Exogenous growth hormone: Effects on the catabolic response to surgically produced acute stress and on postoperative immune function

The first purpose of the present prospective randomized study was to determine if the protein catabolic response after operation could be restrained by administration of hypocaloric parenteral nutrition (HPN) plus human growth hormone (hGH). Our second aim was to determine if the administration of hGH could improve the systemic host defenses, thereby reducing the risk of infection. We performed a placebo-controlled randomized double-blind trial in 180 patients after elective cholecystectomy with or without choledochoduodenostomy (placebo=control group,n=93; hGH-treated group,n=87). The results obtained in this study show that positive nitrogen balance can be achieved during the postoperative period from the first 24 hours onward, with a combination of HPN support (1.0–1.5 g protein/kg/day and 900 kcal/day) together with the administration of small doses (8 IU) of hGH. The potassium balance tended to follow the same positive balance as the nitrogen balance. Our study shows that in the control group, treated only with HPN, a significant decrease in serum levels of some acute-phase proteins (retinol-binding protein, transferrin, prealbumin), albumin, total proteins, and immunoglobulins occurs by the 5th postoperative day. In the GH group the values of all the above-mentioned proteins do not change or tend to rise if compared to preoperative levels. In the GH-treated group liver function appeared to improve at the start of the study. GH and somatomedin C levels were similar in the two groups and had not changed significantly in the control group by the 5th postoperative day. In the GH-treated group a significant increase in serum levels of GH and somatomedin C on postoperative day 5 was observed. Glucose levels in the control group were unaltered, but in the GH-treated group a clear increase in glucose concentration was observed. On the other hand, insulin values on postoperative day 5 in the GH group rose to almost twice those of the control group. After operation the number of normoergic patients in the control group fell from 56 to 40; in the GH-treated group the opposite was the case: the number of normoergic patients increased from 59 to 81. The number of anergic patients remained constant (n=11) in the control group and disappeared in the GH-treated group. Wound infection was found in 16 patients (17.2%) of the control group but in only 3 (3.4%) of the GH-treated group. Hospitalization averaged 12.5 ±7.1 days in the control group versus 9.6 ±3.6 days in the GH-treated group (p < 0.05). With moderate surgical injury (cholecystectomy with or without choledochoduodenostomy) hGH can optimize utilization of adjuvant HPN and overcome the protein catabolic effects of the trauma response. As a result, body cell mass is preserved, wound healing is promoted, and immunologic function is enhanced.