Exercise capacity and body composition in living-donor renal transplant recipients over time

Assessment of body composition by dual-energy X-Ray absorptiometry in renal transplant patients, hemodialysis patients, and a control group of healthy subjects

BACKGROUND

The clinical findings of patients with Chronic Kidney Disease (CKD), which is characterized by malnutrition, sedentary lifestyle, uremia, and catabolism associated with dialysis produce changes in Body Composition (BC), causing increased Fat Mass (FM), decreased in both Lean Mass (LM) and Body Mineral Density (BMD), even despite uremic reversal after a Kidney Transplant (KT); immunosuppressive medications alter BC, increasing the risk of loss of the kidney transplant and cardiovascular diseases.

OBJECTIVE

To demonstrate whether there are differences in BC between a group of patients with KT and a group of patients on Hemodialysis (HD), when comparing them with a control group without the disease.

MATERIALS AND METHODS

In the present observational study, with a comparative design; 125 patients were evaluated (46 with KT, 47 on HD, and 32 from the healthy control group). The BC was evaluated with the full-body Dual-Energy X-Ray Absorptiometry (DEXA) method.

RESULTS

The mean age and standard deviation (X±SD) of the study subjects were: 28.89 ± 5.76, 27.39 ± 5.04, and 29.63 ± 6.34 years for the HD, KT, and control subjects, respectively. The HD patients presented a total FM of 14.98 ± 6.96 kg in comparison with 20.1 ± 6.5 kg for the control group (p = 0.007), and 19.06 ± 7.94 kg for the group with KT (p = 0.02). The total LM was lower in the KT patients in comparison with the control group (p = 0.023). The content and total BMD were lower in both groups of patients with KT and HD.

CONCLUSIONS

Although a comprehensive improvement in BC was expected after kidney transplantation, the results are not close to "normal' values, when compared with those of healthy subjects of the same age.

Dialysis Duration, Time Interaction, and Visceral Fat Accumulation: A 6-Year Posttransplantation Study

BACKGROUND

Kidney transplantation (KT) leads to body composition change, particularly increasing the fat mass. However, limited researches have focused on the long-term follow-up of these changes and factors influencing body composition after KT.

METHODS

This study evaluated body composition in 31 adult KT recipients, measuring body mass index (BMI), the psoas muscle mass index (PMI) representing muscle mass, visceral and subcutaneous adipose tissue (VAT and SAT) representing fat mass, and skeletal muscle radiodensity (SMR) representing muscle quality before KT and at 2, 4, and 6 years posttransplantation using computed tomography. Linear mixed models (LMM) analyzed temporal changes and contributing factors, while growth curve models assessed influence of these factors on body composition changes posttransplantation.

RESULTS

Following KT, BMI, and PMI remained stable, while SAT increased significantly, revealing a 1.30-fold increase from baseline 2 years after transplantation. Similarly, a substantial increase in VAT was observed, with a 1.47-fold increase from baseline 2 years after transplantation with a further 1.75-fold increase 6 years after transplantation. In contrast, SMR decreased with a 0.86-fold decrease from baseline after 2 years. VAT increase was significantly influenced by the interaction between posttransplantation and dialysis duration. Growth curve models confirmed this interaction effect persistently influenced VAT increase posttransplantation.

CONCLUSIONS

The study revealed that KT promoted significant alterations in body composition characterized by increase in the VAT and SAT and a decline in SMR. Notably, dialysis duration and its interaction with posttransplantation duration emerged as significant factors influencing VAT increase.

The Impact of Nutritional Status on Sexual Function in Male Kidney Transplant Recipients

Background and Objectives: Sexual function and nutritional status assessment are relevant topics in chronic kidney disease patients. This study was designed to investigate whether bioelectrical impedance analysis-derived nutritional parameters, nutritional biomarkers, and handgrip strength influence sexual function and to analyze the changes in sexual function after kidney transplantation in men. Materials and Methods: Fifty-four men with kidney failure who had undergone replacement therapy entered the study. In addition, sexual function and nutritional status were evaluated before kidney transplantation and 12 months after. We used the International Index of Erectile Function, bioelectrical impedance analysis, three different malnutrition screening tools, handgrip strength, and anthropometric measurements. The demographic profiles and biochemical nutritional markers were collected. Results: Sexual inactivity was associated with a lower phase angle (6 (1) vs. 7 (1), p < 0.05) and a higher fat mass index (7 (5) vs. 3 (4), p < 0.05). Normal erectile function before kidney transplantation was significantly related to higher fat-free mass (67 (11) vs. 74 (7), p < 0.05) and lean mass (64 (10) vs. 70 (7), p < 0.05). The improvement in erectile function after kidney transplantation was nonsignificant (44% vs. 33%, p = 0.57). Only a weak association between muscle mass and sexual desire 12 months after kidney transplantation was found (rS = 0.36, p = 0.02). Further, linear regression revealed that higher muscle mass could predict better sexual desire after kidney transplantation following adjustment for age, estimated glomerular filtration rate, and diabetes mellitus. Conclusions: Kidney transplantation did not significantly improve erectile dysfunction in our study population. Sexual desire and intercourse satisfaction are the most affected domains in patients with chronic kidney disease. Higher muscle mass predicts higher sexual desire after kidney transplantation. Higher levels of fat-free and lean mass are associated with normal erectile function before kidney transplantation.

Effect of kidney transplantation on indices of cardiorespiratory fitness assessed with cardiopulmonary exercise testing: a systematic review and meta-analysis

BACKGROUND

Patients with kidney failure often present with reduced cardiovascular reserve. Kidney transplantation (KT) is the optimal treatment for patients with end-stage kidney disease as it is associated with longer survival and improved quality of life compared to dialysis.

METHODS

This is a systematic review and meta-analysis of studies using cardiopulmonary-exercise-testing to examine the cardiorespiratory fitness of patients with kidney failure before and after KT. The primary outcome was difference in pre- and post-transplantation values of peak oxygen uptake (VO2peak). Literature search involved three databases (PubMed-Web of Science-Scopus), manual search, and grey literature.

RESULTS

From 379 records initially retrieved, six studies were included in final meta-analysis. A marginal, but not significant, improvement was observed in VO2peak after KT compared to pre-transplantation values (SMD: 0.32, 95%CI -0.02; 0.67). Oxygen consumption at anaerobic threshold was significantly improved after KT (WMD: 2.30 ml/kg/min, 95%CI 0.50; 4.09). Consistent results were shown between preemptive and after-dialysis-initiation transplantation and a trend for improvement in VO2peak was observed at least 3 months post-transplantation, but not earlier.

