Peripheral glucose metabolism in patients with essential hypertension

The present study was designed to determine the effect of essential hypertension on peripheral glucose metabolism during the postabsorptive state and after an oral glucose challenge. Ten normal subjects and nine patients with essential hypertension were studied after an overnight fast (12-14 h) and for 3 h after the ingestion of 75 g of glucose. Peripheral glucose metabolism was analyzed by the forearm technique to estimate muscle exchange of substrate combined with indirect calorimetry. Decreased forearm glucose uptake was observed in hypertensive patients compared to normal subjects (4.9+/-0.6 vs. 8.6+/-0.5 mmol x 100 ml forearm(-1) x 3 h(-1)) with diminished nonoxidative glucose metabolism (2.7+/-0.5 vs. 6.9+/-0.6 mmol x 100 ml forearm(-1) x 3 h(-1)). Muscle glucose oxidation did not differ significantly between groups. Both serum free fatty acid levels and lipid oxidation rates were similar in the normal subjects and the hypertensive patients, and declined in a similar fashion after glucose ingestion. Basal serum insulin levels did not differ significantly between normal and hypertensive patients, whereas the insulinemic response to glucose load was greater among the patients with essential hypertension. These data show that insulin resistance occurring in patients with essential hypertension is accompanied by impaired muscle glucose uptake and nonoxidative metabolism.