Abstract: Subjective The mechanism of muscle cramp in hemodialysis patients is not well understood. This study aimed to determine the association between endothelial dysfunction and hemodialysis-related muscle cramps. Methods: Ten hemodialysis patients with frequent muscle cramps(group A), twelve hemodialysis patients without muscle cramps(group B) were enrolled. The episodes of hemodialysis-related muscle cramps were recorded over a 2-month period. Flow-mediated dilatations were measured in the brachial arteryand plasma levels of vWF were measured on a mid-interdialysis day in second month of the period. Results: The incidence of symptomatic muscle cramps in group A was significnatly higher that in group B. Flow-mediated dilatations were lower significantly in group A, when comparing with group B. While, plasma vWF concentrations were significantly higher in group A. The frequents of hemodialysis-related cramps were associated with values of flow-mediated dilations and the concentrations of plasma vWF in group B. Conclusion: Endothelial dysfunction is associated with frequent hemodialysis-related cramps. Improving endothelial dysfuction may be helpful to reduce the incidence of hemodialysis-related cramps.

Key words: Muscle cramp, Hemodialysis, Endothelial dysfunction