* Division of Nephrology and || Department of Medicine, Taipei Veterans General Hospital, Institute of Clinical Medicine and School of Medicine, National Yang-Ming University, and Municipal Hoping Hospital, Taipei, Taiwan, Republic of China
Address correspondence to: Dr. Wu-Chang Yang, Division of Nephrology, Department of Medicine, Taipei Veterans General Hospital, No. 201, Sec. 2, Shih-Pai Road, Taipei, Taiwan 112, Republic of China. Phone: +886-2-2875-7517; Fax: +886-2-2873-4866; E-mail: wcyang{at}vghtpe.gov.twl1124{at}ms12.hinet.net
Received for publication May 27, 2006.
Accepted for publication December 11, 2006.
Vascular access malfunction, usually presenting with an inadequateaccess flow (Qa), is the leading cause of morbidity and hospitalizationin hemodialysis (HD) patients. Many methods of thermal therapyhave been tried for improving Qa but with limited effects. Thisrandomized trial was designed to evaluate the effect of far-infrared(FIR) therapy on access flow and patency of the native arteriovenousfistula (AVF). A total of 145 HD patients were enrolled with73 in the control group and 72 in the FIR group. A WS TY101FIR emitter was used for 40 min, and hemodynamic parameterswere measured by the Transonic HD02 monitor during HD. The Qa1/Qa2and Qa3/Qa4 were defined as the Qa measured at the beginning/at40 min later in the HD session before the initiation and atthe end of the study, respectively. The incremental change ofQa in the single HD session with FIR therapy was significantlyhigher than that without FIR therapy (13.2 ± 114.7 versus–33.4 ± 132.3 ml/min; P = 0.021). In comparisonwith control subjects, patients who received FIR therapy for1 yr had (1) a lower incidence (12.5 versus 30.1%; P < 0.01)and relative incidence (one episode per 67.7 versus one episodeper 26.7 patient-months; P = 0.03) of AVF malfunction; (2) highervalues of the following parameters, including (Qa4 – Qa3)(36.2 ± 82.4 versus –12.7 ± 153.6 ml/min;P = 0.027), (Qa3 – Qa1) (36.3 ± 166.2 versus –51.7± 283.1 ml/min; P = 0.035), (Qa4 – Qa2) (99.2 ±144.4 versus –47.5 ± 244.5 ml/min; P < 0.001),and (Qa4 – Qa2) – (Qa3 – Qa1) (62.9 ±111.6 versus 4.1 ± 184.5 ml/min; P = 0.032); and (3)a better unassisted patency of AVF (85.9 versus 67.6%; P <0.01). In conclusion, FIR therapy, a noninvasive and convenienttherapeutic modality, can improve Qa and survival of the AVFin HD patients through both its thermal and its nonthermal effects.
For patients who have ESRD and receive hemodialysis (HD) treatment,a well-functioning vascular access is necessary for achievingadequate dialysis and improving the quality of life. Among severaltypes of vascular access, the long-term technical survival isbest for the native arteriovenous fistula (AVF), which accountsfor more than 80% of vascular access in HD patients in Taiwan.Vascular access complications accounted for approximately 20%of HD patient hospitalizations in the United States with a costof $1 billion annually (1). Malfunction of vascular access usuallypresents with inadequate blood flow because of stenosis or thrombosisof the venous outflow tract (2). Approximately 80 to 85% ofAV access failures arise from AV access thromboses, more than80% of which result from AVF stenoses (3). An access flow (Qa),<500 ml/min was associated with an increased risk for accessfailure and predictive of poorer unassisted patency of nativeAVF (4). The pathologic features of stenosis of vascular accessare composed of intimal hyperplasia, proliferation of smoothmuscle cells in the media with subsequent migration to intima,and excessive accumulation of extracellular matrix (5). Despitethese findings, little information is available on how to preventeffectively the stenoses of vascular access in HD patients.
