Testing the Predictability of the Relative Urinary Supersaturation from the Bonn-Risk-Index for Calcium Oxalate Stone Formation

Laube, Norbert; Hergarten, Stefan; Hesse, Albrecht

doi:10.1515/cclm.2001.156

Cited by 10 publications

(6 citation statements)

References 8 publications

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“…The BRI were determined according to Laube et al (2000). The BRI is a newly established method for CaOx crystallization risk determination from unprepared native urine samples (Laube et al 2001(Laube et al , 2002. In a standardized experimental procedure, the BRI is derived from the initial urinary concentration of free ionized Ca (Ca 2þ ): amount of ammonium Ox which has to be titrated to that urine (Ox 22 ) in order to induce a precipitation of CaOx salts, i.e.…”

Section: Methodsmentioning

confidence: 99%

Influence of grapefruit-, orange- and apple-juice consumption on urinary variables and risk of crystallization

et al. 2003

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Alkalizing beverages are highly effective in preventing the recurrence of calcium oxalate (Ox), uric acid and cystine lithiasis. The aim of the present study was to evaluate the influence of grapefruit-juice and apple-juice consumption on the excretion of urinary variables and the risk of crystallization in comparison with orange juice. All investigations were carried out on nine healthy female subjects without any history of stone formation and aged 26 -35 years. Each juice was tested in a 5 d study. During the study, the subjects received a standardized diet. Fluid intake of 2·75 litres was composed of 2·25 litres neutral mineral water, 0·4 litre coffee and 0·1 litre milk. On the fourth and fifth day 0·5 litre mineral water was partly substituted by 0·5 or 1·0 litre juice under investigation respectively. The influence on urinary variables was evaluated in 24 h urine samples. In addition, the BONN risk index of CaOx, relative supersaturation (RS) CaOx crystallization was determined. Due to an increased pH value and an increased citric acid excretion after consumption of each juice, the RS CaOx decreased statistically significantly (P, 0·05) for grapefruit juice, but not significantly for orange and apple juice. The BONN risk index yielded a distinct decrease in the crystallization risk. We showed that both grapefruit juice and apple juice reduce the risk of CaOx stone formation at a magnitude comparable with the effects obtained from orange juice.

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Section: Methodsmentioning

confidence: 99%

Influence of grapefruit-, orange- and apple-juice consumption on urinary variables and risk of crystallization

et al. 2003

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“…Fruits and fruit juices with high citrate content generally are assumed to deliver an alkali load. However, previously published studies on the influence of different citrate-rich fruit juices/beverages on the risk for stone formation have provided conflicting results, with some beverages decreasing the risk for stones whereas others have either no effect or increase the risk (7)(8)(9)(10)(11)(12)(13)(14)(15)(16). One reason might be the different constituents of various beverages.…”

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Comparative Value of Orange Juice versus Lemonade in Reducing Stone-Forming Risk

