The Effect of Intradialytic Combined Exercise on Physical Outcomes in End-Stage Renal Disease Patients
The Effect of Intradialytic Combined Exercise on Physical Outcomes in End-Stage Renal Disease Patients
Hemodialysis (HD) is an important and commonly used renal replacement therapy (RRT) for
 End-Stage Renal Disease (ESRD) patients worldwide. Inadequate HD, impaired exercise capacity
 and declined peripheral muscular strength resulted by HD and ESRD are still disturbing
 problems, which also predicts poor renal prognosis and poor quality of life. The results of
 systematic reviews by the investigators have shown that aerobic exercise and combined
 exercise can improve dialysis efficacy (alleviate uremia symptoms), improve aerobic exercise
 capacity and muscle strength, and improve patients' quality of life, which also supports the
 notion that the National Kidney Foundation Disease Outcomes Quality Initiative (K/DOQI)
 recommends exercise as cornerstone of ESRD rehabilitation. Therefore, this study used the
 effective exercise type of the systematic review results - combined exercise as an
 intervention method to observe its effects on dialysis efficacy, blood pressure, aerobic
 exercise capacity, muscle strength and quality of life.

 The study hypothesized that combined exercise can not only improve dialysis efficacy, but
 also has an interaction effect with intervention duration, which deserves researches'
 attention. Combined exercise will also improve blood pressure (including systolic blood
 pressure and diastolic blood pressure) in patients with ESRD and reduce the symptoms of renal
 hypertension. It will also improve the exercise capacity and muscle strength of ESRD patients
 and improve their quality of life.
Hemodialysis (HD) is an important and commonly used renal replacement therapy (RRT) for
 End-Stage Renal Disease (ESRD) patients worldwide. Single-pool Kt/V (sp Kt/V) is a quantified
 indicator of HD adequacy and has been recommended should be more than 1.2 by The National
 Kidney Foundation Disease Outcomes Quality Initiative (K/DOQI). Inadequate HD predicted
 increased hospitalization time and cost and reduced survival time. Increasing dose or
 frequency were common clinical therapies to improve HD adequacy but were limited by patients'
 poor compliance and greater finical burden. Economical and affordable methods to increase
 urea and other toxins are urgent clinically.

 Physical fitness decline, often accompanied with sedentary lifestyle are also disturbing
 issues for ESRD. And physical fitness reduction would exacerbate with the extension of HD
 years. In addition, patients should sit or lie still for 4 hours during HD and post-dialysis
 fatigue worsened physical function. Exercise capacity and peripheral muscular strength had
 40% to 50% reduction compared to same age and gender, which resulted from metabolic disorders
 and physiological deterioration of HD. Then muscle functionality and cardiorespiratory
 capacity declined and reflected in reduction of physical function which was a risk factor of
 poor renal prognosis and poor quality of life.

 Exercise was an economical way and was recommended by K/DOQI as cornerstone of rehabilitation
 for HD patients. There are kinds of exercise intervention, including aerobic exercise,
 resistance exercise and aerobic and resistance exercise (combined exercise), which showed
 obvious beneficial effects on the recovery for HD patients, such as mitigating patients'
 uremic symptoms, elevating their physical fitness and improving quality of life (QoL) in
 recent 30 years' studies. Previous studies showed that sp Kt/V can be elevated not only by
 single exercise intervention, but also by long term intervention. But there are few studies
 observed the interaction between time and exercise in the long term exercise intervention.
 About physical fitness, exercise, especially aerobic exercise, can increase patients' aerobic
 capacity, such as maximal peak oxygen and walking ability. Exercise also has a marked effect
 on muscle strength, with resistance exercise reducing muscle wasting and enhancing muscle
 strength.

 According to the investigators' previous meta-analysis, both aerobic exercise and combined
 exercise can increase patients' exercise capacity and QoL. Investigators prefer choosing
 combined exercise because few researches regard combined exercise as intervention exercise
 type which can provide more information to future systematic reviews. About the exercise
 time, investigators chose intradialytic exercise for good compliance, professional guidance
 and clinical professional guarantee. As for the duration, intensity and frequency, 6 months,
 moderate intensity and 3 times per week may good for restore blood vessel structure, physical
 function and quality of life from the investigator's previous result. Above all, this study
 aimed to invest the effect of intradialytic combined exercise on sp Kt/V, walking ability,
 muscle strength and QoL.

 The randomized, parallel-controlled trial aimed to compare the effect of 24 weeks combined
 exercise and usual care on hemodialysis efficacy, functional capacity and quality of life in
 patients with ESRD on HD. The protocol of this study was conducted in accordance with the
 Declaration of Helsinki and was reviewed and approved by the Human Research Ethics Committee
 of the Xi'an Jiaotong University Health Science Center (No 2018538), China. Informed consent
 was obtained from participants in this study.

 Data analysis Continuous data were expressed as mean and standard deviation (SD) or median
 and interquartile range according to the normality results. Proportion data were expressed as
 percentage frequency. The demographics of patient in two groups were compared. The Student
 T-test or Mann-Whitney U test where appropriate for the continuous data, and the Chi-square
 test was used for proportion data. The intragroup differences analysis was detected with the
 paired Student T-test or Wilcoxon rank test. Unpaired Student T-test or Mann-Whitney U test
 was evaluated the intergroup difference. In order to compare monthly data of sp Kt/V, two-way
 analysis of variance for repeated measures: group (presence or absence of intervention) and
 time (every 4 weeks) was performed. The differences were considered as statistical
 significant when P-values were ≤0.05. EpiData 3.1 (Odense, Denmark) was used for data entry,
 and the analyses were carried out using Statistical Product and Service Solutions (SPSS) 13.0
 for Windows (Chicago, U.S.A).
Inclusion Criteria:

 -  Adult (age≥18) with stable ESRD.

 -  Receiving≥3 months HD.

 -  HD 3 times per week.

 -  Volunteer for participating this trial.

 Exclusion Criteria:

 -  Unable to exercise (severe musculoskeletal pain at rest or with minimal activity
 precluding walking or stationary cycling; unable to sit, stand or walk unassisted)
 (walking device such as cane or walker allowed).

 -  Had shortness of breath at rest or with activities of daily living (NYHA Class IV).

 -  Had mental disease, disturbance of consciousness and couldn't cooperate with
 investigations and exercise.