Does the interference phenomenon affect strength development during same-session combined rehabilitation program in hemodialysis patients?

INTRODUCTION: This study aimed to assess if an interference effect could blunt the neuromuscular gains induced by a same-session combined rehabilitation in hemodialysis (HD) patients. METHODS: Patients exercised twice a week, for 16 weeks, over their HD sessions. They were either always trained with resistance and endurance exercises (continuous training, "CONT") or alternatively with 1 week of resistance alternated with 1 week of endurance (discontinuous training, "DISC"). Adherence and workload were continuously recorded. Short Physical Performance Battery (SPPB) score, one-leg balance test, and handgrip and quadriceps strength were evaluated before and after training intervention. RESULTS: Adherence to both programs was high (>90%). SPPB score had significantly improved (CONT: +1.5 point, DISC: +1.2 pt, p < 0.001), like one-leg balance test (CONT: +3.7 s, DISC: +5.5 s, p < 0.05), handgrip strength of exercised (CONT: +5.5 kg, DISC: +5.6 kg, p < 0.001) and of nonexercised arm (CONT: +4.4 kg, DISC: +2.8 kg, p < 0.01) as well as maximal quadriceps strength (+22 N·m for dominant and +29 N·m for nondominant leg in both groups, p < 0.001) bearing no difference between the trainings. CONCLUSION: Same-session combined training does not induce an interference effect in HD patients and temporal separation of exercises does not optimize strength gains. These practical data may be relevant for clinicians and practitioners to alternate endurance and resistance exercises.

Dynapaenia and sarcopaenia in chronic haemodialysis patients: do muscle weakness and atrophy similarly influence poor outcome?

BACKGROUND: Sarcopaenia, defined as a decline in both muscle mass and function, has been recognized as a major determinant of poor outcome in haemodialysis (HD) patients. It is generally assumed that sarcopaenia is driven by muscle atrophy related to protein-energy wasting. However, dynapaenia, defined as weakness without atrophy, has been characterized by a different disease phenotype from sarcopaenia. The aim of this study was to compare the characteristics and prognosis of sarcopaenic and dynapaenic patients among a prospective cohort of chronic HD (CHD) patients. METHODS: Two hundred and thirty-two CHD patients were enrolled from January to July 2016 and then followed prospectively until December 2018. At inclusion, weakness and atrophy were, respectively, evaluated by maximal voluntary force (MVF) and creatinine index (CI). Sarcopaenia was defined as the association of weakness and atrophy (MVF and CI below the median) while dynapaenia was defined as weakness not related to atrophy (MVF below the median, and CI above the median). RESULTS: From a total of 187 prevalent CHD patients [65% of men, age 65.3 (49.7-82.0) years], 44 died during the follow-up period of 23.7 (12.4-34.9) months. Sarcopaenia and dynapaenia were observed in 33.7 and 16% of the patients, respectively. Compared with patients with sarcopaenia, patients with dynapaenia were younger and with a lower Charlson score. In contrast, mortality rate was similar in both groups (38 and 27%, respectively). After adjustment for age, sex, lean tissue index, serum albumin, high-sensitivity C-reactive protein (hs-CRP), haemoglobin (Hb), normalized protein catabolic rate (nPCR), dialysis vintage and Charlson score, only patients with dynapaenia were at increased risk of death [hazard ratio (HR) = 2.99, confidence interval 1.18-7.61; P = 0.02]. CONCLUSIONS: Screening for muscle functionality is highly warranted to identify patients with muscle functional impairment without muscle atrophy. In contrast to sarcopaenia, dynapaenia should appear as a phenotype induced by uraemic milieu, characterized by young patients with low Charlson score and poor prognosis outcome independently of serum albumin, hs-CRP, Hb, nPCR and dialysis vintage.

Beyond sarcopenia: frailty in chronic haemodialysis patients.