Infrared radiation is an invisible electromagnetic wave witha longer wavelength than that of visible light. According tothe difference in wavelength, infrared radiation can be dividedinto three categories: Near-infrared radiation (0.8 to 1.5 µm),middle-infrared radiation (1.5 to 5.6 µm), and far-infrared(FIR) radiation (5.6 to 1000 µm) (6). Infrared radiationtransfers energy that is perceived as heat by thermoreceptorsin the surrounding skin (7). The application of FIR radiationincludes food preservation (8) and health promotion (9–10).Animal studies also demonstrated that FIR improves skin bloodflow (11,12), leading to the use of FIR in the treatment ofischemic lesions and necrosis of skin tissue as a result oftrauma, diabetes, and peripheral arterial occlusive disease.In addition, some studies indicated that FIR therapy may improveendothelial function and reduce the frequency of some cardiovasculardiseases (13–15). Because vascular access usually is locatedin the superficial site of the upper extremities of HD patients,FIR therapy may be considered as an alternative therapeuticmodality for improving access flow and the function of the AVF.The objective of this study was to evaluate the effect of FIRon access flow and patency of AVF in HD patients.
Patient Selection
In this study, we included patients who met the following criteria:(1) Receiving 4 h of maintenance HD therapy three times weeklyfor at least 6 mo at Taipei Veterans General Hospital; (2) usinga native AVF as the current vascular access for more than 6mo, without interventions within the last 3 mo; and (3) creationof AVF by cardiovascular surgeons in our hospital with the standardizedsurgical procedures of venous end-to-arterial side anastomosisin the upper extremity.
All patients were receiving dialysis three times weekly on standardbicarbonate dialysate bath (38 mEq/L HCO3–, 3.0 mEq/LCa2+, and 2.0 mEq/L K+), using the volumetric-controlled dialysisdelivery system under constant dialysate flow at 500 ml/min.Patients were anticoagulated by means of systemic heparin, withoutchange of the individual bolus or maintenance dosage throughoutthe study.
This study is a prospective, randomized, controlled trial. Thestudy was based on the Helsinki Declaration (edition 6, revised2000 [16]) and was approved by the Institutional Research Boardof Taipei Veterans General Hospital. In addition, it was registeredat the Cochrane Renal Group registry. After informed consentwas obtained from every study participant, the patients wererandomly allocated to either the FIR group or the control groupby means of a computerized minimization algorithm to ensurebalance between the two groups with respect to history of AVFmalfunction. The participant allocations were concealed frominvestigators by the computerized minimization algorithm, andthe allocation sequence was kept by a study nurse (Cherng-FungHung), who would not tell the investigator the participant allocationuntil the time of intervention.
We recorded the following clinical factors: Age, gender, HDtherapy duration, underlying cause of ESRD (presence or absenceof diabetic nephropathy), and time of AVF malfunction. The primaryend point was the survival time of the AVF with unassisted patency,which was defined as the time from the commencement of the studyto the first episode of AVF malfunction. We defined AVF malfunctionas the need for any interventional procedure (surgery or angioplasty)to correct an occlusive or malfunctioning AVF that cannot sustainan extracorporeal blood flow >200 ml/min during HD afterexclusion of the following stenosis-unrelated events: Infectiouscomplication, progressive aneurysmal formation, or steal syndrome.We also measured the hemodynamic parameters according to thefollowing procedures.
Measurement of Hemodynamic Parameters
The access flow (Qa), cardiac output (CO), and total peripheralresistance were measured during HD by the ultrasound dilutionmethod using the Transonic HD02 hemodialysis monitor (TransonicSystems, Ithaca, NY). The technique is used widely and extensivelyvalidated in the literature (17). In brief, the technique usestwo ultrasound sensors that are attached to the two HD tubinglines, one to the arterial and the other to the venous catheters,approximately 3 to 5 in from the connection of the tubing tothe dialysis needles. Initially, tubing lines are reversed,and ultrafiltration is turned off. A measured bolus of saline(10 ml) is injected into the venous catheter, resulting in changesin sound velocity that are measured by the transducers on thecatheters. This change then is calculated by the Transonic software,giving the result of Qa (ml/min). If Qa could not be obtainedby this method, then it would be measured by the variable pumpflow–based Doppler ultrasound method (4). The CO can bemeasured by injection of 30 ml of saline (37°C) into thevenous catheter without reversing the tubing lines. Total peripheralresistance can be calculated by computer software by dividingthe mean arterial BP by the CO. All of these hemodynamic parameterswere measured twice. When the difference between them was morethan 10%, a third measurement was done. The mean of the twoclosest values was recorded into our database.
