Frailty and Sarcopenia in Older Patients Receiving Kidney Transplantation

Perioperative Considerations in Older Kidney and Liver Transplant Recipients: A Review

With the growth of the older adult population, the number of older adults waitlisted for and undergoing kidney and liver transplantation has increased. Transplantation is an important and definitive treatment for this population. We present a contemporary review of the unique preoperative, intraoperative, and postoperative issues that patients older than 65 y face when they undergo kidney or liver transplantation. We focus on geriatric syndromes that are common in older patients listed for kidney or liver transplantation including frailty, sarcopenia, and cognitive dysfunction; discuss important considerations for older transplant recipients, which may impact preoperative risk stratification; and describe unique challenges in intraoperative and postoperative management for older patients. Intraoperative challenges in the older adult include using evidence-based best anesthetic practices, maintaining adequate perfusion pressure, and using minimally invasive surgical techniques. Postoperative concerns include controlling acute postoperative pain; preventing cardiovascular complications and delirium; optimizing immunosuppression; preventing perioperative kidney injury; and avoiding nephrotoxicity and rehabilitation. Future studies are needed throughout the perioperative period to identify interventions that will improve patients' preoperative physiologic status, prevent postoperative medical complications, and improve medical and patient-centered outcomes in this vulnerable patient population.

Sarcopenia is associated with survival in patients awaiting kidney transplant

BACKGROUND

The relationship of sarcopenia to frailty and other survival determinants in patients waitlisted for kidney transplant is not well characterized. Our goal was to evaluate the relationship of muscle area to functional and frailty metrics and its impact on survival in patients waitlisted for kidney transplant.

METHODS

Among 303 consecutively listed transplant candidates, 172 had a computed scan within 3 months of frailty and biochemical testing that permitted muscle area evaluation. Third lumbar level psoas muscle indices (total bilateral psoas area/height2) were calculated. Testing included frailty metrics, treadmill and pedometer ability, troponin, and brain natriuretic peptide levels. Associations between muscle area, demographic, biochemical, and frailty measures were analyzed. Log-rank test was used to evaluate waitlist survival on the basis of muscle area, and multivariate Cox proportional hazards modeling was used to evaluate factors independently associated with survival.

RESULTS

Demographic factors associated with third lumbar level psoas muscle indices include male sex (P < .001), race (P = .02), age (P = .004), and body mass index (P < .0001). Grip strength, treadmill ability, and Sit-Stands positively correlated with third lumbar level psoas muscle indices (P < .01). Brain natriuretic peptide and Up and Go negatively correlated with third lumbar level psoas muscle indices (P < .01). Survival was significantly associated with third lumbar level psoas muscle indices (P = 0.02). Treadmill ability, Sit-Stands, Up and Go, race and muscle area were most closely associated with waitlist survival on multivariate modeling.

CONCLUSION

Sarcopenia as assessed with muscle area measurements is independently associated with kidney waitlist survival. Functional ability and muscle area may be overlapping, but noncongruent, determinants of waitlist outcomes and may need to be individually assessed to create the most predictive survival model.

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.

Complex management and descriptive cost analysis of kidney transplant candidates: a descriptive cross-sectional study

BACKGROUND

The organisational care needs involved in accessing kidney transplant have not been described in the literature and therefore a detailed analysis thereof could help to establish a framework (including appropriate timing, investment, and costs) for the management of this population. The main objective of this study is to analyse the profile and care needs of kidney transplant candidates in a tertiary hospital and the direct costs of studying them.

METHODS

A descriptive, cross-sectional study was conducted using data on a range of variables (sociodemographic and clinical characteristics, study duration, and investment in visits and supplementary tests) from 489 kidney transplant candidates evaluated in 2020.

RESULTS

The comorbidity index was high (> 4 in 64.3%), with a mean of 5.6 ± 2.4. Part of the study population had certain characteristics that could hinder their access a kidney transplant: physical dependence (9.4%), emotional distress (33.5%), non-adherent behaviours (25.2%), or language barriers (9.4%). The median study duration was 6.6[3.4;14] months. The ratio of required visits to patients was 5.97:1, meaning an investment of €237.10 per patient, and the ratio of supplementary tests to patients was 3.5:1, meaning an investment of €402.96 per patient.

CONCLUSIONS

The study population can be characterised as complex due to their profile and their investment in terms of time, visits, supplementary tests, and direct costs. Management based on our results involves designing work-adaptation strategies to the needs of the study population, which can lead to increased patient satisfaction, shorter waiting times, and reduced costs.

Prevalence of Musculoskeletal and Metabolic Disorders in Kidney Transplant Recipients: A Systematic Review and Meta-Analysis

Introduction

Musculoskeletal disorders could be associated with metabolic disorders that are common after kidney transplantation, which could reduce the quality of life of patients. The aim of this study was to assess the prevalence of both musculoskeletal and metabolic disorders in kidney transplant patients.

Methods

MEDLINE, CINAHL, Cochrane Library, EMBASE and Web of Science were searched from their inception up to June 2023. DerSimonian and Laird random-effects method was used to calculate pooled prevalence estimates and their 95% confidence intervals (CIs).

