Who makes uric acid stones and why—observations from a renal stones clinic

2013 ◽  
Vol 66 (5) ◽  
pp. 426-431 ◽  
Author(s):  
Elizabeth M Stansbridge ◽  
Damian G Griffin ◽  
Valerie Walker
Keyword(s):  
Uric Acid ◽  
Urine Volume ◽  
Renal Stones ◽  
Dominant Factor ◽  
Uric Acid Stone ◽  
Calcium Stones ◽  
Oxalate Excretion ◽  
Stone Formers ◽  
Uric Acid Stones ◽  
Patients With Diabetes

AimsExcessively acidic urine is the dominant factor in uric acid stone formation. Recent evidence implicating insulin resistance has revived interest in its causation. We reviewed data on uric acid stone formers attending a general stones clinic to find out whether this supports and adds to current concepts.MethodsA retrospective database study of 1504 stone formers investigated at the Southampton renal stones clinic from 1990 to March 2007. Uric acid stone formers and idiopathic calcium stone formers were compared using non-parametric tests.ResultsFifty-nine patients (3.9%; 43 men) had uric acid stones. In men the commonest associated conditions were diabetes (20%), gout (20%) and an ileostomy (15%); in women, diabetes (33%), urinary infections (27%) and hyperparathyroidism (20%). Most patients with diabetes (85% of men, 75% of women), however, produced calcium stones. Risk factors did not differ significantly between calcium and uric acid stone formers with diabetes, gout or ileostomies. The median urine pH of men with idiopathic calcium stones was 6.20, idiopathic uric acid stones 5.47, diabetes 5.68, gout 6.05, diabetes and gout 5.20 and ileostomy 5.10. Plasma urate was higher with gout and idiopathic uric acid stones. Urate excretion was increased in gout. Oxalate excretion was lower with idiopathic uric acid stones (new finding). Urine volume decreased and oxalate concentration increased with ileostomy.ConclusionsUric acid stones are increased in diabetes, but most patients with diabetes make calcium stones. Different mechanisms may explain low pH with diabetes, gout and idiopathic stones. Low oxalate excretion with idiopathic urate stones needs confirmation.

scholarly journals A comparison of the metabolic profiles of diabetic and non-diabetic uric acid stone formers

2013 ◽  
Vol 7 (3-4) ◽  
pp. e190-2 ◽  
Author(s):  
Alfonso Fernandez ◽  
Andrew Fuller ◽  
Reem Al-Bareeq ◽  
Linda Nott ◽  
Hassan Razvi
Keyword(s):  
Uric Acid ◽  
Dietary Advice ◽  
Diabetic Patients ◽  
Metabolic Profiles ◽  
Uric Acid Stone ◽  
Metabolic Evaluation ◽  
Urine Ph ◽  
Oxalate Excretion ◽  
Stone Formers ◽  
Uric Acid Stones

Introduction: The aim of this study was to compare the metabolic profiles of diabetic and non-diabetic patients with uric acid stones to understand whether preventive strategies should be tailored to reflect different causative factors.Methods: The results of the metabolic evaluation of patients with uric acid stones identified prospectively from the Metabolic Stone Clinic at St. Joseph’s Hospital, London, Canada were reviewed. Information included patients’ clinical histories, 24 hour urine collections, blood chemistry and stone analysis.Results: Complete data were obtained from 68 patients with uric acid stones. Twenty-two patients had diabetes. There were no statistically significant differences in mean age, body mass index, or history of gout. Among diabetics, pure uric acid stones were identified in 14 patients (63%) and mixed uric acid in 8 (36%). Pure uric acid stones were more common in the diabetic cohort (63% vs. 46%, p = 0.16). Urine pH, serum and urine uric acid levels and 24-hour urine volumes were similar in both groups. The diabetic group had an increased average oxalate excretion (424 μmol/d vs. 324 μmol/d, p = 0.003).Conclusion: The exact etiological basis for the higher oxalate excretion in diabetic uric acid stone formers is unclear. Whether this is a metabolic feature of diabetes, due to dietary indiscretion or the iatrogenic consequence of dietary advice requires further investigation.

Study on Nano- and Microcrystallites in Urines of Uric Acid Stone Patients

2013 ◽  
Vol 655-657 ◽  
pp. 1927-1930 ◽  
Author(s):  
Guang Na Zhang ◽  
Zhi Yue Xia ◽  
Jian Ming Ouyang ◽  
Li Kuan
Keyword(s):  
Electron Microscopy ◽  
Uric Acid ◽  
X Ray Diffraction ◽  
Uric Acid Stone ◽  
Urine Ph ◽  
Stone Formers ◽  
Transmission Electron ◽  
Close Relationship ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

The presence of crystallites in urine is closely related to stones formation. In this article, the components, morphology of nano- and micro-crystallites in urines of 20 uric acid (UA) stone formers as well as their relationship with the formation of UAstones were comparatively studied using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The main constituent of urinary crystallites was uric acid. Their particle size distribution was highly uneven, ranging from several nanometers to several tens of micrometers, and obvious aggregation was observed. These results showed that there was close relationship among stone components, urinary crystallites composition and urine pH.

scholarly journals The diurnal variation in urine acidification differs between normal individuals and uric acid stone formers