FIR Therapy
In this study, a WS TY101 FIR emitter (WS Far Infrared MedicalTechnology Co., Ltd., Taipei, Taiwan) was used for FIR therapy.The electrified ceramic plates of this emitter generate electromagneticwaves with wavelengths in the range between 5 and 12 µm(a peak at 8.2 µm). The top radiator was set at a heightof 25 cm above the surface of the AVF with the treatment timeset at 40 min during HD three times per week.
Study Protocol Effect of FIR Therapy on the Hemodynamic Parameters of HD Patients in a Single HD Session.
The study participants were randomly divided into the treatmentand the control groups. The measurement of Qa and other hemodynamicparameters, including CO, total peripheral resistance, and BP,etc., were recorded in patients at two different time points:Time 1 at the beginning of an HD session and time 2 at 40 minafter time 1. One week later, the same parameters were measuredin patients immediately before and after 40 min of FIR therapyat the beginning of another HD session.
Effect of 1 Yr of FIR Therapy on Access Flow and Unassisted Patency of the AVF in HD Patients.
Every hemodynamic parameter was measured at four different timesin the study patients when they had received HD by the sameAVF when they completed this study. In the control group, wedefined time 1 as the time point at the beginning of the HDsession immediately before the commencement of this study, time2 as the time point at 40 min after time 1, time 3 as that atthe beginning of the HD session when the study was completed,and time 4 as that at 40 min after time 3. In the treatmentgroup, times 1 through 4 were defined the same as that in thecontrol group except that time 3 was that immediately beforeand time 4 was that immediately after FIR treatment during theHD session when the study was completed. For example, Qa1 indicatesaccess flow measured at time 1, Qa2 at time 2, Qa3 at time 3,and Qa4 at time 4. Only the treatment group received 40 minof FIR therapy in every HD session for 1 yr. During the 1-yrfollow-up, patients would be excluded from the study becauseof the following censoring criterion: Renal transplantation,death with a functioning access, shifting to peritoneal dialysis,or loss of follow-up.
Statistical Analyses
Data management and statistical analysis were done using theSPSS statistical software (version 11.0; Chicago, IL). Distributionsof continuous variables in groups were expressed as mean ±SD and compared by t test. All data were tested for normal distributionbefore using t test. Categorical variables, such as the frequencyof AVF malfunction in the treatment group and control subjects,were analyzed by 2 test. The 95% confidence interval for everyvariable also was calculated. Survival curves of unassistedpatency of AVF were calculated by the Kaplan-Meier method andcompared by the log rank test. A statistically significant valuewas P < 0.05.
Patient Characteristics
As shown in Figure 1, a total of 145 patients were enrolledin the study. Among them, 73 patients were randomly distributedto the control group and 72 patients to the FIR treatment group.As listed in Table 1, there was no difference in the demographicand clinical characteristics between the two groups of HD patients.During follow-up, one patient receiving FIR therapy and fourpatients in the control group underwent creation of anothervascular access because of the poor response to angioplasty.In addition, patients were censored at the time of renal transplantation(n = 3), death with a functioning access (n = 5), shifting toperitoneal dialysis (n = 4), or loss of follow-up (n = 1). Thisstudy was terminated on December 31, 2005. Finally, 127 patientscompleted the study with 64 patients in the control group and63 patients in the FIR treatment group.
Figure 1. Flow chart of the study participants for the randomized, controlled trial to evaluate the effect of far-infrared (FIR) therapy on survival of arteriovenous fistula (AVF) in the hemodialysis (HD) patients.
Table 1. Clinical characteristics of the two groups of HD patients with and without FIR treatment during the study perioda
Effect of a Single Session of FIR Therapy on the Hemodynamic Parameters in HD Patients
As shown in Table 2, there was no significant difference inmost of the hemodynamic parameters (e.g., BP, CO, total peripheralresistance) between the single HD session with or without FIRtreatment for the 72 HD patients. However, the incremental changeof access flow [(Qa2 – Qa1)] of these patients in thesingle HD session with FIR therapy was significantly higherthan that without FIR therapy (13.2 ± 114.7 versus –33.4± 132.3 ml/min; P = 0.021).
