought to determine cross-sectional and longitudinal associations of frequency of sauna bathing with high sensitivity C-reactive protein (hsCRP), fibrinogen, leucocyte count and gamma-glutamyltransferase (GGT).

DESIGN

Baseline sauna bathing habits were assessed in 2269 men aged 42-61 years. Concentrations of hsCRP, fibrinogen, leucocyte count, and GGT were determined at baseline and 11 years later. The associations of sauna bathing frequency with baseline and 11-year hsCRP, fibrinogen, leucocyte count, and GGT levels were examined using robust multivariate regression analyses.

RESULTS

In baseline analysis, 4-7 sauna sessions/week (compared with 1 sauna session/week) was associated with -0.84 mg/l (95% CI, -1.55, -0.14; p = .019) lower hsCRP; -0.07 g/l (95% CI, -0.15, 0.02; p = .112) lower fibrinogen; and -0.28 × 10⁹/l (95% CI, -0.51, -0.06; p = .015) lower leucocyte count, after multivariable adjustment. In longitudinal analysis, the corresponding estimates were -1.66 mg/l (95% CI, -3.13, -0.19; p = .027); -0.16 g/l (95% CI, -0.31, -0.02; p = .031); and -0.49 × 10⁹/l (95% CI, -0.85, -0.14; p = .007) respectively. Sauna bathing frequency was not associated with GGT at baseline and 11 years.

CONCLUSION

Observational evidence supports the hypothesis that reduction in inflammation may be one of the pathways linking frequent sauna bathing with decreased risk of acute and chronic disease conditions. KEY MESSAGES Cross-sectional evidence or short-term studies suggest Finnish sauna bathing may exert its beneficial health effects via reduction in inflammation and oxidative stress; however, the long-term effects of sauna bathing on these outcomes are uncertain. In this population-based prospective cohort study, frequent sauna sessions significantly decreased levels of inflammatory markers at baseline and 11-year follow-up; but had no effect on oxidative stress. The health benefits of sauna bathing may in part be mediated via reduced systemic inflammation.

Short-term effects of Finnish sauna bathing on blood-based markers of cardiovascular function in non-naive sauna users

Emerging evidence suggests that sauna bathing is associated with reduced risk of cardiovascular and all-cause mortality events. However, the biochemical pathways by which sauna bathing might confer its effects on cardiovascular function are not certain. We aimed to study the acute effects of Finnish sauna bathing on various blood-based cardiovascular biomarkers. The study included 102 non-naive sauna users (54% male) with mean age of 51.9 years, who had at least one cardiovascular risk factor. Participants underwent a 30-min single sauna session (mean temperature, 73 °C). Biochemical profiling was conducted before, immediately after sauna and 30-min post-sauna. Overall median N-terminal pro-B-type natriuretic peptide (NT-proBNP) level (n = 20 participants) was 46.0 ng/L before sauna exposure, which increased to 50.5 ng/l immediately after sauna (median change, + 12.00%; p < 0.001) and remained persistent at 30-min post-sauna (median change from pre-sauna to post-30-min sauna, + 13.93%; p < 0.001). The changes were more evident in males compared with females. There were no significant changes in overall levels of high sensitivity C-reactive protein, creatine kinase, high sensitivity troponin I, and creatine kinase-MBm. However, levels of creatine kinase increased in males (median change immediately after sauna, + 2.99%; p = 0.024). Levels of NT-proBNP increased after sauna exposure. The increase in levels of creatine kinase was more evident in males. Long-term interventional studies are warranted to evaluate if these biomarkers are involved in pathways underlying the associations of sauna bathing with cardiovascular outcomes.

Clinical Effects of Regular Dry Sauna Bathing: A Systematic Review

Introduction

Many health benefits are claimed by individuals and facilities promoting sauna bathing; however the medical evidence to support these claims is not well established. This paper aims to systematically review recent research on the effects of repeated dry sauna interventions on human health.

Methods

A systematic search was made of medical databases for studies reporting on the health effects of regular dry sauna bathing on humans from 2000 onwards. Risk of bias was assessed according to the Cochrane Collaboration guidelines.

