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Query: UMLS:C0020438 (hypercalciuria)
 2,502 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Effects of aspirin and fish-oil ingestion on caffeine-induced hypercalciuria and renal prostaglandins (PG) were investigated in 12 healthy women. The 11-wk study consisted of 7-d baseline, 5-d aspirin (1000 mg/d), 11-d washout, and two 24-d fish-oil periods (FO-1 and FO-2, respectively, providing 1.5 vs 3.0 g n-3 fatty acids/d) separated by a 4-d washout period. Caffeine-load (CL) tests providing 5 mg caffeine/kg body wt were administered after baseline and each experimental period. Timed urine samples were collected precaffeine (basal) and at 1, 2, and 3 h post-caffeine. PGE2 excretion decreased during tests after aspirin and FO-2. There were significant increases in PGF2 alpha from baseline during each CL test. Hypercalciuria was observed during each CL test and the magnitude of this response was not altered by the experimental treatments. The finding that concentrations of post-caffeine urinary PGF2 alpha paralleled concentrations of urinary calcium supports the possibility that this prostaglandin plays a role in caffeine-induced hypercalciuria.
Am J Clin Nutr 1994 Sep
PMID:Caffeine-induced hypercalciuria and renal prostaglandins: effect of aspirin and n-3 polyunsaturated fatty acids. 807 66

The relative importance of dietary factors in causing hypercalciuria was assessed in 282 unselected patients with calcium oxalate kidney stones. The 124 patients found to be hypercalciuric on either their customary free diet or on a 25-mmol (1000-mg) calcium defined diet (or both), were classified according to their pattern of calcium excretion on the two diets. Unexpectedly, about half of the patients who were hypercalciuric on their free diet exhibited a calcium excretion that fell markedly or normalized on the high-calcium defined diet. These patients were defined as having dietary hypercalciuria. For all 282 patients, multiple-regression analysis suggested that dietary sodium was at least as important as was dietary calcium, and more important than dietary protein, carbohydrate, phosphorus, purine, or oxalate, in contributing to calcium excretion on the free diet. Among the 124 hypercalciuric patients, urinary calcium excretion increased by 0.0193 mmol (0.77 mg) per mmol sodium excretion. Dietary habits, particularly a high sodium intake, may commonly contribute to hypercalciuria in patients with calcium oxalate stones.
Am J Clin Nutr 1994 Sep
PMID:Dietary hypercalciuria in patients with calcium oxalate kidney stones. 807 77

An adult presenting with asymptomatic gross hematuria attributable to hypercalciuria and hyperuricosuria is described. Extensive evaluations for other causes of hematuria were negative, and the gross hematuria resolved with treatment of the hypercalciuria and hyperuricosuria. Hematuria commonly attributable to these metabolic causes in children may also occur in adults. A 24-hour urine collection for the measurement of calcium and uric acid excretion in adults without nephrolithiasis may play an important role in the evaluation of hematuria.
Am J Kidney Dis 1994 Sep
PMID:Macroscopic hematuria secondary to hypercalciuria and hyperuricosuria. 807 79

Exposure to the microgravity environment of space produces a number of physiological changes of metabolic and environmental origin that could increase the potential for renal stone formation. Metabolic, environmental and physicochemical factors that influence renal stone risk potential were examined in 24-hour urine samples from astronauts 10 days before launch and on landing day to provide an immediate postflight assessment of these factors. In addition, comparisons were made between male and female crewmembers, and between crewmembers on missions of less than 6 days and those on 6 to 10-day missions. Results suggest that immediately after space flight the risk of calcium oxalate and uric acid stone formation is increased as a result of metabolic (hypercalciuria, hypocitraturia, pH) and environmental (lower urine volume) derangements, some of which could reflect residual effects of having been exposed to microgravity.
J Urol 1993 Sep
PMID:Alterations in renal stone risk factors after space flight. 834 88