Results

21,879 kidney transplant recipients from 38 studies were analysed. The overall proportion of kidney transplant patients with musculoskeletal disorders was 27.2% (95% CI: 18.4-36.0), with low muscle strength (64.5%; 95% CI: 43.1-81.3) being the most common disorder. Otherwise, the overall proportion of kidney transplant patients with metabolic disorders was 37.6% (95% CI: 21.9-53.2), with hypovitaminosis D (81.8%; 95% CI: 67.2-90.8) being the most prevalent disorder.

Conclusion

The most common musculoskeletal disorders were low muscle strength, femoral osteopenia, and low muscle mass. Hypovitaminosis D, hyperparathyroidism, and hyperuricemia were also the most common metabolic disorders. These disorders could be associated with poorer quality of life in kidney transplant recipients.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier [CRD42023449171].

Abdominal computed tomography measurements of body composition and waitlist mortality in kidney transplant candidates

Body mass index is often used to determine kidney transplant (KT) candidacy. However, this measure of body composition (BC) has several limitations, including the inability to accurately capture dry weight. Objective computed tomography (CT)-based measures may improve pre-KT risk stratification and capture physiological aging more accurately. We quantified the association between CT-based BC measurements and waitlist mortality in a retrospective study of 828 KT candidates (2010-2022) with clinically obtained CT scans using adjusted competing risk regression. In total, 42.5% of candidates had myopenia, 11.4% had myopenic obesity (MO), 68.8% had myosteatosis, 24.8% had sarcopenia (probable = 11.2%, confirmed = 10.5%, and severe = 3.1%), and 8.6% had sarcopenic obesity. Myopenia, MO, and sarcopenic obesity were not associated with mortality. Patients with myosteatosis (adjusted subhazard ratio [aSHR] = 1.62, 95% confidence interval [CI]: 1.07-2.45; after confounder adjustment) or sarcopenia (probable: aSHR = 1.78, 95% CI: 1.10-2.88; confirmed: aSHR = 1.68, 95% CI: 1.01-2.82; and severe: aSHR = 2.51, 95% CI: 1.12-5.66; after full adjustment) were at increased risk of mortality. When stratified by age, MO (aSHR = 2.21, 95% CI: 1.28-3.83; P interaction = .005) and myosteatosis (aSHR = 1.95, 95% CI: 1.18-3.21; P interaction = .038) were associated with elevated risk only among candidates <65 years. MO was only associated with waitlist mortality among frail candidates (adjusted hazard ratio = 2.54, 95% CI: 1.28-5.05; P interaction = .021). Transplant centers should consider using BC metrics in addition to body mass index when a CT scan is available to improve pre-KT risk stratification at KT evaluation.

Malnutrition risk, outcomes, and costs among older adults undergoing elective surgical procedures: A retrospective cohort study

BACKGROUND

We examine here the association between malnutrition risk and adverse health outcomes among older adult patients undergoing elective surgical procedures.

METHODS

We conducted a retrospective study using linked clinical and administrative databases. Malnutrition risk was assessed prior to surgery, defined by unintentional weight loss and decreased food intake. We performed a logistic regression analysis of the primary outcome, a composite adverse outcome measure, including death, bleeding, pneumonia, and other surgical complications. We conducted Fine-Gray proportional hazard regression analysis of hospital length of stay (LOS). We performed a generalized linear regression analysis of in-hospital cost data. All regression analyses controlled for frailty, age, sex, surgical category, and comorbidities.

RESULTS

Of a total of 3457 older adult elective surgical patients (65-102 years), 310 (9.0%) screened positive for malnutrition risk. In multivariable regression analyses, malnutrition risk was associated with an increased risk of the composite adverse outcome (odds ratio [OR] = 1.74; 95% CI = 1.25-2.39), higher hospitalization costs (relative cost = 1.84; 95% CI = 1.59-2.13), and a decreased risk of discharge from the hospital (hazard ratio = 0.67; 95% CI = 0.59-0.77) compared with those who screened negative.

CONCLUSION

Older adult patients with malnutrition risk were at an increased risk of adverse surgical outcomes, had longer LOS in the hospital, and incurred higher costs of care. It is important to screen for malnutrition risk and refer older adults for dietetic consults prior to elective surgery.

[Frailty and chronic kidney disease - the real problem of modern nephrology: A review]

The article deals with the syndrome of frailty or senile asthenia in patients with chronic kidney disease. The questions of prevalence, diagnosis, pathogenesis of this syndrome and its clinical consequences in chronic kidney disease are discussed.

Frailty in kidney transplant candidates and recipients: pathogenesis and intervention strategies

ABSTRACT

With the rapid aging of the global population posing a serious problem, frailty, a non-specific state that reflects physiological senescence rather than aging in time, has become more widely addressed by researchers in various medical fields. A high prevalence of frailty is found among kidney transplant (KT) candidates and recipients. Therefore, their frailty has become a research hotspot in the field of transplantation. However, current studies mainly focus on the cross-sectional survey of the incidence of frailty among KT candidates and recipients and the relationship between frailty and transplantation. Research on the pathogenesis and intervention is scattered, and relevant review literature is scarce. Exploring the pathogenesis of frailty in KT candidates and recipients and determining effective intervention measures may reduce waiting list mortality and improve the long-term quality of life of KT recipients. Therefore, this review explains the pathogenesis and intervention measures for frailty in KT candidates and recipients to provide a reference for the formulation of effective intervention strategies.

