Waon Therapy Improves Quality of Life as Well as Cardiac Function and Exercise Capacity in Patients With Chronic Heart Failure
Mitsuo Sobajima,1 MD, Takashi Nozawa,1 MD, Yasutaka Fukui,1 MD, Hiroyuki Ihori,1 MD, Takashi Ohori,1 MD, Nozomu Fujii,1 MD, and Hiroshi Inoue,1 MD
Summary
Waon therapy (WT), which in Japanese means soothing warmth, is a repeated sauna therapy that improves cardiac and vascular endothelial function in patients with chronic heart failure (CHF). We investigated whether WT could improve the quality of life (QOL) of CHF patients in addition to improving cardiac function and exercise capacity.
A total of 49 CHF patients (69 ± 14 years old) were treated with a 60°C far infrared-ray dry sauna bath for 15 minutes and then kept in a bed covered with blankets for 30 minutes once a day for 3 weeks. At baseline and 3 weeks after starting WT, cardiac function, 6-minute walk distance (6MWD), flow mediated dilation (FMD) of the brachial artery, and SF36-QOL scores were determined.
WT significantly improved left ventricular ejection fraction (LVEF), B-type natriuretic peptide (BNP), 6MWD, and FMD (3.6 ± 2.3 to 5.1 ± 2.8%, P < 0.01). Moreover, WT significantly improved not only the physical (PC) but also mental component (MC) of the QOL scores. WT-induced improvement of PC was negatively correlated with changes in BNP (r = -0.327, P < 0.05), but MC improvement was not related directly to changes in BNP, LVEF, or 6MWD. WT-induced changes in MC were not parallel to PC improvement.
WT improved QOL as well as cardiac function and exercise capacity in patients with CHF. Mental QOL improved independently of WT-induced improvement of cardiac function and exercise capacity. (Int Heart J 2015; 56: 203-208)
R ecent studies have shown that repeated sauna therapy called Waon therapy (WT) improves not only cardiac and endothelial function but also prognosis in patients with chronic heart failure (CHF).1-3) The precise mechanisms of the salutary effects of WT in CHF treatment are not yet fully understood, although WT-induced vasodilation and improvement of endothelial function through up-regulation of endothelial nitric oxide synthase (eNOS) could contribute to the beneficial effects.4,5)
Depressive symptoms are common in patients with CHF and many CHF patients have impairment of all aspects of their quality of life (QOL) as assessed by SF-36 scores.6) Moreover, having depressive illness or impaired QOL in CHF patients is linked to a worse prognosis.7-9) Therefore, QOL would be a more important target for the management of CHF patients. Angiotensin converting enzyme (ACE) inhibitors or β-blockers improve cardiac function and prognosis in patients with CHF.10-12) However, there have been conflicting results as to whether these drugs also improve QOL.13,14)
Depression was found to be related to reduced heart rate variability,15) blunted baroreflex sensitivity,16) and heightened sympathetic nervous activity,17) while WT restored autonomic imbalance in CHF patients who were associated with sympathetic activation and parasympathetic withdrawal.18) Mild warming exhibited sedative effects through the sensory nerve endings,19) and thermal stimulus enhanced plasma levels of β-endorphin.20,21) Accordingly, the present study aimed to investigate whether WT could improve QOL in CHF patients in addition to improving cardiac function and exercise capacity.
Methods Subjects and study design:
The present study was approved by the ethics committee of Toyama University Hospital and written informed consent was obtained from all patients.
A total of 49 consecutive patients who met the following criteria constituted the study group. First, the patient had CHFassociated symptoms of New York Heart Association (NYHA) functional class ≧ II, previous hospitalization for worsening of heart failure, or both. Second, the patient was in a stable condition and not receiving any intravenous injection drugs at the time of enrollment. WT was performed during hospitalization. No medication was changed during the study period.
Waon therapy: The methods of WT were described previously.3) Briefly, once a day for three weeks, patients underwent a far-infrared-ray dry sauna therapy at 60°C for 15 minutes and were then kept supine on a bed outside the bath room for 30 minutes with sufficient warmth provided by blankets resulting in an increase in the core temperature by 1.0°C to 1.2°C. Patients were weighed before and after the sauna therapy, and oral hydration with water was given to compensate for the lost weight.
