Exercise Rehabilitation for People With End-Stage Kidney Disease: Who Will Fill the Gaps?

Exercise rehabilitation is a well established therapy for reducing morbidity and mortality and improving quality of life and function across chronic conditions. People with dialysis-dependent kidney failure have a high burden of comorbidity and symptoms, commonly characterised as fatigue, dyspnoea, and the inability to complete daily activities. Despite more than 30 years of exercise research in people with kidney disease and its established benefit in other chronic diseases, exercise programs are rare in kidney care and are not incorporated into routine management at any stage. In this review, we describe the mechanisms contributing to exercise intolerance in those with end-stage kidney disease and outline the role of exercise rehabilitation in addressing the major challenges to kidney care: cardiovascular disease, symptom burden, and physical frailty. We also draw on existing models of exercise rehabilitation from other chronic conditions to inform the way forward and challenge the status quo of exercise rehabilitation in both practice and research.

Abstract P347: Measures of Microvascular Complications Varies Across Racial/Ethnic Groups Over a Seven Year Period: Post-Hoc Analysis of Action to Control Cardiovascular Risk in Diabetes (ACCORD) Trial Data

Introduction: Type 2 diabetes (T2D) microvascular complications is a major public health issue that disproportionately affects people of color in the U.S. and Canada. There is limited understanding of racial/ethnic disparities in the longitudinal natural history of microvascular complications. We aimed to address this gap in knowledge by examining racial/ethnic differences in microvascular complication-related measures over seven years among T2D adults living in the U.S. and Canada.

Hypothesis: We assessed the hypothesis that measures of microvascular complications vary by race/ethnic group over a period of seven years.

Methods: From 10,251 Action to Control Cardiovascular Risk in Diabetes (ACCORD) (2003-2009) trial participants, we derived 6,683 participants having a baseline and ≥ two years of outcome recordings for our analysis (baseline mean age 62 ± 6.6 years, and 11 ± 7.4 years of diabetes diagnosis). In this longitudinal study, we used T2D microvascular measurements recorded at baseline, yearly for seven years, and during a trial exit period. Neuropathy-related measures analyzed was the Michigan Neuropathy Screening Instrument (MNSI); Nephropathy-related measures included the glomerular filtration rate (eGFR) by four-variable Modification of Diet in Renal Disease equation (ml/min/1.73 m 2 ), urine albumin (mg/dl), and urine albumin : creatinine (mg/g). We examined differences in measurement among Black (n 1 = 1,176), White (n 2 = 4,282), and Other race adults (n 3 = 1,229). We used multigroup latent growth modeling to compare models from fully constrained to unconstrained means, covariances, and residual variances models.

Results: MNSI, eGFR, and urine albumin significantly differed across racial/ethnic groups (ΔX 2 MNSI (2) = 231.8, p<0.001; ΔX 2 eGFR (2) = 489.2, p<0.001; ΔX 2 urine-albumin (2) = 194.6, p<0.001). We noticed that at least one of the means and covariances differed across racial/ethnic groups. The average MNSI trajectory for Other race/ethnicity (intercept=1.88, slope=-0.08) were better than that for Black (intercept=2.07, slope=-0.09) and White adults (intercept=2.67, slope=-0.14). The average eGFR trajectories for Black (intercept=88.86, slope=-1.16) and Other race/ethnicity (intercept=85.68, slope=-1.15) were better than that for White adults (intercept=82.59, slope=-1.36). However, average urine albumin trajectories for Black adults were worst (intercept=10.77, slope=0.98) followed by Other race/ethnicity (intercept=9.36, slope=0.73) and White adults (intercept=7.65, slope=0.57).

Conclusion: Trajectories of microvascular complication-related measures appear to vary by racial/ethnic group. Other race adults, with primarily consists of Hispanics, appeared to at lower risk of neuropathy for years than Black and White adults. Nephropathy outcomes could vary across racial/ethnic group depending on how nephropathy is defined.

