Urinary calcium excretion and its response to oral calcium loading in normal subjects and stone formers

1991 ◽  
Vol 6 (2) ◽  
pp. 113-117 ◽  
Author(s):  
A. Ahmed ◽  
A. K. Pendse ◽  
P. N. Sharma ◽  
P. P. Singh
Keyword(s):  
Normal Subjects ◽  
Urinary Calcium ◽  
Urinary Calcium Excretion ◽  
Calcium Excretion ◽  
Oral Calcium ◽  
Stone Formers ◽  
Calcium Loading

Effect of citrate on the urinary excretion of calcium and oxalate: relevance to calcium oxalate nephrolithiasis.

1989 ◽  
Vol 35 (1) ◽  
pp. 23-28 ◽  
Author(s):  
D M Cowley ◽  
B C McWhinney ◽  
J M Brown ◽  
A H Chalmers
Keyword(s):  
Calcium Oxalate ◽  
Normal Subjects ◽  
Urinary Calcium ◽  
Urinary Calcium Excretion ◽  
Calcium Excretion ◽  
Molar Ratios ◽  
Oxalate Absorption ◽  
Stone Formers ◽  
Calcium Loading ◽  
High Calcium

Abstract Studies in 24 recurrent oxalate stone-formers have shown that values for urinary calcium excretion for this group on at-home diets vary significantly (P less than 0.001) more than values for creatinine excretions. By placing stone-formers on controlled in-hospital diets and measuring their calcium excretions, we were able to predict probable outpatient hypercalciuria (greater than 7.5 mmol/day) with a sensitivity of 95% and a specificity of 95%. In this study, the renal loss of calcium during low-calcium diets was proportional to the absorptive hypercalciuria during high-calcium diets. Calcium loading experiments in fasted stone-formers and normal subjects indicated that citrate, at citrate:calcium molar ratios ranging from 0.12 to 1, stimulated urinary calcium excretion more than did calcium carbonate loading alone. In addition, citrate also significantly (P less than 0.05) increased the excretion of urinary oxalate by two normal subjects for a given load of calcium oxalate. Malabsorption of citrate and possibly other hydroxycarboxylic acids may thus predispose to oxalate nephrolithiasis by promoting calcium and oxalate absorption.

Evidence that postprandial reduction of renal calcium reabsorption mediates hypercalciuria of patients with calcium nephrolithiasis

2007 ◽  
Vol 292 (1) ◽  
pp. F66-F75 ◽  
Author(s):  
Elaine M. Worcester ◽  
Daniel L. Gillen ◽  
Andrew P. Evan ◽  
Joan H. Parks ◽  
Katrina Wright ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Serum Magnesium ◽  
Normal Subjects ◽  
Urinary Calcium ◽  
Idiopathic Hypercalciuria ◽  
Calcium Excretion ◽  
Stone Formers ◽  
Calcium Reabsorption ◽  
Renal Tubular ◽  
Filtered Load

Idiopathic hypercalciuria (IH) is common among calcium stone formers (IHSF). The increased urinary calcium arises from increased intestinal absorption of calcium, but it is unclear whether increased filtered load or decreased renal tubular reabsorption of calcium is the main mechanism for the increased renal excretion. To explore this question, 10 IHSF and 7 normal subjects (N) were studied for 1 day. Urine and blood samples were collected at 30- to 60-min intervals while subjects were fasting and after they ate three meals providing known amounts of calcium, phosphorus, sodium, protein, and calories. Fasting and fed, ultrafiltrable calcium levels, and filtered load of calcium did not differ between N and IHSF. Urine calcium rose with meals, and fractional reabsorption fell in all subjects, but the change was significantly higher in IHSF. The changes in calcium excretion were independent of sodium excretion. Serum parathyroid hormone levels did not differ between N and IHSF, and they could not account for the greater fall in calcium reabsorption in IHSF. Serum magnesium and phosphorus levels in IHSF were below N throughout the day, and tubule phosphate reabsorption was lower in IHSF than N after meals. The primary mechanism by which kidneys ferry absorbed calcium into the urine after meals is via reduced tubule calcium reabsorption, and IHSF differ from N in the magnitude of the response. Parathyroid hormone is not likely to be a sufficient explanation for this difference.

