Glucose concentrations in blood and tissue - a pilot study on variable time lag.
OBJECTIVE
The aim of this pilot study was to acquire insight into the parameters of glycaemic control, especially, (1) the time delay (lag phase) between plasma and tissue glucose concentrations in relation to rise and fall in glucose levels and (2) the rate of glucose increase and decrease.


METHODS
Four healthy people (HP), 4 people with type 1diabetes (DM1) and 4 with type 2 diabetes (DM2) underwent concurrent glucose measurements by means of (1) the continuous glucose monitoring system (CGMS-Medtronic), Medtronic-Minimed, CA, USA, calibrated by the glucometer Calla, Wellion, Austria, and, (2) the Beckman II analyser to measure glucose concentrations in venous plasma. Samples were taken on 4 consecutive days in the fasting state and 4 times after consumption of 50 g glucose. Carelink Personal, MS Excel, Maple and Mat lab were applied to plot the evolution of glucose concentration and analyse the results. The time difference between increase and decrease was calculated for HP, DM 1 and DM 2.


RESULTS
In DM1and DM2, glucose tolerance testing (GTT) resulted in slower transport of glucose into subcutaneous tissue than in HP where the lag phase lasted up to 12 min. The maximum increase/decrease rates in DM1 and DM2 vs HP were 0.25 vs < 0.1 mmol/L/min.


CONCLUSIONS
CGMS is shown to provide reliable plasma glucose concentrations provided the system is calibrated during a steady state. The analysis of glucose change rates improves understanding of metabolic processes better than standard GTT.
Department of Physiology, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic.|Department of Internal Medicine II - Gastroenterology and Hepatology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc.|Institute of Neurology and Geriatrics, Moravsky Beroun.
Rudolf
R
Chlup
BVT Technologies, a.s., Strazek, Czech Republic.
Jan
J
Krejci
Probe Scientific Ltd, Bedford, United Kingdom.
Mark
M
O'Connell
BVT Technologies, a.s., Strazek, Czech Republic.
Blanka
B
Sebestova
BVT Technologies, a.s., Strazek, Czech Republic.
Robert
R
Plicka
BVT Technologies, a.s., Strazek, Czech Republic.
Lucie
L
Jezova
BVT Technologies, a.s., Strazek, Czech Republic.|Heat Transfer and Fluid Flow Laboratory, Faculty of Mechanical Engineering, University of Technology, Brno.
Tereza
T
Brozova
Institute of Neurology and Geriatrics, Moravsky Beroun.|BVT Technologies, a.s., Strazek, Czech Republic.
Blanka
B
Doubravova
Institute of Neurology and Geriatrics, Moravsky Beroun.|BVT Technologies, a.s., Strazek, Czech Republic.
Hana
H
Zalesakova
Institute of Neurology and Geriatrics, Moravsky Beroun.|BVT Technologies, a.s., Strazek, Czech Republic.
Emilia
E
Durajkova
BVT Technologies, a.s., Strazek, Czech Republic.
Jiri
J
Vojtek
Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacky University Olomouc.
Josef
J
Bartek
D001786:Blood Glucose / Q000378:metabolism*; D015190:Blood Glucose Self-Monitoring; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D005215:Fasting / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D010865:Pilot Projects; D040521:Subcutaneous Tissue / Q000378:metabolism*; D013997:Time Factors
D001786:Blood Glucose
calibration; continuous glucose monitoring; diabetes mellitus; glucose transport; lag phase