Faculty Bibliography

BACKGROUND:Older (≥65) KT recipients differ from their younger counterparts in their immune response to immunosuppression (IS) and may have a different risk of malignancy after receiving induction. METHODS:We identified 66 700 adult KT recipients treated with anti-thymocyte globulin (ATG) (n = 40 443) or interleukin-2 receptor antagonist (IL-2RA) (n = 26 327) induction (1/1/1999-12/31/2014) using USRDS/Medicare data. We estimated the risk of first-diagnosed post-KT malignancy associated with induction (ATG vs. IL-2RA) using Cox proportional hazard models. We then tested whether these risks differed between older and younger recipients (Wald test for interaction). Models incorporated inverse probability of treatment weights to adjust for confounders. RESULTS: = 0.01) between younger (HR = 1.18; 95%CI:1.08-1.29) and older (HR = 1.01; 95%CI:0.93-1.09) recipients. CONCLUSIONS:Compared with IL-2RA induction, ATG was associated with elevated post-KT malignancy risk but only among younger recipients. Transplant centers may need to tailor induction IS for younger recipients to mitigate malignancy risk.

Hydroxychloroquine (HCQ) is an antimalarial drug with immunomodulatory effects used to treat systemic lupus erythematosus (SLE) and scleroderma. The antiviral effects of HCQ have raised attention in the context of the COVID-19 pandemic, although safety is controversial. We examined linkages of national transplant registry data with pharmaceutical claims and Medicare billing claims to study HCQ use among Medicare-insured kidney transplant recipients with SLE or scleroderma (2008-2017; N = 1820). We compared three groups based on immunosuppression regimen 7 months-to-1 year post transplant: (a) tacrolimus (Tac) + mycophenolic acid (MPA) + prednisone (Pred) (referent group, 77.7%); (b) Tac + MPA + Pred + HCQ (16.5%); or (c) other immunosuppression + HCQ (5.7%). Compared to the referent group, recipients treated with other immunosuppression + HCQ had a 2-fold increased risk of abnormal ECG or QT prolongation (18.9% vs. 10.7%; aHR,_1.12 1.96_3.42 , p = .02) and ventricular arrhythmias (15.2% vs. 11.4%; aHR,_1.00 1.81_3.29 , p = .05) in the >1-to-3 years post-transplant. Tac + MPA + Pred + HCQ was associated with increased risk of ventricular arrhythmias (13.5% vs. 11.4%; aHR,_1.02 1.54_2.31 , p = .04) and pancytopenia (35.9% vs. 31.4%; aHR,_1.03 1.31_1.68 , p = .03) compared to triple immunosuppression without HCQ. However, HCQ-containing regimens were not associated with an increased risk of death or graft failure. HCQ may be used safely in selected kidney transplant recipients in addition to their maintenance immunosuppression, although attention to arrhythmias is warranted.

OBJECTIVES:Over 40% of individuals in the United States with end-stage kidney disease have obesity. Little is known about renal dietitian perspectives on obesity management in the setting of dialysis dependence. DESIGN AND METHODS:An online 21-item survey was distributed to 118 renal dietitians via individual outreach and a professional organization e-mail listserv. Four themes were explored: the burden of obesity among dialysis patients, concepts of healthy weight loss, weight loss approaches, and challenges of obesity management in dialysis settings. Respondents were asked to rank approaches and biomarkers for obesity management from 0 (least important or not used) to 100 (most important). Free text fields were provided in each category for additional comments. RESULTS:Thirty-one renal dietitians responded to the survey (26% response rate). The majority of respondents (90%) indicated that access to kidney transplantation was the main reason that dialysis patients with obesity desired weight loss. Calorie restriction was rated as the most common weight loss approach, and dry weight as the most important weight loss biomarker. Nearly 40% of respondents do not alter their nutritional approach when dialysis patients with obesity are losing weight, and 42% of respondents do not monitor changes in waist circumference. Exercise, diet counseling, and stress management were variably prioritized as weight loss management strategies. Barriers to obesity management in dialysis settings included lack of time, lack of training in weight loss counseling, and gaps in current renal nutritional guidelines. CONCLUSION:Despite the high prevalence of obesity among individuals with end-stage kidney disease, the results of this survey suggest that current approaches to obesity management in dialysis settings are highly variable. Many renal dietitians lack time to counsel patients on healthy weight loss strategies. Nutritional guidelines are also needed to support people with dialysis dependence and obesity who desire or require weight loss.

