Incidence Of Kidney Stone Disease Research Articles

Artificial Intelligence for Urology Research: The Holy Grail of Data Science or Pandora's Box of Misinformation?

Introduction Artificial intelligence tools such as the large language models (LLMs) Bard and ChatGPT have generated significant research interest. Utilization of these LLMs to study epidemiology of a target population could benefit urologists. We investigated whether Bard and ChatGPT can perform a large-scale calculation of the incidence and prevalence of kidney stone disease. Materials and Methods We obtained reference values from two published studies which used the National Health and Nutrition Examination Survey (NHANES) database to calculate the prevalence and incidence of kidney stone disease. We then tested the capability of Bard and ChatGPT to perform similar calculations using two different methods. First, we instructed the LLMs to access the datasets and independently perform the calculation. Second, we instructed the interfaces to generate customized computer code which could perform the calculation on downloaded datasets. Results While ChatGPT denied the ability to access and perform calculations on the NHANES database, Bard intermittently claimed the ability to do so. Bard provided either accurate results or inaccurate and inconsistent results. For example, Bard's "calculations" for the incidence of kidney stones from 2015-2018 were 2.1% (95% CI: 1.5-2.7), 1.75% (95% CI: 1.6-1.9), and 0.8% (95% CI 0.7-0.9), while the published number was 2.1% (95% CI 1.5-2.7). Bard provided discrete mathematical details of its calculations, however when prompted further, admitted to having obtained the numbers from online sources, including our chosen reference papers, rather than from a de novo calculation. Both LLMs were able to produce code (Python) to use on the downloaded NHANES datasets, however these would not readily execute. Conclusions ChatGPT and Bard are currently incapable of performing epidemiological calculations and lack transparency and accountability. Caution should be used, particularly with Bard, as claims of its capabilities were convincingly misleading, and results were inconsistent.

Association between the American Heart Association’s new “Life’s Essential 8” metrics and kidney stone

PurposeThe incidence of kidney stone disease has increased worldwide, resulting in high medical costs and social burden. Kidney stone disease shares some common features with the risk factors of cardiovascular diseases (CVDs). We investigated the association between cardiovascular health (CVH) based on the Life’s Essential 8 (LE8) score developed by the American Heart Association and the incidence of kidney stone disease.MethodsWe analyzed the data of 29,469 US adults aged 20 years or above from the National Health and Nutrition Examination Survey, 2007–2018. According to the LE8 score, CVH was divided into three categories: poor, intermediate, and ideal. Logistic regression was used to determine the association between CVH and the incidence of kidney stone disease by estimating odds ratios (ORs) and 95% confidence intervals (CIs).ResultsThe average age of the participants was 48.6 years, and 50% of the participants were women. The numbers of participants with poor, intermediate, and ideal CVH were 4149, 19,782, and 5538, respectively. After adjusting for related confounding factors, ideal CVH was associated with a reduction in the odds of kidney stone occurrence as compared to poor CVH (adjusted OR [aOR]: 0.45, 95% CI: 0.35–0.57, p < 0.001). Moreover, if the ideal CVH metrics was ≥ 6, the odds of kidney stone occurrence decreased by up to 61% (aOR: 0.39, 95% CI: 0.30–0.51).ConclusionsIn the present study, ideal CVH, a factor indicative of a healthy lifestyle, was associated with lower odds of kidney stone occurrence.

Caffeine intake and the risk of incident kidney stones: a systematic review and meta-analysis

