Diet-related urine collections: assistance in categorization of hyperoxaluria

Hyperoxaluria, one of the major risk factors for calcium oxalate urolithiasis and nephrocalcinosis, causes significant morbidity and mortality and should therefore be detected and treated as soon as possible. An early, consequent and adequate evaluation, but also a distinction between primary (PH) and secondary hyperoxaluria (SH) is therefore essential. We evaluated the usefulness of three consecutive 24-h urine collections under different diets [usual diet, (A), low oxalate diet, (B), high oxalate diet, (C)] to prove SH, or to find evidence of PH by changes in urinary oxalate excretion (Uox). We retrospectively analyzed results from 96 pediatric patients (47 females and 49 males, age 3–18 years) who presented with a history of nephrolithiasis, nephrocalcinosis and/or persistent hematuria in whom hyperoxaluria was found in an initial urine sample. The typical pattern of SH was found in 34 patients (mean Uox (A) 0.85 ± 0.29, (B) 0.54 ± 0.15 and (C) 0.95 ± 0.28 mmol/1.73m2/d). PH was suspected in 13 patients [(A) 1.21 ± 0.75; (B) 1.47 ± 0.51 and (C) 1.60 ± 0.82 mmol/1.73m2/d], but genetically proven only in 1/5 patients examined. No hyperoxaluria was found in 16 patients. Data were inconclusive in 33 patients. Urine collection under different diets is helpful to diagnose secondary hyperoxaluria and may provide evidence, that urinary oxalate excretion is normal. We have now established this procedure as our first diagnostic step before further, more extensive and more expensive evaluations are performed.

Evaluation of Efficacy of Cucumis melo in Gentamycin and CPD Induced Urolithiasis on Rats

Evaluation of the efficacy of methanolic extract of Cucumis melo in urolithiasis induced by gentamycin and calculi producing diet on Wistar rats. Gentamycin (40 mg/kg, subcutaneously) and calculi-producing diet (CPD) was fed to induce urolithiasis on Wistar rats. The effect of oral administration of methanolic extract of Cucumis melo seed on calcium oxalate urolithiasis has been studied and is compared with the effect of oral administration of Cystone as standard on Wistar rats. Gentamycin and CPD feeding resulted in hyperoxaluria and calcium oxalate deposition as well as increased renal excretion of calcium and oxalate. Supplementation with methanolic extract of Cucumis melo seed reduced the elevated urinary oxalate, showing a regulatory action on endogenous oxalate synthesis. The results indicate that the seed of Cucumis melo is endowed with antiurolithiatic activity. Keywords: C. melo, Hyperoxaluria, calcium oxalate deposition, cystone, hyperoxaluria, analysis of variance

Dietary Restriction: A Major Factor in Prophylaxis against Calcium Oxalate Urolithiasis

Urolithiasis (Ur) Is A Worldwide Problem That Affects All Groups Of Ages. Nearly 80% Of Renal Stones Are Calcium Oxalate (Cao) And 50% Of The Affected Patients Have Recurrent Disease Within 10 Years. Our Prospective Study Was Conducted Over 4 And ½ Years And Evaluated The Role Of Dietary Manipulation In Prophylaxis Against Cao Ur. A Total Of 212 Patients With Recurrent Cao Ur, Who Lacked Anatomical Or Metabolic Derangement, Were Subjected To A Practical And Specific Diet. The Latter Had: (A) Low Salt, Red-Meat And Green Leafy Vegetable, (B) Moderate Amounts Of Milk, Dairy Products, Poultry And Certain Fish-Items, And (C) High Water Intake (2 Liters/Day). A Total Of 66/70 (96%), 87/108(88%) And 146/167(87.4%) Patients Were Stone-Free By The End Of 1, 2 And 3 Years Of Follow Up. The Median Time For Stone-Free Duration Was 33 (28.7-37.3) Months. Adding A Thiazide And Allopurinol To The 19 Patients Who Had Failed Dietary Prophylaxis Prevented Stone Formation In 16 More Patients Leaving Only 3 True Failures. Four Patients Could Not Tolerate The Latter 2 Drugs For Allergy. In Conclusion; Our Practical Dietary Modification Can Aid In Prophylaxis Against Cao Ur. Keywords: Diet, Calcium Oxalate, Urolithiasis, Urinary Tract Stones, Prophylaxis