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.

MO113CALCULATED URINARY CALCIUM-OXALATE SATURATION (ßCAOX) IS NOT SPECIFICALLY ELEVATED IN PATIENTS WITH PRIMARY HYPEROXALURIA

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Bernd Hoppe ◽  
Wolfgang Böhm ◽  
Cristina Martin Higueras
Keyword(s):  
Calcium Oxalate ◽  
Primary Hyperoxaluria ◽  
Urinary Calcium ◽  
Stone Disease ◽  
Urinary Calcium Excretion ◽  
Urine Specimen ◽  
Calcium Excretion ◽  
Stone Formers ◽  
Enzyme Defects ◽  
Urinary Oxalate Excretion

Abstract Background and Aims In the primary hyperoxalurias (PH; types 1-3) recurrent urolithiasis (UL) and/or progressive nephrocalcinosis (NC) are the clinical hallmarks. Three different enzyme defects lead to endogenous oxalate overproduction and to extremely elevated urinary oxalate excretion (UOx). Thus, it seems logical that urine is supersaturated for calcium-oxalate (CaOx). It was, hence, speculated that urinary CaOx saturation (ßCaOx), calculated by computed programs, is significantly higher as compared to that of patients with idiopathic CaOx stones. We now aimed to evaluate and calculate urinary ßCaOx in PH patients according to type, as well as in non-PH patients with UL or NC. Method The computed equilibrium program EQUIL2 was used for the calculation of ßCaOx. For this, 24 h urine specimen of 70 patients with non-PH NC (46 male, 24 female, median age 6.06 (range 0.3-31.4 years)), of 149 idiopathic CaOx UL (90/59 m/f, age 8.5 (0.1-68.6)), of 51 PH 1 patients (31/21, age 12.33 (0.8-63.8)), of 5 PH 2 patients (3/2, age 5.41 (4.3-12.9)) and of 14 PH 3 patients (8/6, age 8.5 (2.9-29.3)) were analyzed for all necessary components. All patients were in stable kidney function (eGFR > 45 ml/min). Results Uox was higher in the PH patients as compared to the non-PH UL or NC patients (p < 0.05). However, there was no statistical difference between the Uox in PH 1 vs PH 2 or PH 3 patients, although, a clear effect of B6 medication was visible in PH1 patients. Urinary calcium excretion was lower (not significant) in PH patients as compared to NC/UL. There was no difference in ßCaOx when PH were compared to non-PH patients and it mostly remained in the normal range. Conclusion Urine ßCaOx is similar in PH and non-PH stone formers. Therefore, calculation of ßCaOx using computed programs is not a reliable parameter to define the definitively extreme CaOx supersaturation of urine from PH patients. This miscalculation is related to a rather lowish urinary calcium excretion in PH as compared to other UL/NC patients. Therefore, we recommend not to use such programs to express the risk of recurrent stone disease or nephrocalcinosis in PH.

Relations between Oxalic Acid, Calcium, Magnesium and Creatinine Excretion in Normal Men and Male Patients with Calcium Oxalate Kidney Stones

1974 ◽  
Vol 46 (3) ◽  
pp. 357-367 ◽  
Author(s):  
A. Hodgkinson
Keyword(s):  
Calcium Oxalate ◽  
Normal Subjects ◽  
Calcium Excretion ◽  
Oxalate Excretion ◽  
Stone Formers ◽  
Calcium Magnesium ◽  
Male Patients ◽  
Calcium And Magnesium ◽  
Magnesium Excretion ◽  
Normal Men

1. The daily excretion of oxalate, calcium, magnesium and creatinine was determined in fifty-two normal men and sixty-five male patients with calcium oxalate-containing renal stones. 2. Direct relationships were found between calcium and oxalate excretion, magnesium and oxalate excretion and calcium and magnesium excretion in both normal subjects and stone-formers. The significance of these relationships is discussed. 3. The mean excretion of calcium and oxalate was significantly higher in the stone-formers, compared with the controls, both calcium and oxalate excretion being raised by about 20%. 4. The effect of oral ingestion of glucose and casein on the rate of excretion of calcium, magnesium, oxalate and phosphate was examined. Glucose increased the rate of calcium and magnesium excretion but had no effect on oxalate excretion and suppressed phosphate excretion. Casein also increased calcium excretion but had little or no effect on magnesium or oxalate excretion, and it increased phosphate excretion. 5. The association of high calcium excretion with high oxalate excretion, in both normal subjects and stone-formers, results in a high degree of supersaturation of the urine with respect to calcium oxalate. The implication of these findings with respect to the cause and treatment of calcium oxalate stones is discussed.

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
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