Respiratory sarcopenia screening in dialysis patients: cross-sectional and multicentre study protocol

BACKGROUND

Respiratory sarcopenia is characterized by the weakness of respiratory muscles associated with sarcopenia due to aging or systemic diseases such as chronic kidney disease (CKD). Patients with CKD undergoing dialysis are particularly susceptible to respiratory muscle weakness caused by factors such as fluid overload and electrolyte imbalance. This weakness not only affects ventilation but also impairs oxygen uptake and delivery to muscle tissue, potentially leading to severe sarcopenia. Thus, the objective of this study is to conduct a respiratory sarcopenia screening in patients with CKD undergoing haemodialysis (HD) and peritoneal dialysis (PD).

METHODS

This is an observational, cross-sectional and multicentre study conducted between March 2023 and March 2025. The study was approved by the Research Ethics Committee at two centres. Sarcopenia diagnosis is determined based on low handgrip strength and amount of appendicular skeletal muscle mass, assessed through bioelectrical impedance analysis. Respiratory sarcopenia is diagnosed in patients with sarcopenia who have low inspiratory muscle strength, evaluated through a manovacuometry test. The severity of sarcopenia and respiratory sarcopenia is defined, respectively, by low physical performance (measured using the Short Physical Performance Battery and Timed-Up and Go test) and pulmonary performance (measured through spirometry). Thus, this study will include 81 patients undergoing dialysis (41 on HD and 40 on PD) from three participating centres.

DISCUSSION

The literature has been focused on respiratory function in CKD; however, the relationship with sarcopenia remains understudied. We believe that, similar to appendicular skeleton muscles, the axial skeleton muscles are also likely to weaken with the presence of chronic disease, such as CKD.

Cardiorespiratory fitness and mortality risk in patients receiving hemodialysis: a prospective cohort

BACKGROUND

Kidney failure reduces life expectancy by one-third compared with the general population, and cardiovascular complications and poor cardiorespiratory fitness (CRF) are the main causes. We aimed to evaluate the association between severely low CRF and all-cause mortality risk in HD patients.

METHODS

This observational prospective cohort study followed-up patients receiving HD from August 2015 until March 2022. Cardiorespiratory fitness was evaluated through the cardiopulmonary exercise test, and the peak oxygen uptake (VO2peak) value was used to determine severely low CRF (< 15 mL∙kg-1∙min-1). Cox regression and univariate Kaplan-Meier analysis were used to evaluate the association of severely low CRF with mortality risk and survival rate.

RESULTS

Forty-eight patients were followed-up for a median of 33.0 [14.3 - 49.3] months. A total of 26 patients had severely low CRF. During the follow-up period, 11 patients (22.92%) died from all causes. From these, eight (30.8%) had severely low CRF. Even so, severely low CRF was not associated with crude death rates for patients stratified by CRF levels (p = 0.189), neither in unadjusted (HR 2.18; CI 95% 0.58-8.23) nor in adjusted (HR 1.32; CI 95% 0.31-5.59) Cox proportional hazard models. As a continuous variable, VO2peak was not associated with mortality risk (HR 1.01; CI 95% 0.84-1.21). Univariate Kaplan-Meier analysis showed that patients with severely low CRF did not have significantly worse survival rates than those with mild-moderate CRF (p = 0.186).

CONCLUSION

Our findings indicated that severely low CRF was not associated with all-cause mortality in patients on HD. Despite severely low CRF being prevalent, larger cohort studies are needed to establish strong conclusions on its association with all-cause mortality.

Estimation of pulmonary artery systolic pressure in hemodialysis patients and its association with cardiorespiratory fitness and pulmonary function

PURPOSE

To evaluate the estimated pulmonary arterial systolic pressure (PASP) through transthoracic echocardiography in hemodialysis (HD) patients and associate it with cardiorespiratory fitness and pulmonary function.

METHODS

This study was a cross-sectional analysis of HD patients that performed evaluations of cardiac function, cardiorespiratory fitness, and pulmonary function, through transthoracic echocardiography, cardiopulmonary exercise test, spirometry, and manovacuometry, respectively. All patients underwent the evaluations on a non-dialysis day.