Odvina

2006

Clinical Journal of the American Society of Nephrology

127

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Foods that are high in citrate content generally are assumed to deliver alkali load when consumed irrespective of the accompanying cation. The object of this randomized, crossover study was to compare the effects of orange juice with those of lemonade on acid-base profile and urinary stone risks under controlled metabolic conditions. Thirteen volunteers (nine healthy subjects and four stone formers) sequentially received distilled water, orange juice, or lemonade while on constant metabolic diet. Twenty-four-hour urine samples were collected for acid-base parameters and stone risk analysis. Orange juice but not lemonade provided alkali as evidenced by higher net gastrointestinal alkali absorption and higher urinary pH and citrate compared with control. Urinary calcium was not significantly different, but urinary oxalate was higher during the orange juice phase. The calculated supersaturation of calcium oxalate was lower in the orange juice phase compared with control. Calculated undissociated uric acid was lower in the orange juice phase compared with both control and lemonade phases. The calculated supersaturation of brushite was significantly higher in the orange juice phase compared with both control and lemonade phases. Despite comparable citrate content, this study showed that orange juice has greater alkalinizing and citraturic effects than lemonade. Consumption of orange juice was associated with lower calculated calcium oxalate supersaturation and lower calculated undissociated uric acid. This short-term study suggests that orange juice consumption could result in biochemical modification of stone risk factors; however, additional studies are needed to evaluate its role in long-term prevention of recurrent nephrolithiasis.Clin J Am Soc Nephrol 1: 1269 -1274, 2006. doi: 10.2215/CJN.00800306 M anagement of recurrent kidney stones requires both diet/lifestyle modification and medical therapy, and one of the important elements of medical therapy is the administration of potassium alkali such as potassium citrate. Potassium citrate has been shown to decrease stone formation rate in patients with idiopathic hypocitraturic calcium nephrolithiasis (1,2), hyperuricosuric (3), and thiazideunresponsive patients (4). Potassium citrate is believed to exert its beneficial effect through its citraturic and urinary alkalinizing actions. The increase in urinary citrate retards spontaneous nucleation and agglomeration of calcium oxalate crystals (5). Moreover, by increasing urinary pH and decreasing urinary content of undissociated uric acid, this treatment is useful in preventing uric acid stones (6).There are patients who are not able to tolerate potassium citrate, however, because of gastrointestinal adverse effects. Some may prefer nonpharmacologic therapy. In such cases, dietary sources of citrate may be considered an option or alternative to pharmacologic agents. Fruits and fruit juices with high citrate content generally are assumed to deliver an alkali load. However, previously published studies on the influence o...

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“…As a result, the urinary relative calcium oxalate supersaturations [based on EQUIL (9 )] change from 13.32, the value obtained from the measured analysis, to 15.58 (ϩ17%). These differences exceed the estimated calculation error of the relative supersaturation of ϳ10% derived from the individual uncertainties in the determinations of the EQUIL input parameters (10 ).…”

Section: Discussionmentioning

confidence: 61%

Influence of Urinary Stones on the Composition of a 24-Hour Urine Sample

Laube¹,

Pullmann

Hergarten

et al. 2003

Clinical Chemistry

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Background: It can be assumed that stones in the urinary tract continuously increase in size by incorporating material from urine. Consequently, urine will exhibit depleted concentrations of lithogenic constituents when urinary stones are present in the patient's urinary tract. Methods: To calculate the influence of the depletion effect, we considered two different models of stone growth. In the first model, the increase in stone size depends only on the urinary concentration of a lithogenic substance; the second model also considers the surface area of the growing stone. The case of only one kidney being affected by stone formation is considered separately. We discuss example calculations involving the formation of calcium oxalate. Results: The calculated depletion effects are of a nonnegligible order of magnitude. Assuming both a measured oxalate concentration of, e.g., 0.37 mmol/L and a reasonable in vivo stone growing rate of 10 mm 3 /day, a relative underestimation of the real "in situ" oxalate concentration between ϳ21% (model 1) and ϳ42% (model 2) occurs. The depletion effect increases markedly with increasing stone growth rate. Conclusions: Metabolic status can be evaluated correctly only in patients who have been declared "stonefree", e.g., after stone removal. Because the expected stone-related depletion effect in most cases is of high clinical relevance, we recommend estimating the effect of the order of magnitude of the depletion on actual urinary composition.

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Testing the Predictability of the Relative Urinary Supersaturation from the Bonn-Risk-Index for Calcium Oxalate Stone Formation

Cited by 10 publications

References 8 publications

Influence of grapefruit-, orange- and apple-juice consumption on urinary variables and risk of crystallization

Influence of grapefruit-, orange- and apple-juice consumption on urinary variables and risk of crystallization

Comparative Value of Orange Juice versus Lemonade in Reducing Stone-Forming Risk

Influence of Urinary Stones on the Composition of a 24-Hour Urine Sample

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