Thirty-one children with the extraordinary urinary frequency syndrome are presented. Several possible etiologies were identified including viral cystitis-urethritis, stress, and hypercalciuria. A case definition is provided and the literature is reviewed. The authors suggest that this problem is more common than is generally appreciated. The condition is usually self-limited, and invasive diagnostic imaging studies are unnecessary when the presentation is typical.
Urology 1993 Sep
PMID:Extraordinary urinary frequency syndrome. 837 34

Presentation of the analytical results from the patients seen for lithiasic disease (LD) over a two-year period at the Hospital Reina Sofia, Tudela. This Hospital covers a homogeneous Health Area including 22 villages and a population of 76,000 people. The clinical cases of 785 patient diagnosed with LD between May 1988 and 1990 May are analyzed. Microhaematuria in fresh urine is detected in 64.20% patients and crystalluria in 33.37%. Significant bacteriuria is present in 5.73% of total patients with prevalence of E. coli in 42.4%. Only 2 cases of hyperparatiroidism were diagnosed during the study period but later another two cases of HPT were detected in bone injuries studied due to rheumatic disease. No normocalcemic HPT cases were diagnosed among suspected cases. The metabolic studies were of little use in our experience, maybe because of non-availability of basic analytical determinations such as citraturia. Nevertheless, higher values of urinary volume, calciuria and uricemia and lower values of magnesemia and magnesiuria were found in lithiasic patients that in control ones. Neither oxaluria or the remaining analytical parameters provide differential data. Hypercalciuria higher than 300 mg in seen in 28.6% of studied patients and in 12.5% of the control group.
Actas Urol Esp 1995 Sep
PMID:[Epidemics of urinary calculi in la Ribera de Navarra (II). Analytic studies]. 866 30

Excessive animal protein consumption is associated with a greater risk of occurrence of renal calcium stone, presumably because of the attendant endogenous acid production. Indeed, chronic acid load enhances urinary calcium excretion possibly through an increased bone calcium release. Because acute studies are best designed to elucidate the mechanism, renal or extra renal, underlying hypercalciuria in the setting of enhanced acid load, we examined the response of 9 healthy adults (8 males, 1 female, aged 38 +/- 3 years, weight 67 +/- 2 kg) and 34 hypercalciuric recurrent calcium stone formers (31 males, 3 females, aged 44 +/- 2 years, weight 72 +/- 2 kg), without any associated disease, to an oral acid load (NH4Cl 2 mmol/kg body wt). After an overnight fast, each patient and control was studied during one one-hour period before and three two-hour periods after their intake of the acid load. An additional group of four time-control subjects (4 males, aged 33 +/- 2 years, weight 66 +/- 2 kg) was studied as the experimental groups except that they did not receive the acid load. On baseline, the three groups exhibited similar glomerular filtration rates, net acid excretions, and plasma calcium and magnesium concentrations. However, fasting urine calcium and magnesium excretions were higher in hypercalciuric calcium stone formers than in healthy control or time-control subjects. In time-control subjects, plasma acid base status, net acid excretion, filtered loads of calcium and magnesium, and urinary calcium and magnesium excretions remained unchanged all over the study. By contrast, after the oral acute acid load, net acid excretion increased and urinary pH decreased similarly in patient and control groups; glomerular filtration rate did not change, as well as plasma calcium and magnesium concentrations. Nevertheless, urinary calcium and magnesium excretions markedly increased, in both groups, independently of changes in tubular sodium handling and in plasma parathyroid hormone concentration. The increase in urinary calcium and magnesium excretions that occurred in the absence of any change in the filtered load of calcium and magnesium was therefore mediated by a decrease in tubular calcium and magnesium reabsorption, independent of PTH, but dependent on changes in net acid excretion. A positive linear relationship between urinary calcium and magnesium excretions suggested that the target tubular site for acid load was the thick ascending limb of Henle's loop. Finally, a negative linear relationship was demonstrated between the acid load-induced increase in urinary calcium excretion and fasting urinary calcium excretion; indeed, the lowest calciuric responses were observed in patients with the highest fasting urinary calcium excretion. Thus there was no additional effect of the acid load-induced inhibition on intrinsic defect in tubular calcium reabsorption which suggests that the tubular target site for acid load and the site of calcium transport defect in idiopathic hypercalciuria may be the same.
Kidney Int 1996 Sep
PMID:Calciuric response to an acute acid load in healthy subjects and hypercalciuric calcium stone formers. 887 75

