Human growth hormone kinetics in critically ill patients

Area of Science:

• Endocrinology
• Metabolic Research
• Critical Care Medicine

Background:

• Exogenous human growth hormone (HGH) shows anabolic effects in surgical patients.
• Contradictory findings exist regarding HGH efficacy in polytrauma patients.
• The pharmacokinetics of recombinant human GH (r-HGH) in critically ill patients require clarification.

Purpose of the Study:

• To assess the pharmacokinetic profile of r-HGH in critically ill, catabolic patients.
• To determine if r-HGH elimination is altered in intensive care unit (ICU) patients.

Main Methods:

• Five catabolic ICU patients received a continuous infusion of r-HGH.
• Endogenous GH secretion was suppressed using somatostatin.
• Pharmacokinetic parameters (half-life, clearance, distribution space) were calculated using a two-compartment model.
• Plasma insulin, glucagon, and amino acid levels were monitored.

Main Results:

• The elimination half-life (t1/2kle) was 19.6 ± 2.3 min, whole body clearance (Cltot) was 2.9 ± 0.4 ml/kg/bw/min, and distribution space (DS) was 76.4 ± 3.8 ml/kg/bw.
• Plasma levels of total amino acids, branched-chain amino acids, and glutamine were significantly elevated during r-HGH infusion.
• These pharmacokinetic parameters did not differ from those reported in healthy volunteers.

Conclusions:

• The elimination of r-HGH in catabolic ICU patients is comparable to healthy individuals.
• This suggests that standard dosing might be applicable for r-HGH therapy in critically ill patients.
• Further research could explore the therapeutic benefits of r-HGH in this patient population.