MO607: Intradialytic Exercise: A Large-Scale Nationwide Implementation Study

BACKGROUND AND AIMS

Intradialytic exercise (IDE) is recommended for HD patients. However, this recommendation is mostly based on research conducted under optimal instead of real-world conditions, limiting generalizability and its implementation into routine clinical care. This study aims to analyze implementation outcomes of IDE in real-world conditions at a large-scale, nationwide level.

METHOD

After a pilot experience in a single unit, all NephroCare Portugal dialysis clinics were invited to initiate an IDE program. A national coordinator was nominated, and a nurse and a doctor were selected in each unit as local coordinators. A simple exercise protocol was designed to be easily applied by current dialysis staff (though some units benefited from exercise science student internships). The IDE protocol includes a bout of aerobic exercise (cycle ergometer) and lower limb resistance exercises (ankle weights).

The RE-AIM (reach, effectiveness, adoption, implementation and maintenance) framework was used to study clinical implementation over the first year. For each RE-AIM dimension, specific implementation outcomes were adapted to IDE. Effectiveness measures included safety (incidence of intradialytic adverse events over 1 year) and physical function at baseline and at 1 year (sit to stand 30, 8-foot up & go, handgrip strength, sit to stand 5 and single leg stance). For safety measures, IDE group was compared to a group of patients that refused IDE. Physical function measures were only applied to IDE patients, and so comparisons were made between low- and high-frequency exercise groups.

RESULTS

Adoption: 21 dialysis units (58.3%). Reach: 1270 eligible patients (55.8%). Main reasons for noneligibility were physical/cognitive incapacity (50.8%) and cardiovascular risk (34.9%). Eligible patients were younger (P &lt; 0.001) and had a better health status (lower comorbidity index: P &lt; 0.001; lower prevalence of diabetes: P &lt; 0.001; lower fat tissue index: P &lt; 0.001; and a higher lean tissue index: P &lt; 0.001). 811 (63.9%) committed to the intervention. Compared with non-IDE patients, IDE patients were younger (&lt;0.001), had a lower dialysis vintage (&lt;0.001), a lower comorbidity index (P &lt; 0.001) and a higher lean tissue index (P = 0.035). Implementation: adherence to exercise sessions was 75.0% ± 19.7%. In 77% of the 50 356 HD treatments, exercise was performed as prescribed. Non-performed exercise sessions (n = 9768) are mostly justified by patient refusal (61.5%) and pain (8.4%). Patients performed 2.2 ± 0.6 exercise sessions/week achieving 86.3 ± 29.0 min/week. Maintenance (setting level): none of the clinics interrupted IDE. Maintenance (patient level): attrition rate was 57.2% mainly due to voluntary withdrawal (52.4%). Comparing to voluntary withdrawals, completers were mainly males (P &lt; 0.001) and had a lower dialysis vintage (P = 0.007), and higher lean tissue index (P = 0.023). Effectiveness: IDE (n = 347) and non-IDE patients (n = 394) were compared. Total incidence of adverse events was lower in IDE, but no significant differences were found (P = 0.808). The individual analysis of each adverse event demonstrated no significant differences for cramps, hypotension, needle dislodgement and other adverse events. Overall physical function improved in IDE (P &lt; 0.001), despite a slight reduction in handgrip strength (P = 0.001). A within-group (low- versus high-frequency exercise) effect was observed, highlighting a deterioration in handgrip strength in the low-frequency group (P = 0.002), whereas no change was observed in the high-frequency group (P = 0.097).

CONCLUSION

Large-scale implementation of IDE is a realistic and safe way to promote physical activity in HD patients with benefits on physical function. Yet, to optimize its generalizability, strategies to increase patients´ acceptability and long-term adherence are needed.

Advances in exercise therapy in predialysis chronic kidney disease, hemodialysis, peritoneal dialysis, and kidney transplantation

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.