Results

Forty clinical studies involving a total of 3855 participants met the inclusion criteria. Only 13 studies were randomized controlled trials and most studies were small (n < 40). Reported outcome measures were heterogeneous with most studies reporting beneficial health effects. Only one small study (n = 10) reported an adverse health outcome of disrupted male spermatogenesis, demonstrated to be reversible when ceasing sauna activity.

Conclusions

Regular dry sauna bathing has potential health benefits. More data of higher quality is needed on the frequency and extent of adverse side effects. Further study is also needed to determine the optimal frequency and duration of distinct types of sauna bathing for targeted health effects and the specific clinical populations who are most likely to benefit.

Neurohumoral Modulation During Waon Therapy in Chronic Heart Failure - Subanalysis of Waon-CHF Study

BACKGROUND

Heart failure (HF) is a disease of neurohumoral dysfunction and current pharmacological therapies for HF have not improved mortality rates, thus requiring additional new strategies. Waon therapy for HF patients may be a complementary strategy with peripheral vasodilation via nitric oxide. We hypothesized that Waon therapy would improve neurohumoral factors, such as natriuretic peptides (NP) and the renin-angiotensin-aldosterone system (RAAS) in HF.Methods and Results:Plasma samples were collected from patients enrolled in the WAON-CHF Study (Waon therapy (n=77) or control (n=73)) before and after the treatment. B-type NP (BNP), C-type NP (CNP), and aldosterone (Aldo) levels were measured by respective specific radioimmunoassays. Although clinical parameters significantly improved in the Waon group compared with the control group, BNP, Aldo, and CNP levels were not statistically different between groups. On subanalysis with patient variables, BNP levels were improved in the Waon group treated with angiotensin-converting enzyme inhibitor/angiotensin-receptor blocker or spironolactone. In addition, Aldo levels were improved in the Waon group patients with diabetes mellitus, hypertension, and inotrope use, and CNP levels were improved in Waon group patients with estimated glomerular filtration rate <60 mL/min/1.73 m². These changes were not observed in the control group.

CONCLUSIONS

Waon therapy may accelerate the favorable actions of RAAS modulators in HF. (WAON-CHF Study: UMIN000006705).

Mild systemic thermal therapy ameliorates renal dysfunction in a rodent model of chronic kidney disease

Thermal therapy has become a nonpharmacological therapy in clinical settings, especially for cardiovascular diseases. However, the practical role of thermal therapy on chronic kidney disease remains elusive. We performed the present study to investigate whether a modified thermal protocol, repeated mild thermal stimulation (MTS), could affect renal damages in chronic kidney disease using a mouse renal ablation model. Mice were subjected to MTS or room temperature (RT) treatment once daily for 4 wk after subtotal nephrectomy (Nx) or sham operation (Sh). We revealed that MTS alleviated renal impairment as indicated by serum creatinine and albuminuria in Nx groups. In addition, the Nx + MTS group showed attenuated tubular histological changes and reduced urinary neutrophil gelatinase-associated lipocalin excretion approximately by half compared with the Nx + RT group. Increased apoptotic signaling, such as TUNEL-positive cell count and cleavage of caspase 3, as well as enhanced oxidative stress were significantly reduced in the Nx + MTS group compared with the Nx + RT group. These changes were accompanied with the restoration of kidney Mn-SOD levels by MTS. Heat shock protein 27, a key molecular chaperone, was phosphorylated by MTS only in Nx kidneys rather than in Sh kidneys. MTS also tended to increase the phosphorylation of p38 MAPK and Akt in Nx kidneys, possibly associated with the activation of heat shock protein 27. Taken together, these results suggest that modified MTS can protect against renal injury in a rodent model of chronic kidney disease.

Waon Therapy for Managing Chronic Heart Failure - Results From a Multicenter Prospective Randomized WAON-CHF Study

BACKGROUND

Waon therapy improves heart failure (HF) symptoms, but further evidence in patients with advanced HF remains uncertain.

