High Oxalate Research Articles

Oxalate Content and Antioxidant Activity of Different Ethnic Foods

There is not enough information on the classification of oxalate content in several foods, particularly in ethnic foods, to recommend their consumption in subjects with urolithiasis (UL). The objective of the present study was to generate reliable information on the oxalate content and antioxidant activity in different foods and classify them by very low, low, medium, high and very high oxalate content and antioxidant activity. The oxalate content of 109 foods including ethnic foods was assessed by an enzymatic assay, and the antioxidant activity was measured by the oxygen radical absorbance capacity to determine the oxalate/antioxidant activity ratio. Oxalate consumption was then evaluated in 400 subjects with overweight and obesity using 24-h dietary recalls. The main foods with high oxalate content were raw spinach, huanzontle, purslane, chard, almond, and toasted and sweetened roasted amaranth. The highest antioxidant activity was found in strawberries, all types of chocolates, roselle, morita peppers, and pinolillo. Subjects with overweight or obesity exceed the dietary oxalate daily intake recommendation. The classification of foods by their oxalate content and antioxidant activity will be very useful to generate nutritional recommendation in different diseases, mainly UL.

P0684HDAC5/KLF2 AXIS REGULATES NLRP3 MEDIATED RENAL INFLAMMATION AND FIBROSIS ASSOCIATED WITH NEPHROCALCINOSIS-RELATED CHRONIC KIDNEY DISEASE

Abstract Background and Aims Role of epigenetic factors like histone deacetylases (HDACs) is largely unexplored in the pathogenesis of Nephrocalcinosis-related chronic kidney disease. The present study was performed to evaluate the functional role of HDAC5 in fibroblast activation in in-vitro and in a mouse model of Nephrocalcinosis-related chronic kidney disease. Method C57BL/6 male mice (6-7weeks old) were procured from registered CPCSEA breeder (Hyderabad, India), NRK49F cell line were generously provided by NCCS (Pune, India). All experimental procedures were approved by the animal ethics committee of the institute. Nephrolithiasis (oxalate nephropathy) was induced by feeding oxalate rich diet (Ssniff, Soest, Germany) to C57/BL6 mice for 10 days. NRK49F cells were stimulated with LPS (1µg/ml) for 2hrs followed by TGF-β (25ng/ml) for 24hrs. To achieve HDAC5 knockdown, the cells were pre-incubated with HDAC5 specific siRNA for 24hrs before stimulating with LPS. In another set of experiment, cells were incubated with 4-sodium phenyl butyrate(PBA) a non-selective HDAC5 and HDAC4 inhibitor at a dose of 1mM. 24 hrs after LPS stimulation cell lysates were analysed for protein expression of α-SMA, Collagen1a, KLF2, NLRP3, HDAC5 and β-actin. Mice fed with high oxalate diet were treated with PBA (500mg/kg) twice a day and on day 10 mice were sacrificed to analyse renal function and fibrosis parameters. Mice kidney tissues were analysed for crystal deposition (pizaalato staining), renal fibrosis (Picrosirius staining), and renal histology (H&E staining). The fibrosis markers were analysed by RT-PCR and immunoblotting. Renal function was determined by plasma BUN and creatinine analysis. Diet containing high oxalate with calcium was provided to mice in the control diet group (negative diet control). Results Renal fibroblasts (NRK 49F) stimulated with LPS and TGF-β showed upregulation of HDAC5, NLRP3, α-SMA, and Collagen-1a. Depletion of HDAC5 expression with HDAC5 siRNA significantly reduced expression of NLRP-3, α-SMA, and Collagen-1 in stimulated NRK49F cells. The expression of KLF2 in HDAC5 depleted cells was found to be upregulated. PBA treatment also reduced the expression of HDAC5 in NRK49F cells and had significant reduction in the expression of NLRP3 along with fibroblast activation markers, while KLF-2 expression was found to be up-regulated. Similar to our observation in stimulated renal fibroblasts, the expression of HDAC5 was found to be upregulated in mouse model of oxalate nephropathy. Treatment with PBA showed significant downregulation of HDAC5 in kidneys of the mice fed with high oxalate diet. Mice treated with PBA showed down regulated renal expression of NLRP3, Collagen1a, α-SMA, TGF-β in comparison to vehicle treated mice. Treatment with PBA showed significant upregulation of KLF2 expression in kidney. PBA treated mice showed significant renal protection during nephrolithiasis as indicated by reduced plasma BUN and creatinine levels. Oxalate crystal deposition index was similar in all high oxalate diet groups. PBA treatment showed overall better renal histological protection observed through H&E (reduced tubular injury score) and picrosirius staining (reduced collagen deposition). Conclusion HDAC5 knockdown or HDAC5 inhibition with PBA attenuates fibroblasts activation by inhibiting NLRP3 expression. Treatment with PBA in mice with Nephrocalcinosis-related chronic kidney disease showed significant protection against renal fibrosis with downregulation of NLRP3 expression. We propose HDAC5 as a novel regulator of fibroblast activation in Nephrocalcinosis-related chronic kidney disease.

