Frailty and Long-Term Post-Kidney Transplant Outcomes

Frailty in Kidney Disease: A Comprehensive Review to Advance Its Clinical and Research Applications

Frailty is a multisystem syndrome of decreased physiologic reserve that has been shown to strongly and independently predict morbidity and mortality. Frailty is prevalent in patients living with kidney disease and occurs earlier in individuals with kidney disease as compared to the general population. In this comprehensive review, we examine clinical and research applications of frailty in kidney disease populations. Specifically, we clarify the definition of frailty and address common misconceptions, review the mechanisms and epidemiology of frailty in kidney disease, discuss challenges and limitations in frailty measurement, and provide updated evidence related to risk factors for frailty, its associated adverse outcomes, and interventions. We further add to the literature in this topic by highlighting the potential applications of frailty measurement in the care of patients with kidney disease and conclude with our recommendations for future research related to this important syndrome.

Unmet Questions About Frailty in Kidney Transplant Candidates

Frailty occurs frequently among patients with advanced chronic kidney disease, especially among women. Assessing frailty in kidney transplant (KT) candidates is crucial for informing them about associated risks. However, there is poor agreement between frailty scales and research on their correlation with transplant outcomes. Being prefrail significantly impacts both graft and patient survival, often beginning with just 1 Fried criterion. Rather than viewing frailty as a categorical state, it should be regarded as a spectrum ranging from 1 to 5 criteria, with the risk of adverse outcomes escalating as frailty worsens. Frailty status fluctuates during the waiting period for KT; hence, a 1-time frailty evaluation is insufficient to determine risks and implement strategies for improving functional status. Further research should investigate the components of frailty that most frequently change during this waiting period and establish strategies to prevent or reverse frailty. Although careful evaluation of frail KT candidates is necessary to prevent early complications and mortality, exclusion based solely on a frailty score is unwarranted. Instead, efforts should focus on timely interventions to enhance their condition before transplantation. Although evidence is limited, exercise programs appear feasible and yield positive results. A pretransplant clinical framework encompassing multimodal prehabilitation-comprising physical therapy, nutritional measures, and psychological support-during the waiting list period may help alleviate the effects of frailty and poor fitness after KT, ultimately improving key outcomes. Despite logistical challenges, there is a pressing need for interventional trials in this area.

Intrinsic capacity and frailty in older adults with end-stage kidney disease undergoing pre-kidney transplant comprehensive geriatric assessment

OBJECTIVE

Frailty has been extensively studied in end-stage kidney disease (ESKD) and kidney transplant (KT) patients. The identification of frailty is useful to predict adverse outcomes among ESKD and KT patients. The recent concept of intrinsic capacity (IC) appears as a good and easy-to-understand tool to screen for and monitor frailty in older adults with ESKD. This study aims to assess the relationships between frailty and IC in older adults with ESKD awaiting KT.

DESIGN

Cross-sectional study SETTING AND PARTICIPANTS: 236 patients from a day-care geriatric unit undergoing pre-KT geriatric assessment between 2017 and 2022 were included in the main sample, and 151 patients in an independent multicentric replication sample.

MEASUREMENTS

Frailty was evaluated using the physical frailty phenotype (PFP) and IC measures using the World Health Organization's screening (step 1) and diagnostic (step 2) tools for five IC domains (vitality, locomotion, audition, cognition, psychology). Multivariate regressions were run to assess relationships between PFP and IC domains, adjusted for age, sex, and comorbidities. Analyses were replicated using another independent multicenter cohort including 151 patients with ESKD to confirm the results.

RESULTS

Impairments in the locomotion, psychology, and vitality IC domains according to WHO screening tools were associated with frailty (odds ratio 9.62 [95% CI 4.09-24.99], 3.19 [95% CI 1.11-8.88], and 3.11 [95% CI 1.32-7.29], respectively). When IC were measured linearly with z-scores, all IC domains except hearing were inversely associated with frailty. In the replication cohort, results were overall similar, with a greater association between psychology domain and frailty.

CONCLUSION

This study highlights the relationship between frailty and IC in ESKD patients. We assume that IC may be assessed and monitored in ESKD patients, to predict and prevent future frailty, and post-KT adverse outcomes.

Age Disparities in Access to First and Repeat Kidney Transplantation

BACKGROUND

Evidence suggests that older patients are less frequently placed on the waiting list for kidney transplantation (KT) than their younger counterparts. The trends and magnitude of this age disparity in access to first KT and repeat KT (re-KT) remain unclear.

METHODS

Using the US Renal Data System, we identified 2 496 743 adult transplant-naive dialysis patients and 110 338 adult recipients with graft failure between 1995 and 2018. We characterized the secular trends of age disparities and used Cox proportional hazard models to compare the chances of listing and receiving first KT versus re-KT by age (18-64 y versus ≥65 y).

RESULTS

Older transplant-naive dialysis patients were less likely to be listed (adjusted hazard ratio [aHR] = 0.18; 95% confidence interval [CI], 0.17-0.18) and receive first KT (aHR = 0.88; 95% CI, 0.87-0.89) compared with their younger counterparts. Additionally, older patients with graft failure had a lower chance of being listed (aHR = 0.40; 95% CI, 0.38-0.41) and receiving re-KT (aHR = 0.76; 95% CI, 0.72-0.81). The magnitude of the age disparity in being listed for first KT was greater than that for re-KT ( Pinteraction  < 0.001), and there were no differences in the age disparities in receiving first KT or re-KT ( Pinteraction  = 0.13). Between 1995 and 2018, the age disparity in listing for first KT reduced significantly ( P  < 0.001), but the age disparities in re-KT remained the same ( P  = 0.16).

CONCLUSIONS

Age disparities exist in access to both first KT and re-KT; however, some of this disparity is attenuated among older adults with graft failure. As the proportion of older patients with graft failure rises, a better understanding of factors that preclude their candidacy and identification of appropriate older patients are needed.