CONCLUSION

Several major indices of cardiorespiratory fitness tend to improve after KT. This finding may represent another modifiable factor contributing to better survival rates of kidney transplant recipients compared to patients undergoing dialysis.

Cardiopulmonary exercise testing in patients with end-stage kidney disease: principles, methodology and clinical applications of the optimal tool for exercise tolerance evaluation

Chronic kidney disease (CKD), especially end-stage kidney disease (ESKD), is associated with an increased risk for cardiovascular events and all-cause mortality. Exercise intolerance as well as reduced cardiovascular reserve is extremely common in patients with CKD. Cardiopulmonary exercise testing (CPET) is a non-invasive, dynamic technique that provides an integrative evaluation of cardiovascular, pulmonary, neuropsychological and metabolic function during maximal or submaximal exercise, allowing the evaluation of functional reserves of these systems. This assessment is based on the principle that system failure typically occurs when the system is under stress and thus CPET is currently considered to be the gold standard for identifying exercise limitation and differentiating its causes. It has been widely used in several medical fields for risk stratification, clinical evaluation and other applications, but its use in everyday practice for CKD patients is scarce. This article describes the basic principles and methodology of CPET and provides an overview of important studies that utilized CPET in patients with ESKD, in an effort to increase awareness of CPET capabilities among practicing nephrologists.

Body composition is associated with tacrolimus pharmacokinetics in kidney transplant recipients

PURPOSE

A population pharmacokinetic (popPK) model may be used to improve tacrolimus dosing and minimize under- and overexposure in kidney transplant recipients. It is unknown how body composition parameters relate to tacrolimus pharmacokinetics and which parameter correlates best with tacrolimus exposure. The aims of this study were to investigate which body composition parameter has the best association with the pharmacokinetics of tacrolimus and to describe this relationship in a popPK model.

METHODS

Body composition was assessed using bio-impedance spectroscopy (BIS). Pharmacokinetic analysis was performed using nonlinear mixed effects modeling (NONMEM). Lean tissue mass, adipose tissue mass, over-hydration, and phase angle were measured with BIS and then evaluated as covariates. The final popPK model was evaluated using goodness-of-fit plots, visual predictive checks, and a bootstrap analysis.

RESULTS

In 46 kidney transplant recipients, 284 tacrolimus concentrations were measured. The base model without body composition parameters included age, plasma albumin, plasma creatinine, CYP3A4 and CYP3A5 genotypes, and hematocrit as covariates. After full forward inclusion and backward elimination, only the effect of the phase angle on clearance (dOFV =  - 13.406; p < 0.01) was included in the final model. Phase angle was positively correlated with tacrolimus clearance. The inter-individual variability decreased from 41.7% in the base model to 34.2% in the final model. The model was successfully validated.

CONCLUSION

The phase angle is the bio-impedance spectroscopic parameter that correlates best with tacrolimus pharmacokinetics. Incorporation of the phase angle in a popPK model can improve the prediction of an individual's tacrolimus dose requirement after transplantation.

Height-adjusted lean body mass and its associations with physical activity and kidney function in pediatric kidney transplantation

BACKGROUND

Although LBM is positively associated with health outcomes, studies assessing determinants for the accrual of ht-LBM, such as physical activity, are limited. This study aimed to assess ht-LBM levels in pediatric kidney transplant recipients and test its association with baseline and contemporaneous variables, including physical activity.

METHODS

A retrospective cross-sectional review was performed on 46 pediatric kidney transplant recipients, and a longitudinal review was performed on a subset of recipients with serial post-transplant (n = 21) and pre/post-transplant (n = 11) ht-LBM measurements. Ht-LBM measurements were obtained using DXA scans.

RESULTS

This cohort was 16.0 (IQR 12.3, 17.7) years old, 56.5% male and 46 ± 45 months post-transplant with a mean ht-LBM of 15.1 ± 2.5 kg/m² . A median ht-LBM increase of 1.6 kg/m² (IQR - 0.1, 2.6 kg/m² ; p < .01) was observed, over 29.2 ± 12.0 months from the earliest post-transplant scan obtained at 46 ± 25 months post-transplant until the most recent post-transplant scan. A 1.7 ± 1.4 kg/m² (p < .01) increase was observed between pre- and post-transplant DXA scans which were taken at 12 ± 11 months pre-transplant and 13 ± 6 months post-transplant, respectively. In separate adjusted models, lower physical activity questionnaire scores (n = 17, beta = 1.55, p = .02), faster rate of estimated glomerular filtration rate decline (beta = 0.05, p < .048) adjusted for annualized change in BSA, and younger age at scan (beta = 0.32, p < .01) were each significant predictors of lower ht-LBM.

CONCLUSIONS

Physical activity and kidney function may influence ht-LBM in the pediatric kidney transplant population.

Changes in Body Composition, Muscle Strength, and Fat Distribution Following Kidney Transplantation

RATIONALE AND OBJECTIVE

Low muscle mass relative to fat mass (relative sarcopenia) has been associated with mortality and disability but has not been examined following transplantation. We studied how measures of body composition change after receipt of a kidney allograft.

STUDY DESIGN

Prospective longitudinal cohort study.

SETTING AND PARTICIPANTS

60 kidney transplant recipients (ages 20-60 years) at the University of Pennsylvania.

EXPOSURE

Kidney transplantation.

OUTCOMES

DXA measures of fat mass index (FMI) and appendicular lean mass index (ALMI; representing muscle mass), CT measures of muscle density (low density represents increased intramuscular adipose tissue), dynamometer measures of leg muscle strength, and physical activity. ALMI relative to FMI (ALM_FMI) is an established index of relative sarcopenia.

ANALYTICAL APPROACH

Measures expressed as age, sex, and race-specific Z-scores for transplant recipients were compared to 327 healthy controls. Regression models were used to identify correlates of change in outcome Z-scores and compare transplant recipients to controls.

RESULTS

At transplantation, ALMI, ALMI_FMI, muscle strength and muscle density Z-scores were lower vs. controls (all p≤0.001). Transplant recipients received glucocorticoids throughout. The prevalence of obesity increased from 18 to 45%. Although ALMI increased following transplantation (p<0.001) and was comparable to controls from 6 months onward, gains were outpaced by increases in FMI, resulting in persistent ALMI_FMI deficits (mean Z-score -0.31 at 24 months, p=0.02 vs controls). Muscle density improved following transplantation despite gains in FMI (p = 0.02). Muscle strength relative to ALMI also improved (p = 0.04) but remained low compared with controls (p=0.01). Exercise increased in the early months following transplantation (p<0.05) but remained lower than controls (p=0.02).