A multi-pumping flow system for spectrophotometric determination of oxalate in tea

A high oxalate uptake from the diet is thought to play a role in the development of hyperoxaluria, a documented risk factor in the formation of calcium oxalate kidney stones. In this sense, a flow system designed with multicommutation is proposed for spectrophotometric determination of oxalate in tea. The procedure is based on the SPADNS method (a complex of zirconium and the trisodium salt of 1,8-dihydroxy-2-(4-sulfophenylazo)-naphthalene-3,6-disulphonic acid), in which the oxalate reacts with the zirconium to form a colorless complex, thus bleaching the red color in a proportional amount to the oxalate concentration. A manifold with three solenoid micro-pumps was used and the decrease in the absorbance of Zr-SPADNS reagent is linear with oxalate concentration in the range of 1.0 to 6.0 mg L−1. The coefficient of variation, sampling rate and detection limit were estimated as 2.6% (4.0 mg L−1, n=10), 120 samples h−1, and 0.30 mg L−1 (99.7% confidence level), respectively, with reagent consumption estimated as 70 μg of SPADNS per determination. Under optimized conditions, no interference was observed in presence of fluoride for the concentration expected in infusions (less than 100 μg L−1). The procedure was applied in different sample infusions included black, green and white tea. The recovery values were between 83 and 108% showing that the proposed protocol is able to determination of oxalate without interference problems in a complex sample after a simple dilution.

Secondary oxalosis induced by xylitol concurrent with lithium-induced nephrogenic diabetes insipidus: a case report

BackgroundXylitol is an approved food additive that is widely used as a sweetener in many manufactured products. It is also used in pharmaceuticals. Secondary oxalosis resulting from high dietary oxalate has been reported. However, reported cases of oxalosis following xylitol infusion are rare.Case presentationA 39-year-old man with a 16-year history of organic psychiatric disorder was hospitalized for a laparoscopic cholecystectomy because of cholecystolithiasis. He had been treated with several antipsychotics and mood stabilizers, including lithium. The patient had polyuria (> 4000 mL/day) and his serum sodium levels ranged from 150 to 160 mmol/L. Urine osmolality was 141 mOsm/L, while serum arginine vasopressin level was 6.4 pg/mL. The patient was diagnosed with nephrogenic diabetes insipidus (NDI), and lithium was gradually discontinued. Postoperative urine volumes increased further to a maximum of 10,000 mL/day, and up to 10,000 mL/day of 5% xylitol was administered. The patient’s consciousness level declined and serum creatinine increased to 4.74 mg/dL. This was followed by coma and metabolic acidosis. After continuous venous hemodiafiltration, serum sodium improved to the upper 140 mmol/L range and serum creatinine decreased to 1.25 mg/dL at discharge. However, polyuria and polydipsia of approximately 4000 mL/day persisted. Renal biopsy showed oxalate crystals and decreased expression of aquaporin-2 (AQP2) in the renal tubules. Urinary AQP2 was undetected. The patient was discharged on day 82 after admission.ConclusionsOur patient was diagnosed with lithium-induced NDI and secondary oxalosis induced by excess xylitol infusion. NDI became apparent perioperatively because of fasting, and an overdose of xylitol infusion led to cerebrorenal oxalosis. Our patient received a maximum xylitol dose of 500 g/day and a total dose of 2925 g. Patients receiving lithium therapy must be closely monitored during the perioperative period, and rehydration therapy using xylitol infusion should be avoided in such cases.