Background: Frailty, characterized by vulnerability, reduced reserves and increased susceptibility to severe events, is a significant concern in chronic haemodialysis (HD) patients. Sarcopenia, corresponding to the progressive loss of muscle mass and strength, may contribute to frailty by reducing functional capacity, mobility and autonomy. However, consensus lacks on the optimal bedside frailty index for chronic HD patients. This study investigated the influence of frailty on chronic HD patient survival and explored the associated factors. Methods: A total of 135 patients were enrolled from January to April 2019 and then followed up prospectively until April 2022. At inclusion, frailty was assessed by the Timed Up and Go (TUG) and Short Physical Performance Battery (SPPB) tests including gait speed, standing balance and lower limb muscle strength. Results: From a total of 114 prevalent chronic HD patients (66% men, age 67.6 ± 15.1 years), 30 died during the follow-up period of 23.7 months (range 16.8-34.3). Deceased patients were older, had more comorbidities and a higher sarcopenia prevalence (P < .05). The TUG and SPPB test scores were significantly reduced in patients who had died [SPPB total score: 7.2 ± 3.3 versus 9.4 ± 2.5; TUG time 8.7 ± 5.8 versus 13.8 ± 10.5 (P < .05)]. Multivariate analysis showed that a higher SPPB score (total value >9) was associated with a lower mortality risk [hazard ratio 0.83 (95% confidence interval 0.74-0.92); P < .03). Each component of the SPPB test was also associated with mortality in univariate analysis, but only the SPPB balance test remained protective against mortality in multivariate analysis. Older age, lower handgrip strength and lower protein catabolic rate were associated with SPPB total scores <9, SPPB balance score and TUG time >10 s. Conclusions: Screening for frailty is crucial in chronic HD patients, and incorporating SPPB, especially the balance test, provides valuable insights. Diminished muscle strength and inadequate protein intake negatively influence the SPPB score and balance in chronic HD patients. Effective identification and management of frailty can therefore improve outcomes. CLINICAL TRIAL REGISTRATION ClinicalTrialsgov: NCT03845452.

Feasibility and early effects of bed-cycling eccentric training: Potential clinical applications.

PURPOSE: This study aimed to evaluate feasibility and early effects of moderate intensity bed-cycling eccentric training on healthy individuals, and establish whether this training modality could be implemented into bedridden patients' routine care. METHODS: Longitudinal study with prepost exercise intervention measurements. The development of a bed-adapted eccentric ergometer allowed to conduct five training sessions during 3 weeks at increasing intensity on 11 healthy individuals. Force-speed relationship, maximal voluntary knee extension force and neural activation of subjects were evaluated before and after the programme. RESULTS: Five training sessions were sufficient to decrease the rate of perceived exertion whereas eccentric power output increased (+40%). After training, maximal voluntary isometric contraction force measured during knee extension had significantly improved in all subjects, with a mean increase of 17%. Maximal cycling power was also significantly higher (+7%) after the training programme. CONCLUSION: Taken together, these results show that moderate load eccentric bed cycling (i) was feasible and efficient, (ii) did not generate excessive individual perception of effort during exercise nor develop major muscular or joint pain after training and (iii) allowed early force and power gains in healthy subjects.

Physical inactivity and protein energy wasting play independent roles in muscle weakness in maintenance haemodialysis patients.

BACKGROUND: Muscle weakness is associated with increased mortality risk in chronic haemodialysis (CHD) patients. Protein energy wasting (PEW) and low physical activity could impair muscle quality and contribute to muscle weakness beyond muscle wasting in these patients. Aim of this study was to assess clinical and biological parameters involved in the reduction of muscle strength of CHD patients. METHODS: One hundred and twenty-three CHD patients (80 males, 43 females; 68,8 [57.9-78.8] y.o.) were included in this study. Maximal voluntary force (MVF) of quadriceps was assessed using a belt-stabilized hand-held dynamometer. Muscle quality was evaluated by muscle specific torque, defined as the strength per unit of muscle mass. Muscle mass was estimated using lean tissue index (LTI), skeletal muscle mass (SMM) assessed by bioelectrical impedance analysis and creatinine index (CI). Voorrips questionnaire was used to estimate physical activity. Criteria for the diagnosis of PEW were serum albumin, body mass index < 23 kg/m2, creatinine index < 18.82 mg/kg/d and low dietary protein intake estimated by nPCR < 0.80g/kg/d. RESULTS: MVF was 76.1 [58.2-111.7] N.m. and was associated with CI (ß = 5.3 [2.2-8.4], p = 0.001), LTI (ß = 2.8 [0.6-5.1], p = 0.013), Voorrips score (ß = 17.4 [2.9-31.9], p = 0.02) and serum albumin (ß = 1.9 [0.5-3.2], p = 0.006). Only serum albumin (ß = 0.09 [0.03-0.15], p = 0.003), Voorrips score (ß = 0.8 [0.2-1.5], p = 0.005) and CI (ß = 0.2 [0.1-0.3], p<0.001) remained associated with muscle specific torque. Thirty patients have dynapenia defined as impaired MVF with maintained SMM and were younger with high hs-CRP (p = 0.001), PEW criteria (p<0.001) and low Voorrips score (p = 0.001), and reduced dialysis vintage (p<0.046). CONCLUSIONS: Beyond atrophy, physical inactivity and PEW conspire to impair muscle strength and specific torque in CHD patients and could be related to muscle quality. TRIAL REGISTRATION: ClinicalTrials.gov NCT02806089.