ACROMEGALY OR CHRONIC-RENAL-FAILURE - A DIAGNOSTIC DILEMMA

Uraemic patients may have markedly elevated serum GH concentrations ye t, for hitherto unknown reasons, they do not develop acromegaly. We di scuss the diagnostic dilemma presented by a 33-year-old Caucasian male with chronic renal failure (creatinine clearance 10 ml/min) secondary to polycystic kidney disease, elevated GH concentrations (fasting con centration of 22.6 rising to 77.9 mU/l 30 minutes after a 75-g oral gl ucose load) as well as acromegalic features. Review of the patient's r elatives and the findings of a normal serum IGF-I concentration and a normal pituitary fossa on magnetic resonance imaging, suggest that the patient's acromegalic appearance is a familial trait and his abnormal GH dynamics a result of his renal failure rather than acromegaly. The patient's normal GH bioactivity and reduced GH binding protein concen tration supports the current belief that chronic renal failure leads t o an increase in peripheral tissue resistance to GH due to decreased G H receptor numbers. These changes, together with reduced IGF-I bioacti vity, may explain why patients with chronic renal failure do not devel op acromegaly in the presence of abnormally elevated levels of GH.