Kidney stone disease is increasingly common in the general population, with a high recurrence rate after stone removal. It has been proven that caffeine consumption can reduce the risk of diseases, such as stroke and dementia. However, the effect of caffeine intake on the incidence of kidney stones has not been determined. This systematic review and meta-analysis were performed to evaluate the association of caffeine intake with the risk of incident kidney stones. PubMed, Web of Science, Scopus, Cochrane and Google Scholar were searched using terms related to coffee, caffeine and kidney stones to find eligible articles up to December 2021. Articles with clear diagnostic criteria for kidney stone disease and the exact intake dose of caffeine were included. The incidence of kidney stone disease was the main outcome. Summarized risk estimates and 95% CIs for the highest and lowest categories of caffeine intake were calculated using a random effects model. Seven studies were included in the final meta-analysis, with 9707 cases of kidney stones and a total of 772,290 cohort members. Compared with the lowest category of caffeine intake, the pooled relative risk (RR) was 0.68 ([95% CI 0.61-0.75], I2 = 57%) for the highest category of caffeine intake. Subgroup analyses showed that caffeine intake had an inverse relationship with the incidence of kidney stones in all subgroups. This study suggests that a higher caffeine intake may be associated with a lower risk of incident kidney stones.

Medical Management of Kidney Stones: a review

The incidence of kidney stone disease has been rising in past decades. The prevalence has doubled in both genders, andthe prevalence ratio is shrinking from 3.4 to 1.3 between males and females. This condition greatly impacts individuals, thehealth care system, and socioeconomic levels. Kidney stone diseases are related to various risk factors and medical conditions.A detailed diagnosis through history taking, urinalysis, metabolic evaluation, and stone analysis is important to direct thetherapy approach. The therapy in managing kidney stone diseases comprises dietary and pharmacological treatment. Inaddition to general advice on sufficient fluid intake, citrate intake, maintaining ideal body weight, and restricting sodium andanimal protein, the therapy should be adjusted based on the specific type of stones.

MP07-03 THE PROTECTIVE ROLE OF ESTROGEN RECEPTOR Β IN RENAL CALCIUM OXALATE FORMATION VIA REDUCING THE LIVER OXALATE BIOSYNTHESIS AND RENAL CELL INJURY

You have accessJournal of UrologyStone Disease: Basic Research & Pathophysiology (MP07)1 Sep 2021MP07-03 THE PROTECTIVE ROLE OF ESTROGEN RECEPTOR Β IN RENAL CALCIUM OXALATE FORMATION VIA REDUCING THE LIVER OXALATE BIOSYNTHESIS AND RENAL CELL INJURY Wei Zhu, Wenbiao Ren, Chawnshang Chang, Edward M. Messing, Jean V. Joseph, Rajat Jain, David Levy, David Bushinsky, Guohua Zeng, and Shuyuan Yeh Wei ZhuWei Zhu More articles by this author , Wenbiao RenWenbiao Ren More articles by this author , Chawnshang ChangChawnshang Chang More articles by this author , Edward M. MessingEdward M. Messing More articles by this author , Jean V. JosephJean V. Joseph More articles by this author , Rajat JainRajat Jain More articles by this author , David LevyDavid Levy More articles by this author , David BushinskyDavid Bushinsky More articles by this author , Guohua ZengGuohua Zeng More articles by this author , and Shuyuan YehShuyuan Yeh More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001980.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Kidney stone is a common disorder that poses a significant health care burden. The incidence of kidney stone disease is lower in premenopausal women than age-matched men, as well as in female animal models with renal calcium oxalate (CaOx) crystal deposition. However, it is unclear if this gender difference is related to altered estrogen/estrogen receptor (ER) signaling. METHODS: Kidney and liver cell lines, HK-2, HKC-8, HepG2, and HEK-293, were used. The shRNA and cDNA of NOX2 and ERβ were applied to study their functions. Hydrogen Peroxide Assay and DHE Staining were used to detect Oxalate treatment effects and ROS in renal cells. The q-PCR and western blot assays were applied to assess the RNA and protein expressions, respectively. ERβ knockout (ERβKO,) and WT female mice were used to compare CaOx formation. Effects of ERβ antagonist was tested in hydroxyl-L-proline (HLP) diet induced CaOx crystal deposition rat model. RESULTS: CaOx is one major composition accounts for majority of kidney stones. We found that ERβ signals could suppress hepatic oxalate biosynthesis via transcriptional up-regulation of the glyoxylate aminotransferase (AGT1) expression in liver cells. Results from renal cell lines also showed that ERβ could function via suppressing the oxalate-induced injury to reduce the reactive oxygen species (ROS) production and decrease the renal calcium oxalate (CaOx) deposition. Mechanism studies showed that ERβ could suppress the oxalate-induced oxidative stress via transcriptional suppression of the NADPH oxidase subunit 2 (NOX2) via binding to the NOX2 5′ promoter. We further applied two in vivo animal models rat fed with 5% HLP diet-induced renal CaOx deposition. Our data demonstrated that mice lacking ERβ (ERβKO) as well as mice or rats treated with ERβ antagonist PHTPP had increased urinary oxalate excretion, renal ROS production as well as renal CaOx crystal deposition. Importantly, targeting ERβ-regulated NOX2 with the NADPH oxidase inhibitor, apocynin, can reduce the renal CaOx crystal deposition in the in vivo animal model. CONCLUSIONS: Results from multiple in vitro cell lines and in vivo mouse/rat models all demonstrate that ERβ may protect against renal CaOx deposition via reducing the hepatic oxalate biosynthesis and oxidative stress-induced renal injury. Source of Funding: This work was partially supported by URMC Urology Research fund, National Natural Science Foundation of China, and George Whipple Professorship Endowment at U of Rochester © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e140-e140 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Wei Zhu More articles by this author Wenbiao Ren More articles by this author Chawnshang Chang More articles by this author Edward M. Messing More articles by this author Jean V. Joseph More articles by this author Rajat Jain More articles by this author David Levy More articles by this author David Bushinsky More articles by this author Guohua Zeng More articles by this author Shuyuan Yeh More articles by this author Expand All Advertisement Loading ...

