Habitual physical activity measured by accelerometer and survival in maintenance hemodialysis patients

Patient-Reported Outcomes in Patients with Chronic Kidney Disease and Kidney Transplant-Part 1

Chronic kidney disease (CKD) is a complex medical condition that is associated with several comorbidities and requires comprehensive medical management. Given the chronic nature of the condition, its frequent association with psychosocial distress, and its very significant symptom burden, the subjective patient experience is key toward understanding the true impact of CKD on the patients’ life. Patient-reported outcome measures are important tools that can be used to support patient-centered care and patient engagement during the complex management of patients with CKD. The routine collection and use of patient-reported outcomes (PROs) in clinical practice may improve quality of care and outcomes, and may provide useful data to understand the disease from both an individual and a population perspective. Many tools used to measure PROs focus on assessing health-related quality of life, which is significantly impaired among patients with CKD. Health-related quality of life, in addition to being an important outcome itself, is associated with clinical outcomes such as health care use and mortality. In Part 1 of this review, we provide an overview of PROs and implications of their use in the context of CKD. In Part 2, we will review the selection of appropriate measures and the relevant domains of interest for patients with CKD.

Integrative Examination of Motor Abilities in Dialysis Patients and Selection of Tests for a Standardized Physical Function Assessment

To reduce the need for a large number of executed physical function tests we examined inter-relations and determined predictive power for daily physical activity of the following tests: 6-min walk, 10 repetition sit-to-stand, time up-and-go, Storke balance, handgrip strength, upper limb tapping and sitting forward bend tests. In 90 dialysis and 140 healthy control subjects we found high correlations between all tests, especially those engaging lower extremities. Sit-to-stand, forward bend and handgrip strength were selected for the test battery and composite motor performance score. Sit-to-stand test was superior in terms of sensitivity to uremia effects and association with daily physical function in adjusted analyses. There was no incremental value in calculating the composite performance score. We propose to standardize the physical function assessment of dialysis patients for cross-sectional and longitudinal observations with three simple, cheap, well-accessible and easily performed test tools: sit-to-stand test, handgrip strength and Human Activity Profile questionnaire.

Physical Activity Dose for Hemodialysis Patients: Where to Begin? Results from a Prospective Cohort Study

OBJECTIVE

Greater physical activity is associated with lower risk of mortality in persons with kidney disease; however, little is known about the appropriate dose of physical activity among hemodialysis patients. Here detected the minimum level of habitual physical activity to help inform interventions aimed at improving outcomes in the dialysis population.

DESIGN

The design was prospective cohort study.

SUBJECTS

Clinically stable outpatients in a hemodialysis unit from October 2002 to March 2014 were assessed for their eligibility to be included in this 7-year prospective cohort study. We used the Youden index to determine the optimal cutoff points for physical activity. The prognostic effect of physical activity on survival was estimated by Cox proportional hazards regression analysis. The number of steps per nondialysis day was recorded by accelerometer at study entry.

MAIN OUTCOME MEASURE

The main outcome measure was all-cause mortality.

RESULTS

There were 282 participants who had a mean age of 65 ± 11 years and 45% were female. A total of 56 deaths occurred during the follow-up period (56 months [interquartile range: 29-84 months]). The cutoff value for the physical activity discriminating those at high risk of mortality was 3,752 steps. After adjustment for the effect of confounders, the hazard ratio in the group of <4,000 steps was 2.37 (95% confidence interval: 1.22-4.60, P = .01) compared with the others.

CONCLUSIONS

Engaging in physical activity is associated with decreased mortality risk among hemodialysis patients. Our findings of a substantial mortality benefit among those who engage in at least 4,000 steps provide a basis for as a minimum initial recommendation kidney health providers can provide for mobility disability-free hemodialysis patients.

Exercise Training in Elderly People Undergoing Hemodialysis: A Systematic Review and Meta-analysis

Introduction

Previous reviews have indicated the effectiveness of exercise in people undergoing hemodialysis. However, these analyses did not take into account whether the subjects were elderly. We performed a systematic review of the effects of exercise training in elderly people undergoing hemodialysis and updated the evidence of exercise for people undergoing hemodialysis by adding recent research data.

Methods

We searched 8 electronic databases up to June 2016. Inclusion criteria were as follows: randomized controlled trial, English publication, subjects aged 18 and older undergoing hemodialysis, evaluation of physical function as an outcome of exercise intervention. We defined elderly as age 60 years and older. The main outcomes were exercise tolerance (peak/maximum oxygen consumption) and walking ability (6-minute walk distance). Secondary outcomes were lower extremity muscle strength and quality of life.

Results

After screening of 10,923 references, 30 comparisons were entered into the analysis. However, because we found only 1 study in which elderly subjects were treated, we could not perform a meta-analysis for these people. For the general population undergoing hemodialysis, supervised exercise training was shown to significantly increase peak/maximum oxygen consumption (standard mean difference, 0.62; 95% confidence interval 0.38-0.87; P < 0.001), 6-minute walk distance (standard mean difference, 0.58; 95% confidence interval 0.24-0.93; P < 0.001), lower extremity muscle strength (standard mean difference, 0.94; 95% confidence interval 0.67-1.21; P < 0.001), and quality of life (standard mean difference, 0.53; 95% confidence interval 0.52-0.82; P < 0.001).

Discussion

Our analysis on the effectiveness of exercise training in elderly people undergoing hemodialysis as compared with nonelderly people was somewhat inconclusive. Future studies should be carried out for elderly people to identify the most favorable exercise program for this population.