Factors associated with frailty in kidney transplant recipients: A cross-sectional study

BACKGROUND

Frailty is prevalent in kidney transplant recipients and associated with multiple health care challenges. The association between frailty and outcomes has been extensively studied in kidney transplant recipients, but the status of frailty and its associated factors are not well studied, hindering efforts to develop strategies to improve care and reduce frailty.

OBJECTIVES

To identify the factors that are associated with frailty in kidney transplant recipients comprehensively.

DESIGN AND PARTICIPANTS

The associated factors of frailty were explored by a cross-sectional study of 185 kidney transplant recipients.

MEASUREMENTS

Data were collected using the general information questionnaire, the Charlson comorbidity index, the Pittsburgh Sleep Quality Index, the Hospital Anxiety and Depression Scale, the Connor-Davidson Resilience Scale, the Perceived Social Support Scale and the Tilburg Frailty Indicator. Data were analyzed using the multiple linear regression analysis.

RESULTS

A total of 75 (40.5%) kidney transplant recipients were assessed as frail by Chinese TFI. Age (β = 0.228), time post-transplant (β = 0.055), sleep quality (β = 0.224) and psychological resilience (β = -0.038) entered the final multiple regression equation and accounted for 41.8% of the total frailty variation (R²  = 0.418, F = 21.31, p < 0.05).

CONCLUSIONS

Frailty was common among kidney transplant recipients. Old age, long time after transplantation, poor sleep quality and low psychological resilience were main associated factors for frailty. Integrated care interventions are therefore needed for this vulnerable population to prevent or delay frailty.

Sarcopenia of kidney transplant recipients as a predictive marker for reduced graft function and graft survival after kidney transplantation

PURPOSE

The association between sarcopenia of kidney transplant recipients and outcome after kidney transplantation (KT) has not yet been fully understood and is still considered controversial. The aim of our study was to analyze the impact of pre-transplant sarcopenia on graft function, postoperative complication rates, and survival of the patients after renal transplantation.

METHODS

In this retrospective single-center study, all patients who underwent KT (01/2013-12/2017) were included. Demographic data, rejection rates, delayed graft function, and graft and patient survival rates were analyzed. Sarcopenia was measured in computed tomography images by the sex-adjusted Hounsfield unit average calculation (HUAC).

RESULTS

During the study period, 111 single KTs (38 women and 73 men) were performed. Living donor kidney transplants were performed in 48.6%. In total, 32.4% patients had sarcopenia. Sarcopenic patients were significantly older (59.6 years vs. 49.8 years; p < 0.001), had a higher body mass index (BMI = 27.6 kg/m2 vs. 25.0 kg/m2; p = 0.002), and were more likely to receive deceased donor kidneys (72.2% vs. 41.3%; p = 0.002). Interestingly, 3 years after KT, the creatinine serum levels were significantly higher (2.0 mg/dl vs. 1.5 mg/dl; p = 0.001), whereas eGFR (39.9 ml/min vs. 53.4 ml/min; p = 0.001) and graft survival were significantly lower (p = 0.004) in sarcopenic transplant recipients. Sarcopenic patients stayed in hospital significantly longer postoperatively than those who were non-sarcopenic.

CONCLUSIONS

At the time of kidney transplantation, sarcopenia was found to predict reduced long-term graft function and diminished graft survival after KT. The early identification of sarcopenic patients can not only enable an optimized selection of recipients, but also the initiation of pre-habilitation programs during the waiting period.

Diagnosis, prevalence, and outcomes of sarcopenia in kidney transplantation recipients: A systematic review and meta-analysis

The prevalence of sarcopenia and its clinical predictors and clinical impact vary among kidney transplant recipients (KTRs), in part because of different diagnostic criteria. This study aimed to assess the reported diagnosis criteria of sarcopenia and compare them in terms of prevalence, clinical predictors, and impact of sarcopenia. The Medline, Embase, and Cochrane Library were searched for the full-length reports published until 28 January 2022. The subgroup analysis, meta-regression, and sensitivity analysis were performed and heterogeneity was assessed using the I² . A total of 681 studies were retrieved, among which only 23 studies (including 2535 subjects, 59.7% men, mean age 49.8 years) were eventually included in the final analysis. The pooled prevalence in these included studies was 26% [95% confidence interval (95% CI): 20-34%, I²  = 93.45%], including 22% (95% CI: 14-32%, I²  = 88.76%) in men and 27% (95% CI: 14-41%, I²  = 90.56%) in women (P = 0.554 between subgroups). The prevalence of sarcopenia diagnosed using low muscle mass was 34% (95% CI: 21-48%, I²  = 95.28%), and the prevalence of using low muscle mass in combination with low muscle strength and/or low physical performance was 21% (95% CI: 15-28%, I²  = 90.37%) (P = 0.08 between subgroups). In meta-regression analyses, the mean age (regression coefficient: 1.001, 95% CI: 0.991-1.011) and percentage male (regression coefficient: 0.846, 95% CI: 0.367-1.950) could not predict the effect size. Lower body mass index (odds ratio (OR): 0.57, 95% CI: 0.39-0.84, I²  = 61.5%), female sex (OR: 0.31, 95% CI: 0.16-0.61, I²  = 0.0%), and higher age (OR: 1.08, 95% CI: 1.05-1.10, I²  = 10.1%) were significantly associated with a higher risk for sarcopenia in KTRs, but phase angle (OR: 0.81, 95% CI: 0.16-4.26, I²  = 84.5%) was not associated with sarcopenia in KTRs. Sarcopenia was not associated with rejections (risk ratio (RR): 0.67, 95% CI: 0.23-1.92, I²  = 12.1%), infections (RR: 1.03, 95% CI: 0.34-3.12, I²  = 87.4%), delayed graft functions (RR: 0.81, 95% CI: 0.46-1.43, I²  = 0.0%), and death (RR: 0.95, 95% CI: 0.32-2.82, I²  = 0.0%) in KRTs. Sarcopenia was found to be very common in KRTs. However, we have not found that sarcopenia had a negative impact on clinical health after kidney transplantation. Large study cohorts and multicentre longitudinal studies in the future are urgently needed to explore the prevalence and prognosis of sarcopenia in kidney transplant patients.