Table 2. Access flow and the hemodynamic parameters of the 72 HD patients in the single HD session with or without FIR therapya
Effect of 1 Yr of FIR Therapy on Access Flow and Unassisted Patency of AVF in HD Patients
In comparison with control subjects, the HD patients who receivedFIR treatment three times per week for 1 yr had higher incrementalvalues of the following changes of access flow regarding boththe initial and final HD sessions: (1) (Qa4 – Qa3) (36.2± 82.4 versus –12.7 ± 153.6 ml/min; P =0.027), (2) (Qa3 – Qa1) (36.3 ± 166.2 versus –51.7± 283.1 ml/min; P = 0.035), (3) (Qa4 – Qa2) (99.2± 144.4 versus –47.5 ± 244.5 ml/min; P <0.001), and (4) (Qa4 – Qa2) – (Qa3 – Qa1)(ml/min; 62.9 ± 111.6 versus 4.1 ± 184.5 ml/min;P = 0.032). As shown in Table 3, these results still are significanteven after they are normalized to CO. As listed in Table 2,the FIR group had a lower incidence of AVF malfunction (12.5%[nine of 72] versus 30.1% [22 of 73]; P < 0.01). Some patientsexperienced multiple episodes of AVF malfunction during thisstudy, so relative incidences of AVF malfunction (number ofincidences per patient months of follow-up) were calculated.The relative incidence of AVF malfunction in the FIR group (oneepisode per 67.7 patient-months) was significantly lower thanthat in the control group (one episode per 26.7 patient-months;P = 0.03; Table 2).
Table 3. Comparison of the access flow and survival of AVF between HD patients with and without FIR therapy for 1 yra
Access Survival
We evaluated the effect of FIR therapy on vascular access survivalin all of the initially included 145 HD patients (72 with FIRand 73 control subjects) in this study. Among them, eight patientsin the FIR group and five patients in the control group werecensored because of reasons other than AVF malfunction, suchas renal transplantation, death with a functioning access, switchingto peritoneal dialysis, and loss to follow-up (Table 1). Consequently,the expected patient numbers that are used as the denominatorfor calculation of the unassisted patency of AVF should be 64for the FIR group and 68 for the control group. As shown inFigure 2, the unassisted patency of AVF at 1 yr was significantlybetter in the FIR group than in the control group (85.9% [55of 64] versus 67.6% [46 of 68]; P < 0.01 by Log rank test).Concerning the safety issue of FIR therapy, no patient complainedof any adverse effect, such as skin burn or allergy to the FIRtherapy, throughout the whole course of the study.
Figure 2. Comparison of 1-yr survival curves for unassisted patency of AVF between the HD patients with or without FIR therapy. P < 0.01 for the comparison between the two survival curves by log rank test.
FIR is an electromagnetic wave with wavelengths that range from5.6 to 1000 µm. The technology of FIR has been appliedwidely in a variety of fields. Our study demonstrated the effectof FIR therapy on (1) increasing the incremental change of Qaboth in a single HD session and after a 1-yr treatment courseand (2) improving the survival of AVF in HD patients after treatmentfor 1 yr. We use the incremental changes of Qa in this studyfor two reasons. First, we would like to control the interferingeffect of the great individual variation in flow. This may explainwhy there was no statistical significance for Qa4 even witha difference of 119.4 ml/min between the two groups but therewas significance for (Qa4 – Qa3) with only a differenceof 48.9 ml/min in Table 3. Second, several incremental changesof Qa were helpful to quantify and elucidate the roles of thevarious effects (e.g., hemodynamic effect of HD, the thermaland nonthermal effects of FIR) in the change of access flow.(Qa4 – Qa3) represents the sum of the thermal effect byFIR and the hemodynamic effect by HD on the change of Qa becauseQa4 was measured after Qa3 by 40 min, during which time bothFIR therapy and HD were received by the patients. (Qa3 –Qa1) stands for the nonthermal effect of 1 yr of FIR on thechange of Qa because the two parameters were measured in thebeginning of the two HD sessions 1 yr apart. (Qa4 – Qa2)indicates the sum of the thermal effect (for 40 min) and thenonthermal effect (for 1 yr) by FIR on the change of Qa. [(Qa4– Qa2) – (Qa3 – Qa1)] represents the thermaleffect of 40 min of FIR on the change of Qa because it is thedifference between (Qa4 – Qa2) and (Qa3 – Qa1),which were mentioned previously. Our results supported thatboth the thermal and the nonthermal effects of FIR can increasethe access flow. Moreover, there is an additive benefit of botheffects because (Qa4 – Qa2) was the item with the greatestdifference (99.2 ± 144.4 for FIR group versus –47.5± 244.5 ml/min for control group; P < 0.001). To correctfor the influence of CO to access flow, the normalization ofQa/CO was done for each individual flow reading, and this numberthen was used for further analysis. After normalization, allof the indices of the previously mentioned incremental changeof Qa attain statistical significance.