Assessment of physical activity, capacity and nutritional status in elderly peritoneal dialysis patients

Background

This study aimed to evaluate the prevalence of sedentarism, and to assess physical capacity and nutritional status in a cohort of older patients on peritoneal dialysis (PD), with respect to age-matched non-dialysis CKD population, using highly accessible, simple methods, namely the Rapid Assessment of Physical activity (RAPA) test and the 30″ Sit-to-stand (STS) test.

Methods

This cross-sectional multicenter study included 151 renal patients older than 60 years; 71 pts. (44 m, age 72 ± 7 yrs) were on PD and 80 pts. (63 m, age 74 ± 7 yrs) were affected by 3–4 stage CKD.

Results

The prevalence of sedentary/underactive patients was double of that of the active patients as assessed by RAPA test, both in the PD (65.3%) and in the CKD (67.5%) cohort.

The 30"STS test showed a reduced physical performance in both groups: 84.5% of PD patients and 87.5% of CKD patients did not reach the expected number of stands by age and gender. A malnutrition-inflammation score (MIS) ≥ 6 occurred in 37 % of PD patients and in 2.5 % of CKD patients. In PD patients, an independent significant association was observed between 30”STS test and MIS (beta -0.510, p = 0.013), as well as between RAPA and MIS (beta -0.544, p = 003) and phase angle (beta -0.506, p = 0.028).

Conclusions

A high prevalence of low- performance capacity and sedentarism has been detected among elderly patients on PD or with CKD stage 3–4. Apart from age, a condition of malnutrition-inflammation was the major determinant of poor physical activity and capacity in PD patients. Better body composition seems to be positively associated with physical activity in PD and with physical capacity in CKD patients. Routine clinical management should include a close evaluation of nutritional status and evaluation of physical activity and capacity which can be easily assessed by RAPA and 30″STS tests.

Changes in physical activity and risk of all-cause mortality in patients on maintence hemodialysis: a retrospective cohort study

Background

A previous cohort study indicated a significant association of lower baseline level of physical activity in hemodialysis patients with elevated risks of mortality. However, there have been no reports regarding the association between changes in physical activity over time and mortality in hemodialysis patients. This study was performed to examine the prognostic significance of physical activity changes in hemodialysis patients.

Methods

This retrospective cohort study was performed in 192 hemodialysis patients with a 7-year follow-up. The average number of steps taken per non-dialysis day was used as a measure of physical activity. Forty (20.8%) patients had died during the follow-up period. The percentage change in physical activity between baseline and 12 months was determined, and patients were divided into three categories according to changes in physical activity. A decrease or increase in physical activity > 30% was defined as becoming less or more active, respectively, while decrease or increase in physical activity < 30% were classified as stable.

Results

Forty seven (24.5%), 51 (26.6%), and 94 (49.0%) patients were classified as becoming less active, becoming more active, and stable, respectively. The hazard ratio on multivariate analysis in patients with decreased physical activity was 3.68 (95% confidence interval, 1.55–8.78; P < 0.01) compared to those with increased physical activity.

Conclusions

Reductions in physical activity were significantly associated with poor prognosis independent of not only patient characteristics but also baseline physical activity. Therefore, improved prognosis in hemodialysis patients requires means of preventing a decline in physical activity over time.

Chronic kidney disease-related physical frailty and cognitive impairment: a systemic review

AIM

The objective of this review was to assess chronic kidney disease-related frailty and cognitive impairment, as well as their probable causes, mechanisms and the interventions.

METHODS

Studies from 1990 to 2015 were reviewed to evaluate the relationship between chronic kidney disease and physical frailty and cognitive impairment. Of the 1694 studies from the initial search, longitudinal studies (n = 22) with the keywords "Cognitive and CKD" and longitudinal or cross-sectional studies (n = 5) with the keywords "Frailty and CKD" were included in final analysis.

RESULTS

By pooling current research, we show clear evidence for a relationship between chronic kidney disease and frailty and cognitive impairment in major studies. Vascular disease is likely an important mediator, particularly for cognitive impairment. However, non-vascular factors also play an important role. Many of the other mechanisms that contribute to impaired cognitive function and increased frailty in CKD remain to be elucidated. In limited studies, medication therapy did not obtain the ideal effect. There are limited data on treatment strategies, but addressing the vascular disease risk factors earlier in life might decrease the subsequent burden of frailty and cognitive impairment in this population. Multidimensional interventions, which address both microvascular health and other factors, may have substantial benefits for both the cognitive impairments and physical frailty in this vulnerable population.

CONCLUSIONS

Chronic kidney disease is a potential cause of frailty and cognitive impairment. Vascular and non-vascular factors are the possible causes. The mechanism of chronic kidney disease-induced physical frailty and cognitive impairment suggests that multidimensional interventions may be effective therapeutic strategies in the early stage of chronic kidney disease. Geriatr Gerontol Int 2017; 17: 529-544.

Characterization of deficits across the spectrum of motor abilities in dialysis patients and the impact of sarcopenic overweight and obesity

BACKGROUND & AIMS

Physical performance deficits in kidney failure predict mortality and quality of life. We aimed to quantify deficits in multiple motor abilities, investigate associations of lean and fat tissue content with test results and analyzed performance of sarcopenic individuals with adipose tissue excess.

METHODS

Ninety hemodialysis patients and 140 healthy controls performed 6-minute walk test, gait speed measurement, sit-to-stand and time up and go tests, upper extremity handgrip and tapping tests, Stork balance and forward bend flexibility tests. Human Activity Profile questionnaire was used to assess habitual activity. Body composition was measured by bioimpedance analysis.