LIMITATIONS

Lack of muscle biopsies precluded assessment of muscle histology and metabolism.

CONCLUSIONS

The two-year interval following kidney transplantation was characterized by gains in muscle mass and strength that were outpaced by gains in fat mass resulting in persistent relative sarcopenia.

Cardiorespiratory fitness in kidney transplant recipients compared to patients with kidney failure: a systematic review and meta-analysis

Patients with kidney failure often present with reduced cardiovascular functional reserve and exercise tolerance. Previous studies on cardiorespiratory fitness examined with cardiopulmonary exercise testing (CPET) in kidney transplant recipients (KTR) had variable results. This is a systematic review and meta-analysis of studies examining cardiovascular functional reserve with CPET in KTR in comparison with patients with kidney failure (CKD-Stage-5 before dialysis, hemodialysis or peritoneal dialysis), as well as before and after kidney transplantation. Literature search involved PubMed, Web-of-Science and Scopus databases, manual search of article references and grey literature. From a total of 4,944 identified records, eight studies (with 461 participants) were included in quantitative analysis for the primary question. Across these studies, KTR had significantly higher oxygen consumption at peak/max exercise (VO₂ peak/VO₂ max) compared to patients with kidney failure (SMD = 0.70, 95% CI [0.31, 1.10], I²  = 70%, P = 0.002). In subgroup analyses, similar differences were evident among seven studies comparing KTR and hemodialysis patients (SMD = 0.64, 95% CI [0.16, 1.12], I²  = 65%, P = 0.009) and two studies comparing KTR with peritoneal dialysis subjects (SMD = 1.14, 95% CI [0.19, 2.09], I²  = 50%, P = 0.16). Across four studies with relevant data, oxygen consumption during peak/max exercise showed significant improvement after kidney transplantation compared to pretransplantation values (WMD = 2.43, 95% CI [0.01, 4.85], I²  = 68%, P = 0.02). In conclusion, KTR exhibit significantly higher cardiovascular functional reserve during CPET compared to patients with kidney failure. Cardiovascular reserve is significantly improved after kidney transplantation in relation to presurgery levels.

A clinical evaluation of VO2 kinetics in kidney transplant recipients

Purpose

Aerobic exercise capacity is reduced in patients with chronic kidney disease, partly due to alterations at the muscular and microvascular level. This study evaluated oxygen uptake (VO₂) kinetics as indicator of muscular oxidative metabolism in a population of Kidney Transplant Recipients (KTRs).

Methods

Two groups of KTRs enrolled 3 (n = 21) and 12 months (n = 14) after transplantation and a control group of healthy young adults (n = 16) underwent cardiopulmonary exercise testing on cycle-ergometer. The protocol consisted in two subsequent constant, moderate-load exercise phases with a final incremental test until exhaustion.

Results

The time constant of VO₂ kinetics was slower in KTRs at 3 and 12 months after transplantation compared to controls (50.4 ± 13.1 s and 43.8 ± 11.6 s vs 28.9 ± 8.4 s, respectively; P < 0.01). Peak VO₂ was lower in KTRs evaluated 3 months after transplantation compared to patients evaluated after 1 year (21.3 ± 4.3 and 26.4 ± 8.0 mL/kg/min; P = 0.04). Blood haemoglobin (Hb) concentration was higher in KTRs evaluated at 12 months (12.8 ± 1.7 vs 14.6 ± 1.7 g/dL; P < 0.01). Among KTRs, τ showed a moderate negative correlation with Peak VO₂ (ρ = − 0.52) and Oxygen uptake efficiency slope (OUES) (r = − 0.57) while no significant correlation with Hb and peak heart rate.

Conclusions

KTRs show slower VO₂ kinetics compared to healthy controls. Hb and peak VO₂ seem to improve during the first year after transplantation. VO₂ kinetics were significantly associated with indices of cardiorespiratory fitness, but less with central determinants of aerobic capacity, thus suggesting a potential usefulness of adding this index of muscular oxidative metabolism to functional evaluation in KTRs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00421-021-04672-x.

Changes in body composition in peritoneal dialysis patients after kidney transplantation

PURPOSE

Serial follow-up data of body composition from peritoneal dialysis (PD) initiation until 1 year after kidney transplantation (KT) would be useful in identifying pathologic or physiologic changes, related to each modality or during the exchange of the modality.

METHODS

Body composition analysis was performed 1 month after PD initiation, repeated annually, immediately before KT, 1 month and 1 year after KT (n = 43). Body composition analysis was performed using a bioimpedance analysis (BIA) machine. The body composition parameters measured using BIA included the water contents, fat mass index (FMI), appendicular muscle mass index (aMMI), and bone mineral content (BMC).

RESULTS

The aMMI values 1 month and 1 year after PD initiation, immediately before KT, and 1 month and 1 year after KT were 7.6 ± 1.5, 7.8 ± 1.4, 8.0 ± 1.4, 6.8 ± 0.9, and 7.0 ± 1.0 kg/m², respectively. The aMMI increased during the first year of PD (P = 0.029) and was maintained during the remaining period of PD (P = 0.413). The value decreased during the first month after KT (P < 0.001) and recovered during the first year after KT (P = 0.010). FMI increased during the first year of PD (P < 0.001) and was maintained during the remaining period of PD (P = 0.214). The value increased during the first year of KT (P < 0.001). BMC was stable during the PD period but decreased after KT. Body waters were maintained during PD and decreased after KT. The presence of low muscle mass (LMM) 1 month after PD initiation or 1 month after KT, was associated with development of LMM 1 year after KT.

CONCLUSION

Our study showed that body composition was significantly changed during the first year after PD or the first month after KT, as evidenced by a decrease in aMMI and BMC and an increase in FMI. Adequate interventions provided at these two points might help maintain proper body composition.

Nutritional status in kidney transplant patients before and 6-month after transplantation: Result of PNSI study

OBJECTIVES

Kidney transplantation is an essential treatment in management of kidney failure patients. The present study evaluated and compared the nutritional status of renal transplant patients before and 6 months after kidney transplantation and in comparison with healthy individuals.

METHODS

A multi-center, case-control study was conducted among 40 kidney transplant recipients and 40 healthy adults. Biochemical tests, anthropometric indices, and dietary intake were collected at baseline and 6 months post-transplant and compared with healthy controls.

