Advertisement

Topics

Clinical significance of uric acid dihydrate in urinary stones.

Summary of "Clinical significance of uric acid dihydrate in urinary stones."

Uric acid crystallizes as an anhydrous compound (UAA), a dihydrate (UAD) or a mixture of both. A monohydrate form is very rare. About 20% of uric acid stones contain a significant amount (≥20%) UAD. It is believed that UAD crystallizes under highly acidic conditions (urine pH ≤ 5.0). Up to now, metabolic data on patients with UAD stones have not been reported in the literature. One hundred and fifty patients with pure uric acid calculi were studied. Stone analysis was performed using X-ray diffraction. According to the stone analysis, they were divided in two groups: 1. UAD (≥20% UAD), 2. UAA (<20% UAD). In all patients the following parameters were examined: age, sex, number of recurrences, body mass index (BMI); blood: creatinine, uric acid, calcium, sodium, and potassium; urine: pH-profiles, volume, calcium, uric acid, citrate, ammonia, and urea. Group 1 (≥20% UAD) consisted of33patientsand group 2 (<20% UAD) of 117 patients. Between these groups, there was a significant difference concerning the number of recurrences, the urine volume, and the urinary excretion of calcium. Patients with ≥20% dihydrate had a mean BMI of 31.6 ± 7.5, a mean number of recurrences of 0.24 ± 0.44, an urine volume of 2.6 ± 0.8 l/24 h, and a calcium excretion of 4.5 ± 2.2 mmol/24 h, whereas those with <20% dihydrate had BMI of 29.9 ± 5.0, 1.10 ± 1.42 recurrences, urine volume of 2.3 ± 1.2 l/24 h, and calcium excretion of 3.2 ± 2.4 mmol/24 h. All the other parameters tested were not significantly different. For the first time, our study shows metabolic data in uric acid patients with a significant amount of UAD. The comparison between this group and those patients with <20% UAD revealed that the first group is less prone to develop recurrences. This is a relevant difference concerning the necessity of metaphylactic measures. We could not confirm in patients with dihydrate if the urinary pH is more acid than in those with insignificant amounts of dihydrate. The higher 24-h urine volume, the higher excretion of calcium, and the higher BMI in the UAD group may be of pathophysiological relevance and requires further attention.

Affiliation

Department of Urology and Paediatric Urology, regioMed Kliniken, Klinikum Coburg, Ketschendorfer Str. 33, 96450, Coburg, Germany, walter.strohmaier@klinikum-coburg.de.

Journal Details

This article was published in the following journal.

Name: Urological research
ISSN: 1434-0879
Pages:

Links

DeepDyve research library

PubMed Articles [29351 Associated PubMed Articles listed on BioPortfolio]

Dual-Energy CT for Quantification of Urinary Stone Composition in Mixed Stones: A Phantom Study.

The purpose of this study was to assess the feasibility of using dual-energy CT to accurately quantify uric acid and non-uric acid components in urinary stones of mixed composition.

Dual energy can accurately differentiate uric acid-containing urinary calculi from calcium stones.

To retrospectively evaluate the accuracy of dual-energy CT (DECT) in the detection of the chemical composition of urinary calculi in correlation with infrared spectroscopic stone analysis.

Serum Uric Acid and Risk of CKD in Type 2 Diabetes.

Serum uric acid may predict the onset and progression of kidney disease, but it is unclear whether uric acid is an independent risk factor for diabetic nephropathy. Our aim was to study the relationsh...

Treatment of the Infected Stone.

Infected kidney stones refer to stones that form because of urinary tract infections with urease-producing bacteria, secondarily infected stones of any composition, or stones obstructing the urinary t...

The Clinical Impact of Accurate Cystine Calculi Characterization Using Dual-Energy Computed Tomography.

Dual-energy computed tomography (DECT) has recently been suggested as the imaging modality of choice for kidney stones due to its ability to provide information on stone composition. Standard postproc...

Clinical Trials [4085 Associated Clinical Trials listed on BioPortfolio]

Study of the Biological and Physical Manifestations of Spontaneous Uric Acid Kidney Stone Disease

This study has two aims: Aim 1: To determine the presence of accumulation of fat within cells and the functional consequences of this in the kidney by correlating kidney fat content with ...

Toxicity of Perirenal Fat in Overweight or Obese Subjects: A Pathophysiological Link Between Uric Acid Stones and Renal Ammonium Formation

Patients who are overweight or obese, diabetic or not, share with those who are suffering from uric stones the same way to remove abnormal acidity of the body in urine, ie a kidney ammonio...

Primary Prevention of Hypertension in Obese Adolescents

The purpose of this study is to examine the consequences of lowering serum uric acid in pre-hypertensive, obese adolescents pathways involved with how uric acid mediated hypertension and r...

Brushite Kidney Stones: A Registry and Database of Clinical and Laboratory Findings

Brushite kidney stones are a unique form of calcium phosphate stones that have a tendency to recur quickly if patients are not aggressively treated with stone prevention measures. Little r...

Effect of Urinary Alkalinization on Urine Uric Acid Precipitation and Crystallization in Adults With Type 1 Diabetes

The purpose of this study is to determine whether alkalinization of urine uric acid by 2 doses of sodium bicarbonate (1950mg) over 24-hours reduces precipitation and crystallization of uri...

Medical and Biotech [MESH] Definitions

Low-density crystals or stones in any part of the URINARY TRACT. Their chemical compositions often include CALCIUM OXALATE, magnesium ammonium phosphate (struvite), CYSTINE, or URIC ACID.

Stones in the URINARY BLADDER; also known as vesical calculi, bladder stones, or cystoliths.

Formation of stones in any part of the URINARY TRACT, usually in the KIDNEY; URINARY BLADDER; or the URETER.

Agents that increase uric acid excretion by the kidney (URICOSURIC AGENTS), decrease uric acid production (antihyperuricemics), or alleviate the pain and inflammation of acute attacks of gout.

Excessive URIC ACID or urate in blood as defined by its solubility in plasma at 37 degrees C; greater than 0.42mmol per liter (7.0mg/dL) in men or 0.36mmol per liter (6.0mg/dL) in women. This condition is caused by overproduction of uric acid or impaired renal clearance. Hyperuricemia can be acquired, drug-induced or genetically determined (LESCH-NYHAN SYNDROME). It is associated with HYPERTENSION and GOUT.

Quick Search
Advertisement
 


DeepDyve research library

Relevant Topics

Gout
According to the National Arthritis Data Workgroup, an estimated 6 million people in the United States report having experienced gout at some point in their lives. In fact, gout is the most common form of inflammatory arthritis in men over the age of 40....

Urology
Benign Prostatic Hyperplasia (BPH) Erectile Dysfunction Urology Urology is the branch of medicine concerned with the urinary tract and diseases that affect it. Examples include urethritis, urethrostenosis and incontinence. Urology is a su...

Radiology
Radiology is the branch of medicine that studies imaging of the body; X-ray (basic, angiography, barium swallows), ultrasound, MRI, CT and PET. These imaging techniques can be used to diagnose, but also to treat a range of conditions, by allowing visuali...