A NONINVASIVE METHOD TO MEASURE SPLANCHNIC GLUCOSE-UPTAKE AFTER ORAL GLUCOSE-ADMINISTRATION

We have developed a noninvasive method to estimate splanchnic glucose uptake (SGU) in humans (oral glucose clamp technique [OG-CLAMP]), whic h combines a hyperinsulinemic clamp with an oral glucose load (oral gl ucose tolerance test). We validated this method in 12 nondiabetic subj ects using hepatic vein catheterization (HVC) during an oral glucose t olerance test. During HVC, splanchnic blood flow increased from 1,395/-64 to 1,935+/-109 ml/min, returning to basal after 180 min and accou nted for 45+/-7% of SGU in lean and 19+/-5% in obese subjects (P < 0.0 5), SGU estimated during the OG-CLAMP was 22+/-2% of the glucose load, and this was significantly correlated (r = 0.90, P < 0.0001) with SGU (35+/-4%) and with first pass SGU (24+/-3%; r = 0.83, P < 0.001) meas ured during HVC, SGU was higher in obese than in lean subjects during OG-CLAMP (27+/-5% vs 18+/-3%,P < 0.01) and HVC (44+/-4% vs 26+/-5%, P < 0.05). In conclusion, SGU during the OG-CLAMP is well correlated to SGU measured during HVC. An increase in splanchnic blood how is a majo r contributor to SGU in lean subjects. SGU is increased in obese subje cts as measured by both methods.