Microdialysis measurement of glucose in subcutaneous adipose tissue up to three weeks in Type 1 diabetic patients

Background: Microdialysis of subcutaneous adipose tissue may provide an opp ortunity to monitor glucose continuously, when the device is connected to a n extracorporal glucose sensor. We assessed whether our microdialysis probe s are capable of measuring adipose tissue glucose over a prolonged period i n Type 1 diabetic patients. Furthermore, the relationship between abdominal skinfold thickness and glucose recovery and the effect of spontaneous gluc ose excursions on its recovery were evaluated. Methods: Microdialysis probes were pairwise inserted subcutaneously into th e abdominal fat and remained in situ for 3 weeks in eight Type 1 diabetic p atients. At days 1, 3, 4, 8, 11, 16, and 18 of probe retention, glucose, as measured by microdialysis, was compared to capillary blood glucose concent rations during a 4 h period. The recovery of glucose obtained by microdialy sis was expressed as a percentage of the capillary blood glucose concentrat ion. Results: Eleven of the 16 inserted probes (69%) were evaluable during the c omplete study. Recovery of glucose was lower at day 1 and 3 (51+/-23% and 5 6+/-18%, respectively, mean+/-S.D.) compared to values found afterwards (67 +/-19%, 72+/-13%, 76+/-14%, 71+/-16%, and 76+/-18%, for day 4, 8, 11, 16, a nd 18, respectively, for all P < 0.05 vs. day 1 and 3). Skinfold thickness was inversely related to the overall 3 week glucose recovery (r = - 0.76; P < 0.03). Recovery was similar over a wide range of capillary blood glucose concentrations. Conclusions: Prolonged in vivo retention of microdialysis probes improves t he recovery and lowers the variability of adipose tissue-sampled glucose in Type 1 diabetic patients. These findings show that microdialysis-based glu cose measurements offer an opportunity for prolonged glucose monitoring. (C ) 2000 Elsevier Science B.V. All rights reserved.