Acute Sarcopenia after Elective and Emergency Surgery

Sarcopenia is an increasingly recognised condition of loss of muscle mass and function. The European Working Group on Sarcopenia in Older People 2 (EWSOP2) updated their definition in 2018, emphasising the importance of low muscle strength in diagnosis. Acute sarcopenia has been arbitrarily defined as sarcopenia lasting less than 6 months. This review highlights the pathophysiology involved in muscle wasting following surgery, focussing on hormonal factors, inflammation, microRNAs, and oxidative stress. Biomarkers such as GDF-15, IGF-1 and various microRNAs may predict post-surgical muscle loss. The impact of existing sarcopenia on various types of surgery and incident muscle wasting following surgery is also described. The gaps in research found include the need for longitudinal studies looking in changes in muscle strength and quantity following surgery. Further work is needed to examine if biomarkers are replicated in other surgery to consolidate existing theories on the pathophysiology of muscle wasting.

Exploring the lived experience of renal cachexia for individuals with end-stage renal disease and the interrelated experience of their carers: Study protocol

Renal cachexia is an important consideration in the person-centred care that is needed in end-stage renal disease (ESRD). However, given that clinical guidelines relating to renal cachexia are largely absent, this is an unmet care need. To inform guidelines and future renal service planning, there is an urgency to understand individuals’ experiences of renal cachexia and the interrelated experiences of the carers in their lives. We report here the protocol for an interpretative phenomenological study which will explore this lived experience. A purposive sampling strategy will recruit individuals living with ESRD who have cachexia and their carers. A maximum of 30 participants (15 per group) dependent on saturation will be recruited across two nephrology directorates, within two healthcare trusts in the United Kingdom. Individuals with renal cachexia undergoing haemodialysis will be recruited via clinical gatekeepers and their carers will subsequently be invited to participate in the study. Participants will be offered the opportunity to have a face-to-face, virtual or telephone interview. Interviews will be audio-recorded, transcribed verbatim and analysed using interpretative phenomenological analysis. NVivo, will be used for data management. Ethical approval for this study was granted by the Office for Research Ethics Committees Northern Ireland (REC Reference: 22/NI/0107). Scientific evidence tends to focus on measurable psychological, social and quality of life outcomes but there is limited research providing in-depth meaning and understanding of the views of individuals with renal disease who are experiencing renal cachexia. This information is urgently needed to better prepare healthcare providers and in turn support individuals with ESRD and their carers. This study will help healthcare providers understand what challenges individuals with ESRD, and their carers face in relation to cachexia and aims to inform future clinical practice guidelines and develop supportive interventions which recognise and respond to the needs of this population.

Frailty in kidney transplantation: a review on its evaluation, variation and long-term impact

The problem of frailty in kidney transplantation is an increasingly discussed topic in the transplant field, partially also generated by the multiple comorbidities by which these patients are affected. The criteria currently used to establish the presence and degree of frailty can be rapidly assessed in clinical practice, even in patients with chronic kidney disease (CKD). The main objectives of this work are: (i) to describe the method of evaluation and the impact that frailty has in patients affected by CKD, (ii) to explore how frailty should be studied in the pre-transplant evaluation, (iii) how frailty changes after a transplant and (iv) the impact frailty has over the long term on the survival of renal transplant patients.

Neutrophil-lymphocyte Ratio and C-Reactive Protein Levels are not Associated with Strength, Muscle Mass, and Functional Capacity in Kidney Transplant Patients

