Development of a miniaturized glucose monitoring system by combining a needle-type glucose sensor with microdialysis sampling method. Long-term subcutaneous tissue glucose monitoring in ambulatory diabetic patients.
OBJECTIVE
To develop a reliable and practical glucose monitoring system by combining a needle-type glucose sensor with a microdialysis sampling technique for long-term subcutaneous tissue glucose measurements.


METHODS
A microdialysis Cuprophan hollow-fiber probe (inner diameter, 0.20 mm; length, 15 mm) was perfused with isotonic saline solution (120 microliters/h) and glucose concentrations in the dialysate were measured by a needle-type glucose sensor extracorporeally. This system was tested both in vitro and in vivo. Subcutaneous tissue glucose concentrations were then monitored continuously in 5 healthy and 8 diabetic volunteers for 7 to 8 days. A hollow-fiber probe was inserted into the abdominal subcutaneous tissue.


RESULTS
This monitoring system achieved excellent results in vitro. Subcutaneous tissue glucose concentrations were measured in a wide range from 1.7 to > 27.8 mM glucose, with a time delay of 6.9 +/- 1.2 min associated with a rise in glucose and 8.8 +/- 1.6 min with a fall in the glucose level (means +/- SE). The overall correlation between subcutaneous tissue (Y) and blood (X) glucose concentration was Y = 1.08X + 0.19 (r = 0.99). The subcutaneous tissue glucose concentration could be monitored precisely for 4 days without any in vivo calibrations and for 7 days by introducing in vivo calibrations.


CONCLUSIONS
Glycemic excursions could be monitored precisely in the subcutaneous tissue by this microdialysis sampling method with a needle-type glucose sensor in ambulatory diabetic patients.
Hashiguchi
Y
Y
Department of Metabolic Medicine, Kumamoto University School of Medicine, Japan.
Sakakida
M
M
Nishida
K
K
Uemura
T
T
Kajiwara
K
K
Shichiri
M
M
D000328:Adult; D015374:Biosensing Techniques; D001786:Blood Glucose / Q000032:analysis*; D003920:Diabetes Mellitus / Q000097:blood*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood; D004867:Equipment Design; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D017551:Microdialysis / Q000295:instrumentation / Q000379:methods; D008904:Miniaturization; D008991:Monitoring, Physiologic / Q000295:instrumentation* / Q000379:methods; D012016:Reference Values; D012044:Regression Analysis
D001786:Blood Glucose; D006442:Glycated Hemoglobin