Hypercalcemia associated with the use of human growth hormone in an adult surgical intensive care unit
J. B. Knox, R. H. Demling, D. W. Wilmore, P. Sarraf and A. A. Santos
Department of Surgery, Brigham and Women's Hospital, Boston, Mass, USA.
BACKGROUND: The anabolic properties of human growth hormone (HGH) may prove
beneficial in critically ill surgical patients. Potential effects of
hypercalcemia with HGH therapy have not been addressed for adult patients
in the intensive care unit. METHODS: We performed a retrospective review of
the past 100 patients treated with HGH in a surgical intensive care unit.
Laboratory data, including serum calcium levels, were recorded at baseline
and during HGH therapy. Additionally, calcium levels in 27 burn patients
receiving HGH were compared with calcium levels in a well-matched group of
27 burn patients not receiving HGH. The incidence and severity of
hypercalcemia were recorded, with attention to contributing factors and
overall outcome. RESULTS: There was a statistically significant increase in
the mean +/- SD serum calcium level with the institution of HGH therapy
(2.50 +/- 0.20 mmol/L [10.0 +/- 0.8 mg/dL] before HGH vs 2.74 +/- 0.27
mmol/L [11.0 +/- 1.1 mg/dL] during HGH, P < .05). Before HGH, 14% of the
patients had hypercalcemia, defined as a calcium level greater than 2.74
mmol/L (11.0 mg/dL). During HGH, 43% of the patients developed
hypercalcemia. Before HGH, no patient exhibited severe hypercalcemia,
defined as a calcium level greater than 3.12 mmol/L (12.5 mg/dL). However,
during HGH, 10% of the patients developed severe hypercalcemia. Elevations
in serum calcium levels were correlated with the duration of HGH therapy
and renal dysfunction. Burn patients receiving HGH exhibited significantly
higher mean +/- SD calcium levels than controls (2.87 +/- 0.32 mmol/L [11.5
+/- 1.3 mg/dL] vs 2.50 +/- 0.17 mmol/L [10.0 +/- 0.7 mg/dL], P < .001).
Studies performed in selected patients demonstrated that alterations in
parathyroid function, vitamin D metabolism, and thyroid function did not
appear to contribute to this effect. CONCLUSION: Prolonged HGH therapy in
critically ill surgical patients may result in severe hypercalcemia,
particularly in patients with altered renal function. Possible mechanisms
for HGH-induced hypercalcemia include increased intestinal absorption and
decreased urinary excretion. Outcome was not adversely affected by this
biochemical alteration, but careful monitoring of calcium levels should be
undertaken in this population receiving HGH.