"Long-Term Health Related Survey Outcome of Pediatric Idiopathic Kidney Stone Formers"

In adults, the overall kidney stone prevalence has increased from 2.6% in the late 1960s to 8.8% in 2012 [1]. This trend was similarly seen in pediatric patients, as the incidence of kidney stone disease (hereafter, KSD) doubled from 6.9% between 1984- 1990 to 14.9% between 2003-2008

Recurrence prevention of kidney stones - pharmacologic and dietary measures

Recurrence prevention of kidney stones - pharmacologic and dietary measures Abstract. Kidney stone episodes are traumatic events for affected patients and the risk of recurrence is high. Both prevalence and incidence of kidney stone disease are rising globally, and associated cost are gigantic. Hence, effective, well-tolerated and cheap measures for recurrence prevention are of utmost importance. In this article, we summarize the possibilities for the prevention of idiopathic calcium stones and uric acid stones, which together are responsible for the bulk of kidney stone episodes. Formally, preventive measures can be divided into dietary and pharmacologic interventions. In daily practice, frequently both approaches have to be combined to achieve a successful long-term recurrence prevention. The biggest challenge in the recurrence prevention of kidney stones is to achieve a sustained adherence to preventive measures in the affected patients.

Features of the clinical course of nephrolithiasis in patients with hyperparathyroidism

Aim. To assess the incidence of kidney stone disease and to identify its clinical course in patients with primary hyperparathyroidism.&#x0D; Methods. 48 medical records of patients hospitalized with primary hyperparathyroidism were retrospectively analyzed. The average age of the patients was 57 [53; 61] years. The medical history, complaints upon admission, the clinical presentation, the results of laboratory test and instrumental examination were studied in evaluating the medical records. The patients were divided into the group with nephrolithiasis (n=33) and the group without nephrolithiasis (n=15). The differences between the two groups were tested for statistical significance by the MannWhitney U test.&#x0D; Results. Among patients with primary hyperparathyroidism, nephrolithiasis was detected in 69% of patients, of which 90% were women in the postmenopausal period. The course of the kidney stone disease in these patients was characterized by frequent recurrence with a predominance of bilateral renal impairment (62%). The duration of nephrolithiasis before the diagnosis of primary hyperparathyroidism was 6 [1; 19] years, and this complication was often the first manifestation of the disease. According to the instrumental examination of kidney in patients with nephrolithiasis, small stones up to 5 mm in diameter were detected in 42% of cases, asymptomatic kidney stones in 15% of cases. A severe complication of primary hyperparathyroidism staghorn calculi were found in 2 (10%) patients. The patients in the group with nephrolithiasis showed higher serum calcium (p=0.022) and parathyroid hormone (p=0.007) levels compared with patients in the group without nephrolithiasis.&#x0D; Conclusion. Nephrolithiasis is a common complication of primary hyperparathyroidism; the presence of nephrolithiasis is associated with more significant changes in calcium and phosphate metabolism and is also characterized by a frequent asymptomatic course, thus requiring attention of specialists to this type of complications in primary hyperparathyroidism.