Narrative Review: Clinical Implications and Assessment of Frailty in Patients With Advanced CKD

Frailty is a multidimensional clinical syndrome characterized by low physical activity, reduced strength, accumulation of multiorgan deficits, decreased physiological reserve, and vulnerability to stressors. Frailty has key social, psychological, and cognitive implications. Frailty is accelerated by uremia, leading to a high prevalence of frailty in patients with advanced chronic kidney disease (CKD) and end-stage kidney disease (ESKD) as well as contributing to adverse outcomes in this patient population. Frailty assessment is not routine in patients with CKD; however, a number of validated clinical assessment tools can assist in prognostication. Frailty assessment in nephrology populations supports shared decision-making and advanced communication and should inform key medical transitions. Frailty screening and interventions in CKD or ESKD are a developing research priority with a rapidly expanding literature base.

[Neurocognitive disorders in chronic kidney disease]

Neurocognitive disorders (NCD) are common in patients with chronic kidney disease (CKD). It is essential to identify and characterize these disorders at an early stage, so as to be able to offer appropriate treatment. In a chronic disease such as CKD, the patient's involvement in decision-making is a major challenge, given the prospects for suppletive treatment: hemodialysis, peritoneal dialysis, kidney transplantation or non-dialytic drug therapy. Many factors are associated with the development and progression of NCD in patients with CKD, and a variety of conditions can influence the outcome of cognitive assessment in these patients.

Advance Care Planning and Palliative Care Consultation in Kidney Transplantation

RATIONALE & OBJECTIVE

Because of the high risk of waitlist mortality and posttransplant complications, kidney transplant (KT) patients may benefit from advance care planning (ACP) and palliative care consultation (PCC). We quantified the prevalence and racial disparities in ACP and PCC among KT candidates and recipients.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

2,575 adult KT candidates and 1,233 adult recipients (2008-2020).

EXPOSURE

Race and ethnicity.

OUTCOMES

All reports of ACP and PCC were abstracted from chart review. ACP was defined as patient self-report of an advance directive, presence of an advance directive in the medical record, or a documented goals-of-care conversation with a provider. PCC was defined as an ordered referral or a documented palliative care note in the medical record.

ANALYTICAL APPROACH

Racial/ethnic disparities in ACP/PCC were estimated using adjusted logistic regression.

RESULTS

21.4% of KT candidates and 34.9% of recipients engaged in ACP. There were racial/ethnic disparities in ACP among KT candidates (White, 24.4%; Black, 19.1%; Hispanic, 15%; other race and ethnicity, 21.1%; P=0.008) and recipients (White, 39.5%; Black, 31.2%; Hispanic, 26.3%; other race and ethnicity, 26.6%; P=0.007). After adjustment, Black KT recipients had a 29% lower likelihood of engaging in ACP (OR, 0.71; 95% CI, 0.55-0.91) than White KT recipients. Among older (aged≥65 years) recipients, those who were Black had a lower likelihood of engaging in ACP, but there was no racial disparity among younger recipients (P=0.020 for interaction). 4.2% of KT candidates and 5.1% of KT recipients engaged in PCC; there were no racial disparities in PCC among KT candidates (White, 5.3%; Black, 3.6%; Hispanic, 2.5%; other race and ethnicity, 2.1%; P=0.13) or recipients (White, 5.5%; Black, 5.6%; Hispanic, 0.0%; other race and ethnicity, 1.3%; P = 0.21).

LIMITATIONS

Generalizability may be limited to academic transplant centers.

CONCLUSIONS

ACP is not common among KT patients, and minoritized transplant patients are least likely to engage in ACP; PCC is less common. Future efforts should aim to integrate ACP and PCC into the KT process.

PLAIN-LANGUAGE SUMMARY

Kidney transplant (KT) candidates and recipients are at elevated risk of morbidity and mortality. They may benefit from completing a document or conversation with their palliative care provider that outlines their future health care wishes, known as advance care planning (ACP), which is a component of palliative care consultation (PCC). We wanted to determine how many KT candidates and recipients have engaged in ACP or PCC and identify potential racial disparities. We found that 21.4% of candidates and 34.9% of recipients engaged in ACP. After adjustment, Black recipients had a 29% lower likelihood of engaging in ACP. We found that 4.2% of KT candidates and 5.1% of KT recipients engaged in PCC, with no racial disparities found in PCC.

Development and Validation of an Abridged Physical Frailty Phenotype for Clinical Use: A Cohort Study Among Kidney Transplant Candidates

BACKGROUND

Frailty is associated with poor outcomes in surgical patients including kidney transplant (KT) recipients. Transplant centers that measure frailty have better pre- and postoperative outcomes. However, clinical utility of existing tools is low due to time constraints. To address this major barrier to implementation in the preoperative evaluation of patients, we developed an abridged frailty phenotype.

METHODS

The abridged frailty phenotype was developed by simplifying the 5 physical frailty phenotype (PFP) components in a two-center prospective cohort of 3 220 KT candidates and tested for efficiency (time to completion) in 20 candidates evaluation (January 2009 to March 2020). We examined area under curve (AUC) and Cohen's kappa agreement to compare the abridged assessment with the PFP. We compared waitlist mortality risk (competing risks models) by frailty using the PFP and abridged assessment, respectively. Model discrimination was assessed using Harrell's C-statistic.

RESULTS

Of 3 220 candidates, the PFP and abridged assessment identified 23.8% and 27.4% candidates as frail, respectively. The abridged frailty phenotype had substantial agreement (kappa = 0.69, 95% CI: 0.66-0.71) and excellent discrimination (AUC = 0.861). Among 20 patients at evaluation, abridged assessment took 5-7 minutes to complete. The PFP and abridged assessment had similar associations with waitlist mortality (subdistribution hazard ratio [SHR] = 1.62, 95% CI: 1.26-2.08 vs SHR = 1.70, 95% CI: 1.33-2.16) and comparable mortality discrimination (p = .51).