RESULTS

Relative performance deficit of dialysis patients in age, sex, height and comorbidity adjusted estimated marginal means was largest for balance and flexibility (-52 and -33%), followed by lower extremity deficits in sit-to-stand, time up and go and 6-minute walk tests (-29, -19 and -15%, respectively), p < 0.05 for all comparisons. Upper extremity performance was less affected. Lean tissue index associated significantly positively with five and fat tissue index associated significantly negatively with two out of nine tests. Sarcopenic overweight and obese individuals exhibited significant deficits mainly in lower extremity tests with worse composite lower extremity score when compared to other categories of body composition.

CONCLUSIONS

Patients with hemodialysis treated kidney failure have largest functional deficits in balance, flexibility and lower extremity functions. Lean and fat mass associate oppositely with physical performance measures and individuals at unfavorable extremes of these indices express significantly impaired lower extremity functions.

Physical Activity in Patients Treated With Peritoneal Dialysis: A Protocol for a Systematic Review

Background:

Patients with chronic diseases are known to benefit from exercise. Despite a lack of compelling evidence, patients with end-stage kidney disease treated with peritoneal dialysis are often discouraged from participating in exercise programs that include resistance training due to concerns about the development of hernias and leaks. The actual effects of physical activity with or without structured exercise programs for these patients remain unclear. The purpose of this study is to more completely define the risks and benefits of physical activity in the end-stage kidney disease population treated with peritoneal dialysis.

Methods/design:

We will conduct a systematic review examining the effects of physical activity on end-stage kidney disease patients treated with peritoneal dialysis. For the purposes of this review, exercise will be considered a purposive subcategory of physical activity. The primary objective is to determine if physical activity in this patient population is associated with improvements in mental health, physical functioning, fatigue and quality of life and if there is an increase in adverse outcomes. With the help of a skilled librarian, we will search MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials for randomized trials and observational studies. We will include adult end-stage kidney disease patients treated with peritoneal dialysis that have participated in an exercise training program or had their level of physical activity assessed directly or by self-report. The study must include an assessment of the association between physical activity and one of our primary or secondary outcomes measures. We will report study quality using the Cochrane Risk of Bias Assessment Tool for randomized controlled trials and the Newcastle–Ottawa Scale for observational studies. Quality across studies will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. The results of this review may help to inform guideline development for exercise recommendations specific to this patient population.

Systematic review registration:

PROSPERO:CRD42016041695.

Prehabilitation for the Frail Patient Approaching ESRD

Frailty is a distinct phenotype that is highly prevalent in chronic kidney disease (CKD) and appears to be more prevalent with decreasing glomerular filtration rate. Exercise training or intervention to increase physical activity may ameliorate poor physical functioning and frailty, and even may improve survival in patients with CKD. Although exercise interventions improve outcomes across the spectrum of CKD, including patients treated with dialysis, patients treated with dialysis face barriers to exercise that patients with predialysis CKD do not. Rehabilitation at earlier stages of CKD (or prehabilitation before dialysis) might be more beneficial than not addressing the decreasing physical functioning and low physical activity until patients are receiving dialysis. This review summarizes available literature on frailty in the CKD and end-stage renal disease population, including exercise interventions and the limited evidence for prehabilitation as a strategy.

The Effect of Chronic Kidney Disease on a Physical Activity Intervention: Impact on Physical Function, Adherence, and Safety

Background

Because chronic kidney disease (CKD) is associated with muscle wasting, older adults with CKD are likely to have physical function deficits. Physical activity can improve these deficits, but whether CKD attenuates the benefits is unknown. Our objective was to determine if CKD modified the effect of a physical activity intervention in older adults.

Methods

This is an exploratory analysis of the LIFE-P study, which compared a 12-month physical activity program (PA) to a successful aging education program (SA) in older adults. CKD was defined as a baseline eGFR < 60 mL/min/1.73 m². We examined the Short Physical Performance Battery (SPPB) at baseline, 6 and 12 months. Secondary outcomes included serious adverse events (SAE) and adherence to intervention frequency. Linear mixed models were adjusted for age, sex, diabetes, hypertension, CKD, intervention, site, visit, baseline SPPB, and interactions of intervention and visit and of intervention, visit, and baseline CKD.

Results

The sample included 368 participants. CKD was present in 105 (28.5%) participants with a mean eGFR of 49.2 ± 8.1 mL/min/1.73 m². Mean SPPB was 7.38 ± 1.41 in CKD participants; 7.59 ± 1.44 in those without CKD (p = 0.20). For CKD participants in PA, 12-month SPPBs increased to 8.90 (95% CI 8.32, 9.47), while PA participants without CKD increased to 8.40 (95% CI 8.01, 8.79, p = 0.43). For CKD participants in SA, 12-month SPPBs increased to 7.67 (95% CI 7.07, 8.27), while participants without CKD increased to 8.12 (95% CI 7.72, 8.52, p = 0.86). Interaction between CKD and intervention was non-significant (p = 0.88). Number and type of SAEs were not different between CKD and non-CKD participants (all p > 0.05). In PA, adherence for CKD participants was 65.5 ± 25.4%, while for those without CKD was 74.0 ± 22.2% (p = 0.12).

Conclusion

Despite lower adherence, older adults with CKD likely derive clinically meaningful benefits from physical activity with no apparent impact on safety, compared to those without CKD.

