Outcomes in randomized controlled trials of exercise interventions in solid organ transplant

Is High-Intensity Interval Training an Option for Post-Kidney Transplant Physical Rehabilitation Programmes? A Scoping Review

Purpose

To systematically and broadly review the literature to show the available information on high-intensity interval training for kidney transplant recipients as an adjunct to physical rehabilitation.

Methods

A scoping review of high-intensity interval training for post-kidney transplant patients was conducted by searching the PubMed, EMBASE (Elsevier), Scopus (Elsevier), Web of Science, and PEDro databases. Full-text records on the subject were included. Articles not published in English were excluded. The selected articles went through careful production quality analysis using the PEDro scale.

Results

The search identified 26 articles, 3 of which met the inclusion criteria. The material demonstrated satisfaction, confidence, improvement in resting heart rate, and absence of adverse effects from high-intensity interval training for kidney transplant recipients.

Conclusion

Based on this scoping review, high-intensity interval training for kidney transplant patients may be beneficial for physical and mental aspects and complement physical rehabilitation programmes, but there is a need for more studies with robust samples and long-term follow-up to confirm these benefits.

Supervised vs home-based exercise program in kidney transplant recipients: A pilot pragmatic non-randomized study

BACKGROUND

Although the benefits of exercise for kidney transplant recipients (KTRs) have been widely demonstrated, these patients experience several barriers in undertaking a structured exercise program in hospital and non-hospital facilities.

AIM

To compare the effects of a supervised moderate-intensity gym-based intervention with a home-based low-intensity walking program on exercise capacity in KTRs.

METHODS

KTRs were asked to choose between two six-month programs. The first group performed a low-intensity interval walking intervention at home-based exercise intervention (HBex). The second group performed a supervised training program at an adapted physical activity gym (Sgym), including aerobic and resistance training. The outcomes, collected at baseline and at the end of the programs, included the 6-minute walking test, the peak oxygen consumption (VO2peak) during a treadmill test, the 5-time sit-to-stand test, and blood pressure.

RESULTS

Seventeen patients agreed to participate and self-selected into the HBex (n = 9) and Sgym (n = 8) groups. Two patients in the Sgym group dropped out because of familial problems. At baseline, patients in the HBex group were significantly older and had lower walking distance, VO2peak, and lower limb strength. Primary outcome changes were significantly greater in the HBex group than in the Sgym group (52 ± 23 m vs 8 ± 34; P = 0.005). No other significant differences between groups were observed. Both groups improved most of the outcomes in the within-group comparisons, with significant variations in VO2 peak.

CONCLUSION

Six-month moderate-intensity supervised or low-intensity home-based training programs effectively improved exercise capacity in KTRs. Gym-based programs combine aerobic and resistance training; however, in-home walking may be proposed for frail KTRs.

Approach to Late Noninfectious Post-Transplant Complications

The management of noninfectious complications in kidney transplant recipients includes a broad spectrum of conditions, including metabolic issues, cardiovascular diseases, and malignancies, each presenting unique challenges for nephrologists managing these patients. Unlike infectious complications, these noninfectious issues require nuanced, multidisciplinary approaches for prevention, diagnosis, and management, emphasizing the need for personalized care plans. Cardiovascular disease is particularly significant, standing as the primary cause of death post-transplantation, with recent data indicating an overtaking of cancer death rates over infections among kidney transplant recipients. The intricacies of managing these patients, influenced by the burden of kidney disease and immunosuppression, highlight the importance of a collaborative care model. Although nephrologists may not directly treat all these conditions, their understanding of the unique aspects of transplant recipients is crucial. They play a pivotal role in coordinating care with specialists such as cardiologists, endocrinologists, hematologists, and oncologists, ensuring comprehensive management that addresses these specific post-transplant complications. This review discusses the epidemiology, underlying mechanisms, clinical manifestations, and management strategies of various noninfectious complications post-kidney transplant, with a focus on cardiovascular, metabolic, oncologic, and hematologic complications.