2012 ◽  
Vol 81 (11) ◽  
pp. 1123-1130 ◽  
Author(s):  
MaryAnn Cameron ◽  
Naim M. Maalouf ◽  
John Poindexter ◽  
Beverley Adams-Huet ◽  
Khashayar Sakhaee ◽  
...  
Keyword(s):  
Uric Acid ◽  
Diurnal Variation ◽  
Uric Acid Stone ◽  
Urine Acidification ◽  
Stone Formers ◽  
Normal Individuals

scholarly journals Kidney Stone Composition in Various Country Around the World

2021 ◽  
Author(s):  
Adam Halinski ◽  
Elenko Popov ◽  
Kamran Hassan Bhattikam ◽  
Luca Boeri ◽  
Jonathan Cloutier ◽  
...  
Keyword(s):  
Uric Acid ◽  
Calcium Phosphate ◽  
Calcium Oxalate ◽  
Urinary Stones ◽  
Stone Composition ◽  
Calcium Stones ◽  
Uric Acid Stones ◽  
The World ◽  
Cystine Stones ◽  
Struvite Stones

Abstract To compare urinary stone composition patterns in different populations around the world in relation to the structure of their population, dietary habits, and climate. 1204 adult patients with urolithiasis and stone analysis was included . International websites were searched to obtain data. We observed 710(59%) patients with calcium oxalate, 31(1%) calcium phosphate, 161(13%) mixed calcium oxalate/calcium phosphate, 15(1%) carbapatite, 110(9%) uric acid, 7(<1%) urate, 100(9%) mixed uric acid/ calcium oxalate, 56(5%) struvite and 14(1%) cystine stones. Calcium stones were the most common in all countries (up to 91%) with the highest rates in Canada and China. Oxalate stones were more common than phosphate or mixed phosphate/oxalate stones except Egypt and India. The rate of uric acid stones, being higher in Egypt, India, Pakistan, Iraq, Poland, and Bulgaria. Struvite stones occurred in less than 5% except India (23%) and Pakistan (16%). Cystine stones occurred in 1%. The frequency of different types of urinary stones varies from country to country. Calcium stones are prevalent in all countries. Uric acid stones seems to depend mainly on climatic factors, being higher in countries with desert or tropical climates. Dietary patterns can also lead to an increase it. Struvite stones are decreasing in most countries.

Pathophysiology and Treatment of Uric Acid Stones

2018 ◽  
Author(s):  
Dustin Whitaker ◽  
Ava Saidian ◽  
Jacob Britt ◽  
Carter Boyd ◽  
Kyle Wood ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Metabolic Syndrome ◽  
Uric Acid ◽  
Urine Volume ◽  
Potassium Citrate ◽  
First Line ◽  
Urine Ph ◽  
Stone Composition ◽  
The Metabolic Syndrome ◽  
Uric Acid Stones

Uric acid is the third most common stone composition and comprises 7 to 10% of all kidney stones sent for analysis. These stones are more common with increasing age and in men. Uric acid stone disease is associated with conditions such as the metabolic syndrome and type 2 diabetes mellitus. Uric acid is produced by the enzyme, xanthine oxidase and is the final product of purine metabolism in humans. Three main factors contribute to the formation of uric acid stones: low urine pH (the most important), hyperuricosuria (rare, includes conditions such as myeloproliferative disorders and Lesch-Nyhan syndrome), and low urine volume. Uric acid stones appear radiolucent on plain radiographs and are ultimately diagnosed via stone analysis. These stones may be treated with medical expulsive therapy, dissolution therapy, or surgical intervention depending on the size, location, and clinical presentation. Urine pH manipulation therapy with potassium citrate is the first-line treatment for the prevention of uric acid stones and attempts at dissolution. Allopurinol should not be offered as the first-line therapy for uric acid stones.  This review contains 3 figures, 1 table and 38 references Key Words: ammonium, diabetes mellitus, epidemiology, management, metabolic syndrome, nephrolithiasis, pathophysiology, potassium citrate, uric acid, urine pH

Uric acid nephrolithiasis: An update

2018 ◽  
Vol 85 (3) ◽  
pp. 93-98 ◽  
Author(s):  
Elisa Cicerello
Keyword(s):  
Uric Acid ◽  
Acid Production ◽  
Stone Formation ◽  
Acid Precipitation ◽  
Urinary Volume ◽  
Uric Acid Stone ◽  
Urinary Ph ◽  
Uric Acid Stones ◽  
Uric Acid Nephrolithiasis ◽  
Metabolic Conditions

Uric acid nephrolithiasis appears to increase in prevalence. While a relationship between uric acid stones and low urinary pH has been for long known, additional association with various metabolic conditions and pathophysiological basis has recently been elucidated. Some conditions such as diabetes and metabolic syndrome disease, excessive dietary intake, and increased endogenous uric acid production and/or defect in ammoniagenesis are associated with low urinary pH. In addition, the phenomenon of global warming could result in an increase in areas with greater climate risk for uric acid stone formation. There are three therapeutic steps to be taken for management of uric acid stones: identification of urinary pH profiles, assessment of urinary volume status, and identification of disorders leading to excessive uric acid production. However, the most important factor for uric acid stone formation is acid urinary pH, which is a prerequisite for uric acid precipitation. This article reviews recent insights into the pathophysiology of uric acid stones and their management.

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