Evaluating the effectiveness of exercise training on elderly patients who require haemodialysis: study protocol for a systematic review and meta-analysis

INTRODUCTION

As the average age of haemodialysis patients rapidly increases around the world, the number of frail, elderly patients has increased. Frailty is well known to be an indicator of disability and a poor prognosis for haemodialysis patients. Exercise interventions have been safely and successfully implemented for middle-aged or younger patients undergoing haemodialysis. However, the benefits of exercise interventions on elderly patients undergoing haemodialysis remain controversial. The main objective of this study is to systematically review the effects of exercise training on the physical function, exercise capacity and quality of life of elderly patients undergoing haemodialysis, and to provide an update on the relevant evidence.

METHODS AND ANALYSES

Published randomised controlled trials (RCTs) that assessed the effectiveness of exercise training on haemodialysis patients with respect to physical function, exercise tolerance and quality of life will be included. Bibliographic databases include MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, CINAHL, Web of Science, PsycINFO and PEDro. The risk of bias of the included RCTs will be assessed using the Cochrane Collaboration's tool and TESTEX. The primary outcome will be physical function and exercise tolerance. This review protocol is reported according to the PRISMA-P 2015 checklist. Statistical analysis will be performed using review manager software (RevMan V.5.3, Cochrane Collaboration, Oxford, England).

ETHICS AND DISSEMINATION

Ethical approval is not required because this study does not include confidential personal data nor does it perform interventions on patients. This review is expected to inform readers on the effectiveness of exercise training in elderly patients undergoing haemodialysis. Findings will be presented at conferences and submitted to a peer-reviewed journal for publication.

PROSPERO REGISTRATION NUMBER

CRD42015020701.

Sarcopenia and Physical Inactivity in Patients With Chronic Kidney Disease

Sarcopenia and physical inactivity synergistically progress in patients with chronic kidney disease (CKD) and are strong predictors of mortality in this population. Exercise training and essential amino acids and vitamin D supplements may contribute to improving sarcopenia and physical inactivity in CKD patients.

Determinants of Slow Walking Speed in Ambulatory Patients Undergoing Maintenance Hemodialysis

Walking ability is significantly lower in hemodialysis patients compared to healthy people. Decreased walking ability characterized by slow walking speed is associated with adverse clinical events, but determinants of decreased walking speed in hemodialysis patients are unknown. The purpose of this study was to identify factors associated with slow walking speed in ambulatory hemodialysis patients. Subjects were 122 outpatients (64 men, 58 women; mean age, 68 years) undergoing hemodialysis. Clinical characteristics including comorbidities, motor function (strength, flexibility, and balance), and maximum walking speed (MWS) were measured and compared across sex-specific tertiles of MWS. Univariate and multivariate logistic regression analyses were performed to examine whether clinical characteristics and motor function could discriminate between the lowest, middle, and highest tertiles of MWS. Significant and common factors that discriminated the lowest and highest tertiles of MWS from other categories were presence of cardiac disease (lowest: odds ratio [OR] = 3.33, 95% confidence interval [CI] = 1.26–8.83, P<0.05; highest: OR = 2.84, 95% CI = 1.18–6.84, P<0.05), leg strength (OR = 0.62, 95% CI = 0.40–0.95, P<0.05; OR = 0.57, 95% CI = 0.39–0.82, P<0.01), and standing balance (OR = 0.76, 95% CI = 0.63–0.92, P<0.01; OR = 0.81, 95% CI = 0.68–0.97, P<0.05). History of fracture (OR = 3.35, 95% CI = 1.08–10.38; P<0.05) was a significant factor only in the lowest tertile. Cardiac disease, history of fracture, decreased leg strength, and poor standing balance were independently associated with slow walking speed in ambulatory hemodialysis patients. These findings provide useful data for planning effective therapeutic regimens to prevent decreases in walking ability in ambulatory hemodialysis patients.

Six-Minute Walk Test in Renal Failure Patients: Representative Results, Performance Analysis and Perceived Dyspnea Predictors

Objectives

Six-minute walk test in dialysis population hasn’t been consistently evaluated for the isolated impact of renal failure and other predictive factors. We measured six-minute walk distance in patients representative for low level of comorbidity and searched for potentially modifiable predictive factors of performance and dyspnea.

Methods

This was a cross-sectional study with hemodialysis patients (N = 90) and control subjects (N = 140). Main outcome measures: six-minute walk test distance and dyspnea severity using the 10-item Borg scale.

Results

Median distance decreased from 600m below the 6^th decade to 420m in the 8^th decade of age. Dialysis dependence predicted 101.5m shorter distance in the adjusted model that explained 70% of variability in results. Adjusted for significant covariates of age, height and spontaneous gait speed, fat mass (but not lean body mass) and serum total iron binding capacity were significantly associated with distance (95% CI for B coefficients -4.6 to –1.4 m/kg and 0.1 to 5 m/μmol/l, respectively). Serum total iron binding capacity as an explanatory variable was superior to C-reactive protein and albumin. Dialysis dependence, odds ratio (OR) 2.97 (1.11–7.94), spontaneous gait speed, OR 0.08 (0.02–0.41), rate-pressure product, OR 1.15 (1.08–1.23) and hemoglobin, OR 0.95 (0.92–0.98) predicted dyspnea in the adjusted model.

Conclusions

Renal failure without the confounding effect of comorbidity is a significant negative predictor of performance at six-minute walk test and perceived level of dyspnea. Body fat mass and serum total iron binding capacity are the main potentially modifiable predictors of performance, total iron binding capacity being superior to C-reactive protein and albumin. Although hemoglobin is not associated with test performance, it negatively predicts perceived shortness of breath.

