Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020438 (hypercalciuria)
 2,502 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Secondary hyperparathyroidism (HP) has been reported to be characteristic of idiopathic hypercalciuria (IHC) of the renal type. Out of the 155 patients with urinary stone disease and a normal plasma calcium level, only 1 had a distinctively increased plasma parathyroid hormone (PTH) level; however, he was found to be hypercalcemic in a second control study. In 33 patients with renal IHC, none had an elevated PTH level measured under normal, low, and high calcium intake. The mean basal PTH level of these patients was identical to that of 86 normal controls; it was significantly lower than that of the patients with primary or secondary HP who had normal PTH levels. During EDTA infusion, seven of eight patients with primary HP and a normal basal PTH level showed PTH responses greater than those observed in six patients with renal IHC, all of the latter responses being in the normal range. Chlorthalidone, given to seven patients with renal IHC during 4 weeks (100 mg/day), did not decrease the PTH levels. Measurement of nephrogenous cAMP performed in only a few patients revealed a slightly increased value in one of them who had an exceptionally severe hypercalciuria. Beside this latter result, no evidence for secondary HP could be found. Although secondary HP is tempting pathophysiological explanation for many characteristics of renal IHC, it seems to be quite rare.
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PMID:Secondary hyperparathyroidism in idiopathic renal hypercalciuria: fact or theory? 679 May 59

Hypercalciuria is the major risk factor promoting stone formation in Dent's disease, also known as X-linked recessive nephrolithiasis, but the effects of diuretics on calcium excretion and other stone risk factors in this disease are unknown. This study examined urine composition in eight male patients with Dent's disease, ages 6 to 49 yr, all of whom were hypercalciuric and had inactivating mutations of CLCN5. Eight males, ages 7 to 34 yr, with idiopathic hypercalciuria (IH) served as controls. Patients were instructed to maintain a consistent intake of sodium, potassium, calcium, and protein. Two consecutive 24-h urine collections were obtained after a baseline period and after 2 wk of chlorthalidone (25 mg), amiloride (5 mg), and the two diuretics in combination, with a week off drug separating the treatment periods in a randomized crossover design. Doses were reduced by half in boys under age 12 yr. Chlorthalidone alone (P < 0.002) and the combination of chlorthalidone and amiloride (P < 0.003) reduced calcium excretion significantly in either patient group. With chlorthalidone, calcium excretion fell to normal (<4.0 mg/kg per d) in all but one patient in each group. Amiloride alone had no significant effect on urinary calcium excretion, in either patient group. In patients with Dent's disease during chlorthalidone therapy, the supersaturation ratios for calcium oxalate and calcium phosphate fell by 25% and 35%, respectively. Mean citrate excretion was reduced by chlorthalidone (P <.04) and by chlorthalidone in combination with amiloride (P <.02). There were no significant differences in the responses to these diuretics between the patient groups in any of the urinary parameters. The intact hypocalciuric response to a thiazide diuretic indicates that inactivation of the ClC-5 chloride channel does not impair calcium transport in the distal convoluted tubule and indicates that thiazides should be useful in reducing the risk of kidney stone recurrence in patients with Dent's disease.
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PMID:Responsiveness of hypercalciuria to thiazide in Dent's disease. 1244 12