Elderberry (Sambucus spp.) interspecific hybridization and its impact on fruit oxalates

AbstractElderberry fruits are a good source of minerals and antioxidants; however, the presence of anti‐nutrients like oxalates may limit their utilization. The presented study which involves chemical evaluation of numerous interspecific hybrids is based on a hypothesis that interspecific genetic recombination may significantly improve the production and the nutritional quality of elderberry fruits. The aim of the first part of this study was to determine the oxalates (total, water‐soluble and insoluble) in fruits of 73 elderberry genotypes. In the second part, the dynamics of oxalate contents during fruit maturation was analysed. The average content of total oxalates in analysed genotypes was 721 ± 33 mg/100 g DW. The majority (91%, on average) were health harmless insoluble oxalates. The average content of total oxalates was increasing at the beginning of maturation and then it began to decrease significantly and reached its minimum value at full maturity, while the average of water‐soluble oxalates was gradually decreasing throughout maturation. Due to relatively high oxalate contents, some of the analysed hybrids should not be used for further breeding process.

A possible case of renal oxalate deposit reported in an African fruit bat (Epomops franqueti)

ABSTRACT We report a possible spontaneous case of oxalate nephrosis in an African fruit bat (Epomops franqueti), incidentally observed in Ibadan, South-West Nigeria, in an anatomical and serological survey of the species. Wild caught bats underwent sedation, intracardial perfusion, necropsy and histopathology. All 15 wild-caught African fruit bats were apparently healthy. However, light microscopy revealed mild oligofocal tubulonephrosis with intraluminal deposition of polarizing crystals interpreted as subclinical oxalate nephrosis in one case. In summary, we suggest a dietary aetiology, based on seasonal availability of high ascorbic acid or oxalate containing fruits. However, exposure to anthropogenic contaminants cannot be completely ruled out.

A REVIEW ON UROLITHIASIS

Urolithiasis is the urinary disorder characterized by formation of stone in the urinary tract, urinary bladder and kidneys.
 Urolithiasis is considered to be a risk of urinary incontinence and may be associated with urinary incontinence.
 A urinary stone commonly occurs in males and are calculated on the basis of their mineral composition. Approximately 80% of urinary stones composed as calcium oxalate and calcium phosphate. Urinary calculi can cause disruption to the urinary system, hydrophoresis, infections and bleeding. Root stone formation is the result of several mechanisms.
 Whereas exceeding supersaturation (i.e. free stone formation) is the cause of uric acid or cystine calculi, infection stones result from bacterial metabolism. Renal calculi can be broadly classified in two large groups: tissue attached and unattached.
 Components in diet increase the risk of stone formation include low intake of fluid and animal protein, sodium, sugar and syrup high corn fruit, oxalate, grape juice, apple juice and cola drinks.
 Vegetarian diets, spices and liquids may be helpful in treating and prevention and kidney stones. Therefore, the best way to prevent kidney stones is to consume a lot of water and a magnesium rich vegan. Common medications used to prevent urolithiasis do not work for all patients, and many have adverse effects that endanger their long-term use.
 Managing today's urolithiasis with open renal surgery is unusual and rarely used, only by the introduction of Extracorporeal Shock wave lithotripsy (ESWL) is useful but it is expensive.
 Herbs and herbal medicines have created interest among people with its clinically proven effects such as immunomodulation and antimutagenic. Also, abusing synthetic drugs due to serious side effects of the drug has allowed humans to return to nature for safe treatment.
 Kew words: hydrophoresis, Urolithiasis

Evaluation of Oxalobacter formigenes DSM 4420 biodegradation activity for high oxalate media content: An in vitro model.