RESULTS

Thirty-five HD patients were evaluated and separated according to the presence of probable pulmonary hypertension (PH) (estimated PASP ≥ 35 mmHg) or not (estimated PASP < 35 mmHg). Those HD patients with probable PH had the worst cardiorespiratory fitness, evaluated by the peak oxygen consumption (VO_2peak) (17.11 ± 4.40 versus 12.90 ± 2.73 mL/kg/min; p = 0.011), and pulmonary function, evaluated by absolute and predicted of forced vital capacity (FVC) (85.52 ± 12.29 versus 71.38 ± 11.63%; p = 0.005) and absolute and predicted of forced expiratory volume in the first second (FEV₁) (83.37 ± 14.98 versus 69.21 ± 13.48%; p = 0.017). The secondary analysis showed that estimated PASP was correlated with VO_2peak (r = - 0.508; p = 0.002), FVC (r = - 0.450; p = 0.007), and FEV₁ (r = - 0.361; p = 0.033). Moreover, the adjusted odds ratio by HD vintage, dry weight and gender showed that increments in VO_2peak (OR 1.62; CI 95% 1.04-2.54; p = 0.034), FVC (OR 39.67; CI 95% 1.74-902.80; p = 0.021), and FEV₁ (OR 39.54; CI 95% 1.89-826.99; p = 0.018) were associated with 1-fold and 39-fold higher chance, respectively, for not having PH. However, all these associations were lost when age was included in the analysis.

CONCLUSIONS

The HD patients with probable PH had the worst cardiorespiratory fitness and pulmonary function. Exploratory analyses showed that greater cardiopulmonary fitness was associated with better cardiac function. Moreover, increments in cardiorespiratory fitness and pulmonary function may increase the chance of not having PH.

Six-minute walk test may be a reliable predictor of peak oxygen uptake in patients undergoing hemodialysis

Background

Cardiorespiratory fitness seems to play an important role in the general health of patients undergoing hemodialysis (HD). However, the prediction of peak oxygen uptake (V̇O2peak) in a clinical setting is not widely adopted for these patients.

Objectives

Evaluate the agreement and reliability between directly and indirectly V̇O2peak measurements in patients undergoing HD.

Methods

This is a cross-sectional study with patients undergoing HD that performed a cardiopulmonary exercise test (CPET) with 5/10 watts incremental load in each minute using a cycle ergometry to directly evaluate the V̇O2peak, and the 6-min walk test (6MWT) in a 30-m corridor to indirect measures it. Both tests were performed on a midweek non-dialysis day. Bland–Altman analysis of agreement limits was used with direct and indirect V̇O2peak values. Intraclass correlation coefficient (ICC) and Cronbach’s Alpha was used to evaluate the reproducibility and reliability between direct and indirect V̇O2peak values.

Results

Twenty-six patients (54.4 ± 14.5 years, 53.8% of male) were evaluated. The V̇O2peak direct mean obtained through CPET was 15.91 ± 5.26 (ml/kg/min), while the indirect mean obtained through 6MWT was V̇O2peak of 14.89 ± 4.21 (ml/kg/min). There was a strong positive correlation between both V̇O2peak values (r = 0.734; p < 0.001). The Bland–Altman analysis demonstrated that the methods agreed with each other (p = 0.103). Also, the ICC (0.829) and Cronbach's Alpha (0.846) showed excellent reproducibility and reliability.

Conclusions

6MWT is a reliable tool for estimating V̇O2peak in patients undergoing HD.

MO602: Combined and Progressive Intradialytic Exercise Training Keeps Stable the Systemic Inflammation, Endothelial Function Markers and Redox State: A Secondary Analysis of a Randomized Controlled Trial

BACKGROUND AND AIMS

Chronic inflammatory conditions and disturbances in oxidative stress are hallmarks of renal damage and may be a trigger to non-pharmacological therapeutic options, such as exercise training, in chronic kidney disease[1,2]. This study aimed to evaluate the effects of 12-week combined and progressive intradialytic exercise training on systemic inflammation, endothelial function markers, and redox state in hemodialysis (HD) patients.

METHOD

This is a secondary analysis of a randomized controlled trial with HD patients[3] randomly allocated into two groups: exercise group (EXG) (n = 19) and usual care/control group (CON) (n = 19). EXG performed a 12-week combined and progressive intradialytic training period 3 times a week. CON maintained their normal HD routine during the same timeframe. Blood samples were obtained before and after the 12-week period to analyze C-reactive protein (CRP), interleukin (IL)-4, IL-6, IL-10, IL-17A, tumoral necrosis factor-alpha (TNF-α), reactive oxygen species (ROS), total antioxidant capacity (TAC), monocyte chemoattractant protein-1 (MCP-1), interferon-gamma (IFN-γ), vascular endothelial growth factor (VEGF), and nitric oxide (NO). The inflammatory balance was evaluated by IL-6/TNF-α, TNF-α/IL-4 and TNF-α/IL-10 ratios.

