The role of potassium in muscle membrane dysfunction in end-stage renal disease

Lotte Hardbo Larsen,Werner J Z'Graggen,Hugh Bostock,S Veronica Tan,Niels Henrik Buus,Hatice Tankisi

doi:10.1016/j.clinph.2021.09.012

Abstract

ObjectiveUremic myopathy is a condition seen in end-stage renal disease (ESRD), characterized by muscle weakness and muscle fatigue, in which the pathophysiology is uncertain. The aim of this study was to assess the role of abnormal serum constituents in ESRD patients by relating them to the excitability properties of the tibialis anterior muscle, at rest and during electrically induced muscle activation, by recording muscle velocity recovery cycles (MVRC) and frequency ramp responses. MethodsEighteen ESRD patients undergoing hemodialysis were evaluated by blood sample, MVRC, and frequency ramp (before and near the end of dialysis treatment), quantitative electromyography, and nerve conduction studies. Patients were compared to 24 control subjects. ResultsIn patients, muscle relative refractory period, early supernormality, late supernormality after 5 conditioning stimuli, and latency of the last of 15 and 30 frequency ramp pulses were strongly associated with potassium levels (p < 0.01), showing depolarization before and normalization in the end of hemodialysis. ConclusionsIn ESRD patients, the muscle membrane is depolarized, mainly due to hyperkalemia. SignificanceSince normal muscle fatigue has been attributed to potassium-induced depolarization, it seems likely that this mechanism is also a major cause of the exaggerated muscle fatigue and weakness in ESRD patients.

Highlights

IntroductionUremic myopathy is a term used in common deficiency of muscle function in patients with end-stage renal disease (ESRD)
Uremic myopathy is a term used in common deficiency of muscle function in patients with end-stage renal disease (ESRD) (Floyd⇑ Corresponding author at: Department of Clinical Neurophysiology, Aarhus et al, 1974; Serratrice et al, 1967)
Excitability measures derived from muscle velocity recovery cycles (MVRC) recordings: (1) Muscle relative refractory period (MRRP), defined as the shortest interpolated inter-stimulus interval (ISI) at which the latencies of the unconditioned and conditioned test response were identical, (2) early supernormality (ESN) measured as the largest percentage latency reduction of conditioned muscle action potential at ISIs < 15 ms, (3) ESN after 5 conditioning stimuli (5ESN), (4) late supernormality (LSN) measured as the average percentage latency reduction between ISIs of 50 and 150 ms, (5) extra-late supernormality following 2 conditioning stimuli (2XLSN) calculated as LSN (2)-LSN, and (6) extra-late supernormality following 5 conditioning stimuli (5XLSN) calculated as LSN(5)-LSN

Summary

Introduction

Uremic myopathy is a term used in common deficiency of muscle function in patients with end-stage renal disease (ESRD) ⇑ Corresponding author at: Department of Clinical Neurophysiology, Aarhus et al, 1974; Serratrice et al, 1967). Uremic myopathy refers to the constellation of functional and occasionally structural muscle abnormalities, in patients with ESRD caused by the uremic state itself (Campistol, 2002).

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