Urine Of Stone Formers Research Articles

Preservation of urine specimens for metabolic evaluation of recurrent urinary stone formers.

Stability of concentrations of urinary stone-related metabolites was analyzed from samples of recurrent urinary stone formers to assess necessity and effectiveness of urine acidification during collection and storage. First-morning urine was collected from 20 adult calcium-stone forming patients at Tomas Bata Hospital in the Czech Republic. Urine samples were analyzed for calcium, magnesium, inorganic phosphate, uric acid, sodium, potassium, chloride, citrate, oxalate, and urine particles. The single-voided specimens were collected without acidification, after which they were divided into three groups for storage: samples without acidification ("NON"), acidification before storage ("PRE"), or acidification after storage ("POST"). The analyses were conducted on the day of arrival (day 0, "baseline"), or after storage for 2 or 7days at room temperature. The maximum permissible difference (MPD) was defined as ±20 % from the baseline. The urine concentrations of all stone-related metabolites remained within the 20 % MPD limits in NON and POST samples after 2days, except for calcium in NON sample of one patient, and oxalate of three patients and citrate of one patient in POST samples. In PRE samples, stability failed in urine samples for oxalate of three patients, and for uric acid of four patients after 2days. Failures in stability often correlated with high baseline concentrations of those metabolites in urine. Detailed procedures are needed to collect urine specimens for analysis of urinary stone-related metabolites, considering both patient safety and stability of those metabolites. We recommend specific preservation steps.

Recurrent Urinary Stone Formers: Imaging Assessment and Endoscopic Treatment Strategies: A Systematic Search and Review.

Background/Objectives: Nephrolithiasis is a heterogeneous disease with a high prevalence and recurrence rate. Although there has been much progress regarding the surgical treatment of stones, a standardized follow-up, especially in recurrent stone formers (SFs), has yet to be decided. This fact leads to the overuse of computed tomography (CT) scans and many reoperations in patients, thus increasing their morbidity and the financial burden on the health systems. This review systematically searched the literature for original articles regarding imaging strategies and endoscopic treatment for patients with recurrent urolithiasis, aiming to identify optimal strategies to deal with these patients. Methods: We systematically searched the Medline database (accessed on 1 April 2024) for articles regarding imaging modalities and endoscopic treatment for patients with recurrent urinary tract lithiasis. Results: No specific follow-up or endoscopic treatment strategy exists for patients with recurrent urolithiasis. CT scan was the imaging modality most used in the studies, followed by X-ray, ultrasonography, and digital tomosynthesis. A transparent algorithm could not be identified. Percutaneous nephrolithotomy (PCNL), retrograde intrarenal surgery (RIRS), and ureteroscopy (URS) were used in the studies for endoscopic treatment. PCNL showed the best stone-free (SFr) rate and lowest hazard ratio (HR) for reoperation. RIRS showed superiority over extracorporeal shockwave lithotripsy for recurrent SFs, but fragments over 4 mm increased the recurrent rate. URS has an increased HR for reoperation for bilateral stones. Conclusions: The heterogeneity of urolithiasis leaves urologists without a standardized plan for recurrent SFs. Thus, each patient's follow-up should be planned individually and holistically. Pre-stenting is not to be avoided, especially in high-risk patients, and SFr status needs to be the aim. Finally, CT scans should not be generally overused but should be part of a patient's treatment plan. Prospective studies are required to define SFr status, the size of significant residual fragments, and the modalities of intervention and follow-up.

Spectrum of 25 (OH) D3 Status in Urinary Tract Stone Formers in North-Eastern Nigeria