Evaluation of cardiac function and Specific Activity Scale (SAS): We performed echocardiography and also evaluated brain natriuretic peptide (BNP), NYHA, 6-minute walk distance (6MWD) and SAS to determine the state of heart failure. The SAS is based on approximations of the metabolic costs of a variety of personal care, housework, occupational, and recreational activities. SAS was determined from interviews about daily physical activities.22) Left ventricular end-diastolic and end-systolic dimensions were measured by 2-dimensional echocardiography (Aplio SSA-770A; Toshiba, Ohtawara, Japan). Left ventricular ejection fraction (LVEF) was calculated using the Teichholz method.
Flow-mediated vasodilation: Vascular endothelial function was evaluated by flow-mediated vasodilation (FMD) of the brachial artery.3) Patients were instructed to fast overnight and to abstain from smoking and consuming any caffeine and medications for at least 12 hours prior to FMD testing. Vasodilation responses of the brachial artery were determined by ultrasound using a semi-automatic device (EF18G; UNEX, Nagoya, Japan). A blood pressure cuff was inflated to 50 mmHg above the systolic blood pressure for 5 minutes. The changes in diastolic diameter were continuously recorded, and FMD was determined as the maximum change in the diameter after cuff release normalized to the baseline diameter (% of baseline diameter).
Natural killer cell activity: Natural killer cells were isolated directly from peripheral blood mononuclear cells. Blood samples were collected in tubes containing citrate phosphate dextrose. Natural killer (NK) cell activity was measured using 51Cr-labeled K562 targets. Effector and target cells were incubated at 37°C for 4.5 hours in plates. A well contained 1 × 104 target cells and 2 × 105 effector cells, and wells with only K562 in the medium or with 1% Triton X were used to evaluate spontaneous and maximum releases. The supernatant was collected and the percentage of cytotoxicity was calculated. SF-36 QOL scores: Patient self-assessment of health-related QOL was performed using the Japan version of SF-36.23,24) SF36 is a generic health survey designed to assess aspects of health that are not specific to disease, treatment, or age. The questionnaire assesses 8 dimensions of physical and mental health: physical functioning (PF, 10 items); role limitations due to physical problems (RP, 4 items); body pain (BP, two items); general perception of health (GH, 5 items); energy and vitality (VT, 4 items); social functioning (SF, two items); role limitations due to emotional problems (RE, 3 items); and mental health (MH, 5 items). Scores for the 8 dimensions were coded, summed and transformed onto a scale from 0 (worst possible health) to 100 (best possible health) using the method described in the user manual. The data are summarized using norm based scores. Norm base scores were calculated by subtracting the adjusted mean scores of the general population sample from the adjusted mean scores of the disease group and dividing this difference by the adjusted standard deviations of the general population. The summarized assessment of each questionnaire was added in areas of physical and mental health; physical (PC) and mental components (MC), respectively.
Statistics: Results are expressed as the mean ± SD. The differences between baseline and post-treatment parametric values were analyzed using the paired Student’s t test. Non-parametric pair-wise comparisons were made using the Wilcoxon rank sum test. Multiple linear regression analysis was performed to identify the independent determinants of Waon therapy-induced changes in the SF36 score, especially PC and MC. A P < 0.05 was considered statistically significant. Statistical analyses were performed with SPSS (SPSS 11.0J; International Business Machines Corporation, Chicago, IL, USA).
Results
The characteristics of the study group are summarized in the Table I. Twenty patients had ischemic cardiomyopathy and 29 patients nonischemic cardiomyopathy. More than 60% of the patients were treated with β-blockers and 86% with angiotensin converting enzyme inhibitors or angiotensin receptor blockers.
The effects of 3-week WT are summarized in Table II. No patient exhibited a worsening of clinical symptoms or suffered from complications due to WT. WT significantly improved NYHA functional class, SAS, and 6MWD. LVEF and NK cell activity were slightly but significantly increased, and plasma levels of BNP were reduced after WT. WT improved vascular endothelial function assessed by FMD.