RESULTS

A significant effect was only observed in CON but not EXG, with decreased IL-6 (median of 9.93 [IQR: 8.31–14.79] to 8.86 [7.88–9.61] pg/mL; P = 0.044), IL-17A (62.26 [48.87–102.44] to 53.33 [45.29–59.58] pg/mL; P = 0.044), and IFN-γ (28.19 [26.44–31.15] to 27.09 [25.85–27.89] pg/mL; P = 0.006) and an increase in ROS (485.98 [333.17–604.83] to 507.31 [443.48–637.04]; P = 0.049).

CONCLUSION

The HD patients who undertook the 12-week combined and progressive intradialytic exercise training did not experience an alteration in systemic inflammation, endothelial function markers and redox state, in contrast with the increased oxidative stress state observed in CON.

FUNDING SOURCES

Hospital de Clínicas de Porto Alegre–Research Incentive Fund (FIPE) (Grant No. 2015–0151) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).

Profile of professionals working in intradialytic exercise programs in Brazil: a national survey

OBJECTIVE

This survey was designed to assess the profile of professionals working in intradialytic exercise programs (IEPs) in Brazil and reveal the motivators and barriers they face.

METHODS

The survey was sent to physiotherapists and exercise physiologists working in IEPs in Brazil. Phone interviews and electronic forms were used to collect the answers to the survey questionnaire.

RESULTS

Forty-one of the 261 included dialysis centers had IEPs; 44 professionals answered the questionnaire over the phone and 26 used the electronic form to do it. A total of 70 professionals (mean age 33.4±7.4 years; 84.3% physiotherapists) answered the questionnaire. Resistance training was the preferred mode of therapy. Most of the IEPs were connected to research and were paid for by private health insurance. The desire to work in a different field (30.0%) and lack of resources (31.4%) were the most prevalent motivator and barrier cited by IEP professionals working in dialysis centers, respectively.

CONCLUSION

The majority of the few professionals that work in IEPs in Brazil are physiotherapists. Lack of resources was the most commonly reported barrier faced by survey respondents.

Aerobic Exercise Increases Vascular Diameter of Arteriovenous Fistula in Hemodialysis Patients

INTRODUCTION

A healthy arteriovenous fistula (AVF) depends on adequate vessel diameter which can be maintained through aerobic exercises. A randomized crossover study was conducted to evaluate the acute effects of aerobic exercise on a cycle ergometer on AVF vascular diameter, through ultrasound, and on blood pressure (BP).

METHODS

Eight hemodialysis (HD) patients completed 2 different occasions in random order with a 7-day washout: (a) exercising moment, in which 30-min aerobic exercise was performed on a cycle ergometer; and (b) resting moment, which was performed 30-min with the patient sitting in a chair. Both occasions were evaluated 1-h before the second weekly HD day.

RESULTS

A significant increase in AVF vascular diameter induced by 30-min aerobic exercise was found (1.15 ± 0.56 to 1.47 ± 0.66 cm; p = 0.042), whereas systolic (p = 0.105) and diastolic BP (p = 0.366) did not change.

CONCLUSIONS

We can conclude that acute aerobic exercise was shown to be effective in improving the AVF vascular diameter in HD patients. The aerobic exercise benefits in endothelium-dependent vasodilation which may be an effective, practical, and economic strategy to maintain AVF patency.

Intradialytic periodized exercise improves cardiopulmonary fitness and respiratory function: A randomized controlled trial

BACKGROUND

Chronic kidney disease (CKD) is a factor that predisposes to gradual physical deconditioning from its early stages leading to cardiorespiratory fitness and musculoskeletal system impairment. We evaluated the effects of combined and periodized intradialytic exercise training on cardiopulmonary fitness and respiratory function in HD subjects.

METHODS

A randomized controlled trial with HD subjects was allocated into two groups: exercise group (EXG) and usual care group (UCG). EXG performed a 12-week combined and periodized intradialytic training. UCG maintained the HD routine.

RESULTS

Thirty-nine HD subjects were analyzed (EXG = 20; UCG = 19). The EXG in comparison with the UCG showed improvements in peak oxygen consumption (Δ3.1[0.4-5.5] vs. -0.2[-2.0-1.5] ml/kg/min; p = 0.003), forced expiratory volume in the first second (Δ0.1[-0.0-0.1] vs. -0.0[-0.1-0.0] L; p = 0.022), forced vital capacity (Δ0.1[0.0-0.2] vs. -0.1[-0.2-0.0] L; p = 0.005), peak expiratory flow (Δ0.4[-0.7-1.2] vs. -0.1[-0.5-0.2] L; p = 0.046), and maximal inspiratory pressure (Δ7.35[-8.5-17.5] vs. -4.0[-18.0-12.0] cmH₂ O; p = 0.028). The EXG, different from the UCG, did not worsen the maximal expiratory pressure (Δ0.1[-8.8-7.5] vs. -2.5[-15.0-9.0] cmH₂ O; p = 0.036). Besides, EXG showed a significant improvement in quadriceps strength (32.05 ± 10.61 vs. 33.35 ± 11.62 kg; p = 0.042).