Many studies, none in northeastern part of Nigeria, investigated the association between serum/plasma vitamin D and nephrolithiasis, with no consistent result, couple with the hot weather (as high as 44oC) in most part of the year in Maiduguri and its surroundings, and assay of vitamin D today is not yet part of evaluation of urinary stone formers in Maiduguri, warrant this study to assess status of vitamin D in urinary tract stone formers in Maiduguri. Patients diagnosed with urinary tract stone disease attending Urology Clinic, University of Maiduguri Teaching Hospital and consented were recruited. The first two who consented were recruited per week for a period of 24 months (1st April 2017 to 31st Match 2019) to cover the seasonal changes in weather for the year. Serum for vitamin D is stored at -20oC for batch analysis. Vitamin D was assayed by ELISA technique (Accu-Bind, 100 North Pointe Drive, Lake Forest, California 92630 USA), other parameters were analyzed weekly using autoanalyzer (Cobas C311, ISN, Roche, Germany). Result indicated 58 (36.2%) of patients had Vitamin D values below the optimal level either having deficiency/insufficiency. Forty-nine (30.6%) showed vitamin D concentration above the optimum level out of which 4 (2.5%) had hypervitaminosis D, while 53 (33.1%) patients had optimal vitamin D values. It showed 17 (10.6%) of patients had hypercalcaemia, however, out of the 114 patients with normocalcaemia, 42 (36.5%) had their values at the upper limit of normal (2.6 mmol/L). It also indicated that though 3 of the hypercalcaemic patients had vitamin D insufficiency, majority (14) are either having optimal level or above optimal vitamin D level. Excessive and prolong exposure to ultraviolet sunlight resulting in raised vitamin D synthesis and action is an important factor associated with urinary tract stone formation in this environment cannot be excluded. The high prevalence of hypercalcaemia in the study cannot be accounted for by raised vitamin D alone, therefore measurement of serum vitamin D (25(OH)D) and PTH in evaluation of urinary tract stone formers in this environment is recommended.

Spectrum of 25 (OH) D3 Status in Urinary Tract Stone Formers in North-Eastern Nigeria

Spectrum of 25 (OH) D3 Status in Urinary Tract Stone Formers in North-Eastern Nigeria

Role of Osteoprotegerin as Novel Marker in Urinary Stone Formers: A Pilot Study

Background: Urinary tract calculus formation can be prevented by identifying molecules and metabolic disturbances that affect this process. Osteoprotegerin (OPG), a cytokine of the TNF receptor superfamily, has been demonstrated to mediate vascular calcification and intimal calcification. Endothelial injury and oxidative stress are known to play a role in urolithiasis in the form of Randall’s plaques. Objectives: The present study aimed to compare 24-h urinary and serum OPG levels of patients with and without urolithiasis. Methods: In this case-control study, 24-h urinary levels of OPG (pg/mL), serum levels of OPG (pg/mL), and creatinine (mg/dL) were measured in both groups. Urinary and serum levels of OPG were determined by enzyme-linked immunosorbent assay (ELISA) using human OPG kits. Results: Mean serum creatinine was 0.86 ± 0.21 mg/dL in the case group and 0.77± 0.16 mg/dL in controls. The difference in the mean serum OPG levels between the cases (227.13 ± 98.02 pg/mL) and controls (47.28 ± 29.61 pg/mL) was highly significant (P value < 0.0001). The difference in the mean 24-h urinary OPG levels between the cases (156.12 ± 174.31 pg/mL) and controls (9.32 ± 23.72 pg/mL) was highly significant (P value < 0.001). Conclusions: There were significantly higher levels of OPG in serum and 24-h urine samples of cases than in controls. Hence, it requires further large studies to make OPG a diagnostic and prognostic marker.

Urinary Stones and Risk of Coronary Heart Disease and Stroke: the Japan Public Health Center-Based Prospective Study.

Aim: Evidence is lacking about whether urinary stones are associated with the subsequent risk of cardiovascular diseases. Herein, we investigated the association between history of urinary stones and the risk of coronary heart disease (CHD) and stroke among middle-aged Japanese.Methods: This cohort study included 89,037 Japanese men and women (45–74 years) registered in the Japan Public Health Center-based prospective study. Cox proportional hazard models were used to calculate the hazard ratios (HRs) and their 95% confidence intervals (CIs) for incident CHD and stroke among Japanese adults with a self-reported history of urinary stones compared with those without it. The following covariates were included in the regression models: age, sex, area, body mass index, and histories of hypertension, diabetes, hyperlipidemia, smoking habit, alcohol intake, and physical activity.Results: In total, 1.31% of Japanese adults reported a positive history of urinary stones. Throughout a median follow-up period of 12 years, 1.16% of Japanese adults developed CHD, and 4.96% developed stroke. No associations were detected between history of urinary stones and the risk of CHD (HR 1.04; 95% CI: 0.64–1.67), stroke (HR 0.92; 95% CI: 0.71–1.20), or total CVD (HR 0.95; 95% CI: 0.75–1.19). Younger urinary stone formers (45–59 years) tended to have a higher, though statistically insignificant, risk of CHD than older urinary stone formers (60–74 years): [(HR 1.15; 95% CI: 0.61–2.15) versus (HR 0.83; 95% CI: 0.40–1.76)], respectively.Conclusion: The history of urinary stones was shown to be not associated with the risk of CVD among Japanese adults.