Lower C-reactive protein and better hemodialysis survival are associated with regular exercise activity: Longitudinal outcomes from the ACTIVE-ADIPOSE special study

Introduction Cross-sectional and longitudinal studies in the general population have shown that a physically active lifestyle may have anti-inflammatory properties, but evidence from studies conducted with maintenance hemodialysis (HD) patients is limited. Methods A multicenter prospective cohort of 755 HD participants aged 20-92 was evaluated in a USRDS special study 2009-2013. Kilocalories/week (kcal/week) of leisure time physical activity (LTPA) was estimated from the Minnesota Leisure Time Activity questionnaire. Predialysis serum samples were obtained concurrent with LTPA report date. Generalized estimating equations (GEE) examined association of participants' LTPA and log-normalized CRP across 24 months. Cox proportional hazards models investigated LTPA and survival over a median follow-up of 718 days. Findings Baseline median CRP concentration was lower for participants with 500+ kcal/week LTPA vs. those with <500 kcal/week LTPA (3.4 mg/L vs. 4.6 mg/L; P = 0.03). Participants who reported lower LTPA (<500 kcal/week) at both baseline and 12 months had a borderline significant increase in CRP concentration (within-group change 4.8 [1.9-10.4] to 5.8 [1.6-15.7]; P = 0.08). Lower LTPA was associated with higher log CRP over 24 months in adjusted GEE analyses (β coefficient = 0.16 [95% CI 0.02-0.31]; P = 0.03). 67/364 (18%) and 43/391 (11%) deaths occurred, respectively, among participants reporting <500 vs. 500+ kcal/week LTPA [adjusted mortality hazard ratio 1.63 (CI, 1.07, 2.47)]. Discussion The data suggest that increased estimated levels of LTPA, a physical activity/exercise opportunity widely applicable to HD patients, may be associated with lower CRP concentration as well as better survival outcome.

The Frail Dialysis Population: A Growing Burden for the Dialysis Community

BACKGROUND

The dialysis population is aging worldwide. It is well known that patients on dialysis have limited functional status, but only recently has frailty been considered.

SUMMARY

The prevalence of frailty among patients on dialysis ranges from 3.4- to 10-fold higher than among community-dwelling elderly, depending on the method of assessing frailty and patient characteristics. Despite its high prevalence and the high overall mortality in the dialysis population, frailty is associated with higher mortality, independent of clinical and demographic characteristics and comorbidity. The prevalence of frailty among patients with non-dialysis-dependent chronic kidney disease (CKD) is also high, and cross-sectional data suggest that the prevalence may increase as CKD progresses. Thus, interventions to improve frailty have the potential to improve quality of life and mortality. Although interventions to improve physical dysfunction have been successful in the population with end-stage renal disease, no studies have specifically targeted frail individuals. Therefore, the extent to which exercise or physical activity interventions are feasible among frail patients and can improve frailty urgently needs to be examined. In the meantime, providers should refer frail patients to physical therapists and encourage them to be more active if possible. In addition, more attention should be focused on the possibility that rehabilitation among patients with earlier stages of CKD could improve dialysis outcomes.

KEY MESSAGES

Frailty is extremely common among patients on dialysis and is independently associated with adverse outcomes. Providers should take advantage of available resources to improve functioning in this population, and research should address the optimal strategy for addressing frailty, including timing of intervention.

A nurse-led case management program on home exercise training for hemodialysis patients: A randomized controlled trial

BACKGROUND

Patients on maintenance hemodialysis suffer from diminished physical health. Directly supervised exercise programs have been shown to be effective at improving physical function and optimizing well-being. However, nurses seldom include an exercise intervention in the care plan for hemodialysis patients.

OBJECTIVES

The purpose of this study was to examine the effects of a 12-week nurse-led case management program on home exercise training for hemodialysis patients.

DESIGN

The study was a randomized, two-parallel group trial.

SETTINGS

Hemodialysis units in two tertiary hospitals in Nanjing, mainland China.

PARTICIPANTS

One hundred and thirteen adult patients who have been in stable condition while on dialysis treatment for more than 3 months were recruited and randomly assigned to either the study group (n=57) or the control group (n=56).

METHODS

Both groups underwent a brief weekly in-center exercise training session before their dialysis sessions for the first 6 weeks. The study group received additional nurse case management weekly for the first 6 weeks and biweekly for the following 6 weeks. The intervention was to facilitate patients in performing regular exercise at home. Outcome measures, including gait speed, 10-repetition sit-to-stand performance, and quality of life were collected at baseline, and at 6 and 12 weeks into the program.

RESULTS

The results revealed that patients in the study group demonstrated greater increases in normal gait speed [F(1,111)=4.42, p=0.038] than the control group. For the study group, a mean increase of 12.02 (±3.03)centimeters/second from baseline to week 12 was found. With regard to the fast gait speed, there was a marginally significant between-group effect [F(1,111)=3.93, p=0.050]. The study group showed a mean improvement of 11.08 (±3.32)cm/s, from baseline to week 12. Patients from both groups showed improvements in their 10-repetition sit-to-stand performance. The between-group differences approached significance [F(1,111)=3.92, p=0.050], with the study group showed greater improvement than the control group. The time taken by the patients in the study group to complete the 10-STS test increased by 5.75 (±3.88)s from baseline to week 12. Significant improvements in quality of life across three time points were found only in the study group.

