Hyperoxaluria in Idiopathic Calcium Stone Disease: Further Evidence of Intestinal Hyperabsorption of Oxalate

Marangella, Martino; Fruttero, B; Bruno, M.; Linari, F

doi:10.1042/cs0630381

Cited by 80 publications

(17 citation statements)

References 19 publications

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“…The low variability of the mean reference oxalate output (Table 1) confirms that none of the volunteers were stone formers as these people would excrete significantly higher levels of oxalate in their urine (Marangella et al, 1982). The low variability of the mean oxalate output suggests that the volunteers avoided other oxalate containing foods as requested.…”

Section: Discussionmentioning

confidence: 89%

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Bioavailability of soluble oxalate from tea and the effect of consuming milk with the tea

2003

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Objectives: To measure the availability of oxalate normally extracted when making tea from two commercially available black teas bought from a supermarket in Christchurch, New Zealand in July 2001. Design, subjects and intervention: A randomized double crossover study. Six students and four staff consumed six cups of each brand of tea both with and without added milk over a 24 h period. A total urine collection was taken for the initial 6 h followed by a further 18 h. The oxalate content of the urine voided was measured using an enzyme kit method and the availability of the soluble oxalate consumed was measured for the 6 h and the total 24 h sample. Setting: University campus. Results: The mean soluble oxalate content of black tea in the two different commercial tea bags was respectively 6.1 and 6.3 mg soluble oxalate=g tea. The mean availability of the oxalate extracted from tea measured over a 6 h period ranged from 1.9 to 4.7% when tea was consumed without milk. The availability of the soluble oxalate from tea ranged from 73.0 to 2.3% for each of the two brands of tea investigated over a 24 h period. Conclusion: These studies show that consuming black tea on a daily basis will lead to a moderate intake of soluble oxalate each day, however the consumption of tea with milk on a regular basis will result in the absorption of very little oxalate from tea. Sponsorship: Lincoln University.

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Section: Discussionmentioning

confidence: 89%

“…Most studies show a peak in oxalate absorption after 1 -6 h in normal subjects following ingestion of oxalate containing food (Barilla et al, 1978;Brinkley et al, 1981Brinkley et al, , 1990Marangella et al, 1982;Liebman & Chai, 1997). This indicates that there is a major uptake of oxalate from the small intestine in healthy humans.…”

Section: Introductionmentioning

confidence: 99%

Bioavailability of soluble oxalate from tea and the effect of consuming milk with the tea

2003

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“…Strong interactions between dietary Ca and dietary oxalate affecting the oxalate absorption have been described (2,(13)(14)(15)(16)(17)(18)(19) as well as denied (20). Ca supplements have been shown to lower the oxalate absorption in several reliable studies (for a review, see (21)).…”

Section: Discussionmentioning

confidence: 99%

“…High Ca in the diet as well as Ca supplements were both described as means to reduce oxalate absorption in patients (2,(13)(14)(15)(16)(17)(18)21). Interpretation of the published data as well as of our first results was hampered by the lack of information on the variation of the oxalate absorption, as well on interindividual variation as on the physiologic, intraindividual variation.…”