Systematic review and meta-analysis of the efficacy of exercise intervention in kidney transplant recipients

BACKGROUND AND OBJECTIVE

There is uncertainty about the beneficial effects of exercise intervention for kidney transplant recipients. The purpose of our meta-analysis is to estimate the efficacy of exercise intervention in kidney transplant recipients.

METHODS

A database search according to the PICOS framework was performed for all published randomized, double-blind, placebo-controlled trials (RCTs) about exercise intervention for kidney transplant recipients. The databases involved include PubMed, Embase, and Cochrane Library.

RESULTS

A total of 16 RCTs (involving 827 patients) in compliance with inclusion criteria were included in our study. The results demonstrated that adequate exercise intervention improved statistically in creatinine clearance [mean difference (MD) =  - 0.29, 95% confidence interval (CI) - 0.46 to - 0.11, p = 0.001], serum urea (MD = - 21.57, 95% CI - 35.84 to - 7.29, p = 0.003), VO2 peak (MD = 3.20, 95% CI 1.97-4.43, p < 0.00001), high-density lipoprotein-cholesterol (HDL-C) (MD = 0.21, 95% CI 0.04-0.37, p = 0.01), 60-s sit to stand test (60-STS) (MD = 14.47, 95% CI 8.89-20.04, p < 0.00001), 6-min walk distance (6-MWD) (MD = 91.87, 95% CI 38.34-145.39, p = 0.0008), and 6-min walk test (6-MWT) (MD = 44.08, 95% CI 20.30-67.87, p = 0.0003) of patients after kidney transplantation. No between-groups differences (p > 0.05) were observed for anthropometric characteristics, body composition, serum cytokine levels, and quality of life short form-36 questionnaire (SF-36).

CONCLUSIONS

In kidney transplant recipients, appropriate exercise intervention improved renal function, cardiopulmonary function, physical performance.

TRIAL REGISTRATION

The PROSPERO registration number is CRD42022357574.

Exercise interventions for adults after liver transplantation

BACKGROUND

The finding that exercise is inversely related to metabolic syndrome after transplantation is novel and suggests that exercise interventions might provide a means for reducing metabolic syndrome complications in liver transplantation recipients. The use of exercise for increasing the physical activity daily levels by more frequent, higher intensity, and longer duration of training sessions, or the sum of these components may be necessary to counteract the effects of the pretransplant reduced activity, metabolic disturbances, and post-transplant immunosuppression, as well as improve physical function and aerobic capacity following liver transplantation. Regular physical activity has a long-term positive impact on recovery following various surgical procedures including transplantation, giving people the opportunity to return to an active life with their families, in society, and in their professional life. Likewise, specific muscle strength training may attenuate the loss of strength after liver transplantation.

OBJECTIVES

To evaluate the benefits and harms of exercise-based interventions in adults after liver transplantation compared to no exercise, sham interventions, or another type of exercise.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 2 September 2022.

SELECTION CRITERIA

We included randomised clinical trials in liver transplantation recipients comparing any type of exercise with no exercise, sham interventions, or another type of exercise.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. all-cause mortality; 2. serious adverse events; and 3. health-related quality of life. Our secondary outcomes were 4. a composite of cardiovascular mortality and cardiac disease; 5. aerobic capacity; 6. muscle strength; 7. morbidity; 8. non-serious adverse events; and 9. cardiovascular disease post-transplantation. We assessed risk of bias of the individual trials using RoB 1, described the interventions using the TIDieR checklist, and used GRADE to assess certainty of evidence.