Oxalate is a common component of many foods typically present as a salt of oxalic acid, which will be excreted in the urine. Hyperoxaluria is known to be a considerable risk factor for urolithiasis, and formation of oxalate kidney stone. Oxalate degradation by the probiotic anaerobic bacterium Oxalobacter formigenes DSM 4420 has high yield and efficiency both in the human colon helping to prevent hyperoxaluria and disorders such as the development of kidney stones and as a novel approach in reducing the high concentration of foodstuff oxalate content such as tea, coffee, and nuts. For determining the effective factors to enhance high concentration oxalate biodegradation activity of Oxalobacter formigenes DSM 4420 Plackett-Burman screening design was applied to evaluate the impact of 10 process variables. After determining the main factors by screening design, a response surface methodology was used to find suitable treatment combination for oxalate biodegradation by this probiotic. A second-order quadratic model estimated that the highest biodegradation of 60.2% was achieved in presence of 1.35 (g/L) inulin, 36.56 (g/L) glucose, 26 (mmol/L) ammonium oxalate, and pH 6. In other word, the optimum point showed that in the above condition the high concentration of ammonium oxalate content of 26 mmoL/L will reach to 9.95 mmoL/L. Reconfirmation experiment showed the validity of predicted optimum conditions. A surface model using the RSM and optimizing this model using the GA technique, resulted in a useful method of finding an optimal set of process parameters.

Oxalic Acid Recovery from High Iron Oxalate Waste Solution by a Combination of Ultrasound-Assisted Conversion and Cooling Crystallization

To achieve the global goals related to renewable energy and responsible production, technologies that ensure the circular economy of metals and chemicals in recycling processes are a necessity. The...

Nefrolitiaziste Tıbbi Beslenme Tedavisi

Dünya çapında nefrolitiazisin prevalansı ve insidansının giderek arttığı bildirilmektedir. Son yıllarda nefrolitiazis alanında önemli ilerlemeler kaydedilmiştir. Taş oluşum nedenleri ve spesifik moleküler defektler daha kapsamlı olarak ortaya konulmaktadır. İdrar yoğunluğunun yanında idrarda çözünen kristallerin miktarı da böbrek taşı oluşumunda etkilidir. İdrar hacminin azalmasıyla birlikte idrardaki çözünen maddelerin saturasyanu değişir ve taş oluşum riski artar. İdrarda okzalat ve fosfor gibi bazı maddelerin yüksek düzeyi ile böbrek taşları oluşabilmektedir. Genler, metabolik ve çevresel etmenler idrar bileşimini etkileyebilmekte ve taş oluşum riskini arttırabilmektedir. Diyet de böbrek taş oluşumuna neden olabilen ya da taş oluşumunu önleyebilen bir etmendir. Diyet uygulamasındaki değişiklikler ise böbrek taşlarının tedavisinde ve önlenmesinde anahtar bir rol oynayabilmektedir. Böbrek taşlarının ortaya çıkışının ya da yenilenmesinin önlenmesinde idrar süper saturasyonunun azaltılması önemlidir. Bu yüzden idrar hacmi 2-2.5 litre olana kadar sıvı alımının arttırılması hedeflenmelidir. Diyetteki okzalat miktarı arttığında veya kalsiyum düşük olduğunda ortaya çıkabilen hiperoksalüri, kalsiyum okzalat taşı oluşumu için risk etmenidir. Gereksiz diyetsel kalsiyum kısıtlamalarından kaçınmak ve okzalattan zengin besinleri diyette kontrol altına almak böbrek taşının önlenmesi için önemlidir. Artmış diyet sodyum alımı, kalsiyum renal tübüler geri emilimini azaltarak böbrek taşı için risk etmeni olan hiperkalsiüriyi tetikleyebileceği için, diyetle sodyum alımının düzenlemesine gidilebilmektedir. Bu yüzden böbrek taşı oluşumunu ve tekrarlamasını önleyebilmek adına çevresel etmenlerden özellikle beslenmenin de kontrol altına alınması gerekebilmektedir.

