A consideration of the hormonal basis and phosphate leak hypothesis of absorptive hypercalciuria
Autor: | Alan S. Kliger, Alice F. Ellison, Robert Lang, Joseph M. Gertner, Lawrence E. Mallette, A E Broadus, Karl L. Insogna, Dan A. Orenlang |
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Rok vydání: | 1984 |
Předmět: |
Adult
Male medicine.medical_specialty Leak Calcitriol Endocrinology Diabetes and Metabolism Clinical Biochemistry chemistry.chemical_element Calcium Biochemistry Urine collection device Phosphates Parathyroid Glands chemistry.chemical_compound Kidney Calculi Endocrinology Internal medicine Calcium Metabolism Disorders medicine Humans Hypercalciuria Kidney Biochemistry (medical) Fasting Middle Aged medicine.disease Phosphate medicine.anatomical_structure chemistry Female Hormone medicine.drug |
Zdroj: | The Journal of clinical endocrinology and metabolism. 58(1) |
ISSN: | 0021-972X |
Popis: | Fifty patients with absorptive hypercalciuria (AH), 25 normal subjects (NS), and 25 nonhypercalciuric patients with stone disease (NHSF) were studied using an oral calcium tolerance test and 24-h urine collections on both a restricted and an unrestricted calcium intake. Mean (+/- SD) fasting fractional calcium excretion was increased in the patients with AH (2.7 +/- 1.1% vs. 1.4 +/- 0.6% in the NS; P less than 0.001) and was negatively correlated with fasting nephrogenous cAMP, suggesting that this renal calcium leak was secondary to parathyroid suppression. Plasma 1,25-dihydroxyvitamin D [1,25-(OH)2D] was elevated in 80% of patients with AH and was high normal in the remaining 20%. Ten patients, selected on the basis of results for 1,25-(OH)2D greater than 4 SD from the normal mean, displayed a particularly severe pattern of abnormalities, including mild hypercalcemia in two patients. Pooled data from the NS and patients with AH revealed a significant negative correlation between the plasma concentration of 1,25-(OH)2D and the renal phosphate threshold (r = -0.40; P less than 0.001), but this correlation lost significance when the NHSF were substituted for the NS as a control group (r = -0.07; P = NS). These findings 1) provide a pathophysiological basis for the increase in fasting calcium excretion commonly observed in hypercalciuric patients, and 2) stress the importance of circulating 1,25-(OH)2D in the pathogenesis of the syndrome, but 3) fail to support the phosphate leak theory of pathogenesis. |
Databáze: | OpenAIRE |
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