CONCLUSIONS

The abridged assessment is an efficient and valid way to identify frailty. It predicts waitlist mortality without sacrificing discrimination. Surgical departments should consider utilizing the abridged assessment to evaluate frailty in patients when time is limited.

PREhabilitation of CAndidates for REnal Transplantation (PreCareTx) study: protocol for a hybrid type I, mixed method, randomised controlled trial

INTRODUCTION

Kidney transplant candidates (KTCs) need to be in optimal physical and psychological condition prior to surgery. However, KTCs often experience compromised functional capacity which can be characterised as frailty. Prehabilitation, the enhancement of a person's functional capacity, may be an effective intervention to improve the health status of KTCs. The PREhabilitation of CAndidates for REnal Transplantation (PreCareTx) study aims to examine the effectiveness of a multimodal prehabilitation programme on the health status of KTCs, and to explore the potential of implementation of prehabilitation in daily clinical practice.

METHODS AND ANALYSIS

This study uses a single centre, effectiveness-implementation hybrid type I study design, comprised of a randomised controlled trial and a mixed-methods study. Adult patients who are currently on the transplant waiting list or are waitlisted during the study period, at a university medical centre in The Netherlands, will be randomly assigned to either prehabilitation (n=64) or care as usual (n=64) groups. The prehabilitation group will undergo a 12-week home-based, tailored prehabilitation programme consisting of physical and/or nutritional and/or psychosocial interventions depending on the participant's deficits. This programme will be followed by a 12-week maintenance programme in order to enhance the incorporation of the interventions into daily life. The primary endpoint of this study is a change in frailty status as a proxy for health status. Secondary endpoints include changes in physical fitness, nutritional status, psychological well-being, quality of life and clinical outcomes. Tertiary endpoints include the safety, feasibility and acceptability of the prehabilitation programme, and the barriers and facilitators for further implementation.

ETHICS AND DISSEMINATION

Medical ethical approval was granted by the Medical Ethics Committee Groningen, Netherlands (M22.421). Written informed consent will be obtained from all participants. The results will be disseminated at international conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov, NCT05489432.

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.

Post-kidney transplant body mass index trajectories are associated with graft loss and mortality

BACKGROUND

Early post-kidney transplantation (KT) changes in physiology, medications, and health stressors likely impact body mass index (BMI) and likely impact all-cause graft loss and mortality.

METHODS

We estimated 5-year post-KT (n = 151 170; SRTR) BMI trajectories using an adjusted mixed effects model. We estimated long-term mortality and graft loss risks by 1-year BMI change quartile (decrease [1st quartile]: change < -.07 kg/m2 /month; stable [2nd quartile]: -.07 ≤ change ≤ .09 kg/m2 /month; increase [3rd, 4th quartile]: change > .09 kg/m2 /month) using adjusted Cox proportional hazards models.

RESULTS

BMI increased in the 3 years post-KT (.64 kg/m2 /year, 95% CI: .63, .64) and decreased in years 3-5 (-.24 kg/m2 /year, 95% CI: -.26, -.22). 1-year post-KT BMI decrease was associated with elevated risks of all-cause mortality (aHR = 1.13, 95% CI: 1.10-1.16), all-cause graft loss (aHR = 1.13, 95% CI: 1.10-1.15), death-censored graft loss (aHR = 1.15, 95% CI: 1.11-1.19), and mortality with functioning graft (aHR = 1.11, 95% CI: 1.08-1.14). Among recipients with obesity (pre-KT BMI≥30 kg/m2 ), BMI increase was associated with higher all-cause mortality (aHR = 1.09, 95% CI: 1.05-1.14), all-cause graft loss (aHR = 1.05, 95% CI: 1.01-1.09), and mortality with functioning graft (aHR = 1.10, 95% CI: 1.05-1.15) risks, but not death-censored graft loss risks, relative to stable weight. Among individuals without obesity, BMI increase was associated with lower all-cause graft loss (aHR = .97, 95% CI: .95-.99) and death-censored graft loss (aHR = .93, 95% CI: .90-.96) risks, but not all-cause mortality or mortality with functioning graft risks.

CONCLUSIONS

BMI increases in the 3 years post-KT, then decreases in years 3-5. BMI loss in all adult KT recipients and BMI gain in those with obesity should be carefully monitored post-KT.

Frailty and Age-Associated Assessments Associated with Chronic Kidney Disease and Transplantation Outcomes

Background. Frailty is often defined as a decrease in physiological reserve and has been shown to be correlated with adverse health outcomes and mortality in the general population. This condition is highly prevalent in the chronic kidney disease (CKD) patient population as well as in kidney transplant (KT) recipients. Other age-associated changes include sarcopenia, nutrition, cognition, and depression. In assessing the contributions of these components to patient outcomes and their prevalence in the CKD and KT patient population, it can be determined how such variables may be associated with frailty and the extent to which they may impact the adverse outcomes an individual may experience. Objectives. We sought to perform a systematic literature review to review published data on frailty and associated age-associated syndromes in CKD and KT patients. Results. Over 80 references pertinent to frailty, sarcopenia, nutrition, cognition, or depression in patients with CKD or KT were identified. Systematic review was performed to evaluate the data supporting the use of the following approaches: Fried Frailty, Short Physical Performance Battery, Frailty Index, Sarcopenia Index, CT scan quantification of muscle mass, health-related quality of life, and assessment tools for nutrition, cognition, and depression. Conclusion. This report represents a comprehensive review of previously published research articles on this topic. The intersectionality between all these components in contributing to the patient’s clinical status suggests a need for a multifaceted approach to developing comprehensive care and treatment for the CKD and KT population to improve outcomes before and after transplantation.

Is It Time to Integrate Frailty Assessment in Onconephrology?

Simple Summary

There are an increasing number of older people living with kidney cancer and/or cancer and kidney disease worldwide, sparking a wider discussion on the impact of frailty and the clinical significance of conducting frailty assessments for this patient population. We provide an update on the current evidence related to frailty assessment in onconephrology and identify areas where further research efforts are anticipated to address knowledge gaps within this topic.