Bone mineral density in adolescent urinary stone formers: is sex important?

Urinary stone disease (USD) is affecting a greater number of children and low bone mineral density (BMD) and increased skeletal fractures have been demonstrated in stone patients; however, the mechanism(s) driving bone disease remain unclear. This pilot study was undertaken to assess an adolescent kidney stone cohort's BMD and evaluate for an inverse correlation between BMD and urine concentration of lithogenic minerals and/or inflammatory levels. Prospective case-control study was carried out at a large pediatric center. 15 participants with USD (12-18years of age, 8 female) were matched by age, sex, and body mass index to 15 controls. Lumbar and total body BMD z-score did not differ between groups. When stone formers were separated by sex, there was a significant difference between male stone formers vs. controls total body BMD z-score (Fig. 1). BMD z-score did not significantly correlate with urine calcium, oxalate, citrate or magnesium. Higher urine IL-13 did significantly correlate with higher total body BMD z-score (r = 0.677, p = 0.018). Total body BMD z-score did significantly correlate with body mass index (BMI) as expected for the control group (r = 0.6321, p = 0.0133). However, this relationship was not present in the USD group (r = -0.1629, p = 0.5619). This is a small but hypothesis-generating study which demonstrates novel evidence of male-specific low BMD in adolescent stone formers. Furthermore, we demonstrated a positive association between urine IL-13 and total body BMD z-score USD patients as well as a lack of a positive BMD and BMI correlations in stone formers.

Better sleep quality could reinforce the relationship between sleep posture and kidney stone laterality in obstructive sleep apnea patients.

Urolithiasis is a common urologic problem among adults worldwide. It is interesting that urinary stones tend to recur on the same side and the pathophysiology of unilateral stone formation is not clearly understood. Researchers found that sleep posture could alter renal perfusion, and subsequent vascular injury may lead to urolithiasis formation. The aim of this study is to retrospectively evaluate the correlations between the specific sleep postures recorded in polysomnography (PSG) and the stone laterality in unilateral urinary stone formers with obstructive sleep apnea (OSA). We retrospectively reviewed patients receiving PSG for the diagnosis of OSA in our institutes between January 1st 2002 and September 30th 2016. Those had a history of unilateral urinary stones which surgical intervention was warranted were included. Supine, prone, right decubitus, and left decubitus sleep postures were determined as patients remained specific postures for more than 50% of their sleep time. The laterality of stones with sleep posture was analyzed with Chi-square test. A student t test was used to assess factors that influenced the ipsilateral stone formation. IBM SPSS Statistics 21 software was adopted to analyze the data, and p value less than 0.05 was considered statistically significant. 117 patients were enrolled in this study, among which 105 (89.7%) were male and 12 were female. The mean age at PSG examination was 53.5 ± 11.5years. 66 patients were diagnosed as left-side urolithiasis, and 51 patients had urinary stones at right side. 58 (49.6%) patients slept predominantly in supine posture, while 53 (45.3%) patients, in decubitus posture, and no patient, in prone posture. A total of 51 patients' stones appeared at the same side as their decubitus posture (p < 0.0001). Shorter sleep stage I ratio (24.3 ± 15.5% versus 52.4 ± 24.7%, p = 0.017), longer sleep stage II + III + IV ratio (66.2 ± 21.9% versus 30.9 ± 2.8, p = 0.049), and less sleep stage change (176.6 ± 69.6 times versus 282.5 ± 91.2 times, p = 0.041) were correlated with stone formation on the same side. Age, gender, body mass index, and other polysomnographic parameters failed to demonstrate associations between the sides of urinary calculi and sleep postures. We discovered that sleep posture is associated with unilateral urolithiasis formation. Favorable sleep quality and less sleep stage changes could consolidate the correlations. Further prospective study is warranted to evaluate the effect of sleep posture and quality on non-OSA patients as well as the preventive effect of sleep posture modification on repeated unilateral stone formers.

Adolescents with urinary stones have elevated urine levels of inflammatory mediators.