The thermal effect of FIR results in vasodilation and increasingQa. According to the report by Vaupel et al. (18), the temperaturecan be increased up to 4°C in 10-mm depth of tissue. Inaddition, infrared therapy may allow multiple energy transferas deep as 2 to 3 cm into subcutaneous tissue without irritatingor overheating the skin like unfiltered heat radiation (19).The skin temperature steadily increased to a plateau at approximately38 to 39°C during the treatment of FIR for 30 to 60 minas long as the distance between the ceramic plate and the skinwas >20 cm (11). Therefore, infrared therapy can be freeof the disadvantages or adverse effects (e.g., burn injury,infection, risk for access failure, prolonged bleeding fromthe previous venipuncture site) of some traditional methodsof thermal therapy. This may explain why these complicationsdid not develop in our patients during this study.
In addition to the thermal effect, the increase in both theaccess flow and AVF patency in this study may result from nonthermaleffects of infrared therapy. In particular, FIR may improveendothelial function, which is observed not only in animal studies(11,12,14) but also in one clinical study (13). Yu et al. (11)suggested that the beneficial effect of FIR therapy on skinblood flow may be related to the l-arginine/nitric oxide (NO)pathway. In this respect, Akasaki et al. (12) found that repeatedFIR therapy could upregulate endothelial NO synthase (eNOS)expression and augment angiogenesis in an apolipoprotein E–deficientmouse model of unilateral hind limb ischemia. Moreover, Ikedaet al. (14) reported that 4 wk of sauna therapy significantlyincreased the serum nitrate concentrations as well as the expressionof mRNA and protein of eNOS in the aortas of TO-2 hamsters.In addition, Imamura et al. (13) showed that 2 wk of repeatedsauna therapy significantly improved vascular endothelial function,resulting in an increase in flow-mediated, endothelium-dependentdilation of the brachial artery from 4 to 5.8% in patients withcoronary risk factors.
Besides activating eNOS expression, inhibiting neointimal hyperplasiaand decreasing oxidative stress are two other nonthermal effectsof FIR therapy. Kipshidze et al. (20) found that nonablativeinfrared laser (NIL) therapy inhibited neointimal hyperplasiaafter percutaneous transluminal coronary angioplasty in cholesterol-fedrabbits for up to 60 d. According to their report, the nonablativedoses of NIL decreased the growth of vascular smooth musclecells (VSMC), but it did not decrease the growth rate of endothelialcells. Because the proliferation of VSMC in the media is animportant pathologic finding of the vascular wall of HD patientswith vascular access stenosis (5), slowing the growth of VSMCmay reduce the frequency of access stenosis. According to thereport by Masuda et al. (21), systolic BP and the increasedurinary 8-epi-prostaglandin F2 levels were significantly lowerin the patients who received a FIR dry sauna for 45 min/d for2 wk. F2-isoprostanes, namely 8-epi-prostaglandin F2, are chemicallystable products of lipid peroxidation, and the level has beensuggested as a reliable marker of oxidative stress in vivo (22).These results suggest that repeated sauna therapy may reduceoxidative stress, which leads to protection against the progressionand complications of atherosclerosis. Because HD patients alsoare exposed to heavy oxidative stress from both inward uremicstatus and outward HD-related technology, the application ofFIR therapy may be considered as an alternative therapeuticmodality for decreasing oxidative stress.