RESULTS

Anthropometric indices of the participants increased in post-transplant period compared to baseline (p < 0.05). The calories, fat, carbohydrates, and selenium intakes also increased in patients compared to before transplantation and healthy controls. The mean score of malnutrition index in patients, before transplantation were: good nutrition status (A) = 42.5%, mild to moderate malnutrition (B) = 52.5%, and severe malnutrition (C) = 5%, that changed to A = 75%, B = 20%, and C = 5% six months after surgery. The mean score of malnutrition index in pre-transplant patients were: A = 42.5%, B = 52.5% and, C = 5%, which changed to A = 75%, B = 20% and C = 5% after 6 months. Experimental results showed that mean plasma levels of albumin, total protein, calcium increased as well as mean plasma levels of magnesium and phosphorus decreased over six months (p < 0.001).

CONCLUSION

Kidney transplantation led to improvement in clinical and nutritional status of patients with renal failure. Improving dietary intakes as part of the medical care process can help improve their medical conditions.

Accuracy of surrogate methods to estimate skeletal muscle mass in non-dialysis dependent patients with chronic kidney disease and in kidney transplant recipients

BACKGROUND & AIMS

Bioelectrical impedance analysis (BIA) and anthropometric predictive equations have been proposed to estimate whole-body (SMM) and appendicular skeletal muscle mass (ASM) as surrogate for dual energy X-ray absorptiometry (DXA) in distinct population groups. However, their accuracy in estimating body composition in non-dialysis dependent patients with chronic kidney disease (NDD-CKD) and kidney transplant recipients (KTR) is unknown. The aim of this study was to investigate the accuracy and reproducibility of BIA and anthropometric predictive equations in estimating SMM and ASM compared to DXA, in NDD-CKD patients and KTR.

METHODS

A cross-sectional study including adult NDD-CKD patients and KTR, with body mass index (BMI) ≥18.5 kg/m². ASM and estimated SMM were evaluated by DXA, BIA (Janssen, Kyle and MacDonald equations) and anthropometry (Lee and Baumgartner equations). Low muscle mass (LowMM) was defined according to cutoffs proposed by guidelines for ASM, ASM/height² and ASM/BMI. The best performing equation as surrogate for DXA, considering both groups of studied patients, was defined based in the highest Lin's concordance correlation coefficient (CCC) value, the lowest Bland-Altman bias (<1.5 kg) combined with the narrowest upper and lower limits of agreement (LoA), and the highest Cohen's kappa values for the low muscle mass diagnosis.

RESULTS

Studied groups comprised NDD-CKD patients (n = 321: males = 55.1%; 65.4 ± 13.1 years; eGFR = 28.8 ± 12.7 ml/min) and KTR (n = 200: males = 57.7%; 47.5 ± 11.3 years; eGFR = 54.7 ± 20.7 ml/min). In both groups, the predictive equations presenting the best accuracy compared to DXA were SMM-BIA-Janssen (NDD-CKD patients: CCC = 0.88, 95%CI = 0.83-0.92; bias = 0.0 kg; KTR: CCC = 0.89, 95%CI = 0.86-0.92, bias = -1.2 kg) and ASM-BIA-Kyle (NDD-CKD patients: CCC = 0.87, 95%CI = 0.82-0.90, bias = 0.7 kg; KTR: CCC = 0.89, 95%CI = 0.86-0.92, bias = -0.8 kg). In NDD-CKD patients and KTR, LowMM frequency was similar according to ASM-BIA-Kyle versus ASM-DXA. The reproducibility and inter-agreement to diagnose LowMM using ASM/height² and ASM/BMI estimated by BIA-Kyle equation versus DXA was moderate (kappa: 0.41-0.60), in both groups. Whereas female patients showed higher inter-agreement (AUC>80%) when ASM/BMI index was used, male patients presented higher AUC (70-74%; slightly <80%) for ASM/height² index.

CONCLUSIONS

The predictive equations with best performance to assess muscle mass in both NDD-CKD patients and KTR was SMM-BIA by Janssen and ASM-BIA by Kyle. The reproducibility to diagnose low muscle mass, comparing BIA with DXA, was high using ASM/BMI in females and ASM/height² in males in both groups.

A randomized, controlled, behavioral intervention to promote walking after abdominal organ transplantation: results from the LIFT study

Kidney transplant recipients (KTRs) and liver transplant recipients (LTRs) have significant post-transplant weight gain and low physical activity. We conducted a home-based, remotely monitored intervention using wearable accelerometer devices to promote post-transplant physical activity. We randomized 61 KTRs and 66 LTRs within 24 months of transplant to: (i) control, (ii) accelerometer or (iii) intervention: accelerometer paired with financial incentives and health engagement questions to increase steps by 15% from baseline every 2 weeks. The primary outcome was weight change. A co-primary outcome for the two accelerometer arms was steps. Participants were recruited at a median of 9.5 [3-17] months post-transplant. At 3 months, there were no significant differences in weight change across the three arms. The intervention arm was more likely to achieve ≥7000 steps compared to control with device (OR 1.99, 95% CI: 1.03-3.87); effect remained significant after adjusting for demographics, allograft, time from transplant and baseline weight. Adherence to target step goals was 74% in the intervention arm, 84% of health engagement questions were answered correctly. A pilot study with financial incentives and health engagement questions was feasible and led KTRs and LTRs to walk more, but did not affect weight. A definitive trial is warranted.

Characterising recovery from renal transplantation and live-related donation using cardiopulmonary exercise testing

BACKGROUND

An association between end-stage renal failure and exercise intolerance exists. Whether live kidney donation impacts on exercise tolerance is unknown. Here recovery post renal transplant and donation using cardiopulmonary exercise testing is investigated.

METHODS

Renal donors (n = 28) and recipients (n = 24) undertook a cardiopulmonary exercise test, Duke activity score index and patient reported health score questionnaires pre-operatively and in the 7th and 14th week post-operatively. Anaerobic threshold, peak oxygen uptake and ventilatory equivalents were measured in relation to activity and reported health scores. Haemoglobin and renal function was recorded.

RESULTS

Recipients showed impaired cardiopulmonary function compared to donors with lower anaerobic threshold (10.5 vs. 14.4 ml/kg/min) and peak oxygen uptake (18.5 vs 23.0 ml/kg/min). Post-operatively the anaerobic threshold of recipients improved and normalised by the 14th week, whereas that in donors fell by ∼20% by the 7th (mean 11.4 ml/kg/min), recovering by the 14th (mean 15.6 ml/kg/min). Reported health but not activity scores showed similar changes.