P1305CARDIAC OUTPUT AND ESTIMATED UPPER BODY BLOOD FLOW

Background and Aims

Cardiopulmonary monitoring during hemodialysis has the potential to improve dialysis adequacy, prevent adverse events, improve quality of dialysis patients’ lives and reduce mortality risks. Under stable conditions the knowledge of upper body oxygen consumption, the difference between arterial and venous oxygen saturation (ScvO2) and hemoglobin concentrations allow the calculation of estimated UBBF (eUBBF; Rosales 2019). We studied the association between eUBBF and cardiac output during hemodialysis.

Method

In patients with a central venous catheter as the vascular access, we simultaneously measured intradialytic central-venous oxygen saturation and hemoglobin levels once per minute using the Crit-Line Monitor (Fresenius Medical Care North America, Waltham, USA). Concomitantly we measured cardiac output (CO) using the Task Force Monitor (CNSystems, Graz, Austria). We depicted CO and eUBBF as box-whiskers in 5 minute periods from 20 to 180 minutes, tested the minute-level time series for stationarity using the Dickey-Fuller test, employed differencing to make the time series stationary, and tested for linear associations using cross-correlations and determined if the CO time series was useful to predict the eUBBF time series using the Granger Causality test.

Results

We studied 13 patients (59±14 years, 5 (38%) male, 93±22 kg pre-dialysis weight 170±7 cm tall) during 34 hemodialyses. CO and UBBF was 4.7±1.0 and 1.3±0.4 L/min, and showed a small trend downward for CO during hemodialysis. Cross-correlations showed no remarkable correlations for all treatments, Granger causality index was less than 20% in 8 treatments however without clearly discernible patterns.

Conclusion

Despite variability in the CO the eUBBF remains stable, a dynamic which pathophysiologically appears plausible. While testing for linear associations yielded no significant relationships, based on the Granger causality test there nevertheless appears to be some form of a relationship which requires some further investigation which will need to also include aspects such as fluid overload, body temperature and total peripheral resistance. Based on this data, cardiopulmonary monitoring appears possible and yields a reliable continuous overview of the hemodynamic status of a patient.

Expressions of Gratitude and Positive Emotion among Hemodialysis Patients: Qualitative Findings

Objectives

The current qualitative inquiry solicited hemodialysis (HD) patients to identify events or incidences that have gone well in their day-to-day life, things they consider to be blessings, and to further reflect on the contributors of such events.

Methods

Hemodialysis patients kept an electronic journal using investigator-purchased tablet computers.

Results

Multiple themes emerged for which HD patients expressed gratitude: 1) life itself, 2) positive or improving health 3) family interactions and social support, 4) clinic resources, favorable treatment therapy, and staff, and 5) other small events.

Conclusions

Clinicians are urged to explore the psychological assets that HD patients possess with a focus on how these might be further cultivated and whether their amplification leads to improved quality of life.

Feasibility of an Internet-based positive psychological intervention for hemodialysis patients with symptoms of depression

BACKGROUND

Depression is a pervasive psychological issue facing hemodialysis (HD) patients. Novel technology-based treatment strategies that deploy psychology-based interventions have not been the focus for therapy and few published studies exist. The aim of the current trial is to determine the feasibility and acceptability of an Internet-based positive psychological intervention in HD patients with comorbid depressive symptoms.

METHODS

HD patients (n = 14) with elevated symptoms of depression were enrolled in a single-arm pre-post trial with clinical assessments at baseline and immediately post intervention. Chairside during regularly scheduled HD treatment, patients utilized a web browser to complete online modules promoting skills for increasing positive emotion over a 5-week period using Apple IPads. Targeted skills included noting of daily positive events, gratitude, positive reappraisal, acts of kindness, and mindfulness/meditation.

RESULTS

Twelve of 14 patients completed the program for an 85.7% retention rate. Participants felt satisfied with each session and offered consistently positive feedback. On average, participants visited the website 3.5 times per week. Significant improvements were evident for depressive symptoms (15.3 vs. 10.9; p = 0.04), as per the Center for Epidemiological Studies Depression Scale.

CONCLUSIONS

An innovative Internet-based positive psychological intervention represents a feasible and useful therapeutic option for HD patients with depressive symptoms.