CONCLUSIONS

The combined and periodized intradialytic exercise training improved cardiopulmonary fitness, respiratory function, inspiratory muscle strength, and quadriceps strength, beyond maintaining the expiratory muscle strength in HD subjects.

Pulmonary function, muscle strength, and quality of life have differed between chronic kidney disease patients and healthy individuals

Chronic kidney disease (CKD) patients have lower pulmonary function, respiratory and peripheral muscle strength values when compared to the general population, which reflects negatively in the quality of life (QoL). The aim of this study was to compare the pulmonary function, respiratory and peripheral muscle strength, and QoL between CKD patients and healthy individuals. Cross-sectional study with a consecutive sample of 39 individuals separated into three groups: nondialysis-dependent CKD in stage 5 (CKD-5), HD group (CKD-HD), and healthy individuals. The tests performed were spirometry, manovacuometry, handgrip strength (HGS), and Medical Outcomes Short-Form Health Survey (SF-36). A significant difference between groups was observed in forced expiratory volume in 1 second (FEV₁ ) and its predicted value (p = 0.004 and p < 0.001, respectively), forced vital capacity (FVC), and its predicted value (p = 0.008 and p < 0.001, respectively), peak expiratory flow (PEF) and its predicted value (p = 0.004 and p < 0.001, respectively), maximal inspiratory pressure (MIP) and its predicted value (p = 0.022), maximal expiratory pressure (MEP) and its predicted value (p = 0.030 and p = 0.009, respectively) in which CKD-5 presented the worst values, followed by CKD-HD and healthy group. The CKD-5 had worse pulmonary function, respiratory muscle strength, and QoL. Moreover, CKD-HD also showed some impairment in pulmonary function and QoL when compared with healthy individuals. Even with the peripheral muscle strength preserved, its decrease is proportional to the pulmonary impairment in the evaluated CKD patients.

Effects of upper limb exercise programs on the arteriovenous fistula in patients on hemodialysis: A systematic review and meta-analysis

BACKGROUND

The arteriovenous fistula (AVF) is a commonly used vascular access for chronic kidney disease (CKD) patients; exercise interventions may boost its maturation and help in its maintenance. A systematic review and meta-analysis of clinical trials on the effects of upper limb exercise programs on the AVF was conducted.

METHODS

The primary outcomes were draining vein diameter (DVD) and draining vein blood flow rate (DVBFR), and secondary outcomes were handgrip strength (HGS) and brachial artery flow rate (BAFR). Quality of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE).

RESULTS

Four studies met the inclusion criteria. When compared to usual care groups, the experimental groups did not improve DVD (mean difference [MD] 0.23, confidence interval [CI] -0.20-0.65). There were significant differences in DVBFR (mL/min) according to the fixed-effect model (MD 141.13, CI 36.84-245.42). HGS (kg) was significantly different between groups (MD 2.95, CI 0.55-5.35), but BAFR (mL/min) was not (MD 91.65, CI -94.72-278.01).

CONCLUSIONS

Although exercise programs did not improve DVD and BAFR, they increased muscle strength and DVBFR. Therefore, experimental exercise programs should be emphasized for AVF maturation and maintenance.Research Registry number: reviewregistry924.

Effects of intradialytic exercise on cardiopulmonary capacity in chronic kidney disease: systematic review and meta-analysis of randomized clinical trials

Patients with chronic kidney disease show poorer functional and cardiorespiratory capacity than healthy individuals, and these impairments result in sedentarism. The aim of this study was to conduct a systematic review and meta-analysis of randomized clinical trials on the effects of different intradialytic exercise protocols on cardiopulmonary capacity in chronic kidney disease patients. The primary outcome was peak oxygen consumption (VO_2peak) and the secondary outcomes were exercise duration and ventilation in the cardiopulmonary test. The quality of the evidence was evaluated using the GRADE guidelines. Seven studies with a total of 124 participants met the inclusion criteria. Compared to the non-exercise group, the exercise group improved in mean VO_2peak (MD 4.06 [IC 0.81; 7.31]). In a separate analysis according to exercise modality, aerobic exercise plus strength training performed better than aerobic exercise alone (MD 5.28 [IC 3.90; 6.66]). In the exercise group, both exercise tolerance values (MD 3.10 [IC 1.70; 4.51]) and ventilation values in the cardiopulmonary test were better than those of the control group (MD 13.10 [IC 7.12; 19.09]). Thus, intradialytic exercise protocols can improve cardiopulmonary function, exercise tolerance and ventilatory efficiency in chronic kidney disease patients.