MAIN RESULTS

We included three randomised clinical trials. The trials randomised 241 adults with liver transplantation, of which 199 participants completed the trials. The trials were conducted in the USA, Spain, and Turkey. They compared exercise versus usual care. The duration of the interventions ranged from two to 10 months. One trial reported that 69% of participants who received the exercise intervention were adherent to the exercise prescription. A second trial reported a 94% adherence to the exercise programme, with participants attending 45/48 sessions. The remaining trial reported a 96.8% adherence to the exercise intervention during the hospitalisation period. Two trials received funding; one from the National Center for Research Resources (US) and the other from Instituto de Salud Carlos III (Spain). The remaining trial did not receive funding. All trials were at an overall high risk of bias, derived from high risk of selective reporting bias and attrition bias in two trials. The results on all-cause mortality showed a higher risk of death in the exercise group versus the control group, but these results are very uncertain (risk ratio (RR) 3.14, 95% confidence interval (CI) 0.74 to 13.37; 2 trials, 165 participants; I² = 0%; very low-certainty evidence). The trials did not report data on serious adverse events excluding mortality or non-serious adverse events. However, all trials reported that there were no adverse effects associated with exercise. We are very uncertain on whether exercise compared with usual care has a beneficial or harmful effect on health-related quality of life assessed using the 36-item Short Form Physical Functioning subscale at the end of the intervention (mean difference (MD) 10.56, 95% CI -0.12 to 21.24; 2 trials, 169 participants; I² = 71%; very low-certainty evidence). None of the trials reported data on composite of cardiovascular mortality and cardiovascular disease, and cardiovascular disease post-transplantation. We are very uncertain if there are differences in aerobic capacity in terms of VO2peak at the end of the intervention between groups (MD 0.80, 95% CI -0.80 to 2.39; 3 trials, 199 participants; I² = 0%; very low-certainty evidence). We are very uncertain if there are differences in muscle strength at end of the intervention between groups (MD 9.91, 95% CI -3.68 to 23.50; 3 trials, 199 participants; I² = 44%; very low-certainty evidence). One trial measured perceived fatigue using the Checklist Individual Strength (CIST). Participants in the exercise group showed a clinically important lower degree of fatigue perception than participants in the control group, with a mean reduction of 40 points in the CIST (95% CI 15.62 to 64.38; 1 trial, 30 participants).  We identified three ongoing studies.

AUTHORS' CONCLUSIONS

Based on very low-certainty evidence in our systematic review, we are very uncertain of the role of exercise training (aerobic, resistance-based exercises, or both) in affecting mortality, health-related quality of life, and physical function (i.e. aerobic capacity and muscle strength) in liver transplant recipients. There were few data on the composite of cardiovascular mortality and cardiovascular disease, cardiovascular disease post-transplantation, and adverse event outcomes. We lack larger trials with blinded outcome assessment, designed according to the SPIRIT statement and reported according to the CONSORT statement.

Identifying Outcome Domains for Clinical Trials of Physical Rehabilitation Among Adults Undergoing Solid Organ Transplantation Using a Delphi Approach

Introduction: A core outcome set (COS) improves the quality of reporting in clinical trials; however, this has not been developed for clinical trials of exercise training among adults undergoing solid organ transplant. Research Question: To explore the perspectives of transplant patients and healthcare professionals on the key outcomes domains that are relevant for clinical trials of exercise in all recipients of transplanted organs. Methods: A Delphi approach was employed with 2 rounds of online questionnaires. Participants rated the importance of outcome domains using a 9-point Likert scale ranging from "not important" to "very important". A score of 7 to 9 (very important) by 70% or more participants and a score of 1 to 3 (not important) by less than 15% participants were required to keep an outcome domain from the first to the second round. Results: Thirty-six participants completed 2 rounds of questionnaires (90% response rate). After Round 1, 8 outcome domains were considered very important in the pretransplant phase; 16 in the early posttransplant; and 17 in the late posttransplant. Only 1 outcome domain, organ rejection in the early posttransplant phase, met the criteria to be considered very important after Round 2. Conclusion: Although consensus was not reached on the core outcome domains, this study provides preliminary information on which domains are higher priority for patients and professionals. Future work should consider a meeting with key stakeholders to allow for deeper discussion to reach consensus on a core outcome set.