Chronic inflammation has been associated with components of sarcopenia; however, these associations are unknown in kidney transplant patients (KTPs). The aim of this study was to associate neutrophil-lymphocyte ratio (NLR) and C-reactive protein (CRP) with strength, muscle mass, and functional capacity in KTPs. A cross-sectional study evaluating 108 KTPs was performed. Strength was evaluated by handgrip strength and five-times-sit-to-stand test (5STS), and appendicular skeletal muscle mass (ASM) was estimated by bioelectrical impedance analysis. The ASM index (ASMI) was calculated using the ASM (kg)/height (m²). Functional capacity was assessed by the 4-m gait speed test and short physical performance battery (SPPB). The electrochemiluminescence method was used for analyzing CRP levels, and the cytometric method XN-3000 Sysmex was used for obtaining leukogram values to calculate the NLR. Linear regression analysis was used to assess the association between systemic inflammation and sarcopenia components, adjusting for confounders. NLR and CRP levels were not associated with handgrip strength (β =  - 0.231, p = 0.389; β =  - 0.291, p = 0.577), 5STS (β =  - 0.114, p = 0.288; β =  - 0.202, p = 0.334), ASM (β =  - 0.027, p = 0.813; β = 0.062, p = 0.788), ASMI (β =  - 0.036, p = 0.242; β = 0.040, p = 0.505), 4-m gait speed (β = 0.013, p = 0.082; β = 0.004, p = 0.769), and SPPB (β = 0.076, p = 0.170; β = 0.152, p = 0.157), respectively. In conclusion, NLR and CRP levels were not associated with muscle mass, strength, and functional capacity in KTPs.

Trade-Off Between Maximal Power Output and Fatigue Resistance of the Knee Extensors for Older Men

This study investigated associations of fatigue resistance determined by an exercise-induced decrease in neuromuscular power with prefatigue neuromuscular strength and power of the knee extensors in 31 older men (65-88 years). A fatigue task consisted of 50 consecutive maximal effort isotonic knee extensions (resistance: 20% of prefatigue isometric maximal voluntary contraction torque) over a 70° range of motion. The average of the peak power values calculated from the 46th to 50th contractions during the fatigue task was normalized to the prefatigue peak power value, which was defined as neuromuscular fatigue resistance. Neuromuscular fatigue resistance was negatively associated with prefatigue maximal power output (r = -.530) but not with prefatigue maximal voluntary contraction torque (r = -.252). This result highlights a trade-off between prefatigue maximal power output and neuromuscular fatigue resistance, implying that an improvement in maximal power output might have a negative impact on neuromuscular fatigue resistance.

Revision of frailty assessment in kidney transplant recipients: Replacing unintentional weight loss with CT-assessed sarcopenia in the physical frailty phenotype

Kidney transplantation (KT) experts did not support the use of subjective unintentional weight loss to measure shrinking in the physical frailty phenotype (PFP); a clinically feasible and predictive measure of shrinking is needed. To test whether unintentional weight loss could be replaced by an assessment of sarcopenia using existing CT scans, we performed a prospective cohort study of adult KT recipients with original PFP (oPFP) measured at admission (December 2008-February 2020). We ascertained sarcopenia by calculating skeletal muscle index from available, clinically obtained CTs within 1-year pre-KT (male < 50 cm² /m² ; female < 39 cm² /m² ) and combined it with the original four components to determine new PFP (nPFP) scores. Frailty was classified by frailty score: 0: non-frail; 1-2: pre-frail; ≥3: frail. Mortality and graft loss hazard ratios (HRs) were estimated using adjusted Cox proportional hazard models. Model discrimination was quantified using Harrell's C-statistic. Among 1113 recipients, 18.6% and 17.1% were frail by oPFP and nPFP, respectively. Compared to non-frail recipients, frail patients by either PFP had higher risks of mortality (oPFP HR = 1.67, 95% CI: 1.07-2.62, C = 0.710; nPFP HR = 1.68, 95% CI: 1.06-2.66, C = 0.710) and graft loss (oPFP HR = 1.67, 95% CI: 1.17-2.40, C = 0.631; nPFP HR = 1.66, 95% CI: 1.15-2.40, C = 0.634) with similar discriminations. oPFP and nPFP are equally useful in risk prediction for KT recipients; oPFP may aid in screening patients for pre-KT interventions, while nPFP may assist in nuanced clinical decision-making.

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.

Validation of the functional assessment of anorexia/cachexia therapy instrument to assess quality of life in maintenance hemodialysis patients with cachexia

BACKGROUND

Many patients on maintenance hemodialysis (MHD) eventually suffer from cachexia. The Functional Assessment of Anorexia/Cachexia Therapy (FAACT) is a tool used to evaluate the quality of life of patients with cachexia related to various diseases, but its suitability for use in MHD patients has yet to be verified. This study aimed to explore the validation of the FAACT in MHD patients by conducting reliability and validity tests.

METHODS

Qualified MHD patients were selected to complete the FAACT and Kidney Disease Quality of Life Short Form 36 (KDQOL-36) questionnaires, and their demographic data and biochemical test results were collected from electronic medical records. Next, the Cronbach's alpha coefficient, paired sample t test and ICC were used to analyze the scale consistency. Additionally, the association between the KDQOL-36 and FAACT was analyzed using Bland-Altman plots and Pearson correlation analysis. Finally, the patients were divided into groups to evaluate discriminant validity.

RESULTS

A total of 299 patients were included in this study. The Cronbach's alpha coefficients of the FAACT and its anorexia-cachexia subscale (ACS) were 0.904 and 0.842, respectively, and their ICC exceeded 0.90. The correlation coefficients between the FAACT and its items ranged from 0.146 to 0.631, and the correlation coefficients between the FAACT and KDQOL-36 dimensions ranged from 0.446 to 0.617. The Bland-Altman plots between the FAACT and KDQOL-36 showed that only 3.3% of the points were outside the 95% limits of agreement. The effects of cachexia status (present or absent) on FAACT and ACS scores had effect sizes of 0.54 (P < 0.001) and 0.60 (P < 0.001), respectively. The FAACT and ACS also significantly discriminated between patients with and without inflammation (P < 0.001).