CONCLUSIONS

Recovery following renal transplantation and donation differ. Transplantation improves renal function resulting in an increase in anaerobic threshold and peak oxygen uptake which essentially normalise by the 14th week post-operatively. Donors suffer a 20% reduction in cardiopulmonary reserve post-operatively, which recovers by the 14th week, suggesting no associated chronic exercise intolerance.IMPLICATIONS FOR REHABILITATIONCardiopulmonary exercise testing is a real-time predictor of functional capacity and thus is used as a pre-operative tool to measure physiological fitness and predict outcomes.Renal failure is associated with exercise intolerance and transplantation is transformational in terms of quality of life, longevity and healthcare cost.Live - related renal donation is increasingly available but whether donation itself carries a long-term health burden has not been previously well established.This study suggests that renal donation is not associated with long-term cardiopulmonary compromise and patients who donate their kidneys recover their previous fitness within 14 weeks.

A Randomized Controlled Trial of an Intensive Nutrition Intervention Versus Standard Nutrition Care to Avoid Excess Weight Gain After Kidney Transplantation: The INTENT Trial

OBJECTIVE

Excessive weight gain is common after kidney transplantation and increases cardiovascular risk. The aim of this randomized controlled trial was to determine whether an intensive nutrition and exercise intervention delivered alongside routine post-transplant care would reduce post-transplant weight gain.

DESIGN

Single-blind, randomized controlled trial.

SUBJECTS AND SETTING

Adult kidney transplant recipients at a regional transplant center were recruited during routine outpatient clinic visits in the first month after transplant. Patients with a body mass index >40 kg/m² or <18.5 kg/m², severe malnutrition, or ongoing medical complications were excluded.

INTERVENTION

Participants were randomized to intensive nutrition intervention (individualized nutrition and exercise counselling; 12 dietitian visits; 3 exercise physiologist visits over 12 months) or to standard nutrition care (guideline based; 4 dietitian visits).

MAIN OUTCOME MEASURES

The primary outcome was weight at 6 months after transplant adjusted for baseline weight, obesity, and gender, analyzed using analysis of covariance. The secondary outcomes included body composition, biochemistry, quality of life, and physical function.

RESULTS

Thirty-seven participants were randomized to the intensive intervention (n = 19) or to standard care (n = 18); one intensive group participant withdrew before baseline. Weight increased between baseline, 6 and 12 months (78.0 ± 13.7 [standard deviation], 79.6 ± 13.0 kg, 81.6 ± 12.9 kg; mean change 4.6% P < .001) but at 6 months did not differ significantly between the groups: 77.0 ± 12.4 kg (intensive); 82.2 ± 13.4 kg (standard); difference in adjusted means 0.4 kg (95% confidence interval: -2.2 to 3.0 kg); analysis of covariance P = .7. No between-group differences in secondary outcomes were observed. Across the whole cohort, total body protein and physical function (gait speed, sit to stand, grip strength, physical activity, and quality of life [all but 2 domains]) improved. However, adverse changes were seen for total body fat, HbA1c, and fasting glucose across the cohort.

CONCLUSIONS

Kidney transplant recipients in the first year after transplant did not benefit from an intensive nutrition intervention compared with standard nutrition care, although weight gain was relatively modest in both groups.

Assessment of physical performance and body composition in male renal transplant patients

BACKGROUND

Renal transplant (RTX) recipients seem to experience a better quality of life compared to dialysis patients. However, the factors responsible for this positive effect are not completely defined. Conceivably, a change in the physical performance of these patients could play a role.

METHODS

To assess this, we measured: (1) waist circumference, fat mass and appendicular fat-free mass (aFFM) by dual-energy X-ray densitometry, (2) physical performance with the Short Physical Performance Battery, and (3) muscle strength with the handgrip test, in 59 male RTX, 11 chronic kidney disease in conservative treatment (CKD) and 10 peritoneal dialysis (PD) patients.

RESULTS

Surprisingly, anthropometric characteristics and body composition were similar among the three groups. However, despite a low aFFM, muscle strength was higher in stable RTX recipients > 5 years after transplantation than in dialyzed patients. Instead, CKD (wait-listed for RTX) had similar muscle strength to RTX patients. Waist circumference in RTX recipients showed a redistribution of body fat with increased central adipose tissue allocation compared to PD. At linear regression analysis, age, weight, height, aFFM, hemoglobin and transplant age were independent predictors of handgrip strength, explaining about 37% of the variance. Age and transplant age accounted for 18 and 12% of variance, respectively.

CONCLUSIONS

Our study demonstrates, for the first time, that clinically stable RTX recipients have greater muscle strength than dialyzed patients and suggests that the handgrip test could be an effective and easy-to-perform tool to assess changes in physical performance in this large patient population.

Different Dietary Patterns and New-Onset Diabetes Mellitus After Kidney Transplantation: A Cross-Sectional Study

OBJECTIVE

To verify the association of dietary patterns and dietary components with new-onset diabetes mellitus after transplantation (NODAT).

DESIGN

Cross-sectional study.

SUBJECTS

Adult kidney transplant recipients, without history of diabetes before transplantation, who received a kidney transplant and were followed up for at least 1 year. One hundred and sixteen subjects recruited between January 2013 and August 2014. Diagnosis of NODAT was established according to the American Diabetes Association criteria for type 2 diabetes.

METHODS

Demographic, clinical, and anthropometric data were collected. Dietary intake was assessed by food frequency questionnaire, administered by a registered dietitian. Dietary patterns were identified by cluster analysis. Chi-square test was used to verify the association between dietary patterns and NODAT. Total energy, fiber, and cholesterol intake were calculated. Consumption of macronutrients, carbohydrates, proteins, and fats (total fats and saturated, monounsaturated, polyunsaturated and trans fatty acids), were expressed in percentage of total energy intake.

RESULTS

Twenty-eight patients developed NODAT in the follow-up period. They presented higher body mass index and body fat percentage, as well as higher levels of triglycerides and urinary protein/creatinine ratio than the non-NODAT group. Two dietary patterns, I and II, were identified. Pattern II was characterized by higher intake of total, saturated, monounsaturated, and trans fats than pattern I. No association between the dietary patterns and NODAT was identified (P = .905), and there was no difference in the distribution of macronutrients, dietary fiber, and dietary cholesterol between the groups with and without NODAT.

CONCLUSION

Posttransplant dietary patterns were not different between patients with and without NODAT. Further larger and prospective studies are needed to evaluate a possible relationship between dietary components and NODAT incidence in kidney transplant recipients.

Nutritional status, energy expenditure, and protein oxidative stress after kidney transplantation

OBJECTIVES

To evaluate the association between nutritional status, resting energy expenditure (REE), and protein oxidative stress in patients after kidney transplantation (KT).