RATIONALE & OBJECTIVE:The current clinical guidelines for vascular access do not have specific recommendations for older hemodialysis patients. Our study aimed to determine the association of age with arteriovenous fistula (AVF) placement, maturation, and primary and secondary patency loss among older hemodialysis recipients. STUDY DESIGN:Retrospective cohort study. SETTING & PARTICIPANTS:A US national cohort of incident hemodialysis patients 67 years or older (N = 43,851) assembled from the US Renal Data System. EXPOSURE:Age at dialysis initiation. OUTCOMES:AVF placement, maturation, primary patency loss, and abandonment. ANALYTICAL APPROACH:Cause-specific and subdistribution proportional hazards models were used to examine the association of age and AVF outcomes, with kidney transplantation, peritoneal dialysis, and death treated as competing events. Age cutoff was identified by restricted cubic splines. We compared crude and inverse probability-weighted cumulative incidence functions using Gray's test. RESULTS:As compared with those aged 67-<77 years, patients 77 years or older had significantly lower probabilities of AVF placement (adjusted cause-specific HR [cHR], 0.96 [95% CI, 0.92-0.99]; adjusted subdistribution HR [sHR], 0.92 [95% CI, 0.89-0.95]; Gray's test P < 0.001) and maturation (adjusted cHR, 0.95 [95% CI, 0.91-0.99]; adjusted sHR, 0.93 [95% CI, 0.90-0.97]; P < 0.001). However, age was not associated with AVF primary (adjusted cHR, 1.05 [95% CI, 1.00-1.11]; adjusted sHR, 1.04 [95% CI, 0.99-1.09]; P = 0.09) or secondary (adjusted cHR, 1.06 [95% CI, 0.94-1.20]; adjusted sHR, 1.05 [95% CI, 0.93-1.18]; P = 0.4) patency loss. LIMITATIONS:Reliance on administrative claims to ascertain AVF outcomes. CONCLUSIONS:The likelihood of AVF maturation is an important consideration for vascular access planning. Age alone should not be the basis for excluding older dialysis patients from AVF creation because maintenance of fistula patency was not reduced with older age despite a modest reduction in fistula maturation.

BACKGROUND:Kidney disease and dialysis significantly impact cognitive function across the age spectrum. Cognitive training (CT) and/or exercise training (ET) are promising approaches to preserve cognitive function among community-dwelling older adults, but have not been tested for cognition preservation in hemodialysis patients of all ages. In this manuscript, we summarize the protocol for the Interventions Made to Preserve Cognitive Function Trial (IMPCT). METHODS:We will perform a 2 × 2 factorial randomized controlled trial (RCT) of eligible adult (≥18 years) hemodialysis initiates (n = 200) to test whether intradialytic CT (brain games on a tablet PC), ET (foot peddlers) and combined CT + ET while undergoing hemodialysis preserves executive function compared to standard of care (SC). Participants will engage in the interventions to which they are randomized for 6 months. The primary objective is to compare, among interventions, the 3-month change in executive function measured using the Trail Making Test A (TMTA) and B (TMTB); specifically, executive function is calculated as TMTB-TMTA to account for psychomotor speed. This primary outcome was selected based on findings from our pilot study. The secondary objectives are to compare the risk of secondary cognitive outcomes, ESKD-specific clinical outcomes, and patient-centered outcomes at 3-months and 6-months. All data collection and interventions are conducted in the dialysis center. DISCUSSION:We hypothesize that receiving intradialytic CT or ET will better preserve executive function than SC but receiving combined CT + ET, will be the most effective intervention. The current trial will be an important step in understanding how intradialytic interventions might preserve cognitive health. TRIAL REGISTRATION:Clinicaltrials.Gov (Date: 8/6/18): # NCT03616535 . Protocol Version: 10 (April 2020). FUNDING:NIDDK R01DK114074.

The outcomes of benzodiazepine and opioid co-prescription are not well-defined in transplant populations. We examined linked national transplant registry and pharmaceutical records to characterize benzodiazepine and opioid use in the years before and after transplant in large US cohort of kidney transplant recipients (2007-2016; N = 98 620), and associations (adjusted hazard ratio, _LCL aHR_UCL ) with death and graft failure. Among the cohort, 15.6% filled benzodiazepine prescriptions in the year before transplant, and 14.0% filled benzodiazepine prescriptions in the year after transplant (short-acting, 9.5%; long-acting, 3.3%; both 1.1%). Use of short-acting benzodiazepines in the year before transplant was associated with a 22% increased risk of death in the year after transplant (aHR, _1.08 1.22_1.38 ), while use of all classes in the year after transplant was associated with increased risk of death from >1 to 5 years (aHR: short-acting _1.29 1.39_1.48 ; long-acting _1.12 1.25_1.40 ; both _1.46 1.74_2.07 ). Recipients who used benzodiazepines were also more likely to fill opioid prescriptions. Recipients who filled both classes of benzodiazepine and the highest level of opioids had a 2.9-fold increased risk of death compared to recipients who did not use either. Co-prescription of benzodiazepines and opioids in kidney transplant recipients is associated with increased mortality. Ongoing research is needed to understand mechanisms of risk relationships.