As shown in Figure 1, CHF patients had lower QOL scores in all components of SF-36, compared to the average scores (= 50 points) of the Japanese general population. Threeweek WT significantly improved the PF, GH, VT, and MH
Table I. Baseline Characteristics
Variables
Age (years)
Men Body mass index (kg/m2)
Cause of heart failure Non-ischemic cardiomyopathy Ischemic cardiomyopathy
Co-morbidities Hypertension Diabetes mellitus Dyslipidemia
Medications
Digoxin
β blocker
ACE inhibitors/ARB
Statins
Diuretics
Non-pharmacological therapy Pacemaker ICD/CRT 69.1 ± 14.3 31 (63%) 21.7 ± 4.2 29 (59%) 20 (41%) 19 (31%) 11 (22%) 17 (35%) 14 (29%) 31 (63%) 42 (86%) 20 (41%) 45 (92%) 4 (8%) 7 (14%) Data are mean ± SD or number (%) of patients. ACE indicates angiotensin converting enzyme; ARB, angiotensin II receptor blocker; ICD, implantable cardioverter-defibrillator; and CRT, cardiac resynchronization therapy.
Table II. Comparisons of Data Between Before and After Waon Therapy Variables Before After P Heart rate (beats/minute) 74 ± 12 73 ± 12 0.41 Systolic BP (mmHg) 108 ± 20 107 ± 23 0.13 Diastolic BP (mmHg) 65 ± 10 62 ± 12 0.09 Body weight (kg) 54 ± 16 54 ± 15 0.45 NYHA class < 0.05 I 6 9 II 15 18 III 28 22 IV 0 0 SAS (METs) 4.3 ± 1.6 4.7 ± 1.4 < 0.01 6MWD (m) 323 ± 122 366 ± 128 < 0.01 LVEDD (mm) 64 ± 12 62 ± 11 < 0.01 LVESD (mm) 54 ± 13 51 ± 13 < 0.01 LVEF (%) 33 ± 13 37 ± 15 < 0.01 Left atrial dimension (mm) 47 ± 8 44 ± 9 < 0.01 BUN (mg/dL) 27 ± 14 27 ± 15 0.83 Creatinine (mg/dL) 1.2 ± 0.9 1.3 ± 1.3 0.22 LDL cholesterols (mg/dL) 113 ± 29 107 ± 27 0.06 HDL cholesterols (mg/dL) 51 ± 15 49 ± 14 0.08 Triglycerides (mg/dL) 121 ± 58 114 ± 50 0.10 Blood sugar (mg/dL) 97 ± 27 95 ± 21 0.62 BNP (pg/dL) 455 ± 474 354 ± 383 < 0.01 Plasma NE (pg/mL) 386 ± 266 351 ± 217 0.27 NK cell activity (%)* 21.2 ± 14.5 24.1 ± 16.7 < 0.05 FMD (%) 3.6 ± 2.3 5.1 ± 2.8 < 0.01 Data are mean ± SD or number of patients. BP indicates blood pressure; NYHA, New York Heart Association; SAS, specific activity scale; 6MWD, 6-minute walk distance; LVEF, left ventricular (LV) ejection fraction; LVEDD and LVESD, LV end-diastolic and end-systolic dimensions, respectively; BNP, B type natriuretic peptide; NE, norepinephrine; NK cell, natural killer cell; and FMD, flow mediated dilation. *NK cell activity was determined in 32 patients.
scores. Both PC and MC, which are summarized assessments of SF-36 questionnaire in each area of physical and mental health, were significantly improved by WT, especially in the nonischemic group (Figure 2). Multivariate analysis revealed that WT-induced changes in PC were independently related to its baseline score before WT, while WT-induced changes in MC were independently related to systolic blood pressure and MC score at baseline (Table III). That is, the improvement of PC and MC was greater in patients with low PC scores before starting WT and in those with low systolic blood pressure and low MC scores before WT, respectively. WT-induced improvement of PC was not related to changes in LVEF or 6MWD, but was negatively correlated with changes in BNP (r = -0.327, P < 0.05), ie, when patients had greater reduction of BNP levels, they had greater improvement of PC scores after WT. However, WT-induced improvement of MC was not related directly to changes in BNP, LVEF, or 6MWD. Thus, WT improved MC scores independently of changes in LV function and exercise tolerance. Moreover, WTinduced improvement of MC was not related to changes in PC (Figure 3). Discussion The major findings of the present study were as follows.