CONCLUSIONS

Home exercise using a nurse-led case management approach is practical and effective in improving the physical function and self-perceived health of stable hemodialysis patients.

Clinical Characteristics of Patients on Hemodialysis With Peripheral Arterial Disease

Patients on hemodialysis (HD; n = 210) were examined for peripheral arterial disease (PAD) using ankle-brachial index (ABI) and toe-brachial index (TBI). The prevalence of PAD was 38.1%. Among patients with PAD, 87.5% were newly diagnosed with PAD, 42.5% were diagnosed with TBI <0.6 despite ABI ≥ 0.9, and 68.7% had no lower limb symptoms. In patients with PAD, the prevalence rate of cerebrovascular disease was 36.3%, coronary artery disease was 42.5%, spinal stenosis was 33.2%, and vertebral fracture 15.0% and was significantly higher than those of the non-PAD patients. Low high-density lipoprotein cholesterol was the most important biomarker among patients with PAD. PAD has been underdiagnosed and untreated in patients on HD because most patients do not have symptoms that could be due to diabetic neuropathy or have insufficient daily activity to experience exertional leg symptoms. Screening for PAD using the ABI and TBI increased diagnostic efficiency in patients on HD and may lead to effective early treatments, including pharmacotherapy, revascularization therapy, and exercise rehabilitation to avoid the worst possible scenario such as lower limb amputation, cardiovascular event, and death.

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.

Cognitive and physical function in chronic kidney disease

PURPOSE OF REVIEW

Both cognitive and physical function are commonly impaired in individuals with chronic kidney disease (CKD), resulting in important impacts on their quality of life and overall health. This review summarizes the burden of cognitive and physical impairment in CKD, focusing on recent research that highlights a possible unifying microvascular cause among these shared comorbid conditions.

RECENT FINDINGS

Multiple small studies have been published recently evaluating cognitive and physical functioning in people with CKD. These studies overall demonstrate a high burden of comorbid conditions in people with CKD, including microvascular disease, that may result in cognitive impairment. Additionally, studies demonstrate that physical function is substantially worse than expected in individuals with CKD, that decreased physical activity is associated with worse outcomes, that frailty is very common and associated with an increased risk of death, and that structured exercise programs have small but tangible short-term effects on markers of physical performance.

SUMMARY

Impaired cognitive function and physical performance are important factors impacting the lives of people with CKD. Further research is necessary to better treat these important comorbid conditions in people with CKD.

Age and anemia management: relationship of hemoglobin levels with mortality might differ between elderly and nonelderly hemodialysis patients

BACKGROUND

The elderly hemodialyzed population is growing. However, little is known about the relationship between hemoglobin level and survival according to age. We investigated the effect of age on the relationship between hemoglobin and survival within the Japan Dialysis Outcomes and Practice Patterns Study (DOPPS) cohort.

METHODS

We enrolled the entire Japan DOPPS phases 3 and 4 population. Patients were divided by the age of 75 years into two groups. Cox's proportional hazard model was used with hemoglobin at every 4 months treated as a time-dependent variable. The interaction of age and hemoglobin was analyzed.

RESULTS

We included 3341 patients in the analyses. The primary outcome occurred in 567 patients during the median follow-up of 2.64 years. Hemoglobin of entire population was 10.3 ± 1.3 g/dL. The median of epoetin dose was 3000 IU/week. Interaction was found between ages stratified by the age of 75 years and hemoglobin values (P = 0.045) with use of Cox's proportional hazard model. The nonelderly population had poorer prognosis with hemoglobin <10 g/dL, while elderly population only with hemoglobin <9 g/dL. For both hemoglobin strata <9, ≥9 and <10 g/dL, interactions between age and hemoglobin were significant. Subgroup analysis indicated that interaction between age and Hb levels was observed only in the nondiabetic nephropathy group. Several sensitivity analyses demonstrated a similar trend with the original analyses and reinforced the robustness.

CONCLUSIONS

The elderly population might tolerate low hemoglobin levels. Our findings open the way for further investigation of individualized anemia management.

Associations of self-reported physical activity types and levels with quality of life, depression symptoms, and mortality in hemodialysis patients: the DOPPS

BACKGROUND AND OBJECTIVES

Physical activity has been associated with better health status in diverse populations, but the association in patients on maintenance hemodialysis is less established. Patient-reported physical activities and associations with mortality, health-related quality of life, and depression symptoms in patients on maintenance hemodialysis in 12 countries were examined.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In total, 5763 patients enrolled in phase 4 of the Dialysis Outcomes and Practice Patterns Study (2009-2011) were classified into five aerobic physical activity categories (never/rarely active to very active) and by muscle strength/flexibility activity using the Rapid Assessment of Physical Activity questionnaire. The Kidney Disease Quality of Life scale was used for health-related quality of life. The Center for Epidemiologic Studies Depression scale was used for depression symptoms. Linear regression was used for associations of physical activity with health-related quality of life and depression symptoms scores. Cox regression was used for association of physical activity with mortality.

RESULTS

The median (interquartile range) of follow-up was 1.6 (0.9-2.5) years; 29% of patients were classified as never/rarely active, 20% of patients were classified as very active, and 20.5% of patients reported strength/flexibility activities. Percentages of very active patients were greater in clinics offering exercise programs. Aerobic activity, but not strength/flexibility activity, was associated positively with health-related quality of life and inversely with depression symptoms and mortality (adjusted hazard ratio of death for very active versus never/rarely active, 0.60; 95% confidence interval, 0.47 to 0.77). Similar associations with aerobic activity were observed in strata of age, sex, time on dialysis, and diabetes status.