METHODS AND RESULTS

In 19 institutes, we prospectively enrolled hospitalized patients with advanced HF, who had plasma levels of B-type natriuretic peptide (BNP) >500 pg/ml on admission and BNP >300 pg/ml regardless of more than 1 week of medical therapy. Enrolled patients were randomized into Waon therapy or control groups. Waon therapy was performed once daily for 10 days with a far infrared-ray dry sauna maintained at 60℃ for 15 min, followed by bed rest for 30 min covered with a blanket. The primary endpoint was the ratio of BNP before and after treatment. In total, 76 Waon therapy and 73 control patients (mean age 66 years, men 61%, mean plasma BNP 777 pg/ml) were studied. The groups differed only in body mass index and the frequency of diabetes. The plasma BNP, NYHA classification, 6-min walk distance (6MWD), and cardiothoracic ratio significantly improved only in the Waon therapy group. Improvements in NYHA classification, 6MWD, and cardiothoracic ratio were significant in the Waon therapy group, although the change in plasma BNP did not reach statistical significance. No serious adverse events were observed in either group.

CONCLUSIONS

Waon therapy, a holistic soothing warmth therapy, showed clinical advantages in safety and efficacy among patients with advanced HF.

Acute Thermotherapy Prevents Impairments in Cutaneous Microvascular Function Induced by a High Fat Meal

We tested the hypothesis that a high fat meal (HFM) would impair cutaneous vasodilation, while thermotherapy (TT) would reverse the detrimental effects. Eight participants were instrumented with skin heaters and laser-Doppler (LD) probes and tested in three trials: control, HFM, and HFM + TT. Participants wore a water-perfused suit perfused with 33°C (control and HFM) or 50°C (HFM + TT) water. Participants consumed 1 g fat/kg body weight. Blood samples were taken at baseline and two hours post-HFM. Blood pressure was measured every 5-10 minutes. Microvascular function was assessed via skin local heating from 33°C to 39°C two hours after HFM. Cutaneous vascular conductance (CVC) was calculated and normalized to maximal vasodilation (%CVCmax). HFM had no effect on initial peak (48 ± 4 %CVCmax) compared to control (49 ± 4 %CVCmax) but attenuated the plateau (51 ± 4 %CVCmax) compared to control (63 ± 4 %CVCmax, P < 0.001). Initial peak was augmented in HFM + TT (66 ± 4 %CVCmax) compared to control and HFM (P < 0.05), while plateau (73 ± 3 % CVCmax) was augmented only compared to the HFM trial (P < 0.001). These data suggest that HFM negatively affects cutaneous vasodilation but can be minimized by TT.

Waon therapy attenuates cardiac hypertrophy and promotes myocardial capillary growth in hypertensive rats: a comparative study with fluvastatin

Cardiac hypertrophy and fibrosis in heart failure with preserved ejection fraction are associated with a pro-inflammatory state and reduced NO bioavailability. Effects on myocardial structural and molecular alterations were compared between Waon therapy (WT; repeated dry sauna therapy) and statin in hypertensive rats. Seven-week-old Dahl salt-sensitive rats were assigned to 4 groups: low-salt (LS) diet, high-salt (HS) diet, HS diet with oral fluvastatin (FL; 10 mg/kg/day for 4 weeks) starting from the age of 9 weeks, and HS diet with WT treatment in a far-infrared dry sauna (39 °C for 15 min followed by 34 °C for 20 min once daily for 4 weeks). HS rats developed left ventricular (LV) hypertrophy with preserved LV systolic function. WT reduced LV wall thickness and myocyte cross-sectional area along with decreased levels of myocardial ANP and BNP mRNA expression compared with HS rats. Reduction in LV fibrosis and increase in capillary density in WT animals were accompanied by reductions in myocardial levels of TGF-β1, MMP2, p22(phox) and gp91(phox) mRNA expression, and increases in myocardial levels of VEGF and HSP90 mRNA and phosphorylated eNOS protein. These effects were comparable between WT and FL animals. WT improves structural and molecular alterations in salt-induced hypertensive rats similarly to fluvastatin.