Characterization of cocoyam (Xanthosoma spp.) corm flour from the Nazareno cultivar

Abstract The present study assessed the physical, chemical, functional, and microbiological properties of cocoyam (Xanthosoma spp.) corm flour made from the Nazareno cultivar. The flour was initially submitted to a water-soaking process in order to reduce its high oxalate content. The soaked flour showed a high dietary fiber content (15.4% insoluble and 2.8% soluble fiber), and can be considered essentially an energy-rich food given its high starch content (60.5%), of which 85.04% was analyzed as amylopectin; it also showed a high potassium content (19.09 mg/g). The anti-nutritional component analysis showed low levels of oxalate (5.55 mg/g), saponins (0.10%) and tannins (0.07%), while phytates were not detected. The flour had a high water and oil absorption capacity (9 - 11 g/g at 90 and 100 °C; 1.2 g/g) and it gelatinized at between 81.81 - 89.58 °C. It was also microbiologically stable after storage for 9 months at room temperature. Development of a multipurpose flour from cocoyam corm could provide a value-added option for the local food industry.

Fibrous osteodystrophy in a Lavradeira filly associated with Brachiaria humidicola ingestion

Fibrous osteodystrophy in horses is due to low calcium ingestion, high phosphorus ingestion, high oxalate ingestion, or a combination of these. Tropical forages usually have high levels of oxalates, which prevents calcium absorption and results in calcium deficiency. The present study reports a case of fibrous
 osteodystrophy in a filly associated with Brachiaria humidicola ingestion. A 1-year-old filly of the Lavradeiro breed was maintained on a pasture with B. humidicola and presented bilaterally enlarged facial bones, a high respiratory rate, noises during inspiration-expiration and dyspnea. Based on its history, age and clinical
 signs, the diagnosis was fibrous osteodystrophy associated with B. humidicola ingestion. Treatment was based on the administration of calcium gluconate, vitamins A, D and E, and clenbuterol. All other horses were transferred to a field with native forage and were supplemented with calcium carbonate. In Roraima state,
 the use of tropical forages in equine feeding is very common and represents a risk factor for the occurrence of fibrous osteodystrophy due to the continuous ingestion of oxalates. In horses, the diagnosis is achieved by clinical exam and treatment aims to correct the imbalance in Ca:P ratio, associated with support therapy.

RETRACTED ARTICLE: Sirt3 suppresses calcium oxalate-induced renal tubularepithelial cell injury via modification of FoxO3a-mediated autophagy

High oxalic acid and calcium oxalate (CaOx)-induced renal tubularepithelial cell (TEC) injury plays a key role in nephrolithiasis. However, themechanism remains unknown. Gene array analysis of the mice nephrolithiasis modelindicated significant downregulation of sirtuin 3 (Sirt3) and activation ofmitogen-activated protein kinase (MAPK) pathway. Kidney biopsy tissues of renalcalculi patients also showed decreased Sirt3 expression. Silencing Sirt3 exacerbatedoxidative stress and TEC death under CaOx stimulation. Restoring Sirt3 expression byoverexpression or enhancing its activity protected renal function and reduced TECdeath both in vitro and in vivo. Inhibiting the MAPK pathway resulted inupregulation of Sirt3 expression, preservation of renal function and decreased celldeath both in vitro and in vivo. Furthermore, Sirt3 could upregulate FoxO3a activitypost-translationally via deacetylation, dephosphorylation and deubiquitination.FoxO3a was found to interact with the promoter region of LC3B and to increase itsexpression, enhancing TEC autophagy and suppressing cell apoptosis and necrosis.Taken together, our results indicate that the MAPK/Sirt3/FoxO3a pathway modulatesrenal TEC death and autophagy in TEC injury.

