The present study was designed to determine the effect of essential hyperte
nsion 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 metaboli
sm was analyzed by the forearm technique to estimate muscle exchange of sub
strate 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 n
on oxidative 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 significant
ly between groups. Both serum free fatty acid levels and lipid oxidation ra
tes 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 patient
s, whereas the insulinemic response to glucose load was greater among the p
atients with essential hypertension. These data show that insulin resistanc
e occurring in patients with essential hypertension is accompanied by impai
red muscle glucose uptake and nonoxidative metabolism.