Abstract

Onconephrology has emerged as a novel sub-specialty of nephrology dedicated to the intersection between the kidney and cancer. This intersection is broad and includes a number of important areas of focus, including concurrent chronic kidney disease (CKD) and cancer, acute kidney complications of cancer, and cancer-treatment-induced nephrotoxicity. The importance of onconephrology is even more evident when considering the global growth in the population of older adults, many of whom are living with some degree of frailty. Furthermore, a considerable proportion of older adults have CKD (some of whom eventually progress to kidney failure) and are at high risk of developing solid tumour and hematologic malignancies. Specific to kidney disease, the association between frailty status and kidney disease has been explored in depth, and tools to capture frailty can be used to guide the management and prognostication of older adults living with kidney failure. Whilst there is emerging data regarding the assessment and impact of frailty in onconephrology, there remains a relative paucity of knowledge within this topic. In this article, we evaluate the definition and operationalization of frailty and discuss the significance of frailty within onconephrology. We review evidence on current approaches to assessing frailty in onconephrology and discuss potential developments and future directions regarding the utilization of frailty in this patient population. A greater awareness of the intersections and interactions between frailty and onconephrology and further efforts to integrate frailty assessment in onconephrology to optimize the delivery of realistic and goal-directed management strategies for patients is needed.

Prehabilitation in Adult Solid Organ Transplant Candidates

Purpose of Review

To highlight the importance of biological age in the context of prehabilitation and to present relevant research regarding prehabilitation prior to solid organ transplantation.

Recent Findings

Studies on the effect of prehabilitation have been performed in kidney-, lung-, liver-, and heart transplant patient populations. Prior to kidney transplantation, exercise interventions have been shown to improve cardiopulmonary- and physical fitness and result in a decreased length of hospital stay postoperatively. Among lung transplant candidates, various methods of prehabilitation have been studied including home-based, outpatient and in-patient programs, consisting of physical training, psychological support, education, and nutritional interventions. Overall, prehabilitation seems to improve or maintain quality of life and exercise capacity in this patient population. Patients undergoing liver transplantation seem to benefit from prehabilitation as well. Not only does it seem safe and feasible, but significant improvements in aerobic and functional capacity have also been found. Regarding heart transplant candidates, both inpatient and outpatient, supervised prehabilitation programs show promising results with improvements in exercise capacities and quality of life.

Summary

Prehabilitation is an effective and safe intervention for improving functional outcomes of solid organ transplant patients. Future studies should evaluate whether prehabilitation translates into improved pre- and post-transplant clinical outcomes.

Patient Perspectives on the Use of Frailty, Cognitive Function, and Age in Kidney Transplant Evaluation

BACKGROUND

The allocation of scarce deceased donor kidneys is a complex process. Transplant providers are increasingly relying on constructs such as frailty and cognitive function to guide kidney transplant (KT) candidate selection. Patient views of the ethical issues surrounding the use of such constructs are unclear. We sought to assess KT candidates' attitudes and beliefs about the use of frailty and cognitive function to guide waitlist selection.

METHODS

KT candidates were randomly recruited from an ongoing single-center cohort study of frailty and cognitive function. Semi-structured interviews were conducted, and thematic analysis was performed. Inductively derived themes were mapped onto bioethics principles.

RESULTS

Twenty interviews were conducted (65% contact rate, 100% participation rate) (60% male; 70% White). With respect to the use of frailty and cognitive function in waitlisting decisions, four themes emerged in which participants: (1) valued maximizing a scarce resource (utility); (2) prioritized equal access to all patients (equity); (3) appreciated a proportional approach to the use of equity and utility (precautionary utility); and (4) sought to weigh utility- and equity-based concerns regarding social support. While some participants believed frailty and cognitive function were useful constructs to maximize utility, others believed their use would jeopardize equity. Patients were uncomfortable with using single factors such as frailty or cognitive impairment to deny someone access to transplantation; participants instead encouraged using the constructs to identify opportunities for intervention to improve frailty and cognitive function prior to KT.

CONCLUSIONS

KT candidates' values mirrored the current allocation strategy, seeking to balance equity and utility in a just manner, albeit with conflicting viewpoints on the appropriate use of frailty and cognitive impairment in waitlisting decisions.

Balancing Equity and Efficiency in Kidney Allocation: An Overview

Organs for transplantation are a scarce resource. Markedly, the transplant community's primary challenge is the stark disparity between the number of patients awaiting deceased donor organ transplants and the rate at which organs become available. However, the allocation of a limited number of organs poses another constant challenge: maintaining an equilibrium between renal transplant utility and equity, that is, striking a balance between the utilitarian argument of medical efficiency and the principle of equity. In this comprehensive overview, the authors delve into the challenge of maintaining an acceptable balance between equity and efficiency and elaborate on some of the factors that might inform a decisionmaker's evaluation of the extent to which a given allocation scheme is efficient or equitable.

Increased mortality after kidney transplantation in mildly frail recipients

Background

Physical Frailty Phenotype (PFP) is the most used frailty instrument among kidney transplant recipients, classifying patients as pre-frail if they have 1–2 criteria and as frail if they have ≥3. However, different definitions of robustness have been used among renal patients, including only those who have 0 criteria, or those with 0–1 criteria. Our aim was to determine the impact of one PFP criterion on transplant outcomes.

Methods

We undertook a retrospective study of 296 kidney transplant recipients who had been evaluated for frailty by PFP at the time of evaluating for transplantation.

Results

Only 30.4% of patients had 0 criteria, and an additional 42.9% showed one PFP criterion. As PFP score increased, a higher percentage of women and cerebrovascular disease were found. Recipients with 0–1 criteria had lower 1-year mortality after transplant than those with ≥2 (1.8% vs 10.1%), but this difference was already present when we only considered those who scored 0 (mortality 1.1%) and 1 (mortality 2.4%) separately. The multivariable analysis confirmed that one PFP criterion was associated to a higher risk of patient death after kidney transplantation [hazard ratio 3.52 (95% confidence interval 1.03–15.9)].