Patient-reported outcomes evaluation and assessment of facilitators and barriers to physical activity in the Transplantoux aerobic exercise intervention

Background

Transplantoux’s MVT exercise intervention prepares organ transplant recipients to cycle or hike up France’s Mont Ventoux. We aimed to assess (i) MVT’s effects on patient-reported outcomes (PROs) and (ii) perceived barriers and facilitators to physical activity.

Methods

Using a hybrid design, a convenience sample of transplant recipients participating in MVT (n = 47 cycling (TxCYC); n = 18 hiking (TxHIK)), matched control transplant recipients (TxCON, n = 213), and healthy MVT participants (HCON, n = 91) completed surveys to assess physical activity (IPAQ), health-related quality of life (HRQOL; SF-36 and EuroQol VAS), mental health (GHQ-12), and depressive symptomatology, anxiety, and stress (DASS-21) at baseline, then after 3, 6 (Mont Ventoux climb), 9, and 12 months. TxCYC and TxHIK participated in a 6-month intervention of individualized home-based cycling/hiking exercise and a series of supervised group training sessions. Barriers and facilitators to physical activity (Barriers and Motivators Questionnaire) were measured at 12 months.

Results

Regarding PROs, except for reducing TxHIK stress levels, MVT induced no substantial intervention effects. For both TxCYC and TxHIK, between-group comparisons at baseline showed that physical activity, HRQOL, mental health, depressive symptomatology and stress were similar to those of HCON. In contrast, compared to TxCYC, TxHIK, and HCON, physical activity, HRQOL and mental health were lower in TxCON. TxCON also reported greater barriers, lower facilitators, and different priority rankings concerning physical activity barriers and facilitators.

Conclusion

Barely any of the PROs assessed in the present study responded to Transplantoux’s MVT exercise intervention. TxCON reported distinct and unfavorable profiles regarding PROs and barriers and facilitators to physical activity. These findings can assist tailored physical activity intervention development.

Trial registration

Clinical trial notation: The study was approved by the University Hospitals Leuven’s Institutional Review Board (B322201523602).

Clinical Implementation of Different Strategies for Exercise-Based Rehabilitation in Kidney and Liver Transplant Recipients: A Pilot Study

Fundamento:

A doença cardiovascular está entre as principais causas de morte entre pacientes transplantados. Embora esses pacientes possam teoricamente se beneficiar de programas de reabilitação baseada em exercícios (RBE), sua implementação ainda é um desafio.

Objetivo:

Apresentamos nossa experiência inicial em diferentes modos de realização de um programa piloto de RBE em receptores de transplante de rim e fígado.

Métodos:

Trinta e dois pacientes transplantados renais ou hepáticos foram convidados para um programa de RBE de 6 meses realizado na academia do hospital, na academia comunitária ou em casa, de acordo com a preferência do paciente. O nível de significância adotado foi de 5%.

Resultados:

Dez pacientes (31%) não completaram o programa. Entre os 22 que completaram, 7 treinaram na academia do hospital, 7 na academia comunitária e 8 em casa. O efeito geral foi um aumento de 11,4% nos METs máximos (tamanho do efeito de Hedges g = 0,39). O grupo de academia hospitalar teve um aumento nos METs de 25,5% (g = 0,58, tamanho de efeito médio) versus 10% (g = 0,25) e 6,5% (g = 0,20) para os grupos de academia comunitária e em casa, respectivamente. Houve efeito benéfico nas pressões arteriais sistólica e diastólica, maior para os grupos academia hospitalar (g= 0,51 e 0,40) e academia comunitária (g= 0,60 e 1,15) do que para os pacientes treinando em casa (g= 0,07 e 0,10). Nenhum evento adverso significativo foi relatado durante o seguimento.

Conclusão:

Programas de RBE em receptores de transplante de rim e fígado devem ser incentivados, mesmo que sejam realizados fora da academia do hospital, pois são seguros com efeitos positivos na capacidade de exercício e nos fatores de risco cardiovascular.