Urinary stones are being recognized more frequently in children. As a result of major advancements in the urological therapies available to children with obstructed uropathy, infection-related stones no longer dominate the clinical manifestations of pediatric urolithiasis. Clinical manifestations of urolithiasis in children differ somewhat from adults and change during childhood. Causes of urolithiasis in children are remarkably similar to those of adults, although diagnostic criteria frequently vary throughout childhood. Hypercalciuria is the most common metabolic cause of pediatric urolithiasis. This article presents a general overview of urolithiasis in children and a practical approach to the medical evaluation of such children.
Semin Nephrol 1996 Sep
PMID:Clinical approach to children with urolithiasis. 889 Mar 95

In humans, idiopathic hypercalciuria is associated with stone formation. To study the mechanisms that are responsible for the excess urine calcium excretion in ways that are difficult to impossible in humans, we have developed a rat model of idiopathic hypercalciuria. Hypercalciuric rats were successively inbred for more than 40 generations to produce a strain in which urine calcium excretion is far greater than that of controls and all rats form kidney stones. Analysis of the model has revealed that the rats not only exhibit increased intestinal calcium absorption but an independent defect in renal tubular resorption and an increased tendency for bone demineralization. These findings closely parallel those in patients with idiopathic hypercalciuria. In the intestine, bone, and kidney there is an increased number of vitamin D receptors which appear to make the rats more sensitive to the effect of 1,25(OH)2D3. Whether the increased number of vitamin D receptors can be directly translated into hypercalciuria and whether the same abnormality is present in humans with idiopathic hypercalciuria remains to be determined.
Semin Nephrol 1996 Sep
PMID:Genetic hypercalciuric stone forming rats. 889 Apr

The present series comprises 2086 consecutive patients who were studied in a stone clinic during a period of 15 years. Each patient was subjected to a comprehensive protocol including a fully biochemical investigation. Calcium stones were by far the commonest accounting for 61% of cases; infection, uric acid/calcium oxalate and cystine stones accounted respectively for 24%, 8%, 5% and 2%. Nephrolithiasis was more prevalent in males with the male to female ratio 1:0.76, on the other hand infection stones were more frequent in females with the male to female ratio 1:1.6. The peak age incidence of renal calcium stones occurred in the third to fifth decades, although about 3.4% reported onset of disease in the first and second decades of life. The onset of cystine stones was always in the first and second decades, while uric acid stones affected older patients. Renal stones were recurrent in about 50% of cases. In a retrospective analysis it was found the interval to first recurrence to be less than 5 years in about half patients. The cystine and uric acid groups had the highest rate of recurrence. In patients with calcium stones a definite metabolic or mechanical cause for their stones was found respectively in 8.2% and 10.1%. Particularly primary hyperparathyroidism was revealed in 2.8%. A metabolic defect could be found in 54% of the patients with idiopathic calcium stones. In these patients with idiopathic calcium stones the prevalence rate of hypercalciuria was 33%. In patients with uric acid stones and with mixed uric acid/calcium oxalate stones a definite metabolic cause for their stones was found respectively in 9.5% and 4.1% whereas an underlying disease of the urinary tract was diagnosed respectively in 8.5% and 6.2%. In patients with struvite stones the incidence of persistent infection was 46% (Proteus 18%). In this group the presence of an underlying disease of the urinary tract was diagnosed in 18.8% whereas a definite metabolic disease was demonstrated in 8.5%, a urinary risk factor for metabolic stone disease in 42% and a previous episode of metabolic stone disease in 33%.
Arch Ital Urol Androl 1996 Sep
PMID:Clinical observations on 2086 patients with upper urinary tract stone. 893 17


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