Background: Exercise capacity is markedly impaired in patients with end-stage renal disease (ESRD) due to neuromuscular dysfunction and reduced oxygen delivery. This study aimed to investigate the effects of NMES during HD on exercise capacity in patients with ESRD. It specifically examined neuromuscular and hemodynamic adaptations. Methods: Twenty-two patients with ESRD were randomized to a neuromuscular electrical stimulation training group (NSTG, n = 11) or a control group (CG, n = 11). The NSTG underwent intradialytic quadriceps NMES three times per week for 12 weeks (40 min/session). Exercise capacity was evaluated via sustained isometric contraction at 50% of maximal voluntary contraction (MVC) until exhaustion. Neuromuscular function was assessed through voluntary activation (ΔVA) and potentiated twitch force (ΔQtw,pot), while muscle oxygenation (ΔO2Hb, ΔHHb, ΔTHb) of the vastus lateralis was continuously monitored using near-infrared spectroscopy. Results: After the intervention, the NSTG showed a significant +20% increase in Tlim (103.9 ± 14.4 s to 123.3 ± 16.6 s; p = 0.01) and +30% improvement in MVC (421.3 ± 24.9 N to 550.4 ± 20.3 N; p < 0.01), while no improvements were observed in CG. Resting VA increased by ≈7% in NSTG (90.2 ± 3.7% to 96.8 ± 2.5%; p = 0.012). Improved muscle oxygenation and reduced twitch force suggest enhanced oxidative capacity and greater peripheral fatigue tolerance. Conclusions: Intradialytic NMES elicited robust improvements in exercise capacity, muscle strength, and oxygen utilization in ESRD patients by enhancing both central activation and peripheral oxidative adaptations. These findings support NMES as a feasible and effective rehabilitative strategy to counteract fatigue and functional decline in the ESRD population.
5 March 2024 in International Urology and Nephrology
Patients with end stage renal disease (ESRD) display many cognitive and physiological alterations resulting from renal failure and physical inactivity. Caffeine intake has been reported to improve cognitive/physical performance in several studies. However, whether the benefits of caffeine intake apply to patients with ESRD remains unknown. The aim of the present study was to explore the effect of caffeine intake on postural balance, cognitive function and functional capacity in patients with ESRD. In a randomized order, 12 patients with ESRD (age: 33.85 ± 8.57 years; Female: 45.5%) performed a battery of tests after either caffeine (CF) (400 mg) or placebo (PLA) ingestion. Postural balance was evaluated using a stabilometric platform. Functional capacity was assessed with the sit-to-stand and up-and-go tests, and for cognitive performances, reaction time test and a vigilance test were used. Results showed a significant improvement in up-and-go test (p = 0.01) and sit-to-stand test performances with CF compared to PLA (p < 0.01). Time of reaction test and vigilance test (p < 0.01) performances were significantly higher with CF. No significant difference was observed in postural balance between CF and PLA. The results of this study suggest that acute caffeine ingestion positively enhances cognitive function and functional capacity in patients with ESRD.
Background: Type 1 diabetes (T1D) is associated with metabolic and neuromuscular impairments that may influence fatigue mechanisms and limit exercise tolerance. Although previous investigations have characterized muscle performance in T1D, the peripheral fatigue threshold, defined as the maximal sustainable level of peripheral fatigue, remains poorly understood in this population. This study aimed to compare the amplitude of the maximal peripheral fatigue threshold between individuals with T1D and healthy controls to elucidate the effects of T1D on neuromuscular function. Methods: Twenty-two participants (11 with T1D and 11 healthy controls) completed two randomized experimental sessions. In each session, 60 quadriceps maximal voluntary contractions (MVCs) were completed, performed for 3 s with 2 s of rest between contractions. One session was conducted under a non-fatigued control condition (CTRL), and the other followed a fatiguing neuromuscular electrical stimulation (FNMES) protocol. Central and peripheral fatigue were evaluated from the pre- to post-exercise changes in potentiated twitch force (ΔPtw) and voluntary activation (ΔVA), respectively. Critical torque (CT) was calculated as the average torque produced during the last 12 contractions, whereas the curvature constant of the torque–duration relationship (W′) was quantified as the area above CT. Results: Although both groups exhibited a decline in pre-exercise Ptw following the FNMES condition, no significant within-group differences in ΔPtw were observed between sessions (T1D: p = 0.34; controls: p = 0.23). Nevertheless, the extent of peripheral fatigue was significantly lower in participants with T1D than in controls (ΔPtw = −38 ± 11% vs. −52 ± 17%; p < 0.05). Additionally, W′ values were reduced by 24% in the T1D group relative to controls during the CTRL condition (p = 0.02), and CT was significantly lower in T1D participants (262 ± 49 N) compared to controls (353 ± 71 N; p < 0.01). A significant positive correlation was observed between ΔPtw and W′ across groups (r2 = 0.62, p < 0.001), suggesting a mechanistic link between peripheral fatigue tolerance and work capacity. Conclusions: The present results indicate that, although individuals with T1D retain the capacity to develop peripheral fatigue, their fatigue threshold and critical torque are markedly attenuated relative to those of healthy individuals. This reduction reflects impaired neuromuscular efficiency and diminished tolerance to sustained contractile activity. The strong relationship between peripheral fatigue and work capacity underscores the contribution of peripheral mechanisms to exercise intolerance in T1D. These results enhance current understanding of fatigue physiology in diabetes and emphasize the need for tailored exercise and rehabilitation strategies to improve fatigue resistance and functional performance in this population.
Introduction: Chronic musculoskeletal pain significantly impacts the quality of life and physical productivity of women engaged in agrarian labour within rural settings. This study examined the efficacy of a hybrid rehabilitation approach specifically designed for this demographic in low-resource environments. Objective: This study aimed to evaluate a hybrid rehabilitation program combining field-based activities and tele-exercises to manage pain and improve functional muscle strength among rural Iraqi women. Methodology: A quasi-experimental pre-test–post-test cohort study was conducted among sixty-six women who had extensive histories of agrarian labour in the Hamdaniya District. The twelve-week intervention integrated home-based exercises delivered via mobile video applications with twice-weekly field sessions featuring culturally familiar games, while physical assessments utilized a handheld dynamometer and the Numeric Rating Scale-11. Results: The data indicated that the majority of participants suffered from severe lower back and extremity pain at baseline. Following the intervention, significant improvements in muscle strength were recorded across all targeted regions, and pain levels transitioned from severe to either moderate or mild, with several cases reaching complete resolution. Discussion: These findings aligned with previous studies suggesting that supervised exercise programs effectively mitigate chronic occupational pain. The results contrasted favourably with traditional clinical models by demonstrating that culturally adapted physical activity increases participant adherence and social engagement in rural communities. Conclusions: The hybrid rehabilitation program successfully reduced chronic pain and enhanced the functional capacity of rural Iraqi women. The model presents a feasible, low-cost therapeutic strategy for improving musculoskeletal health in resource-limited settings.