CONCLUSIONS

The findings are consistent with the health benefits of aerobic physical activity for patients on maintenance hemodialysis. Greater physical activity was observed in facilities providing exercise programs, suggesting a possible opportunity for improving patient outcomes.

Daily physical activity and physical function in adult maintenance hemodialysis patients

BACKGROUND

Maintenance hemodialysis (MHD) patients reportedly display reduced daily physical activity (DPA) and physical performance. Low daily physical activity and decreased physical performance are each associated with worse outcomes in chronic kidney disease patients. Although daily physical activity and physical performance might be expected to be related, few studies have examined such relationships in MHD patients, and methods for examining daily physical activity often utilized questionnaires rather than activity monitors. We hypothesized that daily physical activity and physical performance are reduced and correlated with each other even in relatively healthier MHD patients.

METHODS

Daily physical activity, 6-min walk distance (6-MWT), sit-to-stand, and stair-climbing tests were measured in 72 MHD patients (32 % diabetics) with limited comorbidities and 39 normal adults of similar age and gender mix. Daily physical activity was examined by a physical activity monitor. The human activity profile was also employed.

RESULTS

Daily physical activity with the activity monitor, time-averaged over 7 days, and all three physical performance tests were impaired in MHD patients, to about 60-70 % of normal values (p < 0.0001 for each measurement). Human activity profile scores were also impaired (p < 0.0001). MHD patients spent more time sleeping or in marked physical inactivity (p < 0.0001) and less time in ≥ moderate activity (p < 0.0001). These findings persisted when comparisons to normals were restricted to men or women separately. After adjustment, daily physical activity correlated with 6-MWT but not the two other physical performance tests. Human activity profile scores correlated more closely with all three performance tests than did DPA.

CONCLUSIONS

Even in relatively healthy MHD patients, daily physical activity and physical performance are substantially impaired and correlated. Whether training that increases daily physical activity or physical performance will improve clinical outcome in MHD patients needs to be examined.

Relationship between lower extremity muscle strength and all-cause mortality in Japanese patients undergoing dialysis

BACKGROUND

Skeletal muscle wasting is common and insidious in patients who are undergoing hemodialysis. However, the association between lower extremity muscle strength and all-cause mortality remains unclear in this population.

OBJECTIVE

The purpose of this study was to investigate the prognostic significance of lower extremity muscle strength on 7-year survival in a cohort of patients who were clinically stable and undergoing hemodialysis.

DESIGN

A prospective cohort study was conducted.

METHODS

A total of 190 Japanese outpatients who were undergoing maintenance hemodialysis 3 times per week at a hemodialysis center were followed for up to 7 years. Lower extremity muscle strength was evaluated using a handheld dynamometer at the time of patient enrollment in the study. Muscle strength data were divided by dry weight and expressed as a percentage. A Cox proportional hazards regression model was used to assess the contribution of lower extremity muscle strength to all-cause mortality.

RESULTS

The median age (25th and 75th percentiles) of this study population was 64 years (57 and 72 years), 53.2% of the patients were women, and the time on hemodialysis was 39.0 months (15.9 and 110.5 months) at baseline. During a median follow-up of 36.0 months, there were 30 deaths. With a multivariate Cox model, the hazard ratio in the group with a knee extensor strength of <40% was 2.73 (95% confidence interval=1.14-6.52) compared with that in the ≥40% group.

LIMITATIONS

This was a small-scale observational study, and the mechanisms underlying the higher mortality risk in patients with poor muscle strength undergoing hemodialysis than in other patients undergoing hemodialysis remain to be elucidated.

CONCLUSIONS

Decreased lower extremity muscle strength was strongly associated with increased mortality risk in patients undergoing hemodialysis.

Evaluation of physical activity and its relationship to health-related quality of life in patients on chronic hemodialysis

OBJECTIVE

The aim of this study was to investigate the relationship between physical activity and health-related quality of life (HRQOL) in patients on chronic hemodialysis.

METHODS

A total of 31 men (69.0 ± 11.1 years) and 17 women (66.9 ± 10.0 years) among 61 male and 30 female patients on chronic hemodialysis at Innoshima General Hospital, Onomichi, Japan, were enrolled in this cross-sectional study. Physical activity was evaluated using tri-axial accelerometers. HRQOL and psychological distress were also evaluated using the EuroQol questionnaire (EQ-5D) and the K6 questionnaire, respectively.

RESULTS

Physical activity evaluated by Σ[metabolic equivalents × h per week (METs·h/w)] was 8.1 ± 6.0 METs·h/w, and EQ-5D score was 0.754 ± 0.177. Among all patients, EQ-5D scores were significantly correlated with physical activity over 4 METs on non-hemodialysis treatment days (r = 0.426, p = 0.003). In women, EQ-5D scores were also correlated with physical activity over 4 METs on hemodialysis treatment days and non-hemodialysis treatment days. By stepwise multiple regression analysis, physical activity over 4 METs on non-hemodialysis treatment days was a determinant factor of EQ-5D even after adjusting for age and K6 scores.

CONCLUSION

Physical activity over 4 METs on non-hemodialysis treatment days might be associated with EQ-5D in patients on chronic hemodialysis, especially in women.