Protocol for the IMPACT Trial: Improving Healthcare Outcomes in American Transplant Recipients Using Culturally-Tailored Novel Technology

Kidney transplant (KT) recipients face post-transplant health issues. Immunosuppressive agents can cause hyperlipidemia, hypertension, post-transplant diabetes, and glomerulopathy. Post-transplant weight gain and decreased activity are associated with poor quality of life, sleep, and cardiometabolic outcomes. This study will test the feasibility and acceptability of a culturally tailored diet and exercise intervention for KT patients delivered immediately post-transplant using novel technology. A registered dietitian nutritionist (RDN) and physical rehabilitation therapist will examine participants' cultural background, preferences, and health-related obstacles (with consultation from the transplant team) to create an individualized exercise and meal plan. The RDN will provide medical nutrition therapy via the nutrition care process throughout the course of the intervention. The Twistle Patient Engagement Platform will be used to deliver and collect survey data, communicate with participants, and promote retention. Outcomes to be assessed include intervention feasibility and acceptability and intervention efficacy on patients' adherence, medical, quality of life, and occupational outcomes.

The effects of exercise training in adult solid organ transplant recipients: A systematic review and meta-analysis

Reduced exercise capacity can predispose solid organ transplant (SOT) recipients to higher risk of diabetes, cardiovascular complications, and mortality and impact their quality of life. This systematic review and meta-analysis investigated the effects of exercise training (versus no training) in adult SOT recipients. We conducted an electronic search of randomized controlled trials reporting on exercise interventions in SOT recipients. Primary outcomes were exercise capacity, quadriceps muscle strength, and health-related quality of life (HRQoL). Twenty-nine articles met the inclusion criteria. In 24 studies, there were either high risk of bias or some concerns about the potential risk of bias. There was an increase in exercise capacity (VO₂ peak) (SMD: 0.40; 95%CI 0.22-0.57; P = 0.0) and quadriceps muscle strength (SMD: 0.38; 95%CI 0.16-0.60; P = 0.001) in the exercise vs control groups. There were also improvements in several domains of the SF-36. Diastolic blood pressure improved in the exercise group compared to controls (SMD: -0.22; 95%CI -0.41-0.03; P = 0.02). Despite the considerable variation in exercise training characteristics and high risk of bias in the included studies, exercise training improved maximal exercise capacity, quadriceps muscle strength, HRQoL, and diastolic blood pressure and should be an essential part of the post-transplant care.

Exercise interventions in solid organ transplant candidates: A systematic review

INTRODUCTION

Exercise training may be recommended to solid organ transplant (SOT) candidates to improve fitness and tolerance before surgery. We aimed to determine the acceptance, safety, and effectiveness of exercise interventions in SOT candidates.

METHODS

Online databases were searched. Studies of any design were included. Outcomes of interest were acceptance, safety, exercise capacity, and health-related quality of life.

RESULTS

Twenty-three articles were included. Acceptance ranged from 16% to 100%. In the fifteen studies that assessed adverse events, none mentioned any adverse events occurring during the study. Five out of seven studies reported an increase in maximal exercise capacity post-exercise in the intervention group (range of mean change: 0.45 to 2.9 mL/kg). Eight out of fourteen studies reported an increase in 6-minute walking distance in the intervention group after the training period (range of mean change: 40-105 m). Two articles showed an improvement in the mental composite scores as well as in the physical composite scores post-exercise in the intervention group.

CONCLUSION

There was a lack of significant findings among most randomized controlled trials. Exercise training is acceptable and safe for selective SOT candidates. The effects of exercise training on exercise capacity and quality of life in SOT candidates are unclear.

