The Uremic Environment and Muscle Dysfunction in Man and Rat

Abstract

Background: Patients reaching end-stage renal disease experience debilitating fatigue, with progression of this disease, rendering patients dysfunctional in their everyday lives. Methods: In vivomeasurements of muscle function, assessed using surface electromyography (EMG), were made on 25 patients prior to and after a session of hemodialysis (HD) treatment, alongsidein vitro measurements of muscle function in isolated rat muscles incubated in normal or uremic conditions approximating to those found in uremic rats (rat uremic: RU) or uremic humans (human uremic: HU). Results: HD significantly affected plasma values, e.g. reducing urea (69%), creatinine (62%), potassium (23%) and phosphate (48%) concentrations in patients (all p < 0.01). Treatment also improved the EMG frequency of 2nd dorsal interosseous (fast-twitch) (p < 0.01), although no change was noted for vastus lateralis (slow-twitch). In isolated rat muscles, a uremic environment had no significant effect on slow-twitch soleus during field stimulation, however, in fast-twitch extensor digitorum longus, a significant 23% (RU) and 22% (HU) faster rate of decline in force was measured, compared to controls (p < 0.001 and p < 0.01, respectively). Conclusion: It is concluded that (1) muscle weakness and its electrophysiological correlates may be rapidly induced by uremic solutes and rapidly reversed when the solutes are removed by dialysis, and (2) fast-twitch muscles are more readily affected by uremic conditions than slow-twitch muscles.

Morphological, Electrophysiological, and Metabolic Characteristics of Skeletal Muscle in People with End-Stage Renal Disease: A Critical Review

“…The variation in results may be related to the differences in the electrophysiological techniques used by these studies: Johansen et al 38 used CMAP, whereas Fahal et al 37 used EMG (interferential pattern). The third study, 59 a case series, reported the presence of myopathic changes. The functional measures of strength reported in this study implicitly suggested muscle weakness, since the performance of the ESRD/HD group (age 54.5 e 2.6 years) on the 30-second chair-stand test (12 e 0.8 reps) was comparable to that of women between 75 and 79 years of age.…”

“…37,38,59 Two of these studies 37,38 found statistically significant reductions in muscle strength in participants with ESRD/HD. However, Johansen et al 38 suggested neural mechanisms contributing to muscle weakness, while Fahal et al 37 identified causes intrinsic to the muscle.…”

Clinical Implications of Muscle-Tendon & -Force Interplay: Surface Electromyography Recordings of m. vastus lateralis in Renal Failure Patients Undergoing Dialysis and of m. gastrocnemius in Individuals with Achilles Tendon Damage

“…The sEMG frequency recorded prior to dialysis was generally found to be abnormal, when compared with a normal range of 2 nd dorsal interosseous muscles of the hand and on the thigh m. Vastus lateralis. This study also revealed a clear benefit of haemodialysis in terms of sEMG frequency of the 2 nd dorsal interosseous muscle (Harrison et al, 2006). Moreover, these authors found that the in vivo analysis of sEMG changes with a session of haemodialysis seemed to be limited to relatively fast-twitch muscles, a finding that was supported by a study of isolated rat extensor digitorum longus muscle, in which changes in the uremic environment were shown to exert a rapid loss of contractile force (Harrison et al, 2006).…”

“…It was noted that 50% of patients requiring dialysis had stopped their professional activity as a result of chronic renal failure, attributed to coronary (15% of patients), cardiovascular (23%), and bone or muscle (24%) related conditions (Evans et al, 1985). In a recent study involving patients on haemodialysis, in vivo measurements of muscle function were made using sEMG (Harrison et al, 2006). The sEMG frequency recorded prior to dialysis was generally found to be abnormal, when compared with a normal range of 2 nd dorsal interosseous muscles of the hand and on the thigh m. Vastus lateralis.…”

“…The study used both a single and a double differential electrode configuration, with electrodes (N-00-S & R-00-S; Blue Sensor R, Medicotest A/S, Ølstykke, Denmark) configured as described previously (Harrison et al, 2006). sEMG recordings were taken via an ML 131 amplifier connected to a PowerLab 4/25T A/D converter (AD Instruments, Chalgrove, Oxfordshire, UK) with a further connection to a Mac PowerBook Air with Chart v. 5.5.6 Software, Peak Parameters, and Spike Histogram extensions.…”