CONCLUSIONS

The FAACT and ACS have acceptable reliability and validity in MHD patients and are suitable for measuring the quality of life of MHD patients with cachexia.

Impact of kidney transplantation on functional status

BACKGROUND AND AIMS

Functional capacity (FC) is known to affect morbidity and mortality in kidney transplantation. Despite this important role, little is known about the variables influencing post-transplant FC. Our study aims at identifying these crucial associations.

METHOD

Our study included 16,684 renal transplant recipients (RTR). Patients had transplant between 1 September 2018 and 1 September 2019. Mild functional impairment was defined as those with a KPSS score > or = 80; moderate functional impairment was defined as those with a KPSS score between 50 and 70 and severe functional impairment was defined as those with a KPSS score < or =40. The outcome measured was FC at follow-up one-year post-transplant. Abnormal FC at follow-up was defined as those with KPSS score less than 80%. Normal FC at follow-up was defined as those with KPSS score equal or above 80%. Multivariate logistic regression was used to assess with the relationship between patient characteristics and abnormal functional status post-transplant.

RESULTS

Three groups were identified; those with none-to-mild functional impairment at time of transplant (Group A; n = 8388), those who had moderate impairment at time of transplant (Group B; n = 7694) and those who had severe impairment at time of transplant (Group C; n = 602). Abnormal FC at one-year post transplant was present in 7.69%, 28.89%, 49.49% of patients in group A, B and C, respectively. Glucocorticoid withdrawal was associated with lower risk of developing abnormal FC post-transplant (OR = 0.75, p value = .02, 95% confidence intervals: 0.64 to 0.97), while recipient diabetes was associated with higher risk of abnormal FC (OR = 1.44, p value <.01, 95% confidence intervals: 1.20 to 1.74) in adjusted model.

CONCLUSION

Kidney transplantation is associated with substantial improvement in all stages of FC in KTRs. Glucocorticoid withdrawal and diabetes mellitus are potentially modifiable factors of FC and merit further considerations during pre-transplant workup and post-transplant immunosuppressive therapeutic planning.Key messagesKidney transplantation is associated with substantial improvement in all stages of FC in KTRs.Glucocorticoid withdrawal and diabetes mellitus are potentially modifiable factors of FC and merit further considerations during pre-transplant workup and post-transplant immunosuppressive therapeutic planning.

The innate immune system in human kidney inflammaging

Elderly individuals with chronic disorders tend to develop inflammaging, a condition associated with elevated levels of blood inflammatory markers, and increased susceptibility to chronic disease progression. Native and adaptive immunity are both involved in immune system senescence, kidney fibrosis and aging. The innate immune system is characterized by a limited number of receptors, constantly challenged by self and non-self stimuli. Circulating and kidney resident myeloid and lymphoid cells are all equipped with pattern recognition receptors (PRRs). Recent reports on PRRs show kidney overexpression of toll-like receptors (TLRs) in inflammaging autoimmune renal diseases, vasculitis, acute kidney injury and kidney transplant rejection. TLR upregulation leads to proinflammatory cytokine induction, fibrosis, and chronic kidney disease progression. TLR2 blockade in a murine model of renal ischemia reperfusion injury prevented the escape of natural killer cells and neutrophils by inflammaging kidney injury. Tumor necrosis factor-α blockade in endothelial cells with senescence-associated secretory phenotype significantly reduced interleukin-6 release. These findings should encourage experimental and translational clinical trials aimed at modulating renal inflammaging by native immunity blockade.

Association Between Phase Angle and Sarcopenia in Patients Undergoing Peritoneal Dialysis

Introduction: There is limited data on the association between phase angle (PhA) and sarcopenia using both muscle strength and muscle mass in patients undergoing peritoneal dialysis (PD). We aimed to evaluate the association between PhA and sarcopenia in patients undergoing PD.

Methods: We enrolled prevalent patients undergoing PD (n = 200). The patients were divided into tertiles based on their PhA level: low (n = 66; 1.9–4°), middle (n = 68; 4.1–4.9°), and high tertiles (n = 66; 5–8°). PhA was measured by a bioimpedance analysis. Handgrip strength (HGS) was measured in all the patients. Body compositions were measured by dual energy x-ray absorptiometry (DXA).

Results: Handgrip strength (HGS) and/or lean mass indices showed poorer trends in the low tertile than in the other tertiles. PhA was positively associated with HGS and/or muscle mass index. Multivariate analyses showed that the patients in the low tertile had an odds ratio of 9.8 (p = 0.001) and 52.79 (p < 0.001) for developing sarcopenia compared with those in the middle and high tertiles, respectively. Subgroup analyses using these variables yielded results similar to those from the total cohort.

Conclusion: This study demonstrated that PhA is independently associated with muscle mass, strength, and sarcopenia in patients undergoing PD. This result suggests that PhA can be used as a valuable and simple predictor for identifying patients undergoing PD who are at risk of sarcopenia.

