Interstitial glucose in skeletal muscle of diabetic patients during an oral glucose tolerance test.
OBJECTIVE
The presence of a transcapillary arterial-interstitial gradient for glucose (AIG(glu)) in skeletal muscle may be interpreted as a consequence of intact cellular glucose uptake. We hypothesized that the AIG(glu) decreases in Type 2 diabetes mellitus as a consequence of insulin resistance, whereas it remains intact in Type 1 diabetes.


METHODS
Glucose concentrations were measured in serum and interstitial space fluid of skeletal muscle during an oral glucose tolerance test (OGTT) in patients with Type 1 and Type 2 diabetes and in young and middle-aged healthy volunteers, using microdialysis.


RESULTS
The area under the curve for glucose in serum (AUC(SE)) was higher than in interstitial space fluid of skeletal muscle (AUC(MU)) in healthy young (AUC(SE) = 1147 +/- 332 vs. AUC(MU) = 633 +/- 257 mM/min/ml; P = 0.006), healthy middle-aged volunteers (AUC(SE) = 1406 +/- 186 vs. AUC(MU) = 1048 +/- 229 mM/min/ml; P = 0.001) and in Type 1 diabetic patients (AUC(SE) = 2273 +/- 486 vs. AUC(MU) = 1655 +/- 178 mM/min/ml; P = 0.003). In contrast, in Type 2 diabetic patients AUC(SE) (2908 +/- 1023 mM/min/ml) was not significantly different from AUC(MU) (2610 +/- 722 mM/min/ml; P = NS).


CONCLUSIONS
The present data indicate that AIG(glu) is compromised in Type 2 diabetes in contrast to Type 1 diabetes where it appears to be normal. Because no changes in muscle blood flow were detected, insulin resistance appears to be the main cause for the observed decreased AIG(glu) in skeletal muscle in Type 2 diabetic patients.
Frossard
M
M
Department of Clinical Pharmacology, Division of Clinical Pharmacokinetics, University of Vienna Medical School, A-1090 Vienna, Austria. martin.frossard@meduniwien.ac.at
Blank
D
D
Joukhadar
Ch
Ch
Bayegan
K
K
Schmid
R
R
Luger
A
A
Müller
M
M
D000293:Adolescent; D000328:Adult; D019540:Area Under Curve; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D045604:Extracellular Fluid / Q000378:metabolism; D005947:Glucose / Q000493:pharmacokinetics*; D006801:Humans; D007333:Insulin Resistance; D017551:Microdialysis; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism*
D005947:Glucose