Quantitation of oxalates in corms and shoots of Colocasia esculenta (L.) Schott under drought conditions

Oxalate (calcium oxalate) accumulation in taro plants (Colocasia esculenta (L.) Schott) impacts their nutritional quality, producing acridity, causing lips, mouth and throat tissues swelling if consumed fresh. The oxalate content is related to photosynthesis, through the glycolate–glyoxylate oxidation pathway. The plant’s photosynthetic rate usually increases in non-stressed conditions. Differences in photosynthetic rate are indirectly related to the chlorophyll content index. Protein accumulation and starch variation are also important traits to understand the taro oxalate synthesis caused by drought and how they affect corm quality. The purpose of this study was to quantitate oxalates in taro corms and shoots submitted to drought conditions and to evaluate how stress response can affect the nutritional quality of taro whole-plant. Seven taro genotypes from Madeira, Canaries and Pacific Community (SPC) collections were grown in greenhouse conditions and submitted to different watering regimes for drought tolerance screening. Corms and shoots were harvested and evaluated for oxalates (soluble, insoluble and total), chlorophyll content index (CCI), crude protein, starch, starch solubility in water and starch swelling power. All accessions had very high calcium oxalate content. Drought-tolerant genotypes showed good osmotic response by oxalate precipitation and mobilization through shoot to corm tissues, photosynthesis adaptation by increase of CCI, protein accumulation, and very low starch hydrolysis. Sensitive-drought genotypes showed less mobilization of calcium oxalate, decreased photosynthetic rate and protein synthesis, and slight increase of starch hydrolysis. Variation in taro oxalate content is consistent and significantly correlated with the photosynthetic rate, carbohydrate metabolism and protein synthesis.

The impact of oxalate ions on barium sulfate crystallization

In this manuscript we investigate the impact of oxalate ions on the crystallization of barium sulfate. The organic anion, oxalate, was found to inhibit both nucleation and growth according to atomic force microscopy measurements and dynamic light scattering data. Raman confocal imaging was used to try and determine how the oxalate interacts with the barium sulfate surface. It was found that barium oxalate is only seen at very high oxalate concentrations. At lower concentrations no direct evidence for the presence of oxalate was observed, however, the most probable mode of action for oxalate is via adsorption onto the barium sulfate surface including into key kink or step sites, impacting growth.

Amelioration of hyperoxaluria-induced kidney dysfunction by chemical chaperone 4-phenylbutyric acid.

Hyperoxaluria is characterized by an increased excretion of urinary oxalate which is caused by inherited disorders or high oxalate intake leading to renal stone ailment. Until date, reactive oxygen species and inflammation has been convicted for the progression of kidney stones for which antioxidant therapy has been employed. However, recent studies have linked the association of endoplasmic reticulum stress and oxidative imbalance in the progression of renal diseases. Considering oxidative stress being at forefront in causing hyperoxaluric consequences, current study was designed to correlate the impact of hyperoxaluria and regulation of oxidative imbalance via inhibition of endoplasmic reticulum stress by 4-phenylbutyric acid (4-PBA). Male wistar rats were subdivided into three groups, i.e., normal control (C), hyperoxaluric rats given ethylene glycol (EG), and hyperoxaluric rats treated with 4-PBA (EG + PBA). After 28days of treatment, assessment of antioxidant defence system, inflammation, ER stress, and subsequent unfolded protein response was studied in renal tissue. It was found that the hyperoxaluric insult led to a marked damage to the renal tissue resulting in compromised antioxidant levels, upregulation of ER stress markers along with a steep surge in the extent of inflammation. However, 4-PBA treatment significantly curtailed the deleterious effects of hyperoxaluria by lowering down the level of stress markers as well as normalizing the antioxidant defence enzymes. Therefore, chemical chaperones can be deemed as a new class of drugs for the treatment of hyperoxaluric induced renal damage.