Falls and Fall-Related Injuries Among US Adults Aged 65 or Older With Chronic Kidney Disease

Introduction

Falls are among the leading causes of injury and death among adults aged 65 or older. People with chronic kidney disease (CKD) are at increased risk of falling and of having a serious injury from falls. However, information is limited about risk factors for falls and fall-related injuries among people with CKD.

Methods

We performed a secondary analysis of 157,753 adults (6.1% with CKD) aged 65 or older surveyed in the 2014 Behavioral Risk Factor Surveillance System.

Results

People with CKD were at increased risk of falls (odds ratio [OR] = 1.81; 95% confidence interval [CI], 1.63–2.01) and fall-related injuries (OR = 1.50; 95% CI, 1.27–1.78) even after adjusting for differences in demographic characteristics, health conditions, and lifestyle factors (P < .05 for all). Among people with CKD, women, people diagnosed with diabetes, diabetes duration, and arthritis were all significant predictors of falls and fall-related injuries (P < .05 for all). Lifestyle factors, such as engaging in recent exercise (adjusted odds ratio [AOR] = 0.68; 95% CI, 0.56–0.81) and limited physical function (assessed as difficulty in climbing stairs) (AOR = 2.84; 95% CI, 2.30–3.44), were most closely associated with falls and fall-related injuries.

Conclusion

Adults aged 65 or older with CKD were at increased risk of falling and of suffering an injury as a result of a fall compared with adults in the same age range without CKD. Potentially modifiable factors such as physical function and recent exercise were most closely related to reduced risk for falls and fall-related injuries and may be an appropriate target for fall prevention and rehabilitation programs in people with CKD.

Exercise and CKD: Skeletal Muscle Dysfunction and Practical Application of Exercise to Prevent and Treat Physical Impairments in CKD

Patients with chronic kidney disease experience substantial loss of muscle mass, weakness, and poor physical performance. As kidney disease progresses, skeletal muscle dysfunction forms a common pathway for mobility limitation, loss of functional independence, and vulnerability to disease complications. Screening for those at high risk for mobility disability by self-reported and objective measures of function is an essential first step in developing an interdisciplinary approach to treatment that includes rehabilitative therapies and counseling on physical activity. Exercise has beneficial effects on systemic inflammation, muscle, and physical performance in chronic kidney disease. Kidney health providers need to identify patient and care delivery barriers to exercise in order to effectively counsel patients on physical activity. A thorough medical evaluation and assessment of baseline function using self-reported and objective function assessment is essential to guide an effective individualized exercise prescription to prevent function decline in persons with kidney disease. This review focuses on the impact of kidney disease on skeletal muscle dysfunction in the context of the disablement process and reviews screening and treatment strategies that kidney health professionals can use in clinical practice to prevent functional decline and disability.

It's a Non-Dialysis Day… Do You Know How Your Patient Is Doing? A Case for Research into Interdialytic Activity

Hemodialysis (HD) patients are less active than their healthy counterparts; this is associated with higher mortality. Healthcare workers observe their patients only during HD, which accounts for about 7% of the week. Knowing more about what occurs in between sessions, particularly with respect to physical activity, may improve patient care and prognosis. Yet without a standard method to measure interdialytic activity, it is difficult to compare the effect of interventions. However, it is unclear how interdialytic activity can be accurately measured. Since activity associated with quality of life is multi-dimensional, objective and subjective tools should be used in conjunction. While commercially available tracking devices can be seamlessly incorporated into everyday life and can increase awareness of user's activity, their validation is needed in the HD population. Fertile topics for research should include the relationship between objective and subjective measures in HD patients, and the investigation of physical activity in non-ambulatory HD patients.

Sex differences in ventricular-vascular coupling following endurance training

Introduction

Ventricular and vascular coupling is defined as the ratio of arterial elastance (Ea) to ventricular elastance (Elv) and describes the interaction between the heart and arterial system. There are sex differences in both arterial and ventricular function in response to both acute exercise and aerobic exercise training.

