ABSTRACT
Acromegaly is associated with metabolic disturbances of calcium and phosphorus which can also contribute to renal lithogenesis. In order to characterize these disturbances more precisely, an oral calcium load test was performed on 14 active acromegalic patients. Serum and urinary levels of calcium, phosphorus, uric acid, creatinine and urinary cyclic AMP were determined. Of the 14 patients, 5 (36%) presented hypercalciuria, 5 (36%) presented intestinal calciumhyperabsorption and 6 (43%) had uric acid hyperexcretion. Two patients (14%) presented nephrolithiasis. The medical records of 32 additional acromegalic patients with or without active disease were reviewed for a history of previous stones, which was observed in three cases (9.5%). The present data suggest that nephrolithiasis occurs more frequently among acromegalic patients because of the underlying metabolic disturbances of calcium presented by this population
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Acromegaly/metabolism , Urinary Calculi/metabolism , Acromegaly/complications , Calcium/blood , Calcium/urine , Creatinine/blood , Creatinine/urine , Cyclic AMP/urine , Growth Hormone/blood , Kidney Calculi/etiology , Kidney Calculi/metabolism , Phosphorus/blood , Phosphorus/urine , Prolactin/blood , Spectrophotometry, Atomic , Uric Acid/blood , Uric Acid/urine , Urinary Calculi/etiologyABSTRACT
1. A neuroendocrine role for calcitonin (CT) has been suggested by the finding of CT receptors in the hypothalamus. We have recently shown that salmon calcitonin (sCT) inhibits growth hormone releasing hormone (GHRH)-induced GH secretion in msn by a mechanism apparently independent of changes in peripheral cortisol, glucose, calcium or parathyroid levels. 2. We have further investigated the inhibitory action of sCT on GH secretion by studying the effects of sCT (100 MRC units, im) or placebo on basal and GHRH (1-29) NH2 (50µg, iv) stimulated GH secretion in 6 acromemgalic patients with active disease. 3. Basal GH lelvels were not altered by sCT administration (placebo: 136 ñ 99 µg/1 vs sCT: 99 ñ 53 µg/1). However, the GH response to GHRH was decreased by sCT. The area under the curve was signficantly smaller when patients were treated with sCT compared to placebo controls (placebo: 77202 ñ 57036 vs sCT: 64828 ñ 51909 µg min-1 1-1; P < 0.01). No changes in glucose or calcium levels were observed. 4 These results demonstrate that sCT decresases GHRH-induced GH secretion in acromegalic patients. Although the mechanism of action of sCT on GH secretion is unknown, our results indicate that the inhibitory effect of this peptide on GH secretion is also observed in patients harboring pituitary adenomas