Intra-articular leflunomide-loaded poly(ε-caprolactone) implants to treat synovitis in rheumatoid arthritis

Rheumatoid arthritis is an autoimmune pathology that manifests as chronic inflammatory arthropathy and synovitis. Treatment of rheumatoid arthritis is based on the administration of different types of drugs, including leflunomide, an antirheumatic drug. However, the long-term systemic use of leflunomide may be associated with adverse effects. Local therapy could be an efficient strategy to treat synovitis triggered by rheumatoid arthritis without inducing adverse effects. In this study, leflunomide-loaded poly(ε-caprolactone) implants (leflunomide PCL implants) were evaluated as local drug delivery systems capable of attenuating inflammation and angiogenesis, which represent events of synovitis. Leflunomide PCL implants were designed by hot molding technique; and they were characterized by FTIR and DSC. These analytical techniques demonstrated the chemical integrity and dispersion of drug into the polymeric chains. Then, a spectrophometric method was developed and validated to quantify the leflunomide incorporated into the PCL implants and released from them. Linearity was obtained by ordinary least squares regression method to estimate the linear regression equation. Residues were evaluated considering normality, independence and homoscedasticity. Precision was lower than 5 %, and accuracy ranged from 98 to 104.5 %. Quantitation limit was 2.0 μg mL^-1. PCL implants provided controlled and sustained release of leflunomide for 30 consecutive days after inserting these systems in the subcutaneous tissue of mice. The main mechanisms of drug delivery were solubilization and diffusion from polymer. Then, a non-biocompatible sponge was inserted into the subcutaneous tissue of mice to function as a frame to develop the inflammatory and angiogenic processes. Leflunomide PCL implants were inserted in direct contact with the sponge. At 4, 7 and 10 days after-sponge implantation, the key components of inflammatory angiogenesis were measured to verify the regression of these events induced by drug. Leflunomide controlled released from polymeric implants downregulated the neutrophil and monocyte/macrophage infiltration due to the reduced expression of myeloperoxidase (MPO) and N-acetyl-β-d-glucosaminidase (NAG), respectively. As the influx of these pro-inflammatory cells was modulated by leflunomide, the production of nitric oxide (NO), a pro-inflammatory substance, reached low concentrations in the sponge. As a consequence of the modulation of inflammation at the pathological site, the angiogenic process was downregulated, since the hemoglobin levels in the sponge were drastically reduced. The accumulation of leflunomide in the pathological site did not induce nephrotoxicity or hepatototoxicity, as confirmed by histological analyses. Finally, intra-articular leflunomide PCL implants represent a potential therapeutic alternative to treat locally the synovitis triggered by rheumatoid arthritis without inducing systemic adverse effects.

Percepção dos idosos jovens e longevos gaúchos quanto aos espaços públicos em que vivem

Em 2050, o número de brasileiros residindo em áreas urbanas passará dos 200 milhões e 29% da população será composta por idosos. Os idosos longevos possuem 80 anos ou mais, os idosos jovens são aqueles que apresentam idade entre 60 e 79 anos. O objetivo foi verificar a diferença da percepção de idosos jovens e longevos do Rio Grande do Sul quanto ao ambiente urbano em que vivem. Estudo de base populacional, observacional, descritivo, retrospectivo, com paradigma de análise quantitativa, analisou dados da pesquisa Perfil dos Idosos do RS, realizado pelo Instituto de Geriatria e Gerontologia da PUCRS em parceria com a Escola de Saúde Pública do RS. A amostra foi composta por 6913 questionários respondidos por idosos de 59 cidades. A análise dos dados foi realizada com cada um dos grupos etários e as variáveis independentes foram testadas pelo Qui-Quadrado, sendo o nível de significância menor que 0,05. Como resultado, a percepção de dificuldades, como poucos bancos, falta de faixas de segurança, tempo de sinal muito curto para pedestres, degraus muito altos e mau cheiro dos banheiros públicos, foi maior entre os idosos jovens. Os idosos longevos perceberam menos esses fatores, porém, referiram que frequentam menos os ambientes comunitários.