The role of fluid intake in the prevention of kidney stone disease: A systematic review over the last two decades.

The incidence of kidney stone disease (KSD) is rising worldwide; hence, more focus must be directed toward its etiology and risk factors. Increasing fluid intake is recommended as the most ideal prevention; yet, there is inconsistent evidence surrounding optimum volumes and types of fluid that affect stone formation. This review aimed to analyze the published literature on fluid intake and types of fluid consumed and their impact on KSD prevention. Papers were acquired from databases: MEDLINE, EMBASE, PubMed, CINAHL, and Cochrane Library. Included English language studies that involved adults consuming beverages along with a standardized diet in relation to KSD. Those failing to control dietary factors were excluded. After an initial search of 1099 papers, 9 (541 participants) were included in the final review. Six varieties of water and ten different types of juices were investigated. Higher fluid intake was associated with increased urine output and reduced stone formation. Water with high calcium content seemingly increased the rate of calcium oxalate (CaOx) stone formation. The relative supersaturation of CaOx in urine was decreased with grapefruit, apple, orange juices, and sodas, whereas cranberry juice increased it. Plum juice and the energy drink Gatorade had no effect on stone formation. Fluids low in calcium seem to reduce the risk of KSD. Certain varieties of fluid, such as grapefruit, apple, and orange juices reduce urine CaOx saturation, with a subsequent reduction in stone formation. Findings from this review could contribute to primary prevention for those at risk of KSD.

MP10-04 THE PROTECTIVE ROLES OF ESTROGEN RECEPTOR β IN RENAL CALCIUM OXALATE CRYSTAL FORMATION VIA REDUCING THE LIVER OXALATE BIOSYNTHESIS AND RENAL OXIDATIVE STRESS-MEDIATED CELL INJURY

INTRODUCTION AND OBJECTIVE:Kidney stone is a common disorder that poses a significant health care burden. The incidence of kidney stone disease is lower in premenopausal women than age-matched men,...

Kidney stone disease: an update on its management in primary care.

The incidence of kidney stone disease (urolithiasis) is rising, with a lifetime risk of 10–15%, and a recurrence rate of 50% within 10 years.1 Associated complications include significant pain secondary to renal colic, urinary tract infection (UTI) and urosepsis, and chronic kidney disease. The increasing burden of urolithiasis means that optimising its management in primary care is important. Patients with suspected renal colic (colicky intermittent abdominal and/or flank pain, and haematuria), with no known history of urinary stones, should be offered urgent imaging within 24 hours.2 If signs of a possible UTI are present, initial management should include empiric antibiotics, and urine should be sent for culture. Non-contrast computed tomography of the kidneys, ureters, and bladder (CT KUB) is the first-line investigation (sensitivity ∼95%, specificity ∼98%); however, ultrasound is indicated for children and pregnant women (sensitivity ∼84%, specificity ∼53%).3 Patients with known urinary stones also require urgent referral if their pain is uncontrolled with oral analgesia, or if they have signs of sepsis. For patients whose symptoms have settled, less urgent imaging can be requested, as long as there are no other clinical concerns. Renal function should also be checked. Stones <4 mm have a …

A content analysis of 'Water Apps' and prevention of urological diseases: Do apps really help?