METHODOLOGY

The study evaluated 35 patients transplanted at the time of hospital discharge and 3 months after regarding: body composition, REE (by indirect calorimetry), and injury factor (IF); serum urea, creatinine, glucose, albumin, total protein, advanced oxidation protein products (AOPP), vitamin C.

RESULTS

Three months after discharge, there was an improvement in renal function, nutritional status, and oxidative stress, with a standardization in the REE/kg. There was an increase in body weight, mainly in fat mass. The correlations showed that a greater cold ischemia time resulted in a deeper decline in vitamin C; a longer hospital length stay resulted in a greater reduction in AOPP; the higher preoperative body weight showed greater increases in body fat and glucose after transplantation. For decreases in REE and IF, there were increases in total protein. Finally, at hospital discharge there was a greater gain in weight, lower albumin, and total protein among individuals who had rejection episodes.

DISCUSSION

The KT improves many of metabolic abnormalities, with the improvement of nutritional status, oxidative stress, and normalization of REE.

Prediction of Fat-Free Mass in Kidney Transplant Recipients

BACKGROUND

Individualization of drug doses is essential in kidney transplant recipients. For many drugs, the individual dose is better predicted when using fat-free mass (FFM) as a scaling factor. Multiple equations have been developed to predict FFM based on healthy subjects. These equations have not been evaluated in kidney transplant recipients. The objectives of this study were to develop a kidney transplant specific equation for FFM prediction and to evaluate its predictive performance compared with previously published equations.

METHODS

Ten weeks after transplantation, FFM was measured by dual-energy X-ray absorptiometry. Data from a consecutive cohort of 369 kidney transplant recipients were randomly assigned to an equation development data set (n = 245) or an evaluation data set (n = 124). Prediction equations were developed using linear and nonlinear regression analysis. The predictive performance of the developed equation and previously published equations in the evaluation data set was assessed.

RESULTS

The following equation was developed: FFM (kg) = {FFMmax × body weight (kg)/[81.3 + body weight (kg)]} × [1 + height (cm) × 0.052] × [1-age (years) × 0.0007], where FFMmax was estimated to be 11.4 in males and 10.2 in females. This equation provided an unbiased, precise prediction of FFM in the evaluation data set: mean error (ME) (95% CI), -0.71 kg (-1.60 to 0.19 kg) in males and -0.36 kg (-1.52 to 0.80 kg) in females, root mean squared error 4.21 kg (1.65-6.77 kg) in males and 3.49 kg (1.15-5.84 kg) in females. Using previously published equations, FFM was systematically overpredicted in kidney-transplanted males [ME +1.33 kg (0.40-2.25 kg) to +5.01 kg (4.06-5.95 kg)], but not in females [ME -2.99 kg (-4.07 to -1.90 kg) to +3.45 kg (2.29-4.61) kg].

CONCLUSIONS

A new equation for FFM prediction in kidney transplant recipients has been developed. The equation may be used for population pharmacokinetic modeling and clinical dose selection in kidney transplant recipients.

Physical function and body composition in kidney transplant recipients over time with physiotherapy intervention

Introduction:

The long-term usage of immunosuppressants post-kidney transplantation often results in adverse effects such as weight gain, osteoporosis and an increased risk of cardiovascular diseases. Physical activity has been shown to have a protective effect against these adverse effects. This paper aims to investigate the changes over time in physical function and body composition in kidney transplant recipients with a home exercise regimen prescribed by a physiotherapist.

Methods:

Forty-two kidney transplant recipients aged 45 ± 12 years were recruited before transplant and reviewed at fixed time points after transplant. Body composition, hand grip strength and functional exercise capacity were measured at every session. A home exercise regimen was prescribed and modified when appropriate.

Results:

There was an observed trend towards an improvement in functional exercise capacity in terms of six-minute walk distance. There was no change in body weight, fat mass and skeletal muscle mass.

Conclusion:

There may be a need to provide supervised exercise training programmes for kidney transplant recipients in bringing about positive changes in body composition as well as ensure compliance to exercise training after transplant. Further research is needed for more conclusive results.

The effect of intensive nutrition interventions on weight gain after kidney transplantation: protocol of a randomised controlled trial

BACKGROUND

Weight gain and obesity are common after kidney transplantation, particularly during the first year. Obesity is a risk factor for the development of new-onset diabetes after transplantation, and is associated with reduced graft survival. There is a lack of evidence for effective interventions to prevent weight gain after kidney transplantation.

METHODS/DESIGN

The effect of INTEnsive Nutrition interventions on weight gain after kidney Transplantation (INTENT) trial is a single-blind (outcomes assessor), randomised controlled trial to assess the effect of intensive nutrition interventions, including exercise advice, on weight gain and metabolic parameters in the first year after transplantation. Participants will be randomised during the first post-transplant month to either standard care (four visits with a renal dietitian over twelve months) or intensive nutrition intervention (eight visits with a renal dietitian over the first six months, four visits over the second six months, and three visits over the first six months with an exercise physiologist). In the intensive intervention group, nutrition counselling will be provided using motivational interviewing techniques to encourage quality engagement. Collaborative goal setting will be used to develop personalised nutrition care plans. Individualised advice regarding physical activity will be provided by an exercise physiologist. The primary outcome of the study is weight at six months after transplant, adjusted for baseline (one month post-transplant) weight, obesity and gender. Secondary outcomes will include changes in weight and other anthropometric measures over 12 months, body composition (in vivo neutron activation analysis, total body potassium, dual-energy X-ray absorptiometry, and bioelectrical impedance), biochemistry (fasting glucose, lipids, haemoglobin A1c and insulin), dietary intake and nutritional status, quality of life, and physical function.

DISCUSSION

There are currently few randomised clinical trials of nutrition interventions after kidney transplantation. The INTENT trial will thus provide important data on the effect of intensive nutrition interventions on weight gain after transplant and the associated metabolic consequences. Additionally, by assessing changes in glucose metabolism, the study will also provide data on the feasibility of undertaking larger multi-centre trials of nutrition interventions to reduce the incidence or severity of diabetes after transplantation.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry Number: ACTRN12614000155695.

