Metabolic Response to Claudication in Peripheral Arterial Disease: A Microdialysis Pilot Study

This is a pilot study, and the objective of the study was to investigate the possible uses of microdialysis in the calf muscle to assess the metabolic response to intermittent claudication (IC) and in addition evaluate the simultaneous systemic inflammatory reaction.

Dialysate and venous blood sampling was performed before, during and after walking on a treadmill to maximal tolerable claudication (controls 10 min) using 1 microdialysis catheter inserted in the gastrocnemius muscle, 1 subcutaneously in the pectoral region (as a reference), and a peripheral venous catheter.

A total of 9 participants were recruited, 6 patients with IC and 3 healthy control subjects. At baseline, patients with IC and control subjects did not differ in metabolic findings (glucose, lactate, pyruvate, and glycerol) in the gastrocnemius muscle. Subcutaneous glucose concentration was higher in control subjects. After physical exertion, gastrocnemius and subcutaneous glycerol, lactate, and pyruvate concentrations increased in patients with IC. Plasma concentrations of tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), interleukin-1ß (IL-1ß), hepatocyte growth factor, and vascular endothelial growth factor were higher in IC subjects at baseline, and TNF-α, IL-6, and IL-18 increased after walking as did IL-6 and IL-1ß in control subjects. The muscle catheters did not show any signs of harm.

Microdialysis can be used to study the ongoing metabolic response during walking and claudication. Our results suggest both an acute local and a systemic inflammatory reaction during development of claudication.