| Autor: |
Hess, B., Lippuner, K., Takkinen, R., Villiger, L., Ackermann, D., Jaeger, P. |
| Zdroj: |
Nephrology Dialysis Transplantation; Sep1995, Vol. 10 Issue 9, p1614-1619, 6p |
| Abstrakt: |
The calciuric response after an oral calcium load (l000 mg elemental calcium together with a standard breakfast) was studied in 13 healthy male controls and 21 recurrent idiopathic renal calcium stone formers, 12 with hypercalciuria (U×V>7.50 mmol/24 h) and nine with normocalciuria. In controls, serum 1,25(OH) vitamin D3 (calcitriol) remained unchanged 6 h after oral calcium load (50.6±5.1 versus 50.9±5.0 pg/ml), whereas it tended to increase in hypercalciuric (from 53.6±3.2 to 60.6±5.4 pg/ml, =0.182) and fell in normocalciuric stone formers (from 45.9±2.6 to 38.1±3.3 pg/ml, =0.011). The total amount of urinary calcium excreted after OCL was 2.50±0.20 mmol in controls, 2.27±0.27 mmol in normocalciuric and 3.62±0.32 mmol in hypercalciuric stone formers (=0.005 versus controls and normocalciuric stone formers respectively); it positively correlated with serum calcitriol 6 h after calcium load (=0.392, =0.024). Maximum increase in urinary calcium excretion rate, δCa-E, was inversely related to intact PTH levels in the first 4 h after calcium load, i.e. more pronounced PTH suppression predicted a steeper increase in urinary calcium excretion rate. Twenty-four-hour urine calcium excretion rate was inversely related to the ratio of δ calcitriol/δPTH after calcium load (=−0.653, =0.0001), indicating that an abnormally up-regulated synthesis of calcitriol and consecutive relative PTH suppression induce hypercalciuria. Finally, late absorption of calcium as suggested by maximum urinary calcium excretion beyond 4 h after oral calcium load was as rare in hypercalciuric stone formers (2 of 12) as in controls (1 of 13) and did not occur in normocalciuric stone formers. [ABSTRACT FROM PUBLISHER] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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