Expression Analysis of Oxalate Metabolic Pathway Genes Reveals Oxalate Regulation Patterns in Spinach.

Spinach (Spinacia oleracea L.) is one of most important leafy vegetables because of its high nutritional value and high oxalate content, which can be toxic with negative effects on human nutrition. Ammonium and nitrate can effectively regulate oxalate accumulation, although the mechanisms underlying the oxalate biosynthesis and regulation are still undetermined in plants. In the present study, we identified 25 putative genes that are involved in the oxalate biosynthetic and degradation pathway, before analyzing the oxalate content and the expression levels of the corresponding proteins under normal growth conditions, with or without ammonium and nitrate treatments, using high and low oxalate-accumulated spinach genotypes. The two cultivars exhibited different profiles of total oxalate and soluble oxalate accumulation. The high oxalate concentrations in spinach were as a result of the high transcription levels of the genes that are involved in oxalate biosynthesis under normal growth conditions, such as SoGLO2, SoGLO3, three SoOXACs, SoMLS, SoMDH1, SoMDH2, and SoMDH4. The results revealed that the ammonium and nitrate were able to control the oxalate content in leaves, possibly because of the different transcription levels of the genes. The oxalate content is regulated by complex regulatory mechanisms and is varied in the different varieties of spinach. The results from this research may be used to assist the investigation of the mechanism of oxalate regulation and breeding for reduced oxalate content in spinach.

A case series on Averrhoa bilimbi induced acute oxalate nephropathy; an experience from a tertiary center in Kerala, India

Background: Averrhoa bilimbi is a commonly used fruit in South India for various home preparations and as a traditional remedy for hypercholesterolemia and hypertension. As it belongs to Oxalidaceae family, fruit has high oxalate content, causing calcium oxalate crystal deposition in renal tubules, resulting in acute oxalate nephropathy (AON) when consumed in large quantities. Case Series: We present a series of 24 patients from 11 hospitals in the State of Kerala who developed acute renal failure after some days of intake of Irumban puli fruit juice. Seven patients needed hemodialysis while the other three improved with conservative management. Conclusions: We conclude that it is not safe to consume high oxalate containing fruits, especially in concentrated forms, that too in large quantities.

MP24-19 ENTERAL NUTRITION FORMULAS WITH HIGHER OXALATE CONTENT MAY CONTRIBUTE TO HIGHER OXALATE ABSORPTION AND URINARY EXCRETION IN PATIENTS REQUIRING NUTRITION SUPPORT