Pretransplant Comprehensive Geriatric Assessment in Older Patients with Advanced Chronic Kidney Disease

BACKGROUND

In older patients with advanced chronic kidney disease (CKD), the decision of kidney transplantation (KT) is a challenge for nephrologists. The use of comprehensive geriatric assessment (CGA) is increasingly gaining interest into the process of decision-making about treatment modality choice for CKD. The aim of this study was to assess the prevalence of geriatric impairment and frailty in older dialysis and nondialysis patients with advanced CKD using a pretransplant CGA model and to identify geriatric impairments influencing the geriatricians' recommendations for KT.

METHODS

An observational study was conducted with retrospective data from July 2017 to January 2020. Patients aged ≥65 years with advanced CKD, treated or not with dialysis, and referred by the nephrologist were included in the study. The CGA assessed comorbidity burden, cognition, mood, nutritional status, (instrumental) activities of daily living, physical function, frailty, and polypharmacy. Geriatric impairments influencing the geriatricians' recommendations for KT were identified using univariate and multivariate logistic regressions.

RESULTS

156 patients were included (74.2 ± 3.5 years and 62.2% on dialysis). Geriatric conditions were highly prevalent in both dialysis and nondialysis groups. The rate of geriatric impairments was higher in dialysis patients regarding comorbidity burden, symptoms of depression, physical function, autonomy, and frailty. Geriatrician's recommendations for KT were as follows: favorable (79.5%) versus not favorable or multidisciplinary discussion needed with nephrologists (20.5%). Dependence for Instrumental Activities of Daily Living (IADL) (odds ratio [OR] = 3.01 and 95% confidence interval [CI] = 1.30-7.31), physical functions (OR = 2.91 and 95% CI = 1.08-7.87), and frailty (OR = 2.66 and 95% CI = 1.07-6.65) were found to be independent geriatric impairments influencing geriatrician's recommendations for KT.

CONCLUSIONS

Understanding the burden of geriatric impairment provides an opportunity to direct KT decision-making and to guide interventions to prevent functional decline and preserve quality of life.

Impact of kidney transplant morbidity on elderly recipients' outcomes

BACKGROUND AND AIMS

Nowadays, advanced age does not represent an absolute contraindication to kidney transplantation (KT). However, aging is frequently associated with multiple comorbidities and lower performance status, making KT candidates less surgically fit. Limited data are available on the impact of KT morbidity on elderly recipients' outcomes.

METHODS

Retrospective study on a single center cohort of 130 KT recipients over 65 years old, representing 16.2% of KT clinical series, during the period 2000-2018. Number and severity of comorbidities were evaluated with the Charlson Comorbidity index (CCI).

RESULTS

The median age at transplantation was 67 [IQR66-71] years and median CCI was 5 [IQR4-6]. The prevalence of postoperative complications with a Clavien-Dindo (C-D) severity score > 2 was 29%. Increasing age did not predict KT morbidity in terms of C-D score > 2, infectious, respiratory, cardiologic, urologic or vascular complications, delayed graft function, symptomatic lymphocele, bleeding, acute or chronic rejection. Conversely, CCI score was a predictor of overall complications with C-D score > 2, cardiologic, respiratory and vascular complications, and bleeding. Among others, CCI score, post-KT cardiologic complications, C-D score > 2 were identified as significant predictors of both early mortality and graft loss in univariate analysis. Increasing recipient age did not correlate with graft loss risk and graft loss did not impact patient survival. C-D score > 2 was a predictor of poor survival even in multivariate analysis.

CONCLUSIONS

Elderly recipients showed a significant vulnerability to KT morbidity which correlates with CCI. While graft loss did not impact recipient survival, severe postoperative complications (C-D > 2) were independently associated increased mortality.

Effects of body mass index on kidney transplant outcomes are significantly modified by patient characteristics

Body mass index (BMI) is a known risk factor associated with kidney transplant outcomes and is incorporated for determining transplant candidate eligibility. However, BMI is a coarse health measure and risks associated with BMI may vary by patient characteristics. We evaluated 296 807 adult (age > 17) solitary kidney transplant recipients from the Scientific Registry of Transplant Recipients (2000-2019). We examined effects of BMI using survival models and tested interactions with recipient characteristics. Overall, BMI demonstrated a "J-Shaped" risk profile with elevated risks for overall graft loss with low BMI and obesity. However, multivariable models indicated interactions between BMI with recipient age, diagnosis, gender, and race/ethnicity. Low BMI was relatively higher risk for older recipients (>60 years), people with type I diabetes, and males and demonstrated no additional risk among younger (18-39) and Hispanic recipients. High BMI was associated with elevated risk for Caucasians and attenuated risk among African Americans and people with type II diabetes. Effects of BMI had variable risks for mortality vs graft loss by recipient characteristics in competing risks models. The association of BMI with posttransplant outcomes is highly variable among kidney transplant recipients. Results are important considerations for personalized care and risk stratification. Findings suggest that transplant contraindications should not be based on absolute BMI thresholds but modified based on patient characteristics.

