TY - JOUR

T1 - The effect of intensive insulin therapy on the insulin-regulatable glucose transporter (GLUT4) expression in skeletal muscle in type 1 diabetes

AU - Andersen, P H

AU - Vestergaard, H

AU - Lund, S

AU - Vedel, Peter

AU - Junker, Steffen

AU - Kahn, B B

AU - Pedersen, O

PY - 1993/10

Y1 - 1993/10

N2 - Studies in normal man and rodents have demonstrated that the expression of the dominant glucose transporter in skeletal muscle, GLUT4, is regulated by insulin at supraphysiological circulating levels. The present study was designed to determine whether intensified insulin replacement therapy for 24 h given to patients with Type 1 diabetes in poor metabolic control was associated with an adaptive regulation of GLUT4 mRNA and protein levels in vastus lateralis muscle. Nine Type 1 diabetic patients with a mean HbA1c of 10.3% were included in the protocol. After intensified treatment with soluble insulin for 24 h the fasting plasma glucose concentration decreased from 20.8 +/- 2.3 (SD) to 8.7 +/- 2.3 mmol 1-1, whereas the fasting serum insulin level increased from 0.06 +/- 0.02 to 0.17 +/- 0.09 nmol 1-1. However, despite a 2.8-fold increase in serum insulin levels and more than a halving of the plasma glucose concentration for at least 15 h no significant alterations occurred in the amount of GLUT4 protein (0.138 +/- 0.056, poor control vs 0.113 +/- 0.026 arb. units, improved control, p = 0.16) or GLUT4 mRNA (96432 +/- 44985, poor control vs 81395 +/- 25461 arb. units, improved control, p = 0.54). These results suggest, that in spite of evidence that high insulin levels affect GLUT4 expression in muscle, changes in serum insulin within the physiological range do not play a major role in the short-term regulation of GLUT4 expression in Type 1 diabetic patients.

AB - Studies in normal man and rodents have demonstrated that the expression of the dominant glucose transporter in skeletal muscle, GLUT4, is regulated by insulin at supraphysiological circulating levels. The present study was designed to determine whether intensified insulin replacement therapy for 24 h given to patients with Type 1 diabetes in poor metabolic control was associated with an adaptive regulation of GLUT4 mRNA and protein levels in vastus lateralis muscle. Nine Type 1 diabetic patients with a mean HbA1c of 10.3% were included in the protocol. After intensified treatment with soluble insulin for 24 h the fasting plasma glucose concentration decreased from 20.8 +/- 2.3 (SD) to 8.7 +/- 2.3 mmol 1-1, whereas the fasting serum insulin level increased from 0.06 +/- 0.02 to 0.17 +/- 0.09 nmol 1-1. However, despite a 2.8-fold increase in serum insulin levels and more than a halving of the plasma glucose concentration for at least 15 h no significant alterations occurred in the amount of GLUT4 protein (0.138 +/- 0.056, poor control vs 0.113 +/- 0.026 arb. units, improved control, p = 0.16) or GLUT4 mRNA (96432 +/- 44985, poor control vs 81395 +/- 25461 arb. units, improved control, p = 0.54). These results suggest, that in spite of evidence that high insulin levels affect GLUT4 expression in muscle, changes in serum insulin within the physiological range do not play a major role in the short-term regulation of GLUT4 expression in Type 1 diabetic patients.

KW - Adult

KW - Biopsy

KW - Blood Glucose

KW - DNA

KW - Diabetes Mellitus, Type 1

KW - Female

KW - Glucose Transporter Type 4

KW - Hemoglobin A, Glycosylated

KW - Humans

KW - Insulin

KW - Male

KW - Monosaccharide Transport Proteins

KW - Muscle Proteins

KW - Muscles

KW - RNA

M3 - Journal article

C2 - 7505214

VL - 10

SP - 699

EP - 706

JO - Diabetic Medicine

JF - Diabetic Medicine

SN - 0742-3071

IS - 8

ER -