You have accessJournal of UrologyStone Disease: Basic Research & Pathophysiology II1 Apr 2018MP24-19 ENTERAL NUTRITION FORMULAS WITH HIGHER OXALATE CONTENT MAY CONTRIBUTE TO HIGHER OXALATE ABSORPTION AND URINARY EXCRETION IN PATIENTS REQUIRING NUTRITION SUPPORT Kristina L. Penniston, Eve A. Palmer, Riley C. Medenwald, Sarah N. Johnson, Leema M. John, David J. Beshensky, and Ibrahim A. Saeed Kristina L. PennistonKristina L. Penniston More articles by this author , Eve A. PalmerEve A. Palmer More articles by this author , Riley C. MedenwaldRiley C. Medenwald More articles by this author , Sarah N. JohnsonSarah N. Johnson More articles by this author , Leema M. JohnLeema M. John More articles by this author , David J. BeshenskyDavid J. Beshensky More articles by this author , and Ibrahim A. SaeedIbrahim A. Saeed More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.772AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Patients requiring oral and/or enteral nutrition support for nutritional needs can form calcium oxalate (CaOx) kidney stones. Dietary oxalate, if excessive, can contribute to CaOx stones when unopposed by appropriate calcium. The oxalate concentration of oral/enteral nutrition formulas is not known. We assessed various formulas for oxalate. METHODS Adult and pediatric oral/enteral nutrition formulas commonly used in hospitals as well as in home feeding regimens were selected. Formulas designed for oral and enteral consumption (or either) were included (table); completely elemental (hydrolyzed) or modular formula products were not. Multiple samples (N, table) of each formula were acidified, heated, and centrifuged. Supernatants were filtered and analyzed for oxalate by ion chromatography. Oxalate concentration (mg/L±SD), relative standard deviation (SD) between samples (coefficient of variation; CV), and calcium:oxalate ratios (mg:mg/L of formula) were calculated. RESULTS Of 35 formulas analyzed, 9 were excluded due to inconsistent results and high CVs. Results for the 26 remaining formulas are shown (table). Oxalate concentration ranged from 4-140 mg oxalate/L of formula. Due to highly variable calcium content, calcium:oxalate ratios varied widely between formulas (from 0-286) with lower ratios suggesting higher potential for oxalate absorption. There was no difference between mean oxalate concentration of enteral vs. oral formulas (45 vs. 46 mg/L; P=0.92). Formulas designated for enteral use tended to have lower relative SDs (mean CV 16% vs. 21% for oral formulas), likely due to the generally more complex matrix of oral formulas, which contributed to more analytical variability. Depending on the formula, a patient requiring 1.5 L daily could obtain anywhere from 12-150 mg oxalate. CONCLUSIONS Patients requiring oral and/or enteral nutrition support are at risk for a high exogenous oxalate load depending on the formula ingested and on the bioavailability of oxalate. Patients with a history of or at high risk for urolithiasis would benefit from strategies to reduce the bioavailability of oxalate and urinary oxalate excretion, which may include supplemental calcium with feedings or use of an appropriate lower oxalate formula. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e297-e298 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Kristina L. Penniston More articles by this author Eve A. Palmer More articles by this author Riley C. Medenwald More articles by this author Sarah N. Johnson More articles by this author Leema M. John More articles by this author David J. Beshensky More articles by this author Ibrahim A. Saeed More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Urinary stone risk factors in the descendants of patients with kidney stone disease.

Evidence has indicated that immediate family members of nephrolithiasis patients had high opportunity to develop stones. However, they are usually not regarded to be at risk, since it is unclear if there are any lithogenic abnormalities found in non-stone-forming nephrolithiasis relatives. Our aim was to investigate urinary metabolic abnormalities in the children of nephrolithiasis patients, compared with the general population. The 24-h urinary metabolic profile was studied for 28 calcium oxalate nephrolithiasis patients (NL) and 46 of their descendants (ND), as well as 40 non-stone-forming volunteers (V) and 34 of their descendants (VD). There was no difference between age, gender, and serum creatinine between NL vs. V (parental groups) and ND vs. VD (descendant groups). High urinary oxalate in nephrolithiasis and urinary calcium in their descendants was detected. In addition, an elevated urinary excretion rate of calcium, phosphate, protein, and albumin, along with low citrate excretion and high urinary supersaturation was observed in both the nephrolithiasis patients and their descendants. Approximate 17.8-24.4% of the nephrolithiasis descendants had a urinary supersaturation higher than the nephrolithiasis level, but none was found in VD group. The level of urinary supersaturation index was correlated with urinary protein and albumin excretion in nephrolithiasis family. It was demonstrated that nephrolithiasis offspring carried several urinary metabolic risks predisposing to stone formation which are similar to their parents, and about one in every five nephrolithiasis children had nephrolithiasis level urinary supersaturation.