Posttransplant muscle mass measured by urinary creatinine excretion rate predicts long-term outcomes after liver transplantation

Long-term survival in orthotopic liver transplant (OLT) recipients remains impaired because of many contributing factors, including a low pretransplant muscle mass (or sarcopenia). However, influence of posttransplant muscle mass on survival is currently unknown. We hypothesized that posttransplant urinary creatinine excretion rate (CER), an established noninvasive marker of total body muscle mass, is associated with long-term survival after OLT. In a single-center cohort study of 382 adult OLT recipients, mean ± standard deviation CER at 1 year posttransplantation was 13.3 ± 3.7 mmol/24 h in men and 9.4 ± 2.6 mmol/24 h in women. During median follow-up for 9.8 y (interquartile range 6.4-15.0 y), 104 (27.2%) OLT recipients died and 44 (11.5%) developed graft failure. In Cox regression analyses, as continuous variable, low CER was associated with increased risk for mortality (HR = 0.43, 95% CI: 0.26-0.71, P = .001) and graft failure (HR = 0.42, 95% CI: 0.20-0.90, P = .03), independent of age, sex, and body surface area. Similarly, OLT recipients in the lowest tertile had an increased risk for mortality (HR = 2.69; 95% CI: 1.47-4.91, P = .001) and graft failure (HR = 2.77, 95% CI: 1.04-7.39, P = .04), compared to OLT recipients in the highest tertile. We conclude that 1 year posttransplant low total body muscle mass is associated with long-term risk of mortality and graft failure in OLT recipients.

Importance of physical capacity and the effects of exercise in heart transplant recipients

One of the most important prognostic factors in heart failure patients is physical capacity. Patients with very poor physical performance and otherwise eligible, may be listed as candidates for heart transplantation (HTx). After such surgery, life-long immunosuppression therapy is needed to prevent rejection of the new heart. The dark side of immunosuppression is the increased risk of infections, kidney failure, cancer and advanced atherosclerosis (cardiac allograft vasculopathy), with the two latter conditions as the main causes of later mortality. In a worldwide perspective, 50% of the HTx patients survive past 10 years. Poor aerobic capacity prior to graft deterioration is not only limited to the failing heart, but also caused by peripheral factors, such as limited function in the skeletal muscles and in the blood vessels walls. Exercise rehabilitation after HTx is of major importance in order to improve physical capacity and prognosis. Effects of high-intensity interval training (HIT) in HTx recipients is a growing field of research attracting worldwide focus and interest. Accumulating evidence has shown that HIT is safe and efficient in maintenance HTx recipients; with superior effects on physical capacity compared to conventional moderate exercise. This article generates further evidence to the field by summarizing results from a decade of research performed at our center supported by a broad, but not strict formal, literature review. In short, this article demonstrates a strong association between physical capacity measured after HTx and long-term survival. It describes the possible “HIT-effect” with increased levels of inflammatory mediators of angiogenesis. It also describes long-term effects of HIT; showing a positive effect in development of anxiety symptoms despite that the improved physical capacity was not sustained, due to downregulation of exercise and intensity. Finally, our results are linked to the ongoing HITTS study, which investigates safety and efficiency of HIT in de novo HTx recipients. Together with previous results, this study may have the potential to change existing guidelines and contribute to a better prognosis for the HTx population as a whole.

Physical Activity in Kidney Transplant Recipients: A Review

Physical activity has known health benefits and is associated with reduced cardiovascular risk in the general population. Relatively few data are available for physical activity in kidney transplant recipients. Compared to the general population, physical activity levels are lower overall in kidney recipients, although somewhat higher compared to the dialysis population. Recipient comorbid condition, psychosocial and socioeconomic factors, and long-term immunosuppression use negatively affect physical activity. Physical inactivity in kidney recipients may be associated with reduced quality of life, as well as increased mortality. Interventions such as exercise training appear to be safe in kidney transplant recipients and are associated with improved quality of life and exercise capacity. Additional studies are required to evaluate long-term effects on cardiovascular risk factors and ultimately cardiovascular disease outcomes and patient survival. Currently available data are characterized by wide variability in the interventions and outcome measures investigated in studies, as well as use of small sample-sized cohorts. These limitations highlight the need for larger studies using objective and standardized measures of physical activity and physical fitness in kidney transplant recipients.