The effect of mild hypercalcaemia on the growth hormone (GH), C-peptide and glucose
responses to arginine infusion in patients with insulin-dependent idiopathic diabetes
mellitus (ID) was compared with that observed in patients whose diabetes was secondary
to idiopathic haemochromatosis (IH) and chronic pancreatitis (CP). The summated GH
responses to arginine infusion alone were similar in all three groups. Mild hypercalcaemia
significantly diminished the GH response to arginine in patients with secondary diabetes,
but not in those with ID. As the blood glucose and C-peptide responses were similar
in the presence of a normal or raised serum calcium, the differences in GH response
could not be ascribed to changes in blood glucose levels or to alterations in endogenous
insulin release. For reasons as yet unknown, hypercalcaemia appears to have more of
a stabilizing effect on the pituitary somatotrophic granules of those with secondary
diabetes than in those with ID.
Diabetes Mellitus
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Hypercalcaemia
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Arginine Stimulation
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Growth Hormone
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C-Peptide
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Haemochromatosis