Section: Discussionmentioning

confidence: 99%

Dependence of Oxalate Absorption on the Daily Calcium Intake

Unruh¹,

Voß

Sauerbruch³

et al. 2004

Journal of the American Society of Nephrology

139

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Abstract. Two to 20% of ingested oxalate is absorbed in the gastrointestinal tract of healthy humans with a daily 800 mg calcium intake. Calcium is the most potent modifier of the oxalate absorption. Although this has been found repeatedly, the exact correlation between calcium intake and oxalate absorption has not been assessed to date. Investigated was oxalate absorption in healthy volunteers applying 0.37 mmol of the soluble salt sodium [ 13 C 2 ]oxalate in the calcium intake range from 5 mmol (200 mg) calcium to 45 mmol (1800 mg) calcium. Within the range of 200 to 1200 mg calcium per day, oxalate absorption depended linearly on the calcium intake. With 200 mg calcium per day, the mean absorption (Ϯ SD) was 17% Ϯ 8.3%; with 1200 mg calcium per day, the mean absorption was 2.6% Ϯ 1.5%. Within this range, reduction of the calcium supply by 70 mg increased the oxalate absorption by 1% and vice versa. Calcium addition beyond 1200 mg/d reduced the oxalate absorption only one-tenth as effectively. With 1800 mg calcium per day, the mean absorption was 1.7% Ϯ 0.9%. The findings may explain why a low-calcium diet increases the risk of calcium oxalate stone formation.For decades, a mainstay in the treatment of patients with calcium (Ca) urinary stones has been a Ca-restricted diet (1). Reduction of the Ca content of the diet reliably reduced the amount of Ca excreted in urine. This reduction was believedbut never proven-to reduce the risk of Ca stone formation. By contrast, already in 1969, a Ca-restricted diet was shown to increase the gastrointestinal absorption of oxalate (2), leading to increased amounts of oxalate in the urine and an increased risk of the formation of Ca oxalate stones. Therefore, to reduce oxalate absorption and the resulting risk of formation of Ca oxalate stones, high-Ca supplements were routinely prescribed to obese patients after ileal bypass surgery (3). The reason why these contradictory and confusing recommendations persisted for so long is the lack of prospective studies and the fact that analysis of oxalate remained unreliable (4) until the mid-1980s. Consequently, the amount of dietary oxalate excreted in urine and its role for renal stone formation were underestimated (5). The fact that a low-Ca diet emerged as a risk factor for Ca oxalate calculi and that a high-Ca diet emerged as a protective factor in two large epidemiologic studies (6,7) is still frequently ignored. Hence, the advice to restrict Ca may still be given to patients with recurrent Ca oxalate urinary stones.We wanted to clear up the confusion generated by the contradictory results as well as the contradictory recommendations, and to answer the following question: To what extent does Ca intake influence the gastrointestinal oxalate absorption? Therefore, we quantitatively measured the dependence of oxalate absorption on Ca intake. The physiologic daily dietary Ca intake lies between approximately 370 and 1200 mg. Intakes of less than 300 mg Ca never occur in adults except in those who reduce food intake to lose weight. ...

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“…Increased dietary oxalate absorption has been implicated in the etiology of calcium oxalate nephrolithiasis both in the presence and apparent absence of intestinal disease (1)(2)(3)(4)(5)(6). Until recently most investigators had concluded that oxalate was absorbed by a passive, noncarrier-mediated pathway and that increased absorption resulted from increased passive permeability and/or increased solubility of oxalate (2)(3)(4)(7)(8)(9)(10)(11)(12)(13)(14).…”

Section: Introductionmentioning

confidence: 99%

Oxalate transport by anion exchange across rabbit ileal brush border.

Knickelbein¹,

Aronson²,

Dobbins³

1986

J. Clin. Invest.

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This study demonstrates the presence of oxalate transporters on the brush border membrane of rabbit ileum. We found that an inside alkaline (pH = 8.5 inside, 6.5 outside) pH gradient stimulated I14Cloxalate uptake 10-fold at 1 min with a fourfold accumulation above equilibrated uptake at 5 min. 1 mM 4,4'-disothiocyanostilbene-2,2'-disulfonate (disodium salt; DIDS) profoundly inhibited the pH-gradient stimulated oxalate uptake. Using an inwardly directed K+ gradient and valinomycin, we found no evidence for potential sensitive oxalate uptake. In contrast to Cl:HCO3 exchange, HCO3 did not stimulate oxalate uptake more than was seen with a pH gradient in the absence of HCO3. An outwardly directed Cl gradient (50 mM inside, 5 mM outside) stimulated oxalate uptake 10-fold at 1 min with a fivefold accumulation above equilibrated uptake. Cl-stimulated oxalate uptake was largely inhibited by DIDS. Addition of K+ and nigericin only slightly decreased the Cl gradient-stimulated oxalate uptake, which indicates that this stimulation was not primarily due to the Cl gradient generating an inside alkaline pH gradient via Cl:OH exchange. Further, an outwardly directed oxalate gradient stimulated 36CI uptake. These results suggested that both oxalate:OH and oxalate:Cl exchange occur on the brush border membrane. To determine if one or both of these exchanges were on contaminating basolateral membrane, the vesicle preparation was further fractionated into a brush border and basolateral component using sucrose density gradient centrifugation. Both exchangers localized to the brush border component. A number of organic anions were examined (outwardly directed gradient) to determine if they could stimulate oxalate and Cl uptake. Only formate and oxaloacetate were found to stimulate oxalate and Cl uptake. An inwardly directed Na gradient only slightly stimulated oxalate uptake, which was inhibited by DIDS.

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Hyperoxaluria in Idiopathic Calcium Stone Disease: Further Evidence of Intestinal Hyperabsorption of Oxalate

Cited by 80 publications

References 19 publications

Bioavailability of soluble oxalate from tea and the effect of consuming milk with the tea

Bioavailability of soluble oxalate from tea and the effect of consuming milk with the tea

Dependence of Oxalate Absorption on the Daily Calcium Intake

Oxalate transport by anion exchange across rabbit ileal brush border.

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