Urinary stones are increasing in children, primarily during adolescence. Although urinary stones are often viewed in the context of intermittent stone events, increasing evidence indicates that stones are a metabolic process associated with chronic kidney disease and cardiovascular disease. These aforementioned stone-associated conditions may have pediatric origins. To compare urine inflammatory markers in otherwise healthy stone forming children versus matched controls. Urine samples were collected from 12 adolescents with urinary stones along with 15 controls. The levels of 30 urine cytokines were measured using a Mesoscale 30-Plex Human Cytokine panel and normalized to urine creatinine levels. Macrophage inflammatory protein 1β and interleukin 13 levels were significantly elevated in the urine of the stone forming adolescents compared to controls. Interleukin 17A was elevated in the urine of controls. This study indicates that urine levels of cytokines involved in chronic inflammation and fibrosis are elevated inurinary stone formers as early as adolescence. Because stone formers are at risk for chronic kidney disease, macrophage inflammatory protein 1β and interleukin 13 represent investigative targets.

The effect of serum levels of vitamin D in stone recurrencein patients with urinary tract stone

Introduction: The role of vitamin D in kidney stone disease and its effect on stone formation is still controversial. Objectives: To find out the possible role of 25(OH) D3 as an intrinsic factor in urinary calcium stone formers (SFs; individuals with one episode during the last 5 years and individuals with more than one episode during the last 5 years), we investigated the effect of serum levels of vitamin D on recurrence of urinary stones in SFs and control subjects (non-SFs). Patients and Methods: A total of 30 patients with first episode of urolithiasis (group A) and 30 patients with more than one episode of urolithiasis during the last 5 years (group B) aged 18 or older enrolled in this study and underwent metabolic evaluation including the measurement of serum level of 25(OH)D3, parathyroid hormone (PTH), calcium and uric acid. Thirty age and sex-matched patients who had never urinary stone episode (non-SFs) were considered as control group. The patients in this study were selected among those admitted in Urology Department of Kashani hospital during the last year. Individuals excluded from the study were subjects with hyperparathyroidism or with the previous history of hyperparathyroidism. Results: Mean level of 25(OH) D3 was positively correlated with recurrent stone (mean 19.89 ± 7.6 in the control group versus 47.21 ± 19.77 in the group with the recurrent stone disease). The recurrent stone group (SFs) had the higher serum level of 25(OH) D3 than the control. No correlation was observed between the serum levels of PTH and 25(OH) D3 (r = 0. 13, P = 0.11) in both control and urinary SFs group. Conclusion: High serum level of vitamin D has an important effect on the pathogenesis of repeated urolithiasis. High serum levels of 25(OH) D3 were detected in the group with recurrent kidney stone disease. But it seems there was no relation between serum level of vitamin D3 and one episode of urolithiasis. Based on the results of this study, the high level of vitamin D3 may have a significant role in inducing the recurrence of urinary stone.

Determination of Urinary Oxalate with Arylamine Glass-Bound Sorghum Oxalate Oxidase and Horseradish Peroxidase

We describe an enzymic colourimetric method for determination of oxalate level in urine using arylamine glass-bound sorghum leaf oxalate oxidase and horseradish peroxidase. The method is based on quantification of H2O2 generated from oxidation of urinary oxalate by immobilized oxalate oxidase, by a colour reaction consisting of 4-aminophnazone, phenol and immobilized peroxidase as chromogen. Minimum detection limit of the method was 0.05 mmol/l. Analytical recovery of added oxalate in urine was 96.8± 3.0% (mean ±S.D.). Within and between day coefficient of variation (CV) for urinary oxalate in urine were &lt; 3.5% and &lt;6.46 % respectively. The urinary oxalate values in apparently healthy and urinary stone formers as measured by the present method were correlated with those by modified Sigma Kit method (r= 0.929). The method has the advantages that it provides ca 200 times reuse of oxalate oxidase and peroxidase and free from interferences by Cl- and NO3- normally found in urine. Int J Appl Sci Biotechnol, Vol 4(3): 346-351

Prevalence of Hyperoxaluria in Urinary Stone Formers: Chronological and Geographical Trends and a Literature Review.