IntroductionMaintaining hydration reduces incidence of kidney stone disease (KSD), chronic kidney disease (CKD) and urinary tract infections (UTIs). Mobile applications (apps) measuring hydration are gaining in usage, allowing users to monitor intake whilst also taking into account the signs and symptoms of dehydration. Our study looked at the water apps in the management and/or prevention of urological disease.Material and methodsThe original android app store (Google Play Store), and the Apple App Store (iOS App Store) were searched using the term ‘hydration’, ‘fluid’ and ‘water’. All apps from each distribution platform, with a minimum of 100 reviews, were then selected and analysed.ResultsAfter identification of 51 applications (13 from Apple App Store, and 38 from Google Play Store), 45 were free to download and 6 were paid (cost range: $2.19–$7.97). While none of the apps facilitated measurement of urine output and colour, 12 mentioned signs and symptoms of dehydration. Furthermore, when calculating required fluid intake, the level of activity was considered by 31 apps. With regards to information provision, only one of the apps included advice or education about urological conditions associated with poor hydration. None of the apps gave advice on hydration related to CKD and UTI.ConclusionsMobile phone apps are a well-established tool for measuring fluid intake. However, they provide little information regarding the importance of hydration, and don’t utilise other measures such as level of activity, urine output or colour. Considering the increasing popularity of fitness and hydration apps in our daily lives, the developers need to make them more comprehensive and informative.

Extracorporeal shockwave lithotripsy in children: results of treatment in cases of large renal stones

Background. The incidence of kidney stone disease (KSD) in children varies from 1% to 5%. Pediatric surgery of KSD employs methods similar to surgical technologies used for adults: extracorporeal shockwave lithotripsy (ESWL), ureterolithotripsy (ULT), retrograde intrarenal surgery (RIRS), percutaneous nephrolithotomy (PCNL), open and laparoscopic lithotomy. ESWL remains the method of choice for urolithiasis management in children; however, the number of publications describing application of minimally invasive procedures (PCNL, RIRS) for large stones in children is increasing. The said existing tendency determines the need for a comparative study in order to reveal the efficiency and safety of ESWL and PCNL/RIRS as treatment methods for large stones in children. Objectives. The study results of the ESWL use in the treatment of children with stones greater than 2 cm. Materials and methods. During the period from 2013 through 2018, ESWL was performed for 146 patients (70 (47.9%) boys and 76 (52.5%) girls) to treat 170 stones. Age of the patients: 6 months to 17 years (mean age: 73 months). Stones were found on the left side in 96 (61.1%) patients, on the right side — in 58 (38.8%) cases, bilaterally — in 16 (9.41%) children. Large stones exceeding 2 cm were diagnosed in 16 patients (8 (50%) boys and 8 (50%) girls). Urolithiasis was revealed on the right side in 3 (18.7%) patients, on the left side — in 11 (68.7%) cases, bilaterally — in 2 (12.5%) children. All patients were subdivided into 2 subgroups: Subgroup I — 6 (37.5%, 7 kidneys) patients with staghorn urolithiasis, Subgroup II — 10 (62.5%, 11 kidneys) patients with non-staghorn stones. Postoperative complications were evaluated in accordance with the Clavien-Dindo classification. Results. In Subgroup I, complete elimination of C-1 stones in one patient took two ESWL sessions (16.67%). Three (50%) children needed 3 ESWL sessions. One (16.67%) child underwent 4 fragmentations. One (16.67%) patient with bilateral C-2 stones had 2 ESWL on the right side, 2 ESWL of the left-side calculus, and 1 ESWL session of stone fragments in distal ureter with prior insertion of ureteral catheter. In Subgroup II, a single ESWL session was sufficient to eliminate a calculus completely in 3 cases (30%). 2 patients (20%) had to undergo two ESWL sessions. 3 patients (30%) needed three ESWL sessions. Four ESWL sessions were carried out for one child (10%). One patient with bilateral stones underwent 2 sessions on the left side, 3 sessions on the right side, the child also had an ESWL to correct the steinstrasse condition in the lower third segment of the left ureter. Grade IIIb postoperative complications according to the Clavien-Dindo classification were observed in 1 (14.9%) patient of Subgroup I and in one (9.09%) patient of Subgroup II. No lithogenesis recurrences were registered. Conclusions. In cases of children suffering from concrements larger than 2 centimetres, ESWL is a safe and efficient procedure even without prior urine derivation resulting in lower incidence of complications compared with other minimally invasive KSD treatment technologies.