Apart from the previously mentioned nonthermal mechanisms (improvingendothelial function, inhibiting neointimal hyperplasia, andlowering the level of oxidative stress), one possible explanationfor the higher unassisted patency of AVF in our patients maybe an increase of the access flow after 1 yr of FIR therapy.The access flow is an important parameter for predicting theprognosis of vascular access. A shorter survival of vascularaccess was associated with a lower value of Qa or a significantdecrease from the previous Qa within a period. According toKidney Disease Outcomes Quality Initiative guidelines for vascularaccess, HD patients with Qa <600 ml/min or Qa <1000 ml/minthat has decreased by >25% during 4 mo should be referredfor fistulogram to detect potential stenotic lesions (23). Ourprevious study found that the unassisted patency of vascularaccess at 6 mo was significantly poorer in patients with Qa<500 ml/min than in those with Qa >500 ml/min (13.6 versus92.2%) (4). Therefore, the increase of Qa may contribute tothe higher patency of AVF of our patients in this study.
As to the limitation of this study, the result should not beextrapolated to HD patients who use AV graft as their vascularaccess because we included only patients with AVF. Moreover,this study was not done in patients with new AVF but ratherin a group of patients with preexisting AVF. Although we randomlyassigned our study patients by controlling for many possiblefactors, individual variation of vascular condition still couldinfluence the final result. Therefore, it is necessary to performa large-scale, prospective, randomized, controlled trial toevaluate the effect of FIR therapy on the primary unassistedpatency of the de novo AVF that is created in HD patients inthe future. Although the precise mechanisms for the beneficialeffects of FIR still need further investigation, the betterunassisted patency of AVF after 1 yr of FIR therapy may resultfrom the increase of Qa, which could be associated with boththermal effect–induced vasodilation and nonthermal effectsof inhibiting intimal hyperplasia as well as improving endothelialdysfunction by enhancing the activity of eNOS and/or loweringthe level of oxidative stress.
Our study provides evidence that FIR therapy, a convenient andnoninvasive technology, may be an effective therapeutic modalityin improving access flow and patency of the AVF in HD patients.
This work was supported by grant NSC 95-2314-B-075-070 fromthe National Science Council and grant V95-ER2-003 from TaipeiVeterans General Hospital in Taiwan.
We thank the clinicians who referred the patients and collectedblood samples: Dr. Yee-Yung Ng, Dr. Tsai-Hun Wu, Dr. Der-CherngTarng, Dr. Jinn-Yang Chen, Dr. Yao-Ping Lin, and Dr. Chiao-LinChuang at Taipei Veterans General Hospital. We thank ProfessorWilliam Durante at the University of Missouri for help in correctionsin English. We also thank Cheng-Fang Hong for technical support.
Footnotes
Published online ahead of print. Publication date availableat www.jasn.org.
Paun M, Beach K, Ahmad S, Hickman R, Meissner M, Plett C, Strandness DE Jr: New ultrasound approaches to dialysis access monitoring.
Am J Kidney Dis 35
: 477
–481, 2000[Medline]
Windus DW: Permanent vascular access: A nephrologist’s view.
Am J Kidney Dis 21
: 457
–471, 1993[Medline]
Lin CC, Chang CF, Chiou HJ, Sun YC, Chiang SS, Lin MW, Lee PC, Yang WC: Variable pump flow-based Doppler ultrasound method: A novel approach to the measurement of access flow in hemodialysis patients.
J Am Soc Nephrol 16
: 229
–236, 2005[Abstract/Free Full Text]
Roy-Chaudhury P, Sukhatme VP, Cheung AK: Hemodialysis vascular access dysfunction: A cellular and molecular viewpoint.
J Am Soc Nephrol 17
: 1112
–1127, 2006[Abstract/Free Full Text]
Toyokawa H, Matsui Y, Uhara J: Promotive effects of far-infrared ray on full-thickness skin wound healing in rats.
Exp Biol Med 228
: 724
–729, 2003[Abstract/Free Full Text]
Capon A, Mordon S: Can thermal lasers promote skin wound healing?
Am J Clin Dermatol 4
: 1
–12, 2003[CrossRef][Medline]
Lloyd BJ, Farkas BE, Keener KM: Characterization of radiant emitters used in food processing.
J Microw Power Electromagn Energy 38
: 213
–224, 2003[Medline]
Honda K, Inoue S: Sleep-enhancing effects of far-infrared radiation in rats.
Int J Biometeorol 32
: 92
–94, 1998[CrossRef]
Udagawa Y, Nagasawa H: Effects of far-infrared ray on reproduction, growth, behaviour and some physiological parameters in mice.