Exercise limitation following transplantation

Organ transplantation is one of the medical miracles or the 20th century. It has the capacity to substantially improve exercise performance and quality of life in patients who are severely limited with chronic organ failure. We focus on the most commonly performed solid-organ transplants and describe peak exercise performance following recovery from transplantation. Across all of the common transplants, evaluated significant reduction in VO2peak is seen (typically renal and liver 65%-80% with heart and/or lung 50%-60% of predicted). Those with the lowest VO2peak pretransplant have the lowest VO2peak posttransplant. Overall very few patients have a VO2peak in the normal range. Investigation of the cause of the reduction of VO2peak has identified many factors pre- and posttransplant that may contribute. These include organ-specific factors in the otherwise well-functioning allograft (e.g., chronotropic incompetence in heart transplantation) as well as allograft dysfunction itself (e.g., chronic lung allograft dysfunction). However, looking across all transplants, a pattern emerges. A low muscle mass with qualitative change in large exercising skeletal muscle groups is seen pretransplant. Many factor posttransplant aggravate these changes or prevent them recovering, especially calcineurin antagonist drugs which are key immunosuppressing agents. This results in the reduction of VO2peak despite restoration of near normal function of the initially failing organ system. As such organ transplantation has provided an experiment of nature that has focused our attention on an important confounder of chronic organ failure-skeletal muscle dysfunction.

Reduced functional measure of cardiovascular reserve predicts admission to critical care unit following kidney transplantation

BACKGROUND

There is currently no effective preoperative assessment for patients undergoing kidney transplantation that is able to identify those at high perioperative risk requiring admission to critical care unit (CCU). We sought to determine if functional measures of cardiovascular reserve, in particular the anaerobic threshold (VO₂AT) could identify these patients.

METHODS

Adult patients were assessed within 4 weeks prior to kidney transplantation in a University hospital with a 37-bed CCU, between April 2010 and June 2012. Cardiopulmonary exercise testing (CPET), echocardiography and arterial applanation tonometry were performed.

RESULTS

There were 70 participants (age 41.7±14.5 years, 60% male, 91.4% living donor kidney recipients, 23.4% were desensitized). 14 patients (20%) required escalation of care from the ward to CCU following transplantation. Reduced anaerobic threshold (VO₂AT) was the most significant predictor, independently (OR = 0.43; 95% CI 0.27-0.68; p<0.001) and in the multivariate logistic regression analysis (adjusted OR = 0.26; 95% CI 0.12-0.59; p = 0.001). The area under the receiver-operating-characteristic curve was 0.93, based on a risk prediction model that incorporated VO₂AT, body mass index and desensitization status. Neither echocardiographic nor measures of aortic compliance were significantly associated with CCU admission.

CONCLUSIONS

To our knowledge, this is the first prospective observational study to demonstrate the usefulness of CPET as a preoperative risk stratification tool for patients undergoing kidney transplantation. The study suggests that VO₂AT has the potential to predict perioperative morbidity in kidney transplant recipients.

Change in body compositions of Asian recipients after kidney transplantation

Kidney transplantation and accompanying medical conditions may result in changes in body composition. Such changes have been evaluated in Caucasian recipients, but not in Asian recipients. Herein, we conducted a study on Asian recipients because Asians have a different body composition from Caucasians. A total of 50 Asian recipients was enrolled as a prospective cohort. Using bioelectrical impedance analysis, body composition (muscle and fat mass) was assessed after 2 weeks (baseline), and at 1, 3, 6, 9, and 12 months following kidney transplantation. To find predictors related to changes, the data were analyzed by multivariate analysis using forward selection. All of the patients had good graft function during the study period. Patients gained approximately 3 kg within 1 yr of kidney transplantation. The proportion of muscle mass significantly decreased (P(trend) = 0.001) and the proportion of fat mass significantly increased over time (P(trend) = 0.002). The multivariate results revealed that male recipients, deceased donor type, and low protein intake were associated with an increase in fat mass and a decrease in muscle mass. The results from this study may help to investigate differences in body composition changes between races, as well as the factors related to these changes.

Percentages of water, muscle, and bone decrease and lipid increases in early period after successful kidney transplantation: a body composition analysis

BACKGROUND

Successful kidney transplantation (KT) can theoretically reconstitute body composition of a patient with chronic kidney disease (CKD). However, the practical changes have not been well documented. We evaluated changes in body composition among candidates before and 1 year after KT.

METHODS

We enrolled 37 male and 18 female kidney recipients eligible for comparison of their body mass index (BMI), body composition, and lipid metabolism before and 1 year after KT. Twenty-one patients had been induced with a calcineurin inhibitor, mycophenolate mofetil, steroid, and basiliximab, and 34 others underwent steroid withdrawal on postoperative day 3. The body composition was analyzed using bioelectrical impedance. We also analyzed changes in BMI and lipid profiles.

RESULTS

There was no significant change in BMI (21.4 ± 3.1 vs 21.7 ± 3.5 kg/m(2)). Regarding body composition, the water level decreased significantly (61.2 ± 4.9% vs 58.3 ± 5.3%; P < .05). In contrast, fat significantly increased (16.4 ± 6.7% vs 20.3 ± 7.1%; P < .05). More interestingly, successful KT significantly decreased the muscle and bone mass at 1 year after KT (37.3 ± 5.1% vs 34.8 ± 4.7%; 16.3 ± 2.1% vs 15.2 ± 2.1%; respectively; P < .05). Serum lipid profiles of total cholesterol, low-density lipoprotein cholesterol, and triglyceride worsened after KT. Comparing the 2 protocols, there was no difference in any item.

CONCLUSIONS

Care must be taken even after successful KT to avoid dyslipidemia, which is a risk factor for cardiovascular disease. Well programmed dietary and/or exercise protocols to prevent muscle atrophy and fat gain should be considered even after successful KT.

Pharmacokinetics of tacrolimus according to body composition in recipients of kidney transplants

Background

Currently, the dosage of tacrolimus used after transplantation is based on the patient's body weight. However, there is a low correlation between body weight and body composition in kidney transplant recipients. In this study, we evaluate the pharmacokinetics of tacrolimus according to body composition in 18 Korean kidney transplant recipients with stable graft function.

Methods

Body composition parameters were calculated using bioelectrical impedance analysis. Pharmacokinetic profiles were determined 0, 1, 2, 3, and 4 hours after treatment with tacrolimus and were compared between high- and low-level median body composition groups. The values of C₀, C₁, C₂, C₃, and C₄ were used in determining an abbreviated area under the curve (AUC) for tacrolimus.