Mortality from kidney stone disease (KSD) as reported in the literature over the last two decades: a systematic review.

Current trends show a rising incidence of kidney stone disease (KSD) globally, with a lifetime risk of 10% and increasing hospital admissions. However, it is not perceived as a life-threatening condition and there are no publications examining its mortality rate. The aim of this review was to report on the number of KSD mortalities in the literature from the past two decades, identify risk factors, and to summarize their key learning points. A search was conducted for full-text English language articles that reported on KSD associated mortality, following intervention or conservative treatment, published between 1999 and 2017, using PubMed, MEDLINE, EMBASE, Scopus, CINAHL, Clinicaltrials.gov, Google Scholar and The Cochrane Library. Study quality and risk of bias assessment was undertaken using a validated critical appraisal tool from the Joanna Briggs Institute. Of the 2786 articles identified, 34 were included. Of the total number of reported mortalities (2550), 21% were related to intervention. Sepsis was the leading cause of mortality. Risk factors identified were patients with multiple co-morbidities, spinal cord injury or neurogenic bladder and high stone burden. The main recommendations suggested were to treat pre-operative UTI or use prophylactic antibiotics and to reduce operative duration. The included studies were of moderate to good quality. Pre-procedural optimization of the patients is the key to avoiding KSD mortality, and care should be taken in patients with multiple co-morbidities. Surgeons should meticulously plan for patients with high stone burden to reduce their operative time, as mortality can be procedural related.

Incidence of kidney stone disease in Icelandic children and adolescents from 1985 to 2013: results of a nationwide study.

An increase in the incidence of kidney stone disease has been reported for all age groups worldwide. To examine this trend, we conducted a nationwide study of the epidemiology of kidney stones in Icelandic children and adolescents over a 30-year period. Computerized databases of all major hospitals and medical imaging centers in Iceland were searched for International Classification of Diseases and radiologic and surgical procedure codes indicative of kidney stones in patients aged < 18years, followed by a thorough medical record review. Age-adjusted incidence was calculated for the time intervals 1985-1989, 1990-1994, 1995-1999, 2000-2004, 2005-2009, and 2010-2013. Time trends in stone incidence were assessed by Poisson regression. The prevalence of stone disease for the years 1999-2013 was alsodetermined. Almost all the 190 patients (97%) that we identifiedhad symptomatic stones, and acute flank or abdominal pain and hematuria were the most common presenting features. The total annual incidence of kidney stones increased from 3.7/100,000 in the first 5-year interval to 11.0/100,000 during the years 1995-2004 (p < 0.001) and decreased thereafter to 8.7/100,000 in 2010-2013 (p = 0.63). The incidence rise was highest in girls aged 13-17years, in whom it rose from 9.8/100,000 in 1985-1989 to 39.2/100,000 in 2010-2013 (p < 0.001), resulting in an overall female predominance in this age group. The mean annual prevalence of stone diseasein 1999-2013 was 48/100,000 for boys and 52/100,000 for girls. We found a significant increase in the incidence of childhood kidney stone disease, driven by a dramatic increase of stone frequency in teenage females which is poorly understood and warrants further study.

In vitro evidence of the promoting effect of testosterone in kidney stone disease: A proteomics approach and functional validation