Nutrition-Based Management of Inflammaging in CKD and Renal Replacement Therapies

Access to renal transplantation guarantees a substantial improvement in the clinical condition and quality of life (QoL) for end-stage renal disease (ESRD) patients. In recent years, a greater number of older patients starting renal replacement therapies (RRT) have shown the long-term impact of conservative therapies for advanced CKD and the consequences of the uremic milieu, with a frail clinical condition that impacts not only their survival but also limits their access to transplantation. This process, referred to as “inflammaging,” might be reversible with a tailored approach, such as RRT accompanied by specific nutritional support. In this review, we summarize the evidence demonstrating the presence of several proinflammatory substances in the Western diet (WD) and the positive effect of unprocessed food consumption and increased fruit and vegetable intake, suggesting a new approach to reduce inflammaging with the improvement of ESRD clinical status. We conclude that the Mediterranean diet (MD), because of its modulative effects on microbiota and its anti-inflammaging properties, may be a cornerstone in a more precise nutritional support for patients on the waiting list for kidney transplantation.

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.

Novel approaches to sarcopenic obesity and weight management before and after kidney transplantation

PURPOSE OF REVIEW

Although a widely recognized and complex pathophysiological condition, sarcopenic obesity remains less appreciated and may elude diagnosis and workup in both kidney transplant waitlisted candidates and kidney transplant recipients. The lack of consensus definition, and practical diagnostic tools for evaluating waitlisted candidates and transplant recipients are barriers to early detect and initiate therapeutic management for sarcopenic obesity. Although sarcopenia leads to poor clinical outcomes, posttransplant obesity yields conflicting results. Exercise and nutritional managements are common therapies for sarcopenic obese patients; however, surgery weight loss or bariatric surgery in both transplant candidates and potential living kidney donors shows promising benefits for kidney transplant access in waitlist obese candidates but may require to be selected for appropriate patients.

RECENT FINDINGS

Pathogenesis and management for sarcopenia and obesity are interconnected. The benefits of exercise to improve muscle mass and function is clear in waitlist kidney transplant candidates and transplant recipients. However, there are several barriers for those to increase exercise and improve physical activity including patient, provider, and healthcare or environmental factors. The advantages of fat mass reduction to lose weight can promote muscle mass and strength. However, epidemiological data regarding the obesity paradox in dialysis-dependent patients when overnutrition provides survival benefits for this population should be taken into account when performing weight loss especially bariatric surgery.

SUMMARY

Barriers in providing optimal care to kidney transplant waitlisted candidates and transplant recipients may partly result from underdiagnosis of sarcopenic obesity; notwithstanding that this entity has increasingly been more recognized. Mechanistic studies to better understand pathogenesis of sarcopenic obesity will help determine pathogenesis and clinical tools for diagnosis of this entity, which can facilitate further studies related to the outcomes and weight management to ultimately improve kidney transplant outcomes.

Organ allocation in the age of the algorithm: avoiding futile transplantation - utility in allocation

PURPOSE OF REVIEW

This review describes and questions the evolution of allocation systems from local team decisions in the 20th century to patient-oriented allocation using complex algorithm predicting transplant benefit.

RECENT FINDINGS

The opening years of the 2000s have seen the implementation of prioritization scores aiming at increasing transparency and reducing waitlist mortality. The 2010s have underlined the necessity of drawing the upper limits of how sick a patient can be while still ensuring acceptable survival. More complex algorithms evaluating transplant benefit have been implemented in allocation systems to take this issue into account.

SUMMARY

Allocation algorithms are becoming more and more complex, integrating numerous parameters from both donor and recipient to achieve optimal matching. The limitations of implementing these complex algorithms are represented by the evermoving waiting list demography, geographic disparities between recipients and donors, team policy adaptation to rule changes, and implicit biases within the transplant community. Survival as the only metric by which to define benefit may be seen as restrictive; quality of life may be a fruitful measure for better defining benefit in organ transplantation in the future.

Association of Karnofsky Performance Status with waitlist mortality among older and younger adults awaiting kidney transplantation

Patients with end-stage renal disease (ESRD) have impaired functional status compared with the general population. We sought to explore the association between Karnofsky Performance Status (KPS) and death/delisting from the kidney transplantation waitlist and whether this association differed by age. Patients listed for single-organ kidney transplantation in the United Network for Organ Sharing/Organ Procurement and Transplantation Network from January 1, 2015, to January 1, 2018, were included. We performed competing-risk regression analyses to determine the association between KPS ("Severely impaired", "Moderately impaired", "Non-impaired") and death/delisting, with deceased-donor kidney transplantation as a competing risk. We tested for interactions between age and KPS on death/delisting. Of the 89,819 patients analyzed, 39% were impaired (KPS < 80) and 20% were aged ≥ 65 years. Older age and lower KPS were independently associated with higher risk of death/delisting (age 45-64 years, HR 1.97 [95% CI 1.73-2.24]; age ≥ 65 years, HR 3.62 [95% CI 3.33-3.92] compared with age < 45 years; moderately impaired, HR 1.68 [95% CI 1.45-1.95]; severely impaired, HR 4.80 [95% CI 3.71-6.21] compared with non-impaired). Lower KPS was associated with higher risk of death/delisting among all ages, but this effect was slightly less pronounced among individuals aged ≥ 65 years. Performance status should be used when counseling patients with ESRD on their risks for death/delisting.