Conclusions

Listed kidney transplant candidates frequently show only one PFP frailty criterion. This has an independent impact on patient survival after transplantation.

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.

Long-Term Trajectories of Frailty and Its Components After Kidney Transplantation

BACKGROUND

Frailty is common and associated with poor outcomes among kidney transplant (KT) recipients. While frailty improves in the first 3 months post-KT with restored kidney function, longer-term trajectories are likely to plateau/decline due to aging and other stressors (eg, immunosuppression). We evaluated longer-term post-KT trajectories of the physical frailty phenotype (PFP) and its components in adult patients at 2 centers.

METHODS

PFP components were measured at admission, 1, 3, 6 months, 1 year, and annually thereafter post-KT. We used adjusted mixed-effects models to describe repeated measures of continuous components (weight, gait speed, grip strength, activity) and generalized estimating equations to quantify longitudinal, binomial response patterns (PFP; exhaustion).

RESULTS

Among 1 336 recipients (mean age = 53) followed for a median of 1.9 years (interquartile range [IQR] = 0.1-3.2), likelihood of frailty declined in the first 2.5 years post-KT (adjusted odds ratio [aOR] = 0.96, 95% confidence interval [CI]: 0.95, 0.98), but increased after 2.5 years post-KT (aOR = 1.03, 95% CI: 1.00, 1.05). In the first 2.5 years post-KT, recipients demonstrated increases in weight (0.4 lbs/month, 95% CI: 0.3, 0.5), grip strength (0.2 kg/month, 95% CI: 0.1, 0.2), and activity (23.9 kcal/month, 95% CI: 17.5, 30.2); gait speed remained stable (-0.01 s/month, 95% CI: 0.01, 0.003). Additionally, likelihood of becoming exhausted declined post-KT (OR = 0.99, 95% CI: 0.98, 1.00). After 2.5 years post-KT, recipients demonstrated decreased grip strength (-0.07 kg/month, 95% CI: -0.12, -0.01) and activity (-20 kcal/month, 95% CI: -32.3, -8.2); they had stable weight (-0.003 lbs/month, 95% CI: -0.17, 0.16), gait speed (-0.003 s/month, 95% CI: -0.02, 0.01), and likelihood of becoming exhausted (OR = 1.01, 95% CI: 0.99, 1.02).

CONCLUSION

Despite frailty improvements in the first 2.5 years, recipients' frailty worsened after 2.5 years post-KT. Specifically, they experienced gains in strength, activity, and exhaustion in the first 2.5 years post-KT, but declined in strength and activity after 2.5 years post-KT while experiencing persistent slowness. Clinicians should consider monitoring recipients for worsening frailty after 2.5 years despite shorter-term improvements.

Outcomes of Frail Patients While Waiting for Kidney Transplantation: Differences between Physical Frailty Phenotype and FRAIL Scale

Frailty is associated with poorer outcomes among patients waiting for kidney transplantation (KT). Several different tools to measure frailty have been used; however, their predictive value is unknown. This is a prospective longitudinal study of 449 KT candidates evaluated for frailty by the Physical Frailty Phenotype (PFP) and the FRAIL scale. During the study period, 296 patients received a KT, while 153 remained listed. Patients who did not get receive a transplant were more frequently frail according to PFP (16.3 vs. 7.4%, p = 0.013). Robust patients had fewer hospital admissions during the 1st year after listing (20.8% if PFP = 0 vs. 43.4% if ≥1, and 27.1% if FRAIL = 0 vs. 48.9% if ≥1) and fewer cardiovascular events (than FRAIL ≥ 1) or major infectious events (than PFP ≥ 1). According to PFP, scoring 1 point had an impact on patient survival and chance of transplantation in the univariate analysis. The multivariable analysis corroborated the result, as candidates with PFP ≥ 3 had less likelihood of transplantation (HR 0.45 [0.26–0.77]). The FRAIL scale did not associate with any of these outcomes. In KT candidates, pre-frailty and frailty according to both the PFP and the FRAIL scale were associated with poorer results while listed. The PFP detected that frail patients were less likely to receive a KT, while the FRAIL scale did not.

Frailty among chronic kidney disease patients on the kidney transplant waiting list: the sex–frailty paradox

Background

Frailty is defined as decreased physiologic reserve and resistance to stressors that predisposes patients towards poor health results. Its prevalence in chronic kidney disease (CKD) patients who are kidney transplant (KT) candidates is high. Frailty is associated with a higher rate of complications and mortality after transplant. It is unknown whether frailty phenotype differs depending on sex in this population.

Methods

This was a prospective longitudinal study of 455 KT candidates evaluated for frailty by physical frailty phenotype at the time of inclusion on the KT waiting list. Pre-frailty was defined as the presence of two criteria and frailty as three or more criteria. Univariate and multivariate analyses searched for associations of frailty status, frailty components and gender differences.

Results

Thirty percent of the total cohort resulted to be pre-frail (20%) or frail (10.3%), but disparities were observed between sexes, with 22.5% of men and 47.2% of women falling into one of these categories. Among frailty criteria, women presented with a higher percentage of exhaustion (39.6% versus 17%) and slowness (22.2% versus 9.6%) compared with men. Comorbidity burden was higher among frail men, whereas social factors were poorer between frail women. Disability was common among those patients who were frail, both men and women.

Conclusions

Frailty is twice as frequent in advanced CKD women as men. Frailty criteria distribution and phenotype seem to differ among sexes, which might have implications in terms of specific and individualized interventions to improve their status before transplantation.

Visceral Fat Obesity Correlates with Frailty in Middle-Aged and Older Adults

BACKGROUND

Frailty and obesity are associated with poor outcomes in older adults. Previous studies have shown that excessive visceral fat leads to frailty by promoting inflammation. However, the association between visceral fat obesity (VFO) and frailty has not been elucidated. We aimed to investigate the correlation between VFO and frailty in middle-aged and older adults.