To report chronological trends and geographical distributions related to the prevalence of hyperoxaluria in stone-forming patients. We systematically reviewed the existing literature between 1982 and 2013 seeking studies that assessed for hyperoxaluria (>45 mg/day [499.5 μmol/24 hour]) in recurrent stone formers. Studies that performed 24-hour urine analysis for urine oxalate in patients with recurrent urinary stones were included. Studies were divided chronologically and by geographical region, and prevalence rates of hyperoxaluria were compared between groups. Our literature search provided 22 peer-reviewed articles involving 3636 patients in total. Ten studies were performed between 1982 and 2000, and 12 studies were performed between 2001 and 2013. The prevalence of hyperoxaluria in stone-forming patient cohorts was 24.8% and 45.1% (p = 0.019) in studies performed between 1982 and 2000 and 2001 and 2013, respectively. Hyperoxaluria rates were significantly higher in non-American cohorts compared with American cohorts (40.7% vs 23.0%; p = 0.018). Reported hyperoxaluria rates were higher in Asian countries compared with Western countries (56.8% and 23.8%; p < 0.001). The prevalence of hyperoxaluria in stone-forming patients has increased over the past two decades and may be a contributing factor to the rising global prevalence of urolithiasis. A geographical disparity in hyperoxaluria may exist between Asian and Western countries. Future studies are needed to explain these trends and their consequences.

Short-Term Tolvaptan Increases Water Intake and Effectively Decreases Urinary Calcium Oxalate, Calcium Phosphate and Uric Acid Supersaturations

Some patients cannot effectively increase water intake and urine volume to prevent urinary stones. Tolvaptan, a V2 receptor antagonist, blocks water reabsorption in the collecting duct and should decrease urinary supersaturation of stone forming solutes, although this action has never been proved. We conducted a double-blind, randomized, placebo controlled, crossover study of 21 calcium urinary stone formers stratified into majority calcium oxalate (10 patients) and calcium phosphate (11) groups. Patients received 45 mg tolvaptan per day or placebo for 1 week, followed by a washout week and crossover to tolvaptan or placebo for week 3. A 24-hour urine sample was collected at the end of weeks 1 and 3. Tolvaptan vs placebo decreased urinary osmolality (mean ± SD 204 ± 96 vs 529 ± 213 mOsm/kg, p <0.001) and increased urinary volume (4.8 ± 2.9 vs 1.8 ± 0.9 L, p <0.001). The majority of urinary solute excretion rates, including sodium and calcium, did not change significantly, although oxalate secretion increased slightly (from mean ± SD 15 ± 8 to 23 ± 8 mg per 24 hours, p = 0.009). Mean ± SD urinary calcium oxalate supersaturation (-0.01 ± 1.14 vs 0.95 ± 0.87 dG, p <0.001), calcium phosphate supersaturation (-1.66 ± 1.17 vs -0.13 ± 1.02 dG, p <0.001) and uric acid supersaturation (-2.05 ± 4.05 vs -5.24 ± 3.12 dG, p=0.04) all dramatically decreased. Effects did not differ between the calcium oxalate and calcium phosphate groups (p >0.05 for all interactions). Tolvaptan increases urine volume and decreases urinary supersaturation in calcium stone formers. Further study is needed to determine if long-term use of V2 receptor antagonists results in fewer stone events.

PD4-03 A COMPARISON OF CALCULATED ABSORBED RADIATION ORGAN DOSES AND IMAGE QUALITY FOR ITERATIVE VERSUS FILTERED BACK PROJECTION CT IN KIDNEY STONE PATIENTS

