The treatment of
burn patients with recombinantly derived
human growth hormone (rHGH) appears effective in counteracting
protein catabolism. However, exogenous
growth hormone is frequently associated with
hyperglycemia, an aspect which may limit its usefulness. Therefore, to assess the affect of rHGH on
glucose utilization, 13 severely burned patients (65% +/- 4 TBSA
burn; mean +/- SEM) began receiving on admission either placebo or rHGH (0.2 mg/kg.d) in a double-blind randomized fashion. While hypermetabolic (percentage REE/predicted REE 1.41 +/- 0.11) fasting oxygen consumption and CO2 production were measured using indirect calorimetry prior to and then during a hyperinsulinemic euglycemic clamp. This experiment demonstrated that rHGH significantly reduced
glucose uptake and inhibited
glucose oxidation compared to the placebo patients. Since the decreases in
glucose oxidation and uptake were proportional,
glucose utilization (percentage
glucose uptake oxidized) remained similar in both patient groups. Furthermore, the hyperinsulinemic clamp lowered the plasma
amino acid concentrations in the control patients while rHGH-treated patients had no significant alterations. In conclusion, exogenous
growth hormone therapy induces an
insulin resistance in
burn patients. Furthermore, since the
glucose utilization did not change, it is likely that the mechanism of
insulin resistance is due to a deficiency in
glucose transport.