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)

The bone loss and hypercalciuria induced by immobilization or the decreased gravitational forces of space are well described. Using a model of bedrest immobilization, the ability of a potent aminobisphosphonate, alendronate, to avert hypercalciuria and stone-forming propensity was tested. Sixteen male subjects participated in a randomized, placebo-controlled trial in which they received either 20 mg of alendronate or placebo 2 weeks prior to and during 3 weeks of strict bedrest. Parameters of bone and calcium metabolism and urinary crystallization of stone-forming salts were measured before and at the end of bedrest. In the placebo group, bedrest increased urinary calcium (209 +/- 47 to 267 +/- 60 mg/day, p < 0.01) and the saturation of calcium phosphate. Before bedrest, the alendronate group had a significantly lower serum calcium (8.8 +/- 0.4 vs. 9.6 +/- 0.5 mg/dl, p < 0.01) and higher serum PTH (62.4 +/- 33.1 vs. 23.1 +/- 7.5 pg/ml, p < 0.01) compared with the placebo group. Moreover, the alendronate group had a lower urinary calcium (75 +/- 41 mg/day) and saturation of calcium oxalate and calcium phosphate. These effects of alendronate were sustained during bedrest. Following bedrest in the alendronate group, urinary calcium rose to 121 +/- 50 mg/day, a value less than that in the placebo group before or during bedrest. Similarly, urinary saturation of calcium oxalate and calcium phosphate rose with bedrest in the alendronate-treated patients but remained lower than values obtained in placebo-treated patients before or during bedrest. Alendronate inhibits bone mineral loss and averts the hypercalciuria and increased propensity for the crystallization of stone-forming calcium salts which occurs during 3 weeks of strict bedrest.
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PMID:Prevention of hypercalciuria and stone-forming propensity during prolonged bedrest by alendronate. 761 Sep 38

The negative effect on bone due to the glucocorticoid excess is mediated by the direct action of cortisol in reducing bone apposition and increasing bone resorption, and by indirect mechanisms such as the calcium malabsorption, hypercalciuria and hypogonadism. The condition of overt hypercortisolism, also called Cushing's syndrome, leads to osteoporosis and fractures in up to the 70% of cases, even in the presence of normal gonadal status and in males. The recovery from Cushing's syndrome leads to a normalization of bone mineral density only after several years, even if some data show that the risk of fractures normalizes after one year from the cure. Alendronate has been demonstrated to be useful to accelerate the restoration of normal bone mass after the cure of Cushing's syndrome Several studies, even not all, have been demonstrated that also the condition of asymptomatic or "subclinical" hypercortisolism (often associated to adrenal adenoma) is associated to a reduction of bone mineral density and increased prevalence of fracture even in the presence of eugonadal status and in males. Unfortunately, data regarding the effect of the normalization of cortisol secretion on bone mass and risk of fractures are lacking. On the other hand, it is known that osteoporotic fractures may be the clinical presentation of an otherwise asymptomatic hypercortisolism. In a recent study we have demonstrated that in a population of outpatients with established osteoporosis and without known or clinically evident secondary causes, the prevalence of subclinical hypercortisolism is about 10%. This finding suggests that the presence of subclinical hypercortisolism has to be taken in to account when evaluating patients with unexplainable established osteoporosis.
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PMID:[Role of cortisol hypersecretion in the pathogenesis of osteoporosis]. 1871 63