Impact of Short Daily at Home Hemodialysis on Attenuation of Vascular Calcification

Special Article - Chronic Kidney Diseases

Austin J Nephrol Hypertens. 2015;2(1): 1029.

Impact of Short Daily at Home Hemodialysis on Attenuation of Vascular Calcification

Hiromichi Suzuki1*, Tsutomu Inoue1, Tomohiro Kikuta1, Tsuneo Takenaka2 and Hirokazu Okada1

1Department of Nephrology, Saitama Medical University, Japan

2Department of Nephrology, International University of Health and Welfare, Medical University Hospital, Japan

*Corresponding author: Hiromichi Suzuki, Department of Nephrology, Saitama Medical University, 38 Moroyama-machi, Iruma-gun, Saitama, 350-0495, Japan

Received: November 15, 2014; Accepted: January 05, 2015; Published: January 07, 2015


Vascular Calcification (VC) has a significant effect in cardiovascular disease on dialysis patients. However no pharmacological interventions have been demonstrated for prevention and/or attenuation of VC. Recent advances with frequent hemodialysis have shown the reduction of hyperphosphatemia. This has led to the idea that there is a strong relation between VC and hyperphosphatemia which suggests therefore, that frequent hemodialysis may reduce VC.

Aim: To examine whether short daily at-home hemodialysis reduces VC.

Method: Using Volume Viewer software with a 16-detector CT scan, the total calcification volume of the aorta was calculated with a cut-of of 130 House field Units. Abdominal CT scans were taken prior to and 3 years after the start of short daily at-home hemodialysis in 37 patients (average age 52 ± 7.0 years, male 33). The underlying kidney diseases were chronic glomeurlonephritis (33), diabetic nephropathy (2) and congenital kidney disease (2).

Results: The mean base line calcification score of the abdominal aorta was 7.59 ± 3.49 (cm3), which was reduced by short daily at-home hemodialysis to 6.69 ± 3.57 at the end of the study (P<0.05). Besides, short daily at-home hemodialysis produced normalization of blood pressure, reduction of blood urea nitrogen and serum phosphate, which contribute to vascular calcification.

Conclusion: This is the first demonstration that short daily at-home hemodialysis reduces calcification of the abdominal aorta through attenuation of hyperphosphatemia. (Words: 222).

Keywords: High Dose Hemodialysis; Abdominal Aorta; Hyperphosphatamia; Blood Pressure Control Albumin


Cardiovascular disease is the leading cause of death in patients receiving dialysis therapy [1]. This increased risk of cardiovascular disease is usually attributed to traditional risk factors such as blood pressure and volume control, and also non-traditional risk factors such as bone / mineral metabolism, sympathetic nervous system over-activity, retention of uremic toxins, and inflammation. Two of the strongest risk factors for cardiovascular morbidity and mortality are Vascular Calcification (VC), and higher serum phosphate concentration. VC is highly correlated with cardiovascular morbidity and mortality, and linked to aging, diabetes and Chronic Kidney Disease (CKD) [2,3]. Higher serum phosphate has been consistently associated with cardiovascular events and mortality in cohort studies of both CKD patients and those with normal kidney function [4,5]. Higher serum phosphate and VC are thought to lead to be causally related. Disorders of bone and mineral metabolism can result in VC and reduced vascular compliance, thereby resulting in increased myocardial ischemia, cardiac dysfunction, and sudden cardiac death. This causal pathway is supported by several trials with calcium-free phosphate binder, which indicated that phosphate is a modifiable risk factor for mitigating the progression of coronary calcification in hemodialysis patients [6]. Previously only one case report in which nocturnal Hemodialysis (HD) resolved massive uremic tumoral calcinosis of 44-year-old man in association with reduction of Ca x phosphorus was reported [7]. With this paradigm in mind, it seems logical to test the strength of association between VC and phosphate in other settings. Recent reports have demonstrated that frequent / extended hours (“high-dose”) HD facilitates control of hyperphosphatemia, allowing more liberal dietary intake and freedom from phosphorus binders [8,9]. This study aims to extend those observations, and test the following clinical question: in prevalent HD patients from Japan, does high-dose home HD result in a decrease in VC, prevalent over a 3 year period?


Study overview and design

This study is a single center, prospective, observational study. The primary objective was to compare abdominal aortic calcification at the inception of high-dose home HD [10] to that after 3 years of follow-up. Ethical clearance and confirmation of scientific validity was provided by the Institutional Review Board of Saitama Medical University.

Setting and participants

The setting for this study is the Kidney Disease Center, Saitama Medical University, in Moroyama, Japan. At the time of writing, the center had more than 198 dialysis patients, with 90, 60 and 48 on facility HD, home HD, and peritoneal dialysis respectively.

Thirty-seven HD patients were recruited from hospital HD facilities. Each participant was followed-up for 3 years, with last follow-up completed March 2013. All participants provided informed consent. Key inclusion criteria included: participants were willing and able to perform home HD, aged > 20 years, with duration of dialysis >1 year, and able to provide informed consent. Key exclusion criteria included: those with significant co-morbidity anticipated to reduce life expectancy to <6 months, and those with contraindications to study procedures including CT scanning.

Primary exposure and outcome variables

The primary exposure in the study was high-dose home HD, defined as HD in the home, performed by the patient, with 3-5 hour treatments at a frequency of typically 6 (and no less than 5) times per week. Prior to high-dose home HD, all participants were treated with conventional facility HD in a hospital HD unit, with 4 hour treatments 3 times per week. After study enrollment, all patients underwent home HD training for at least a period of 3 months, transitioning to high dose home HD after completion of training.

HD treatments in the hospital and at home were performed using low flux polysalphose dialyzers (1.5-2.0 m2APS Asahi Medical R Tokyo, Japan), bicarbonate-based dialysate containing 1.25 mmol/L calcium and 134 mmol/ sodium. High-dose home HD was performed using Nikkiso DBB-27 machines (Nikkiso Co., Tokyo, Japan) with the MH-500CX water treatment system (Japan Water System Co., Tokyo, Japan). Typical blood flows were 200 ml/min for both facility and high-dose home HD. Typical dialysate flows were approximately 200 ml/min.

The primary outcome measure in this study was abdominal aortic calcification, measured at baseline and after 3 years followup determined by CT. CT scans were performed with a 16-detector CT scan {Prime Purpose MDCT (GE Healthcare, Milwaukee, WI USA)}. Scanning time was 0.5s for two contiguous 1.25 mm sections and 20+5 seconds for the entire zone of interest. Examination was performed during a single, unforced, withheld inspiration. During scanning with the tube rotating at 2 rotations/second and the table moving at 55 mm/s with a 1:1.375 scanning pitch, images were obtained with an effective section thickness of 10 mm. Scanning was performed with 120 kVp and 350 mAs, standard resolution, and a 28- 36 cm field of view. The total duration of the procedure was 5 min. The range of CT scanning is shown in Figure 1 [11]. Volume acquisitions were analyzed using Volume Viewer software (GE Healthcare). The abdominal aorta was segmented manually. In order to reduce errors due to noise, a cut-off of 130 Housefield Units (HU) was applied. The total calcification volume was calculated as the sum of all voxels in the remaining volume [12].