BACKGROUND & AIMS:To date, studies evaluating the association between frailty and mortality in patients with cirrhosis have been limited to assessments of frailty at a single time point. We aimed to evaluate changes in frailty over time and their association with death/delisting in patients too sick for liver transplantation. METHODS:Adults with cirrhosis, listed for liver transplantation at 8 US centers, underwent ambulatory longitudinal frailty testing using the liver frailty index (LFI). We used multilevel linear mixed-effects regression to model and predict changes in LFI (ΔLFI) per 3 months, based on age, gender, model for end-stage liver disease (MELD)-Na, ascites, and hepatic encephalopathy, categorizing patients by frailty trajectories. Competing risk regression evaluated the subhazard ratio (sHR) of baseline LFI and predicted ΔLFI on death/delisting, with transplantation as the competing risk. RESULTS:We analyzed 2,851 visits from 1,093 outpatients with cirrhosis. Patients with severe worsening of frailty had worse baseline LFI and were more likely to have non-alcoholic fatty liver disease, diabetes, or dialysis-dependence. After a median follow-up of 11 months, 223 (20%) of the overall cohort died/were delisted because of sickness. The cumulative incidence of death/delisting increased by worsening ΔLFI group. In competing risk regression adjusted for baseline LFI, age, height, MELD-Na, and albumin, a 0.1 unit change in ΔLFI per 3 months was associated with a 2.04-fold increased risk of death/delisting (95% CI 1.35-3.09). CONCLUSION:Worsening frailty was significantly associated with death/delisting independent of baseline frailty and MELD-Na. Notably, patients who experienced improvements in frailty had a lower risk of death/delisting. Our data support the longitudinal measurement of frailty, using the LFI, in patients with cirrhosis and lay the foundation for interventional work aimed at reversing frailty. LAY SUMMARY:Frailty, as measured at a single time point, is predictive of death in patients with cirrhosis, but whether changes in frailty over time are associated with death is unknown. In a study of over 1,000 patients with cirrhosis who underwent frailty testing, we demonstrate that worsening frailty is strongly linked with mortality, regardless of baseline frailty and liver disease severity. Notably, patients who experienced improvements in frailty over time had a lower risk of death/delisting. Our data support the longitudinal measurement of frailty in patients with cirrhosis and lay the foundation for interventional work aimed at reversing frailty.

PURPOSE OF REVIEW:Chronic kidney disease (CKD) is characterized by poor levels of physical activity which contribute to increased morbidity across the disease trajectory. The short nature, small samples, and poor methodology across most studies have failed to translate the role of exercise in CKD into its adoption as a frontline adjunct therapeutic option. This review focuses on recent advances surrounding the benefits of exercise interventions across the CKD spectrum. RECENT FINDINGS:Key recent advances in exercise studies have focused on the efficacy of novel intervention strategies across the CKD spectrum. These include high-intensity interval training, virtual reality gaming, intradialytic yoga, electrical stimulation of muscles, blood flow restriction training, and protocols combining exercise with nutritional supplementation. Research is also beginning to explore the role of prehabilitation for patients prior to dialysis and kidney transplantation. SUMMARY:Studies continue to demonstrate wide-ranging benefits of exercise across CKD; however, implementation of exercise remains scarce. Future research needs include evaluating the efficacy of larger and/or more comprehensive interventions on clinically important outcomes. It is hoped with increasing global evidence, high-quality clinical studies, and sustained clinician and patient engagement, exercise programs will become better prioritized in the nephrology field.

BACKGROUND:Falls occur in 28% of hemodialysis patients and increase the risk of physical impairment, morbidity, and mortality. Therefore, it is likely that kidney transplantation (KT) candidates with recurrent falls are less likely to access KT and more likely to experience adverse post-KT outcomes. METHODS:We used a 2-center cohort study of KT candidates (n = 3666) and recipients (n = 770) (January 2009 to January 2018). Among candidates, we estimated time to listing, waitlist mortality, and transplant rate by recurrent falls (≥2 falls) before evaluation using adjusted regression. Among KT recipients, we estimated risk of mortality, graft loss, and length of stay by recurrent falls before KT using adjusted regression. RESULTS:Candidates with recurrent falls (6.5%) had a lower chance of listing (adjusted hazard ratio [aHR] = 0.68, 95% confidence interval [CI], 0.56-0.83) but not transplant rate; waitlist mortality was 31-fold (95% CI, 11.33-85.93) higher in the first year and gradually decreased over time. Recipients with recurrent falls (5.1%) were at increased risk of mortality (aHR = 51.43, 95% CI, 16.00-165.43) and graft loss (aHR = 33.57, 95% CI, 11.25-100.21) in the first year, which declined over time, and a longer length of stay (adjusted relative ratio [aRR] = 1.13, 95% CI, 1.03-1.25). In summary, 6.5% of KT candidates and 5.1% of recipients experienced recurrent falls which were associated with adverse pre- and post-KT outcomes. CONCLUSIONS:While recurrent falls were relatively rare in KT candidates and recipients, they were associated with adverse outcomes. Transplant centers should consider employing fall prevention strategies for high-risk candidates as part of comprehensive prehabilitation.