To assess the effects of hypoglycemia on glucose absorption by examining the systemic appearance of 3-OMG (a glucose analogue that is transported by the same mechanism as glucose) after oral administration.
Six healthy males 22–31 yr of age were studied during a hypoglycemic (50 mg [2.7 mM]/100 ml) and a euglycemic (90 mg [5.0 mM]/100 ml) glucose clamp. At 50 min after exposure to insulin, an oral glucose load containing 20 g of glucose and 4.5 g of 3-OMG dissolved in 300 ml of tap water was administered. Insulin administration was interrupted 30 min after oral glucose administration.
Plasma glucose was clamped at 88 ± 1.3 mg (4.9 ± 0.1 mM)/100 ml during euglycemia and at 50 ± 1.9 mg (2.7 ± 0.1 mM)/100 ml during hypoglycemia. Concentrations of glucagon, growth hormone, cortisol, and epinephrine were significantly elevated during hypoglycemia. After 60 min, circulating 3-OMG concentrations increased to zeniths of 11.4 ± 0.2 mg (585 ± 10.0 mM)/100 ml (hypoglycemia) and 11.6 ± 1.1 mg (585 ± 56.0 μM)/100 ml (euglycemia; P = 0.95). Absorption of 3-OMG was evident between 15 and 20 min after administrations in both situations. Serum insulin was significantly lower during hypoglycemia compared with the control situation (345 ± 50 microM [hypoglycemia], 445 ± 50 μM [euglycemia], P = 0.03).
We conclude that hypoglycemia does not seem to affect intestinal absorption of glucose as judged by systemic appearance of 3-OMG.