Incidence of kidney stone disease in males is 2- to 4-fold greater than in females. This study aimed to determine effects of testosterone on kidney stone disease using a proteomics approach. MDCK renal tubular cells were treated with or without 20nM testosterone for 7days. Cellular proteins were extracted, resolved by 2-DE, and stained with Deep Purple fluorescence dye (n=5 gels derived from 5 independent samples/group). Spot matching, quantitative intensity analysis, and statistics revealed significant changes in levels of nine protein spots after testosterone treatment. These proteins were then identified by nanoLC-ESI-Qq-TOF MS/MS. Global protein network analysis using STRING software revealed α-enolase as the central node of protein–protein interactions. The increased level of α-enolase was then confirmed by Western blotting analysis, whereas immunofluorescence study revealed the increased α-enolase on cell surface and intracellularly. Functional analysis confirmed the potential role of the increased α-enolase in enhanced calcium oxalate monohydrate (COM) crystal-cell adhesion induced by testosterone. Finally, neutralization of surface α-enolase using anti-α-enolase antibody successfully reduced the enhanced COM crystal–cell adhesion to the basal level. Our data provided in vitro evidence of promoting effect of testosterone on kidney stone disease via enhanced COM crystal–cell adhesion by the increased surface α-enolase. Biological significanceThe incidence of kidney stone disease in male is 2- to 4-fold greater than in female. One of the possible factors of the male preference is the higher testosterone hormone level. However, precise molecular mechanisms that testosterone plays in kidney stone disease remained unclear. Our present study is the first exploratory investigation on such aspect using a proteomics approach. Our data also provide a novel mechanistic aspect of how testosterone can impact the risk of kidney stone formation (i.e. the discovery that testosterone increases alpha-enolase expression on the surface of renal tubular cells that is responsible, at least in part, for crystal–cell adhesion).

Metabolic Syndrome and Kidney Stone Disease: A Systematic Review of Literature.

Worldwide obesity has more than doubled since 1980 with more than 600 million obese patients in 2014. Metabolic syndrome (MetS) is the co-occurrence of metabolic abnormalities, including centrally distributed obesity, hypertension, dyslipidemia, and hyperglycemia. With a concurrent rise in the incidence of kidney stone disease, we wanted to conduct a systematic review focused on the association of MetS to nephrolithiasis. A systematic review was performed according to the Cochrane and preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines on all English language articles for the following relevant keywords: association, metabolic syndrome, metabolic syndrome traits, syndrome X, nephrolithiasis, kidney stones, and renal calculi. Our inclusion criteria were studies comparing the prevalence of kidney stone disease in patients with and without MetS. The initial literature search identified 355 potentially relevant studies. After screening, 22 full text articles were reviewed and 6 (219,255 patients) were included in the final review. All studies displayed increasing odds of nephrolithiasis with increasing number of MetS traits, where patients with three or more MetS traits tended to have a higher prevalence of nephrolithiasis. Studies also showed different significant components of MetS contributing to nephrolithiasis. Our review shows a definite association of MetS with kidney stone disease. Although multifactorial in etiology, lifestyle and dietary factors seem to be increasingly important in prevention of stone disease.

LithoVue™: A new single-use digital flexible ureteroscope.

LithoVue™: A new single-use digital flexible ureteroscope.

Comprehensive flexible ureteroscopy (FURS) simulator for training in endourology: The K-box model