You have accessJournal of UrologyImaging/Radiology: Uroradiology I1 Apr 2015PD4-03 A COMPARISON OF CALCULATED ABSORBED RADIATION ORGAN DOSES AND IMAGE QUALITY FOR ITERATIVE VERSUS FILTERED BACK PROJECTION CT IN KIDNEY STONE PATIENTS Rishi Modh, Akira Yamamoto, James Mason, Elizabeth Vorhis, Lori Deitte, Cyrus Monroe, Anna Mench, Rebecca H. Lamoureux, Izabella Lipnharski, Jacob Batson, Derek Lee, Carl Henriksen, Manuel Arreola, and Benjamin Canales Rishi ModhRishi Modh More articles by this author , Akira YamamotoAkira Yamamoto More articles by this author , James MasonJames Mason More articles by this author , Elizabeth VorhisElizabeth Vorhis More articles by this author , Lori DeitteLori Deitte More articles by this author , Cyrus MonroeCyrus Monroe More articles by this author , Anna MenchAnna Mench More articles by this author , Rebecca H. LamoureuxRebecca H. Lamoureux More articles by this author , Izabella LipnharskiIzabella Lipnharski More articles by this author , Jacob BatsonJacob Batson More articles by this author , Derek LeeDerek Lee More articles by this author , Carl HenriksenCarl Henriksen More articles by this author , Manuel ArreolaManuel Arreola More articles by this author , and Benjamin CanalesBenjamin Canales More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.315AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Methods commonly used to reduce patient radiation exposure, such as standard Filtered Back Projection CT (FBP CT), may still result in significant image noise and decreased image quality. Adaptive Iterative Dose Reduction (AIDR), a CT image reconstruction algorithm, has been touted to lower patient radiation dose while maintaining adequate diagnostic quality. Our group recently developed a validated method to estimate CT patient absorbed dose based on statistical modeling and post-mortem dosimetry. The purpose of this study is to determine absorbed dose in urinary stone patients undergoing FBP CT compared to AIDR CT and compare the quality of the scans. METHODS After IRB approval, we reviewed records of all patients who underwent stone protocol CT scan from 11/1/12 – 7/1/13 at our single institution which houses 2 ADR-capable and 4 FBP CT scanners, a modified form of random assignment. Clinical and radiological data was then recorded from patients found to have urinary tract stones. Two blinded, board-certified radiologists independently reviewed data sets for image quality (1–5), noise (1–3), and calculi (number, size, location),and discrepancies were resolved by a blinded third board-certified radiologist. Absorbed skin and internal abdominal organ doses were calculated using equations that utilize the scanner-reported CT dose Index (CTDI) and the patient central effective diameter. Statistical analysis was performed using Fisher's Exact and paired t tests. RESULTS Of the 54 patients who met inclusion criteria, 28 patients underwent FBP CT while 26 underwent AIDR. Both groups were similar in regard to gender, race, BMI(31.7 +/- 9.9), stone burden detected, image quality, and image noise. Absorbed skin dose was 42.9 ± 19.9 mGy for FBP CT and 27.4 ± 35.0 mGy (p<0.001) for AIDR CT, while mean internal organ doses were 20.12 ± 9.7 mGy (FBP CT) and 6.9 ± 3.8 mGy (p<0.001, ADIR). Mean CTDI for all stone protocol FBP CT studies was 31.4 ± 11.8 mGy compared to 15.4 ± 13.9 mGy (p<0.05) for AIDR CT. CONCLUSIONS In our random cohort and using a validated absorbed dose formula, urinary stone patients who underwent AIDR CT had 36% and 65% reduction in skin and internal organ dose (respectively) compared to FBP CT, without compromising scan readability. Measured CT output using CTDI did not correlate to calculated patient absorbed dose and should not be used as a valid patient dose parameter. AIDR technology decreases radiation doses in urinary stone formers undergoing stone protocol CT and may replace FBP CT as the standard of care in CT imaging. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e87 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Rishi Modh More articles by this author Akira Yamamoto More articles by this author James Mason More articles by this author Elizabeth Vorhis More articles by this author Lori Deitte More articles by this author Cyrus Monroe More articles by this author Anna Mench More articles by this author Rebecca H. Lamoureux More articles by this author Izabella Lipnharski More articles by this author Jacob Batson More articles by this author Derek Lee More articles by this author Carl Henriksen More articles by this author Manuel Arreola More articles by this author Benjamin Canales More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Urolithiasis and Urinary Tract Infection Among Patients With Inflammatory Bowel Disease: A Review of US Emergency Department Visits between 2006 and 2009

To compare patients with inflammatory bowel disease (IBD) to a general population of urinary stone formers who present to US emergency departments with infected urolithiasis. Patients with IBD are at risk for both infection and stone formation, however studies investigating emergent urolithiasis presentations for this population are limited. Using the Nationwide Emergency Department Sample (2006-2009) we identified all patients presenting to the US emergency departments with a diagnosis of upper tract urolithiasis. We then described a subgroup with the concomitant diagnosis of IBD. We compared rates of urinary tract infection (UTI), sepsis, organ failure, admission, and mortality between the 2 groups. Using multivariate analysis, we determined whether or not IBD was a predictor of UTI, sepsis, and hospitalization. Overall, 14,352 patients had concomitant IBD and urolithiasis. IBD patients with urolithiasis presented with infections (10.4% vs 9.1%; P<.001), sepsis (0.6% vs 0.2%; P<.001), and end-organ failure (6.3% vs 1.6%; P<.001) more frequently than non-IBD patients. They were also more likely to have characteristics independently associated with infection and sepsis, such as older age and female gender. In adjusted analyses, IBD was an independent predictor of infection (odds ratio [OR]= 1.3 [1.14-1.46]; P<.0001), sepsis (OR= 1.8 [1.09-2.92]; P<.0001), and admission (OR= 3.3 [3.04-3.64]; P<.0001). IBD patients with urinary calculi have greater odds of UTI, renal failure, and sepsis compared to the general stone-forming population. The increased occurrence and severity of infected urolithiasis in this select group of patients warrants screening for stone disease, improved outpatient medical management, and early elective surgery for detected stones.