Purpose

To examine the effects of aerobic exercise training on elastances and the coupling ratio in young adult men and women. We hypothesized a reduction in the coupling ratio in both sexes due to a decrease in Ea that would be more pronounced in men and an increase in Elv that would be larger in women.

Methods

Fifty-three healthy, young adults completed the study. Central pulse wave velocity and heart volumes were measured before and after an 8-week aerobic training intervention. Elastances were calculated as Ea = end-systolic pressure/stroke volume and Elv = end-systolic pressure/end-systolic volume and indexed to body surface area.

Results

After the intervention, women augmented indexed and un-indexed Elv from 2.09 ± 0.61 to 2.52 ± 0.80 mmHg/ml, p < 0.05, and reduced the coupling ratio from 0.72 ± 18 to 0.62 ± 15, p < 0.05, while men maintained their pre-training ratio (from 0.66 ± 0.20 to 0.74 ± 0.21, p > 0.05). Women also reduced end-systolic pressure (from 91 ± 10 to 87 ± 10 mmHg), and both groups reduced central pulse wave velocity (from 6.0 ± 1.0 to 5.6 ± 0.6 m/s, p < 0.05).

Conclusion

We conclude that after 8 weeks of aerobic training, only women reduced their coupling ratio due to an increase in Elv. This suggests that aerobic exercise training elicits sex-dependent changes in the coupling ratio in young, healthy individuals.

Elderly persons with ICU-acquired weakness: the potential role for β-hydroxy-β-methylbutyrate (HMB) supplementation?

Intensive care unit (ICU)-acquired weakness is common and characterized by muscle loss, weakness, and paralysis. It is associated with poor short-term outcomes, including increased mortality, but the consequences of reduced long-term outcomes, including decreased physical function and quality of life, can be just as devastating. ICU-acquired weakness is particularly relevant to elderly patients who are increasingly consuming ICU resources and are at increased risk for ICU-acquired weakness and complications, including mortality. Elderly patients often enter critical illness with reduced muscle mass and function and are also at increased risk for accelerated disuse atrophy with acute illness. Increasingly, intensivists and researchers are focusing on strategies and therapies aimed at improving long-term neuromuscular function. β-Hydroxy-β-methylbutyrate (HMB), an ergogenic supplement, has shown efficacy in elderly patients and certain clinical populations in counteracting muscle loss. The present review discusses ICU-acquired weakness, as well as the unique physiology of muscle loss and skeletal muscle function in elderly patients, and then summarizes the evidence for HMB in elderly patients and in clinical populations. We subsequently postulate on the potential role and strategies in studying HMB in elderly ICU patients to improve muscle mass and function.

Arterial stiffness and walk time in patients with end-stage renal disease

BACKGROUND

End-stage renal disease patients experience increased prevalence of cardiovascular disease. Heart-artery interaction may be shifted, impacting blood pressure lability, and exercise tolerance. The coupling ratio consists of the ratio of indexed arterial elastance (EaI, arterial load) to ElvI, a measure of cardiac contractility or stiffness. Our purpose was to explore the relationship between elastances and functional capacity. We hypothesized that arterial stiffness (central pulse wave velocity, PWV) and elastances would be correlated to shuttle walk time.

METHODS

We used applanation tonometry, ultrasonography, and a shuttle walk test to evaluate our hypothesis. Spearman's correlations were used to assess relationships between variables. Block regression was also performed.

RESULTS

Forty-two subjects on maintenance hemodialysis participated. Average age=44±5 years, body surface area=2.01 kg/m(2). Mean EaI=4.45 and mean ElvI=6.89; the coupling ratio=0.82. Mean aortic pulse pressure=51 mmHg and PWV=9.6 m/s. PWV(r=-0.385) and EaI (r=-0.424) were significantly and inversely related to walking time while stroke volume index (SVI) was positively correlated to shuttle walk time (r=0.337), p<0.05 for all.