Results

The mean body mass index (BMI) and body composition values were as follows: BMI, 24.3 kg/m²; lean mass, 49.8 kg; and fat mass, 17.4 kg. There were no statistical differences in pharmacokinetic profiles between groups with different BMIs. However, the C₀ and C₄ in the high-fat group were significantly elevated compared with those of the low-fat group (P=0.024 and 0.031, respectively). Furthermore, the C₀, C₂, C₃, and C₄ and the AUC were significantly different between the two lean mass groups (P=0.007, 0.038, 0.047, 0.015, and 0.015, respectively). Other variables, such as waist circumference and arm muscle circumference, did not differentiate between the pharmacokinetic profiles of tacrolimus.

Conclusion

Taken together, these data suggest that tacrolimus dose monitoring based on body composition may provide adequate dosage leading to favorable long-term outcomes.

Leptin, insulin resistance, and metabolic changes 5 years after renal transplantation

OBJECTIVE

To evaluate leptin, insulin resistance (IR), and changes in body composition and lipid profile within 5 years after renal transplantation.

DESIGN

Longitudinal study.

SETTING

Hospital de Clínicas de Porto Alegre/RS, Brazil.

SUBJECTS

Thirty-two renal transplant recipients were followed up for 5 years after transplantation.

METHODS

Data were collected at transplantation time (T₁) and after 3 months (T₂), 1 year (T₃), and 5 years (T₄). Leptin serum levels, IR assessed by homeostasis model assessment (HOMA) index, lipid profile, and anthropometric measurements were analyzed. Data were compared with a control group at baseline.

RESULTS

At T₁, pretransplant patients had leptin levels (ng/mL) (11.9 [9.2 to 25.2]) higher than the control group (7.7 [5.2 to 9.9]; P < .0001). After transplantation, levels decreased at T₂ and T₃, but increased at T₄ to values similar to those seen at T₁ (T₄: 9.2 [5.7 to 21]; P = 1). HOMA also decreased at T₂, but increased at T₄ to identical levels (T₁: 2.1 [1.63 to 2.23], T₄: 2.1 [1.6 to 2.85]; P = 1). No significant changes in body fat percentage (BF%) were observed; however, the arm muscle circumference increased significantly at T₄ (P < .0001). At T₂, total cholesterol, triglycerides, and low-density lipoprotein cholesterol increased, whereas at T₄, lipid profile moved toward T₁ levels. By linear regression analysis, gender, BF%, and HOMA were independent predictors of leptin levels. A trend toward higher body mass index was observed in woman who also presented higher leptin and lower HOMA levels.

CONCLUSION

Leptin levels and HOMA decrease in the immediate posttransplant period and remain reduced for at least 1 year. Five years post transplantation, leptin, IR, BF%, and lipids have a profile similar to those in the pretransplant period. This metabolic profile is possibly associated with the elevated incidence of cardiovascular diseases observed in the late posttransplant period.

Exercise training for adults with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a worldwide public health problem. In the National Kidney Foundation Disease Outcomes Quality Initiative guidelines it is stressed that lifestyle issues such as physical activity should be seen as cornerstones of the therapy. The physical fitness in adults with CKD is so reduced that it impinges on ability and capacity to perform activities in everyday life and occupational tasks. An increasing number of studies have been published regarding health effects of various regular exercise programmes in adults with CKD and in renal transplant patients.

OBJECTIVES

We aimed to: 1) assess the effects of regular exercise in adults with CKD and kidney transplant patients; and 2) determine how the exercise programme should be designed (e.g. type, duration, intensity, frequency of exercise) to be able to affect physical fitness and functioning, level of physical activity, cardiovascular dimensions, nutrition, lipids, glucose metabolism, systemic inflammation, muscle morphology and morphometrics, dropout rates, compliance, adverse events and mortality.

SEARCH STRATEGY

We searched the Cochrane Renal Group's specialised register, CENTRAL, MEDLINE, EMBASE, CINAHL, Web of Science, Biosis, Pedro, Amed, AgeLine, PsycINFO and KoreaMed. We also handsearched reference lists of review articles and included studies, conference proceeding's abstracts. There were no language restrictions.Date of last search: May 2010.

SELECTION CRITERIA

We included any randomised controlled trial (RCT) enrolling adults with CKD or kidney transplant recipients undergoing any type of physical exercise intervention undertaken for eight weeks or more. Studies using less than eight weeks exercise, those only recommending an increase in physical activity, and studies in which co-interventions are not applied or given to both groups were excluded.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of study and data quality were performed independently by the two authors. Continuous outcome data are presented as standardised mean difference (SMD) or mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

Forty-five studies, randomising 1863 participants were included in this review. Thirty two studies presented data that could be meta-analysed. Types of exercise training included cardiovascular training, mixed cardiovascular and resistance training, resistance-only training and yoga. Some studies used supervised exercise interventions and others used unsupervised interventions. Exercise intensity was classed as 'high' or 'low', duration of individual exercise sessions ranged from 20 minutes/session to 110 minutes/session, and study duration was from two to 18 months. Seventeen per cent of studies were classed as having an overall low risk of bias, 33% as moderate, and 49% as having a high risk of bias.The results shows that regular exercise significantly improved: 1) physical fitness (aerobic capacity, 24 studies, 847 participants: SMD -0.56, 95% CI -0.70 to -0.42; walking capacity, 7 studies, 191 participants: SMD -0.36, 95% CI-0.65 to -0.06); 2) cardiovascular dimensions (resting diastolic blood pressure, 11 studies, 419 participants: MD 2.32 mm Hg, 95% CI 0.59 to 4.05; resting systolic blood pressure, 9 studies, 347 participants: MD 6.08 mm Hg, 95% CI 2.15 to 10.12; heart rate, 11 studies, 229 participants: MD 6 bpm, 95% CI 10 to 2); 3) some nutritional parameters (albumin, 3 studies, 111 participants: MD -2.28 g/L, 95% CI -4.25 to -0.32; pre-albumin, 3 studies, 111 participants: MD - 44.02 mg/L, 95% CI -71.52 to -16.53; energy intake, 4 studies, 97 participants: SMD -0.47, 95% CI -0.88 to -0.05); and 4) health-related quality of life. Results also showed how exercise should be designed in order to optimise the effect. Other outcomes had insufficient evidence.

AUTHORS' CONCLUSIONS

There is evidence for significant beneficial effects of regular exercise on physical fitness, walking capacity, cardiovascular dimensions (e.g. blood pressure and heart rate), health-related quality of life and some nutritional parameters in adults with CKD. Other outcomes had insufficient evidence due to the lack of data from RCTs. The design of the exercise intervention causes difference in effect size and should be considered when prescribing exercise with the aim of affecting a certain outcome. Future RCTs should focus more on the effects of resistance training interventions or mixed cardiovascular- and resistance training as these exercise types have not been studied as much as cardiovascular exercise.