Does obesity or hyperuricemia influence lithogenic risk profile in children with urolithiasis?

BackgroundThere are indications that obesity and hyperuricemia may influence the formation and composition of urinary stones. The aim of our study was to determine the effect of obesity and hyperuricemia on the urinary lithogenic risk profile in a large cohort of pediatric patients.MethodsThe study population comprised 478 children with urolithiasis and 517 healthy children (reference group). We studied the effects of obesity on the lithogenic profile by dividing the patients with urolithiasis into two groups based on body mass index Z-score (patients who were overweight/obese vs. those with normal weight for age) and comparing the two groups. To study the effect of hyperuricemia on the lithogenic profile, we divided the patients with urolithiasis into two groups based on the presence or not of hyperuricemia (110 patients with urolithiasis accompanied by hyperuricemia vs. 368 patients with urolithiasis and normal serum uric acid levels) and compared the groups.ResultsAmong the children and adolescents with urolithiasis and hyperuricemia, there was a significantly lower excretion of crystallization inhibitors (citrates, magnesium). We also found significantly negative correlations between serum uric acid levels and the urine citrate/creatinine ratio (citrate/cr.; r = −0.30, p < 0.01), as well as the magnesium/cr. ratio (Mg/cr.; r = −0.33, p < 0.01). There was no statistically significant differences in the urinary excretion of oxalates, citrates, calcium, phosphorus, magnesium and uric acid between children with urolithiasis who were either overweight or obese and children with urolithiasis who had a normal body weight.ConclusionsIn our pediatric patient cohort, hyperuricemia was associated with a decrease in the excretion of crystallization inhibitors in the urine, but the clinical relevance of this observation needs to be confirmed in future studies. Obesity and overweight had no direct influence on the lithogenic risk profile in the urinary stone formers in our study, but there was an indication that higher serum uric acid may be associated with impairment in renal function, which in turn could influence the excretion of lithogenic parameters.

Early Prediction of Urolithiasis Occurrence - An Analyzer Based on Nanotechnology

In view of the status and shortages of clinical diagnosis of urinary stone disease, a kind of early diagnostic analyzer of urinary stones based on nanotechnology was put forward in this article. The relationship between the properties of urinary crystallites and formation of urinary stones was studied by detecting the urinary crystallites of less than 1000 nm in more than 300 cases of urinary stone formers and more than 300 cases of healthy controls. The average diameter, particle size distribution and the amount ratio of urine crystallites with different size in the two kinds of urines were significantly different. Base on these data we developed an intelligent diagnosis analyzer of urinary stones, which could help for early prediction of urolithiasis occurrence. The analyzer made no damage to human body for the reason of urine detection. The result analysis is simple, direct, fast and low-cost, and it overcomes some shortages of the existing detection technology on urolithiasis.

Role of 1,25-dihydroxy vitamin D3 and parathyroid hormone in urinary calcium excretion in calcium stone formers.

PurposeTo find out the possible role of 1,25(OH)2 vitamin D3 [1,25(OH)2D3] and parathyroid hormone (PTH) as intrinsic factors in urinary calcium stone formers (SFs), we investigated their relationship with serum and urinary biochemical parameters.Materials and MethodsA total of 326 calcium SFs (male: 204, female: 122) were enrolled and underwent outpatient metabolic evaluations including 1,25(OH)2D3 and PTH as well as serum and 24-hour urinary biochemical parameters. As control, 163 age- and sex-matched (2:1) individuals (non-SFs) who have never urinary stone episode were included.Results1,25(OH)2D3 level was positively correlated with urinary calcium excretion (r=0.347, p<0.001). The hypercalciuric group and recurrent SFs had higher serum 1,25(OH)2D3 levels than the normocalciuric group (p<0.001) and first SFs (p=0.050). In the adjusted multiple linear regression analysis, serum 1,25(OH)2D3 level (β=0.259, p<0.001) and serum PTH level (β=-0.160, p<0.001) were significantly correlated with urinary calcium excretion. The patients in highest tertile of 1,25(OH)2D3 had a more than 3.1 fold risk of hypercalciuria than those in the lowest tertile (odds ratio=3.14, 95% confidence interval: 1.431-6.888, p=0.004). No correlation was observed between PTH and 1,25(OH)2D3 (R=0.005, p=0.929) in calcium SFs, while a negative correlation was found in controls (R=-0.269, p=0.001).Conclusion1,25(OH)2D3 was closely correlated with urinary calcium excretion, and high 1,25(OH)2D3 levels were detected in the hypercalciuric group and in recurrent SFs. However, 1,25(OH)2D3 was not correlated with PTH in calcium SFs. These findings suggest that 1,25(OH)2D3 might be important intrinsic factor for altered calcium regulation in SFs.