Effects of Waon therapy on chronic fatigue syndrome: a pilot study

OBJECTIVE

Chronic fatigue syndrome (CFS) is a disabling condition of unknown etiology, and no definitive therapy has been identified to date. We developed Waon therapy, a form of thermal therapy using a far-infrared dry sauna, and in this study herein examined its feasibility and safety in patients with CFS.

METHODS

Ten consecutive inpatients with CFS stayed in a 60°C sauna for 15 minutes and then rested on a bed under a blanket for an additional 30 minutes outside the sauna room. The treatments were performed once a day, five days a week for four weeks. Perceived fatigue, the primary outcome measure, was evaluated using a numerical rating scale before, during (two weeks after the commencement of therapy) and after therapy. The pain level, evaluated using a numerical rating scale, mood, assessed using the Profile of Mood States questionnaire, and performance status, assessed using a scale developed for CFS patients were also examined before and after therapy.

RESULTS

Perceived fatigue significantly decreased after therapy, although no significant reductions were observed during therapy. In addition, a negative mood, including anxiety, depression and fatigue, and the performance status significantly improved after therapy. However, the levels of pain and vigor did not change significantly. No patients reported any adverse effects during the therapy.

CONCLUSION

These findings suggest that Waon therapy may be a useful and safe treatment for CFS.

Thermal vasodilation using a portable infrared thermal blanket in decompensated heart failure

Adjunctive and non-pharmacological therapies, such as heat, for the treatment of heart failure patients have been proposed. Positive results have been obtained in clinically stable patients, but no studies of the use of thermal therapy in patients with decompensated heart failure (DHF) have been reported. An open randomized clinical trial was designed in patients with DHF and controls. We studied 38 patients with a mean age of 56.9 years. A total of 86.8% were men, and 71% had nonischemic myocardiopathy. All participants were using dobutamine, and the median brain natriuretic peptide (BNP) level was 1396 pg/mL. An infrared thermal blanket heated the patients, who were divided into 2 groups: group T (thermal therapy) and group C (control). Group T underwent vasodilation using the thermal blanket at 50°C for 40 minutes in addition to drug treatment. The cardiac index increased by 24.1% (P = 0.009), and systemic vascular resistance decreased by 16.0% in group T (P < 0.024) after thermal therapy. Heat as a vasodilator increased the cardiac index and lowered systemic vascular resistance in DHF patients. These data suggest thermal therapy as a therapeutic approach for the adjuvant treatment of DHF patients.

The effect of a single Finnish sauna bath after aerobic exercise on the oxidative status in healthy men

BACKGROUND

The aim of this study was to determine the effect of Finnish sauna as a regeneration method post-exercise on the oxidant-antioxidant balance in healthy men.

MATERIAL

43 men aged 24.0 ± 4.3 years performed a 30-min aerobic exercise on a cycle ergometer and rested for 39 min at a room temperature (Day 1; 20°C) or in a sauna for post-workout recovery (Day 2; 90°C, air humidity 10%). Blood was taken 3 times during both study days: Before the exercise (baseline), 20 and 40 min after the recovery. Methods. The activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) was determined in the subjects' erythrocytes. The concentration of thiobarbituric acid reactive substances (TBARS) was measured both in plasma (TBARSpl) and in the erythrocytes (TBARSer).

RESULTS

A 12.7% increase in the TBARSpl concentration versus the baseline was observed 40 min after the Finnish sauna (p < 0.01). The CAT activity observed 20 and 40 min after the sauna was also found higher by 8.1% and 8.9%, respectively, in comparison with the baseline (p < 0.05). In turn, the TBARSer concentration was lower by 17.5% 40 min after the recovery in the sauna, as compared with the TBARSer concentration 40 min after the recovery at the room temperature (p < 0.05).

CONCLUSIONS

A single Finnish sauna bath as a source of free radicals per se is able to reduce oxidative stress induced by a 30-min aerobic exercise in healthy men.

Effect of a steam foot spa on geriatric inpatients with cognitive impairment: a pilot study

Purpose

To investigate whether a steam foot spa improves cognitive impairment in geriatric inpatients.