scholarly journals CALCIUM

2010 ◽  
Vol 17 (04) ◽  
pp. 698-701
Author(s):  
MUHAMMAD ISHAQ ◽  
ISRAR AHMED AKHUND ◽  
MOULA BUX LAGHARI ◽  
Muhammad Sabir
Keyword(s):  
Urinary Tract ◽  
Serum Calcium ◽  
Upper Urinary Tract ◽  
Urinary Calcium ◽  
Stone Disease ◽  
Urinary Calcium Excretion ◽  
Calcium Excretion ◽  
Stone Formers ◽  
Study Results ◽  
Urinary Tract Stone

Aims & Objectives: To evaluate the effects of Serum Calcium and Urinary Calcium excretion on upper urinary tract stone diseases in the Peshawar (a high stone incidence belt). Subjects & Methods: One hundred patients (age 20-60years) who were suffering severely from upper urinary tract stone disease were selected from LRH and Hayatabad Medical Complex Hospitals of Peshawar, same numbers of healthy controls from the same region were also selected for the study. Results: When results were summed up and testParameters were compared, it was seen that mean Serum Calcium in stone formers was greater than that of non-stone formers (P<0.001). Same pattern was also observed (P< 0.001) in both groups regarding mean urinary calcium excretion. Conclusions: We concluded that calcium is a definitive risk factor in upper urinary tract stone disease. However we suggest further work and research on wide scale population inorder to evaluate this relation. 

Indomethacin Lowers Urinary Calcium Excretion in Normal Volunteers and Normocalciuric Stone-Formers

Urolithiasis ◽  
1981 ◽  
pp. 723-725
Author(s):  
W. C. Carter ◽  
P. V. Halushka ◽  
D. Jones ◽  
B. Roof ◽  
S. N. Rous ◽  
...  
Keyword(s):  
Urinary Calcium ◽  
Urinary Calcium Excretion ◽  
Calcium Excretion ◽  
Normal Volunteers ◽  
Stone Formers

scholarly journals Role of 1,25-Dihydroxy Vitamin D3and Parathyroid Hormone in Urinary Calcium Excretion in Calcium Stone Formers

2014 ◽  
Vol 55 (5) ◽  
pp. 1326 ◽  
Author(s):  
Won Tae Kim ◽  
Yong-June Kim ◽  
Seok Joong Yun ◽  
Kyung-Sub Shin ◽  
Young Deuk Choi ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Urinary Calcium ◽  
Urinary Calcium Excretion ◽  
Calcium Excretion ◽  
Calcium Stone ◽  
Stone Formers

A Study of the Renal Excretion of Calcium by the Production of a Constant Level of Hypercalcemia in Normal and Abnormal Human Subjects

1971 ◽  
Vol 49 (5) ◽  
pp. 469-478 ◽  
Author(s):  
William H. Shaw
Keyword(s):  
Vitamin D ◽  
Serum Calcium ◽  
Incidental Finding ◽  
Human Subjects ◽  
Renal Calculi ◽  
Normal Subjects ◽  
Urinary Calcium ◽  
Constant Level ◽  
Urinary Calcium Excretion ◽  
Calcium Excretion

The relationship between urinary calcium excretion and serum calcium was studied at stable serum calcium levels, both normal and elevated. The linearity of this relationship being known, the slope of this line could be determined by sampling only at its lower and upper ends, that is, by measuring urine and serum calcium at a resting level and at a constant level of hypercalcemia produced by a calcium infusion. This method permitted three sets of measurements at each of the two levels, and also tended to eliminate the factor of renal delay time. The procedure was performed with normal subjects, with normals given vitamin D2 or parathyroid extract, and with subjects having hyperparathyroidism, sarcoidosis, and recurrent renal calculi. In the normal subjects the gradient of the slope appeared to indicate that there is no maximal tubular reabsorptive capacity for calcium, in the range sampled at any rate. The slopes of the various abnormal subjects mostly did not differ markedly from those of the normals. One incidental finding was that resting levels of urinary calcium excretion were significantly depressed 24 h following vitamin D2 administration, despite unchanged serum calcium levels.

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