In Vivo 14
: 321
–326, 2000[Medline]
Yu SY, Chiu JH, Yang SD, Hsu YC, Lui WY, Wu CW: Biological effect of far-infrared therapy on increasing skin microcirculation in rats.
Photodermatol Photoimmunol Photomed 22
: 78
–86, 2006[CrossRef][Medline]
Akasaki Y, Miyata M, Eto H, Shirasawa T, Hamada N, Ikeda Y, Biro S, Otsuji Y, Tei C: Repeated thermal therapy up-regulates endothelial nitric oxide synthase and augments angiogenesis in a mouse model of hindlimb ischemia.
Circ J 70
: 463
–470, 2006[CrossRef][Medline]
Imamura M, Biro S, Kihara T: Repeated thermal therapy improves impaired vascular endothelial function in patients with coronary risk factors.
J Am Coll Cardiol 38
: 1083
–1088, 2001[Abstract/Free Full Text]
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: Repeated sauna therapy increases arterial endothelial nitric oxide synthase expression and nitric oxide production in cardiomyopathic hamsters.
Circ J 69
: 722
–729, 2005[CrossRef][Medline]
Kihara T, Biro S, Ikeda Y: Effects of repeated sauna treatment on ventricular arrhythmias in patients with chronic heart failure.
Circ J 68
: 1146
–1151, 2004[CrossRef][Medline]
The World Medical Association, Inc.: World Medical Association Declaration of Helsinki. Available at: http://www.wma.net/e/policy/b3.htm. Accessed June 2005
Krivitski NM: Theory and validation of access flow measurement by dilution technique during hemodialysis.
Kidney Int 48
: 244
–250, 1995[Medline]
Vaupel P, Stofft E: Waterfiltered infrared A radiation compared with conventional infrared radiation or fango paraffine pack: Temperature profiles in local thermal therapy. In:
Thermal Therapy with Waterfiltered Infrared A Radiation, 2nd Ed., edited by Vaupel P, Stuttgart, Hippokrates, 1995
, pp 135
–147
Hartel M, Hoffmann G, Wente MN, Martignoni ME, Buchler MW, Friess H: Randomized clinical trial of the influence of local water-filtered infrared A irradiation on wound healing after abdominal surgery.
Br J Surg 93
: 952
–960, 2006[CrossRef][Medline]
Kipshidze N, Nikolaychik V, Muckerheidi M, Keelan MH, Chekanov V, Maternowski M, Chawla P, Hernandez I, Iyer S, Dangas G, Sahota H, Leon MB, Roubin G, Moses JW: Effect of short pulsed nonablative infrared laser irradiation on vascular cells in vitro and neointimal hyperplasia in a rabbit balloon injury model.
Circulation 104
: 1850
–1855, 2001
Patrono C, FitzGerald GA: Isoprostanes: Potential markers of oxidant stress in atherothrombotic disease.
Arterioscler Thromb Vasc Biol 17
: 2309
–2315, 1997[Abstract/Free Full Text]
National Kidney Foundation: Kidney Disease Outcomes Quality Initiative (NKF K/DOQI) clinical practice guidelines for vascular access.
Am J Kidney Dis 37
: S137
–S181, 2001[Medline]
This article has been cited by other articles:
C.-C. Lin, X.-M. Liu, K. Peyton, H. Wang, W.-C. Yang, S.-J. Lin, and W. Durante Far Infrared Therapy Inhibits Vascular Endothelial Inflammation via the Induction of Heme Oxygenase-1
Arterioscler Thromb Vasc Biol,
April 1, 2008;
28(4):
739 - 745.
[Abstract][Full Text][PDF]
,
Top
Abstract
Introduction
(Qa4 – Qa3) (36.2 ± 82.4 versus –12.7 ± 153.6 ml/min; P = 0.027), 
2 test. The 95% confidence interval for every variable also was calculated. Survival curves of unassisted patency of AVF were calculated by the Kaplan-Meier method and compared by the log rank test. A statistically significant value was P < 0.05. 
levels were significantly lower in the patients who received a FIR dry sauna for 45 min/d for 2 wk. F2-isoprostanes, namely 8-epi-prostaglandin F2