Methods

Geriatric inpatients with cognitive impairment were given a steam foot spa treatment at 42°C for 20 minutes for 2 weeks (5 days/week). Physiological indicators such as blood pressure, percutaneous oxygen saturation, pulse, tympanic temperature, and sleep time and efficiency were assessed. Cognitive function and behavioral and psychological symptoms of dementia were assessed using the Mini-Mental State Examination, Dementia Mood Assessment Scale, and Dementia Behavior Disturbance scale.

Results

Significant decreases in systolic (P < 0.01) and diastolic blood pressure (P < 0.05) along with a significant increase in tympanic temperature (P < 0.01) were observed after the steam foot spas. A significant improvement was seen in the Mini-Mental State Examination score (P < 0.01) and the overall dementia severity items in Dementia Mood Assessment Scale (P < 0.05).

Limitations

Japanese people are very fond of foot baths. However, it is difficult to understand why inpatients cannot receive steam foot baths. In this study, a control group was not used. Raters and enforcers were not blinded.

Conclusion

The results of this pilot study suggest that steam foot spas mitigate cognitive impairment in geriatric inpatients.

Mitochondria as a source and target of lipid peroxidation products in healthy and diseased heart

The heart is a highly oxidative organ in which cardiomyocyte turnover is virtually absent, making it particularly vulnerable to accumulation of lipid peroxidation products (LPP) formed as a result of oxidative damage. Reactive oxygen and nitrogen species are the most common electrophiles formed during lipid peroxidation and lead to the formation of both stable and unstable LPP. Of the LPP formed, highly reactive aldehydes are a well-recognized causative factor in ageing and age-associated diseases, including cardiovascular disease and diabetes. Recent studies have identified that the mitochondria are both a primary source and target of LPP, with specific emphasis on aldehydes in cardiomyocytes and how these affect the electron transport system and Ca(2+) balance. Numerous studies have found that there are functional consequences in the heart following exposure to specific aldehydes (acrolein, trans-2-hexanal, 4-hydroxynonenal and acetaldehyde). Because these LPP are known to form in heart failure, cardiac ischaemia-reperfusion injury and diabetes, they may have an underappreciated role in the pathophysiology of these disease processes. Lipid peroxidation products are involved in the transcriptional regulation of endogenous anti-oxidant systems. Recent evidence demonstrates that transient increases in LPP may be beneficial in cardioprotection by contributing to mitohormesis (i.e. induction of anti-oxidant systems) in cardiomyocytes. Thus, exploitation of the cardioprotective actions of the LPP may represent a novel therapeutic strategy for future treatment of heart disease.

Waon therapy upregulates Hsp90 and leads to angiogenesis through the Akt-endothelial nitric oxide synthase pathway in mouse hindlimb ischemia

BACKGROUND

Thermal therapy, namely Waon therapy, has previously been reported to regulate nitric oxide (NO) and endothelial NO synthase (eNOS) and augment ischemia-induced angiogenesis in mice and improve limb ischemia in patients with peripheral artery disease. The aim of this study was to clarify the precise mechanism by which Waon therapy augments angiogenesis in mice with hindlimb ischemia.

METHODS AND RESULTS

Unilateral hindlimb ischemia was induced in apolipoprotein E-deficient mice and Waon therapy was performed for 5 weeks. Heat shock protein 90 (Hsp90), phosphorylated-Akt, and phosphorylated-eNOS were detected in arterial endothelial cells of ischemic hindlimbs and all were upregulated by Waon therapy compared to controls. Waon therapy also increased serum concentrations of nitrite and nitrate. Capillary density and the ischemic limb/normal side blood perfusion ratio monitored by laser Doppler perfusion imaging in the Waon therapy group were significantly increased beyond those in the control group. The effect of Waon therapy on angiogenesis through the activation of the Hsp90/Akt/eNOS pathway was attenuated by the administration of a Hsp90 inhibitor.

