Level of skeletal muscle glucose transporter protein correlates with insulin-stimulated whole body glucose disposal in man

The content of GLUT4 glucose transporter mRNA and protein were measured in samples of the vastus lateralis muscle of normal volunteers subjected to a 4-h hyperinsulinaemic, euglycaemic clamp. Plasma glucose concentration was clamped at 5.3±0.1 mmol/l, and serum insulin concentration was maintained at 740±5 pmol/l. Whole body glucose uptake averaged 38.3±2.2 μmol · kg^-1 · min^-1, 62% of this being due to disposal via non-oxidative pathways. A significant correlation existed between basal levels of GLUT4 protein and the rate of whole body glucose disposal (r=0.77, p<0.02) and non-oxidative glucose disposal (r=0.80, p<0.02). There was no correlation between GLUT4 protein content and oxidative glucose disposal (r=0.08, NS). These observations are consistent with an important role for skeletal muscle GLUT4 protein in whole body glucose disposal.