METHODS

A total of 483 adults aged ≥45 years were recruited. Estimated visceral fat area (eVFA) and total fat (TF) were determined by bioimpedance analysis. Waist circumference, body mass index (BMI), and waist-to-hip ratio (WHR) were recorded. Frailty was assessed using the Fried frailty phenotype. Logistic regression analysis was used to analyze the association between frailty and other variables. Spearman correlation coefficients were calculated to assess the correlations between the frailty phenotype score, eVFA/TF, and other factors.

RESULTS

Frail adults were older and had higher waist circumference, eVFA metabolic indicators, and coronary artery disease incidence. Participants with frailty had a higher prevalence of VFO than those without. After adjusting for age, sex, and chronic diseases, frailty was associated with eVFA but not waist circumference, WHR, or BMI. Spearman correlation analysis showed that the frailty phenotype score was positively associated with eVFA and BMI in women but not men. After adjusting for age, frailty was not associated with BMI or WHR. The eVFA/TF ratio was negatively correlated with grip strength and walking speed and positively correlated with the clinical frailty scale score in middle-aged and older adults.

CONCLUSION

Middle-aged and older adults with VFO had a higher risk of frailty. Frailty was associated with a higher eVFA but not with BMI or WHR. The frailty score was positively associated with eVFA and BMI in women, but not in men. A higher eVFA was correlated with worse physical function, even after adjusting for TF.

Psychosocial characteristics of patients evaluated for kidney transplant and associations with functional and frailty metrics at a veterans affairs hospital

BACKGROUND

The effect of psychosocial problems on listing outcomes and potential interactions with functional metrics is not well-characterized among Veteran transplant candidates.

METHODS

The results from psychosocial evaluations, frailty metrics, and biochemical markers were collected on 375 consecutive Veteran kidney transplant candidates. Psychosocial diagnoses were compared between patients listed or denied for transplant. Functional abilities were compared among patients with or without psychosocial diagnoses and then evaluated based on reason for denial.

RESULTS

Eighty-four percent of patients had a psychosocial diagnosis. Common issues included substance or alcohol abuse (62%), psychiatric diagnoses (50%), and poor adherence (25%). Patients with psychiatric diagnoses, cognitive impairments, and poor adherence were more likely to be denied for transplant (P < .05). Patients with depression, PTSD, and anxiety did not have worse functional ability, but experienced more exhaustion than patients without these problems. Patients denied for medical but not purely psychosocial reasons had worse troponin and functional metrics compared with listed patients.

CONCLUSION

Over 80% of patients with a psychosocial diagnosis were listed; however, poor adherence was a particularly important reason for denial for purely psychosocial reasons. Patients with psychosocial diagnoses generally were not more functionally limited than their counterparts without psychosocial diagnoses or those listed for transplant.

Cognitive disorders in patients with chronic kidney disease: specificities of clinical assessment

Neurocognitive disorders are frequent among chronic kidney disease (CKD) patients. Identifying and characterizing cognitive impairment (CI) can help to assess the ability of adherence to CKD risk reduction strategy, identify potentially reversible causes of cognitive decline, modify pharmacotherapy, educate the patient and caregiver and provide appropriate patient and caregiver support. Numerous factors are associated with the development and progression of CI in CKD patients and various conditions can influence the results of cognitive assessment in these patients. Here we review clinical warning signs that should lead to cognitive screening; conditions frequent in CKD at risk to interfere with cognitive testing or performance, including specificities of cognitive assessment in dialysis patients or after kidney transplantation; and available tests for screening and observed cognitive patterns in CKD patients.

Frailty in CKD and Transplantation

The population is aging. Although older adults have higher rates of comorbidities and adverse health events, they represent a heterogeneous group with different health trajectories. Frailty, a clinical syndrome of decreased physiological reserve and increased susceptibility to illness and death, has emerged as a potential risk stratification tool in older patients with chronic kidney disease (CKD). Frailty is commonly observed in patients with CKD and associated with numerous adverse outcomes, including falls, decreased quality of life, hospitalizations, and death. Multiple pathologic factors contribute to the development of frailty in patients with CKD, including biological mechanisms of aging and physiological dysregulation. Current interventions to reduce frailty are promising, but additional investigations are needed to determine whether optimizing frailty measures improves renal and overall health outcomes. This review of frailty in CKD examines frailty definitions, the impact of frailty on health outcomes across the CKD spectrum, mechanisms of frailty, and antifrailty interventions (e.g., exercise or senescent cell clearance) tested in CKD patients. In addition, existing knowledge gaps, limitations of current frailty definitions in CKD, and challenges surrounding effective antifrailty strategies in CKD are considered.

The Risk of Postkidney Transplant Outcomes by Induction Choice Differs by Recipient Age

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Background.

Among adult kidney transplant (KT) recipients, the risk of post-KT adverse outcomes differs by type of induction immunosuppression. Immune response to induction differs as recipients age; yet, choice of induction is barely tailored by age likely due to a lack of evidence of the risks and benefits.

Methods.

Using Scientific Registry of Transplant Recipients data, we identified 39336 first-time KT recipients (2010–2016). We estimated the length of stay (LOS), acute rejection (AR), graft failure, and death by induction type using logistic and Cox regression weighted by propensity score to adjust for confounders. We tested whether these estimates differed by age (65+ versus 18–64 y) using a Wald test.

Results.

Overall, rabbit antithymocyte globulin (rATG) was associated with a decreased risk of AR (odds ratio = 0.79, 95% confidence interval [CI], 0.72-0.85) compared with basiliximab. The effect of induction on LOS and death (interaction P = 0.03 and 0.003) differed by recipient age. Discharge was on average 11% shorter in rATG among younger recipients (relative time = 0.89; 95% confidence interval [CI], 0.81-0.99) but not among older recipients (relative time = 1.01; 95% CI, 0.95-1.08). rATG was not associated with mortality among older (hazard ratio = 1.05; 95% CI, 0.96-1.15), but among younger recipients (hazard ratio = 0.87; 95% CI, 0.80-0.95), it was associated with reduced mortality risk.