Theoretical modeling of the urinary supersaturation of calcium salts in healthy individuals and kidney stone patients: Precursors, speciation and therapeutic protocols for decreasing its value

BackgroundSupersaturation (SS) of urinary salts has been extensively invoked for assessing the risk of renal stone formation, but precursors have often been ignored. Our objectives were to establish by computer modeling, which urinary components are essential for calculating reliable SS values, to investigate whether unique equilibrium processes occur in the urine of stone formers (SF) which might account for their higher SS levels relative to healthy controls (N), to determine the relative efficacies of three different, widely-used protocols for lowering urinary SS of calcium salts and to examine the influence of precursors. MethodsUrinary data from published studies were consolidated into three N–SF cohort pairs and were selected for modeling using the speciation program JESS. SS values of calcium oxalate monohydrate (COM) and its precursors calcium oxalate di- and tri-hydrate (COD, COT), as well as those of hydroxyapatite (HAP) and its precursors octacalcium phosphate (OCP) and brushite (Bru) were calculated. A pragmatic approach for the statistical analysis of the modeling outputs was developed and applied. ResultsThirteen urinary parameters were identified as being crucial for the accurate calculation of SS of calcium oxalate (CaOx) and calcium phosphate (CaP) salts. Chloride, sulfate and ammonium, or combinations thereof, have frequently been omitted from SS calculations, thereby giving erroneously high values for these parameters. Subtle differences occur in the urinary equilibrium processes of SF and N. SS (OCP) and SS (HAP) are more sensitive to dilution effects than the other urinary salts. Decreasing urinary Ca and decreasing Ox are equally efficacious in reducing SS of CaOx salts, and are marginally superior to increasing urinary volume. Decreasing urinary calcium and increasing urinary volume are equally efficacious in reducing SS of CaP salts. SS of precursors follow the Ostwald Lussac empirical rule and undergo the same changing trends in different urinary scenarios. ConclusionsResearchers are advised to include all of the 13 identified urinary parameters in their calculations of SS of Ca salts, in order to attain better accuracy. Differences in achieving speciation equilibria in N and SF contribute towards higher values of SS in SF, but in a minor way only. Increasing urinary volume is confirmed as the most realistically efficacious strategy for decreasing SS of urinary calcium salts. SS of HAP should be assigned equal importance to that of Bru in considering the stone-forming potential of urine. Precursors of CaOx and CaP salts should be taken into account when investigating stone forming mechanisms.

Using 24-Hour Urinalysis to Predict Stone Type

We determined the accuracy of 24-hour urinalysis in predicting stone type and identify the associations between 24-hour urine elements with stone type. We performed a retrospective review of 503 stone formers with stone composition analysis and 24-hour urinalysis available. Analysis of 24-hour urine elements across stone types was performed using Fisher's exact test and ANOVA. Multinomial logistic regression was used to predict stone type based on 24-hour urinalysis. A total of 280 (56%) patients had predominantly calcium oxalate, 103(20%) had uric acid, 93 (19%) had calcium phosphate, 16 (3%) had mixed and 11(2%) had other stone types. There were several significant patient characteristics and 24-hour urinalysis differences across stone type groups. The statistical model predicted 371 (74%) calcium oxalate, 78 (16%) uric acid, 52 (10%) calcium phosphate, zero mixed and 2 (less than 1%) other stone types. The model correctly predicted calcium oxalate stones in 85%, uric acid in 51%, calcium phosphate in 31%, mixed in 0% and other stone types in 18% of the cases. Of the predicted stone types, correct predictions were 61%, 69%, 56% and 71% for calcium oxalate, uric acid, calcium phosphate and other stones types, respectively. The overall accuracy was 64%. Plots were used to explore the associations between each 24-hour urine element with each predicted stone type adjusted for all the others urinary elements. A 24-hour urinalysis alone does not accurately predict stone type. However, it may be used in conjunction with other variables to predict stone composition.