Does growth hormone allow more efficient nitrogen sparing in postoperative patients requiring parenteral nutrition? A double-blind, placebo-controlled randomised trial.
OBJECTIVE
Growth hormone (GH) has a strong anabolic effect and is thought to be useful in improving the efficacy of parenteral nutrition (PN) to preserve muscle mass (MM) in the postoperative setting. Unfortunately, the negative clinical outcome of GH treatment in intensive care patients limits its use in this setting, but demands answers to the mechanism behind the action of this therapy.


METHODS
In a double-blind randomised controlled study consecutive patients after major abdominal surgery were divided into four groups of either 1/2-PN (0.13 g N/kg/day and 52% of calories as lipid) or full-strength PN (Full-PN) (0.3 g N/kg/day and 65% of calories as lipid) receiving daily injections of either GH (8-16 IU) or placebo for a period of 14 days postoperative. Outcome measures included MM derived from measures of total body potassium (40K counting) and total body nitrogen (TBN) (in vivo neutron capture technique); Fat mass from skin folds; serum insulin like growth factor-I (IGF-I) and its binding proteins (IGFBP).


RESULTS
From 43 major upper GI surgical patients randomised 35 completed the study (one patient died from sepsis in the half-strength PN (1/2-PN)+GH group). 1/2-PN (n=11) lost TBN (P=0.001), MM (P=0.005) but not fat. Full-PN (n=9) maintained TBN, MM (P=0.056) and fat. 1/2-PN+GH (n=8) maintained TBN and fat but lost MM (P=0.038). Full-PN+GH (n=7) maintained TBN and MM but lost fat (P=0.018). Two-way ANOVA indicated that PN input (P=0.031) and not GH had a significant effect on MM. GH caused a significant rise in IGF-I levels (290+/-67 and 454+/-71 microg/l for 1/2-PN+GH and Full-PN+GH, respectively) and restored serum IGFBP3 and the acid labile subunit to normal, by the postoperative day 9.


CONCLUSIONS
After major gastrointestinal surgery, GH causes a marked hepatic IGF-I response and nitrogen retention but its effect on body composition was more significant with a high PN input. Further, Full-PN alone was sufficient to prevent nitrogen loss and preserved MM and addition of GH does not provide further metabolic advantage.
Sevette
Andre
A
University of Sydney, Departments of Surgery, North Shore Hospital, Sydney, St. Leonards, NSW 2065, Australia.
Smith
Ross C
RC
Aslani
Alireza
A
Kee
Anthony J
AJ
Hansen
Ross
R
Barratt
S McG
SM
Baxter
Robert C
RC
D000005:Abdomen / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001823:Body Composition / Q000187:drug effects*; D003131:Combined Modality Therapy; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D013006:Growth Hormone / Q000494:pharmacology*; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D010288:Parenteral Nutrition; D011184:Postoperative Period; D011197:Potassium Radioisotopes; D011446:Prospective Studies; D016896:Treatment Outcome
D018969:Insulin-Like Growth Factor Binding Proteins; D011197:Potassium Radioisotopes; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D009584:Nitrogen