Conclusions.

rATG should be considered to prevent AR, especially among recipients with high-immunologic risk regardless of age; however, choice of induction should be tailored to reduce LOS and risk of mortality, particularly among younger recipients.

Changes in Functional Status Among Kidney Transplant Recipients: Data From the Scientific Registry of Transplant Recipients

BACKGROUND

With stressors of dialysis prekidney transplantation (KT) and restoration of kidney function post-KT, it is likely that KT recipients experience a decline in functional status while on the waitlist and improvements post-KT.

METHODS

We leveraged 224 832 KT recipients from the national registry (SRTR, February 1990-May 2019) with measured Karnofsky Performance Status (KPS, 0%-100%) at listing, KT admission, and post-KT. We quantified the change in KPS from listing to KT using generalized linear models. We described post-KT KPS trajectories using adjusted mixed-effects models and tested whether those trajectories differed by age, sex, race, and diabetes status using a Wald test among all KT recipients. We then quantified risk adverse post-KT outcomes (mortality and all-cause graft loss [ACGL]) by preoperative KPS and time-varying KPS.

RESULTS

Mean KPS declined from listing (83.7%) to admission (78.9%) (mean = 4.76%, 95% confidence interval [CI]: -4.82, -4.70). After adjustment, mean KPS improved post-KT (slope = 0.89%/y, 95% CI: 0.87, 0.91); younger, female, non-Black, and diabetic recipients experienced greater post-KT improvements (Pinteractions < 0.001). Lower KPS (per 10% decrease) at admission was associated with greater mortality (adjusted hazard ratio [aHR] = 1.11, 95% CI: 1.10, 1.11) and ACGL (aHR = 1.08, 95% CI: 1.08, 1.09) risk. Lower post-KT KPS (per 10% decrease; time-varying) were more strongly associated with mortality (aHR = 1.93, 95% CI: 1.92, 1.94) and ACGL (aHR = 1.84, 95% CI: 1.83, 1.85).

CONCLUSIONS

Functional status declines pre-KT and improves post-KT in the national registry. Despite post-KT improvements, poorer functional status at KT and post-KT are associated with greater mortality and ACGL risk. Because of its dynamic nature, clinicians should repeatedly screen for lower functional status pre-KT to refer vulnerable patients to prehabilitation in hopes of reducing risk of adverse post-KT outcomes.

Cytomegalovirus Serostatus and Functional Impairment in Liver Transplant Recipients in the Current Era

BACKGROUND

Whether donor (D+) or recipient (R+) cytomegalovirus (CMV) seropositivity is associated with functional impairment in liver transplant recipients is not known.

METHODS

Patients included adult liver transplant recipients in the Organ Procurement and Transplantation Network database transplanted over a five-year period from 1 January 2014-31 December 2018. Functional status in the database was assessed using Karnofsky performance scale. A logistic regression model that controlled for potential confounders was used to examine the association of CMV serostatus and functional status. Variables significantly associated with functional status (p < 0.05) were then used to develop propensity score and propensity score matched analysis was conducted where each patient was compared with a matched-control with the same propensity score.

RESULTS

Among 30,267 adult liver transplant recipients, D+ or R+ patients had significantly lower functional status at last follow-up than the D-R- cohort (OR 0.88, 95% CI 0.80-0.96, p = 0.007). In propensity score matched model, D+ or R+ patients had significantly lower functional status than matched-controls (p = 0.009). D+ or R+ CMV serostatus (p = 0.018) and low functional level (p < 0.001) were also independently associated with infections as cause-of-death.

CONCLUSIONS

D+ or R+ liver transplant recipients had lower functional status and higher risk of deaths due to infections. Future studies are warranted to examine the mechanistic basis of these findings in the setting of transplantation.

Development and Validation of an Inflammatory-Frailty Index for Kidney Transplantation

BACKGROUND

Physical frailty phenotype is characterized by decreased physiologic reserve to stressors and associated with poor outcomes, such as delirium and mortality, that may result from post-kidney transplant (KT) inflammation. Despite a hypothesized underlying pro-inflammatory state, conventional measures of frailty typically do not incorporate inflammatory biomarkers directly. Among KT candidates and recipients, we evaluated the inclusion of inflammatory biomarkers with traditional physical frailty phenotype components.

METHODS

Among 1154 KT candidates and recipients with measures of physical frailty phenotype and inflammation (interleukin 6 [IL6], tumor necrosis factor alpha [TNFα], C-reactive protein [CRP]) at 2 transplant centers (2009-2017), we evaluated construct validity of inflammatory-frailty using latent class analysis. Inflammatory-frailty measures combined 5 physical frailty phenotype components plus the addition of an individual inflammatory biomarkers, separately (highest tertiles) as a sixth component. We then used Kaplan-Meier methods and adjusted Cox proportional hazards to assess post-KT mortality risk by inflammatory-frailty (n = 378); Harrell's C-statistics assessed risk prediction (discrimination).

RESULTS

Based on fit criteria, a 2-class solution (frail vs nonfrail) for inflammatory-frailty was the best-fitting model. Five-year survival (frail vs nonfrail) was: 81% versus 93% (IL6-frailty), 87% versus 89% (CRP-frailty), and 83% versus 91% (TNFα-frailty). Mortality was 2.07-fold higher for IL6-frail recipients (95% CI: 1.03-4.19, p = .04); there were no associations between the mortality and the other inflammatory-frailty indices (TNFα-frail: 1.88, 95% CI: 0.95-3.74, p = .07; CRP-frail: 1.02, 95% CI: 0.52-2.03, p = .95). However, none of the frailty-inflammatory indices (all C-statistics = 0.71) improved post-KT mortality risk prediction over the physical frailty phenotype (C-statistics = 0.70).

CONCLUSIONS

Measurement of IL6-frailty at transplantation can inform which patients should be targeted for pre-KT interventions. However, the traditional physical frailty phenotype is sufficient for post-KT mortality risk prediction.

