Far Infrared Therapy on Peripheral Artery Disease in Hemodialysis Patients

Peripheral Artery Disease in Patients on Maintenance Hemodialysis: Risk Factors and the Effect of FIR Therapy

The prevalence of peripheral artery disease (PAD) defined as ankle-brachial index (ABI) less than 0.9 was about 15~30% in patients with end stage renal disease (ESRD), which was higher than those with normal renal function. A lower ABI and a higher brachial-ankle pulse wave velocity (baPWV) are good markers to predict the risk of PAD and atherosclerosis respectively. In addition, baPWV>2,100 cm/s was shown to be related to potential PAD. ABI <0.9 was positively associated with vascular access failure in hemodialysis (HD) patients and our previous study has demonstrated that far infrared (FIR) therapy can improve access flow and unassisted patency of atrioventricular (AV) fistula. The aims of this study are to evaluate (1) the frequency of and (2) risk factors associated with abnormal ABI and PWV as well as (3) the effect of FIR on ABI and PWV and markers related to endothelial dysfunction in HD patients.

In this study, 300 HD patients will be enrolled to receive ABI and baPWV and about 90 patients (30% according to the literature review) who have abnormal ABI (<0.9) or baPWV (>2100 cm/sec) will be randomly allocated to FIR group (receiving FIR therapy for 40 minutes thrice weekly) and control group (without FIR therapy). In patients with abnormal ABI or baPWV, the effect of single or one-year treatment of FIR on the following items will be studied: (1) ABI, (2) baPWV and (3) markers related to endothelial dysfunction [including low and high density lipoprotein cholesterol (LDL and HDL), asymmetric dimethylarginine (ADMA), hypersensitive C-reactive protein (hsCRP), matrix metalloproteinase-9 (MMP-9)]. The effect of FIR on PAD or cardiovascular events during one year of follow-up will also be studied. This study will allow us to identify the frequency of and the risk factors associated with abnormal ABI & PWV as well as the effect of single or one-year FIR therapy on ABI & PWV in HD patients.

ankle-brachial index (ABI), brachial-ankle pulse wave velocity (baPWV), far infrared therapy (FIR), hemodialysis (HD), peripheral artery disease (PAD), Peripheral artery disease in hemodialysis

In this study, a WSTM TY101 FIR emitter (WS Far Infrared Medical Technology Co., Ltd., Taipei, Taiwan) will be used for FIR therapy. The electrified ceramic plates of this emitter generate electromagnetic waves with wavelengths in the range between 3 and 25 μm (a peak between 5 to 6 μm). The irradiating power density is 10 and 20 mili watt<mw>/cm2 when the top radiator is set at a distance between 30 and 20 cm above the skin surface respectively. In this study, the top radiator will be set at a height of 25 cm above the surface of bilateral lower legs and the treatment time will be set at 40 minutes for patients on maintenance HD.

A WSTM TY101 FIR emitter (WS Far Infrared Medical Technology Co., Ltd., Taipei, Taiwan) will be used for FIR therapy. The electrified ceramic plates of this emitter generate electromagnetic waves with wavelengths in the range between 3 and 25 μm (a peak between 5 to 6 μm). The irradiating power density is 10 and 20 mili watt<mw>/cm2 when the top radiator is set at a distance between 30 and 20 cm above the skin surface respectively. In this study, the top radiator will be set at a height of 25 cm above the surface of bilateral lower legs and the treatment time will be set at 40 minutes for patients on each HD section for a year.

The values of the ABI were measured 10 to 30 min before HD. The ABIs will be measured by using an ABI-form device (VP1000,Colin, Komaki, Japan). The ABI will be calculated by the ratio of the ankle systolic BP divided by the arm systolic BP. The systolic BP of the arm without dialysis access and the value of the ankle systolic BP will be used for the calculation. All of the ABI and PWV will be measured twice. If the difference between them was more than 10%, a third measurement was done. The mean of the two closest values was recorded into our data base.

Each time at the four different timings (from time 1 to time 4), we will collect blood sample 5 ml for measuring markers related to endothelial dysfunction, including low density lipoprotein cholesterol (LDL), high density lipoprotein cholesterol (HDL), asymmetric dimethylarginine (ADMA), hypersensitive C-reactive protein (hsCRP), matrix metalloproteinase-9 (MMP-9).

Inclusion Criteria: In this study, we will include 300 patients who have received 4 hours of maintenance HD therapy three times weekly for at least 3 months Exclusion Criteria: Patients with life expectancy less than 1 year Patients with history of active malignancy