The metabolism of the diabetic foot: in vivo investigation with microdialysis.

Background: Many amputations might be delayed or prevented by more effective clinical supervision of the diabetic foot ulcer. The aim of this study was to measure the local metabolism on the edge of a diabetic ulcer and compare it to healthy subcutaneous tissue.

Patients And Methods: In 5 non-fasting diabetic patients, we inserted a microdialysis catheter into the edge of a diabetic ulcer and a reference catheter into healthy abdominal subcutaneous tissue, and recorded the local concentrations of glucose, lactate and glycerol during rest.

Results: The concentrations of glucose in the ulcers were 7.8 mM (SEM 1.9) and in the reference tissue 10.6 mM (SEM 1.8) (p = 0.4). The concentrations of lactate were 2.9 mM (SEM 0.7) and 2.1 mM (SEM 0.7) (p = 0.2), while those of glycerol were 290 microM (SEM 84) vs 98 microM (SEM 7.2) (p = 0.002).

Interpretation: This study shows that microdialysis can detect differences in dialysate concentrations of metabolites in diabetic ulcers and a reference tissue, providing valuable information concerning metabolites in the diabetic foot ulcer. Future studies should combine the technique with measurements of local blood flow.