Association of habitual physical activity measured by an accelerometer with high-density lipoprotein cholesterol levels in maintenance hemodialysis patients

After confirming the relationship between high-density lipoprotein cholesterol (HDL-C) levels and mortality in hemodialysis patients for study 1, we investigated the effect of physical activity on their HDL-C levels for study 2. In study 1, 266 hemodialysis patients were monitored prospectively for five years, and Cox proportional hazard regression confirmed the contribution of HDL-C to mortality. In study 2, 116 patients were recruited after excluding those with severe comorbidities or requiring assistance from another person to walk. Baseline characteristics, such as demographic factors, physical constitution, primary kidney disease, comorbid conditions, smoking habits, drug use, and laboratory parameters, were collected from patient hospital records. An accelerometer measured physical activity as the number of steps per day over five consecutive days, and multiple regression evaluated the association between physical activity and HDL-C levels. Seventy-seven patients died during the follow-up period. In study 1, we confirmed that HDL-C level was a significant predictor of mortality (P = 0.03). After adjusting for patient characteristics in study 2, physical activity was independently associated with HDL-C levels (adjusted R² = 0.255; P = 0.005). In conclusion, physical inactivity was strongly associated with decreased HDL-C levels in hemodialysis patients.

Functional cardiovascular reserve predicts survival pre-kidney and post-kidney transplantation

Exercise intolerance is an important comorbidity in patients with CKD. Anaerobic threshold (AT) determines the upper limits of aerobic exercise and is a measure of cardiovascular reserve. This study investigated the prognostic capacity of AT on survival in patients with advanced CKD and the effect of kidney transplantation on survival in those with reduced cardiovascular reserve. Using cardiopulmonary exercise testing, cardiovascular reserve was evaluated in 240 patients who were waitlisted for kidney transplantation between 2008 and 2010, and patients were followed for ≤5 years. Survival time was the primary endpoint. Cumulative survival for the entire cohort was 72.6% (24 deaths), with cardiovascular events being the most common cause of death (54.2%). According to Kaplan-Meier estimates, patients with AT <40% of predicted peak VO2 had a significantly reduced 5-year cumulative overall survival rate compared with those with AT ≥40% (P<0.001). Regarding the cohort with AT <40%, patients who underwent kidney transplantation (6 deaths) had significantly better survival compared with nontransplanted patients (17 deaths) (hazard ratio, 4.48; 95% confidence interval, 1.78 to 11.38; P=0.002). Survival did not differ significantly among patients with AT ≥40%, with one death in the nontransplanted group and no deaths in the transplanted group. In summary, this is the first prospective study to demonstrate a significant association of AT, as the objective index of cardiovascular reserve, with survival in patients with advanced CKD. High-risk patients with reduced cardiovascular reserve had a better survival rate after receiving a kidney transplant.

Physical activity and exercise training: a relevant aspect of the dialysis patient's care

Sedentary lifestyle is frequent in hemodialysis patients whose physical capabilities are largely reduced when compared with healthy subjects, and evidence exists that sedentary dialysis patients are at higher risk of death as compared to non-sedentary ones. Dialysis patients may suffer from cardiovascular disease, diabetes, malnutrition, depression, which limits their exercise capacity; conversely, regular physical exercise may favor rehabilitation and correction of several cardiovascular, metabolic and nutritional abnormalities. Many observational, population-based studies show that the level of physical activity is related to quality of life and nutritional status, as well as to the survival probability. Intervention studies are instead lacking; a randomized controlled multicenter trial is in progress in Italy to assess the effect of home-based exercise programs on survival and hospitalization rate in stable dialysis patients. Implementation of physical activity should be one of the goals of dialysis care management, but several barriers prevent a widespread implementation of physical exercise programs in the dialysis units. A lack of patients' or care-givers' motivation or willingness, and structural or functional resources are the most frequent obstacles to exercise implementation. Since the hemodialysis population is quite heterogeneous for physical abilities and comorbidities, exercise in not for everyone and individual prescription is required for a correct and safe implementation of physical activity.

MRI correlates of protein deposition and disease severity in postmortem frontotemporal lobar degeneration

BACKGROUND

Frontotemporal lobar degeneration (FTLD) can be classified based on the presence of the microtubule-associated protein tau and the TAR DNA binding protein-43 (TDP-43). Future treatments will likely target these proteins, therefore it is important to identify biomarkers to help predict protein biochemistry.

OBJECTIVE

To determine whether there is an MRI signature pattern of tau or TDP-43 using a large cohort of FTLD subjects and to investigate how patterns of atrophy change according to disease severity using a large autopsy-confirmed cohort of FTLD subjects.

METHODS

Patterns of gray matter loss were assessed using voxel-based morphometry in 37 tau-positive and 44 TDP-43-positive subjects compared to 35 age and gender-matched controls, and compared to each other. Comparisons were also repeated in behavioral variant frontotemporal dementia (bvFTD) subjects (n = 15 tau-positive and n = 30 TDP-43-positive). Patterns of atrophy were also assessed according to performance on the Clinical Dementia Rating (CDR) scale and Mini-Mental State Examination (MMSE).

RESULTS

The tau-positive and TDP-43-positive groups showed patterns of frontotemporal gray matter loss compared to controls with no differences observed between the groups, for all subjects and for bvFTD subjects. Patterns of gray matter loss increased in a graded manner by CDR and MMSE with loss in the frontal lobes, insula and hippocampus in mild subjects, spreading to the temporal and parietal cortices and striatum in more advanced disease.

CONCLUSION

There is no signature pattern of atrophy for tau or TDP-43; however, patterns of atrophy in FTLD progress with measures of clinical disease severity.