CONCLUSIONS

It is suggested that Waon therapy upregulates Hsp90, which contributes to the activation of the Akt/eNOS/NO pathway, and induces angiogenesis in mice with hindlimb ischemia.

Novel device that produces carbon dioxide mist for myocardial infarction treatment in rats

BACKGROUND

Carbon dioxide (CO(2)) baths have been used to treat a variety of diseases, but developing an artificial bath of highly concentrated CO(2) is difficult. Here, we tried the efficacy of a novel device instead of a CO(2) bath.

METHODS AND RESULTS

Using a device equipped with double fluid nozzles, CO(2) gas and H(2)O were compounded and compressed at 4 barometric pressures. As a result, CO(2) gas was dissolved in H(2)O, which contained a few micrometers of CO(2) particles, namely, a CO(2) mist. Wistar rats with myocardial infarction (MI) by ligation of the left coronary artery were percutaneously administered CO(2) mist or CO(2) gas alone or no treatment for 30 min daily. With regard to tissue blood flow during treatment, the group treated with CO(2) mist had significantly increased tissue oxygenated hemoglobin levels and tissue saturation levels, and significantly decreased deoxygenated hemoglobin levels compared with the group treated with CO(2) gas. After 4 weeks treatment, the group treated with CO(2) mist had a significantly improved ejection fraction by echocardiography compared with the untreated group. Interestingly, the group treated with CO(2) mist had significantly increased nitrate concentrations in serum and vascular endothelial growth factor mRNA expression levels in the myocardium compared with the untreated group.

CONCLUSIONS

Our new mist production device may be potentially useful for the treatment of heart failure caused by MI.

Far infrared radiation (FIR): its biological effects and medical applications

Far infrared (FIR) radiation (λ = 3-100 μm) is a subdivision of the electromagnetic spectrum that has been investigated for biological effects. The goal of this review is to cover the use of a further sub-division (3- 12 μm) of this waveband, that has been observed in both in vitro and in vivo studies, to stimulate cells and tissue, and is considered a promising treatment modality for certain medical conditions. Technological advances have provided new techniques for delivering FIR radiation to the human body. Specialty lamps and saunas, delivering pure FIR radiation (eliminating completely the near and mid infrared bands), have became safe, effective, and widely used sources to generate therapeutic effects. Fibers impregnated with FIR emitting ceramic nanoparticles and woven into fabrics, are being used as garments and wraps to generate FIR radiation, and attain health benefits from its effects.

Pathophysiology of myocardial reperfusion injury: preconditioning, postconditioning, and translational aspects of protective measures

Heart diseases due to myocardial ischemia, such as myocardial infarction or ischemic heart failure, are major causes of death in developed countries, and their number is unfortunately still growing. Preliminary exploration into the pathophysiology of ischemia-reperfusion injury, together with the accumulation of clinical evidence, led to the discovery of ischemic preconditioning, which has been the main hypothesis for over three decades for how ischemia-reperfusion injury can be attenuated. The subcellular pathophysiological mechanism of ischemia-reperfusion injury and preconditioning-induced cardioprotection is not well understood, but extensive research into components, including autacoids, ion channels, receptors, subcellular signaling cascades, and mitochondrial modulators, as well as strategies for modulating these components, has made evolutional progress. Owing to the accumulation of both basic and clinical evidence, the idea of ischemic postconditioning with a cardioprotective potential has been discovered and established, making it possible to apply this knowledge in the clinical setting after ischemia-reperfusion insult. Another a great outcome has been the launch of translational studies that apply basic findings for manipulating ischemia-reperfusion injury into practical clinical treatments against ischemic heart diseases. In this review, we discuss the current findings regarding the fundamental pathophysiological mechanisms of ischemia-reperfusion injury, the associated protective mechanisms of ischemic pre- and postconditioning, and the potential seeds for molecular, pharmacological, or mechanical treatments against ischemia-reperfusion injury, as well as subsequent adverse outcomes by modulation of subcellular signaling mechanisms (especially mitochondrial function). We also review emerging translational clinical trials and the subsistent clinical comorbidities that need to be overcome to make these trials applicable in clinical medicine.