Frailty and kidney transplant candidates

Frailty is a concept that has been mainly developed in geriatrics and it came from the need of identifying subjects at risk to develop complications when they faced a stressful event. Frail patients have higher risk of mortality, poor outcomes and disability, and this is independent from their age or comorbidities. Chronic kidney disease patients present with high prevalence of frailty, especially those who are in renal replacement therapy. Frail or pre-frail patients on the kidney transplant waiting list represent 20-30%, and these patients are proven to have poorer results after the transplant, which is a stressful event itself. Tools for frailty assessment, both scales or indexes, may be useful to identify which subjects might be at risk for complications after transplant, and this is necessary to adapt our clinical practice and minimize morbidity. The most used frailty scale in kidney patients is Fried scale, which is based in five phenotypic items. Besides that, knowing frail population allows potential interventions such as prehabilitation while the patient is waiting for the kidney transplant, which the aim of improving their vulnerability prior to transplant and, therefore, optimizing results after transplant. More studies are needed amongst kidney patients to improve and prevent frailty.

Frailty in China: From Research to Practice

Although geriatric research in general has increased in recent years, there is no effective treatment for frailty. Among older adults, those with frailty have an increased risk of falls, disability, and death. The population of older adults has increased rapidly in China, and resulting in an increased demand for medical care services for older adults, including those with frailty. However, much of the research on frailty has been conducted in Europe and the United States, and European and American standards for frailty are not always applicable to Chinese individuals. Clinicians and researchers in China have shown increasing interest in frailty in recent years. Here, we reviewed the current state of frailty research in China.

[Frailty and kidney transplant candidates]

Frailty is a concept that has been mainly developed in geriatrics and it came from the need of identifying subjects at risk to develop complications when they faced a stressful event. Frail patients have higher risk of mortality, poor outcomes and disability, and this is independent from their age or comorbidities. Chronic kidney disease patients present with high prevalence of frailty, especially those who are in renal replacement therapy. Frail or pre-frail patients on the kidney transplant waiting list represent 20-30%, and these patients are proven to have poorer results after the transplant, which is a stressful event itself. Tools for frailty assessment, both scales or indexes, may be useful to identify which subjects might be at risk for complications after transplant, and this is necessary to adapt our clinical practice and minimize morbidity. The most used frailty scale in kidney patients is Fried scale, which is based in five phenotypic items. Besides that, knowing frail population allows potential interventions such as prehabilitation while the patient is waiting for the kidney transplant, which the aim of improving their vulnerability prior to transplant and, therefore, optimizing results after transplant. More studies are needed amongst kidney patients to improve and prevent frailty.

Protocolized exercise improves frailty parameters and lower extremity impairment: A promising prehabilitation strategy for kidney transplant candidates

BACKGROUND

Frailty and decreased functional status are risk factors for adverse kidney transplant (KT) outcomes. Our objective was to examine the efficacy of an exercise intervention on frailty and decreased functional status in a cohort of patients with advanced chronic kidney disease (CKD).

METHODS

We conducted a prospective study involving 21 adults with ≥stage 4 CKD who were (a) frail or pre-frail by Fried phenotype and/or (b) had lower extremity impairment [short physical performance battery score ≤10]. The intervention consisted of two supervised outpatient exercise sessions per week for 8 weeks.

RESULTS

Among our cohort, median participant age was 62 years (interquartile range, 53-67) and 85.7% had been evaluated for KT. Following the study, participants reported satisfaction with the intervention and multiple frailty parameters improved significantly, including fatigue, physical activity, walking time, and grip strength. Lower extremity impairment also improved (90.5%-61.9%, P = .03). No study-related adverse events occurred.

CONCLUSIONS

Preliminary data from this study suggest that a supervised, outpatient exercise intervention is safe, acceptable, feasible, and associated with improved frailty parameters, and lower extremity function, in patients with advanced CKD. Further studies are needed to confirm these findings and determine whether this prehabilitation strategy improves KT outcomes.

Frailty Prevalence in Younger End-Stage Kidney Disease Patients Undergoing Dialysis and Transplantation

BACKGROUND

Frailty, originally characterized in community-dwelling older adults, is increasingly being studied and implemented for adult patients with end-stage kidney disease (ESKD) of all ages (>18 years). Frailty prevalence and manifestation are unclear in younger adults (18-64 years) with ESKD; differences likely exist based on whether the patients are treated with hemodialysis (HD) or kidney transplantation (KT).

METHODS

We leveraged 3 cohorts: 378 adults initiating HD (2008-2012), 4,304 adult KT candidates (2009-2019), and 1,396 KT recipients (2008-2019). The frailty phenotype was measured within 6 months of dialysis initiation, at KT evaluation, and KT admission. Prevalence of frailty and its components was estimated by age (≥65 vs. <65 years). A Wald test for interactions was used to test whether risk factors for frailty differed by age.

RESULTS

In all 3 cohorts, frailty prevalence was higher among older than younger adults (HD: 71.4 vs. 47.3%; candidates: 25.4 vs. 18.8%; recipients: 20.8 vs. 14.3%). In all cohorts, older patients were more likely to have slowness and weakness but less likely to report exhaustion. Among candidates, older age (odds ratio [OR] = 1.79, 95% CI: 1.47-2.17), non-Hispanic black race (OR = 1.30, 95% CI: 1.08-1.57), and dialysis type (HD vs. no dialysis: OR = 2.06, 95% CI: 1.61-2.64; peritoneal dialysis vs. no dialysis: OR = 1.78, 95% CI: 1.28-2.48) were associated with frailty prevalence, but sex and Hispanic ethnicity were not. These associations did not differ by age (pinteractions > 0.1). Similar results were observed for recipients and HD patients.

CONCLUSIONS

Although frailty prevalence increases with age, younger patients have a high burden. Clinicians caring for this vulnerable population should recognize that younger patients may experience frailty and screen all age groups.