Effect of 50 and 100 g glucose loads on peripheral muscle glucose metabolism in normal man.

The present study was designed to determine the effects of 50 and 100 g glucose loads on forearm muscle glucose uptake, oxidation and nonoxidative glucose metabolism in normal man. Ten healthy male subjects were studied during the postabsorptive state (12-14 h overnight fast) and for 3 hours following glucose ingestion. Peripheral glucose metabolism was analysed by the use of the forearm technique to estimate muscle exchange of substrate combined with indirect calorimetry. Greater forearm muscle uptake and nonoxidative metabolism of glucose were observed in the subjects during the G.100 study than during the G.50 study (G.100 = 178.9 +/- 19.7 and 155.3 +/- 23.0 vs 103.5 +/- 16.6 and 85.2 +/- 16.7 mg/100 g forearm muscle. 3 h, respectively). the muscle glucose oxidation did not show significant difference after the two glucose loads. Insulin levels reached after 100 g glucose ingestion were significantly higher than after the 50 g glucose load. In conclusion, this study revealed a dose-dependent metabolic response in the muscular tissue of normal subjects to oral glucose loads of 50 and 100 g, with respect to forearm muscle glucose uptake and nonoxidative glucose metabolism. The oxidative responses of the muscle tissue to the oral glucose challenges seem not to be directly proportional to the ingested meals.