Glucose-monitoring with continuous subcutaneous microdialysis in neonatal diabetes mellitus

Neonatal diabetes mellitus can be extremely brittle. In this situation close glucose monitoring is essential for adequate insulin treatment. Continuous subcutaneous microdialysis is a promising approach for the babies to reduce the painful stress caused by diagnostic blood sampling. The goal of this study was to evaluate the feasibility of continuous subcutaneous microdialysis for glucose monitoring in a baby with neonatal diabetes and to assess the correlation between the blood and the subcutaneous glucose profile.

During a period of seven days glucose monitoring was performed on a six month old infant with neonatal diabetes mellitus. In addition to frequent capillary blood glucose determinations, a continuous subcutaneous microdialysis device was used for the detection of the subcutaneous interstitial glucose concentration.

Subcutaneous tissue glucose concentrations were measured in a wide range from 1.7 to 23.8 mM. Variations in the adipose tissue glucose concentration closely paralleled changes in the capillary blood glucose. Based on 104 reference pairs there was a high overall correlation (r = 0.89) between the subcutaneous interstitial tissue (X) and the blood (Y) glucose concentration (Y = 1.1 X + 0.29). However the glucose profiles demonstrated a considerable variation of the time lag, up to one hour, between blood and subcutaneous interstitial glucose concentration.

Continuous subcutaneous microdialysis helps the glucose monitoring of infants with diabetes mellitus by providing additional informations about the rise and fall of the glucose concentration. Further studies should focus on how to get a tighter link between blood glucose and the subcutaneous interstitial glucose concentration in the area around the microdialysis probe. Thus monitoring the subcutaneous interstitial glucose concentration will become a reliable procedure for real-time glucose monitoring.