CONCLUSIONS

We conclude that, like other clinical populations, both arterial and heart function predict walking ability and represent potential targets for intervention; arterial stiffness and SVI are strongly related to shuttle walk time in patients with ESRD.

Effect of sex on wasted left ventricular effort following maximal exercise

Wasted left ventricular effort (∆Ew) refers to work required of the left ventricle to eject blood that does not result in increased stroke volume and is related to left ventricular hypertrophy. Literature shows that men and women have differing ventricular and vascular responses to and following exercise. Our purpose was to determine how ∆Ew changes post-exercise in men and women and examine potential mechanisms. We hypothesized a reduction in ∆Ew that would be greater in men and that central pulse wave velocity and wave intensity (WIA) would be related to ∆Ew. Blood pressures, central pulse wave velocity (cPWV), and WIA were obtained at rest, 15 and 30 min after maximal exercise. Both sexes reduced ∆Ew post-maximal exercise (p>0.05 for interaction), but women had higher ∆Ew at each time point (p<0.05). The first peak of WIA increased 15 min post-exercise only in women (p<0.05). cPWV was attenuated (p<0.05) in women at 15 min and men at 30 min (p<0.05) post-exercise with a significant time by sex interaction (p<0.05). WIA (1st peak) was correlated (p<0.05) to ∆Ew in both sexes before and 15 min post-exercise, but cPWV was only associated with ∆Ew in men at 30 min post-exercise. We conclude that both sexes decrease ∆Ew after maximal exercise, but vascular and ventricular changes associated with the attenuation of ∆Ew are not uniform between sexes.

Autosomal recessive hypercholesterolaemia in Sardinia, Italy, and mutations in ARH: a clinical and molecular genetic analysis

BACKGROUND

Autosomal recessive hypercholesterolaemia (ARH) is caused by mutations in a putative adaptor protein called ARH. This recessive disorder, characterised by severe hypercholesterolaemia, xanthomatosis, and premature coronary artery disease, is rare except on the island of Sardinia, Italy. Our aim was to ascertain why ARH is more common on Sardinia than elsewhere.

METHODS

We obtained detailed medical histories, did physical examinations, measured concentrations of lipoproteins, and harvested genomic DNA from 28 Sardinians with ARH from 17 unrelated families. We sequenced the coding regions and consensus splice sites of ARH in probands from these families, and from 40 individuals of non-Sardinian origin who had an autosomal recessive form of hypercholesterolaemia of unknown cause.

FINDINGS

Two ARH mutations, a frameshift mutation (c432insA) in exon 4 (ARH1) and a nonsense mutation (c65G-->A) in exon 1 (ARH2), were present in all of the 17 unrelated families with ARH. Three of the ARH alleles contained both mutations, as a result of an ancient recombination between ARH1 and ARH2. No regional clustering of the three mutant alleles within Sardinia was apparent. Furthermore, four Italians from the mainland with autosomal recessive hypercholesterolaemia were homozygous for ARH1.

INTERPRETATION

The small number, high frequency, and dispersed distribution of ARH mutations on Sardinia are consistent with these mutations being ancient and maintained in the Sardinian population because of geographic isolation.

Autosomal recessive hypercholesterolemia caused by mutations in a putative LDL receptor adaptor protein

Atherogenic low density lipoproteins are cleared from the circulation by hepatic low density lipoprotein receptors (LDLR). Two inherited forms of hypercholesterolemia result from loss of LDLR activity: autosomal dominant familial hypercholesterolemia (FH), caused by mutations in the LDLR gene, and autosomal recessive hypercholesterolemia (ARH), of unknown etiology. Here we map the ARH locus to an approximately 1-centimorgan interval on chromosome 1p35 and identify six mutations in a gene encoding a putative adaptor protein (ARH). ARH contains a phosphotyrosine binding (PTB) domain, which in other proteins binds NPXY motifs in the cytoplasmic tails of cell-surface receptors, including the LDLR. ARH appears to have a tissue-specific role in LDLR function, as it is required in liver but not in fibroblasts.