Over the last two decades there has been an increase in the incidence of kidney stone disease with a simultaneous rise in the use of ureteroscopy for its management [1]. Flexible ureteroscopy training is variable and still largely dependent on high fidelity models and virtual reality (VR) simulation, both of which are expensive and not readily available in many parts of the world. There is also a lack of good quality bench trainers. In a recent survey of endourologists worldwide, flexible ureteroscopy was considered as a first line treatment for stones <2 cm [2]. With this in mind, we have developed a new portable bench-training box model for training in flexible ureteroscopy and endourology. This is a low-cost reusable model for flexible ureteroscopy training allowing the user to manipulate the scope, place a guidewire and access sheath, use a basket to catch/relocate the stone and finally to use a Holmium YAG laser to fragment the stone. K-box The K-box (K – Box®, Porges-Coloplast, France) is a new generation portable bench-training model for flexible ureteroscopy. It is made of polyurethane and consists of 4 independent boxes with each of these boxes representing a different training model with three separate entry and exit points (Figures 1, ​,2).2). It also comes with a ‘tool tray’, which can be used within the boxes for various training exercises. To use the K-box and perform the exercises, the trainees need to have an endoscope, camera system and screen, light source and disposables such as guidewires, access sheaths, baskets and stents. Trainees can familiarize themselves with different flexible ureterscope movements such as pronation/supination, forward/backward movement, scope deflection and grasping/releasing of objects/stones mimicking the movements in the renal pelvicalyceal system. In addition to this, it allows step-by-step guidewire and access sheath placement along with stone fragmentation (Figures 3, ​,4).4). Although the exercises are done with the box closed while the trainee is watching the screen, when a trainee is unsure or lost in the training model they have the option of opening the flap which enables them to see their position (almost being a surrogate for a radiological image/fluoroscopy). The newly designed flexible ureteroscopy training model allows the surgeon to make the specific movements required when performing flexible ureteroscopy in humans. Figure 1 K-box and its components (1.1 – portable K-box, 1.2 – box open (left) and closed (right), 1.3 – tool tray, 1.4 – K-box with water to use with laser for stone fragmentation). Figure 2 K-box with all four boxes with embossed markings (opened view) showing various configurations for manipulation of the objects within it. Figure 3 Step by step technique (3.1 – placement of guidewire, 3.2 – placement of access sheath, 3.3 – placement and manipulation of flexible ureteroscope). Figure 4 Manipulation in the pelvicalyceal system (4.1 – stone basketing with a flexible ureteroscope via the access sheath, 4.2 – movement of object from A to B). These boxes can either be used separately or in combination in any random order. A silicone aerosol spray can be used to make the inside surfaces of K-box smoother to minimize friction. To enable laser use, the K-box can be used with water allowing fragmentation of stones.

Effect of being overweight on urinary metabolic risk factors for kidney stone formation.

The prevalence and incidence of kidney stone disease have increased markedly during the past several decades, and studies have demonstrated that inappropriate dietary habits are leading to more obesity and overweight (OW) in children and adults, which may be important in stone formation. Obese and OW patients share most of the same risk factors for cardiovascular morbidity, while the impact of being OW, rather than obese, on urinary metabolic parameters of kidney stone formers (KSF) is less well known. The aims of this study were to investigate urinary metabolic parameters, stone composition and probability of stone formation (Psf) in OW KSF when compared with normal weight (NW) and obese KSF. The kidney stone database for KSF attending a large metabolic stone clinic was investigated. Patients with a recorded BMI, confirmed diagnosis of kidney stone disease and full metabolic evaluation were divided into three categories: BMI ≤25.0 kg/m(2) (NW group), BMI 25-30 kg/m(2) (OW group) and BMI >30.0 kg/m(2) (obese group). Twenty-four hour urinary volume (U.Vol), pH (U.pH), calcium (U.Ca), oxalate (U.Ox), citrate (U.Cit), uric acid (U.UA), magnesium (U.Mg), sodium (U.Na) and potassium (U.K) excretions, along with stone composition and Psf, were then compared among the groups. A total of 2132 patients were studied, of whom 833 (39%) were NW, 863 (40.5%) were OW and 436 (20.5%) were obese. OW and obese KSF were older (mean age 43 ± 15 in NW, 48 ± 13 in OW and 50 ± 12 years in obese; P for trend <0.001), demonstrated increased female predominance and higher prevalence of diabetes, hypertension and gout. There were no statistically significant differences in U.Vol and U.Mg among the groups. However, significantly higher levels of U.Ca, U.Ox, U.Cit, by crude analysis, and U.UA (3.3 ± 1.1 versus 3.8 ± 1.2 versus 4.0 ± 1.2 mmol/L; P < 0.001 for trend), U.Na (151 ± 57 versus 165 ± 60 versus 184 ± 63 mmol/L; P < 0.001 for trend), and lower U.pH (6.3 ± 0.5 versus 6.1 ± 0.5 versus 6.0 ± 0.6; P < 0.001 for trend) by both crude and multivariate adjusted analysis models were demonstrated in OW and obese KSF. Stone composition data (N = 640) showed a significantly higher incidence of uric acid stones in OW and obese groups (P for trend < 0.001). In addition, higher Psf for CaOx, UA and CaOx/UA stone types were detected in OW and obese compared with NW KSF. Similar to obese KSF, OW KSF show clear alterations in metabolic urinary profiles that are associated with increased overall risk of stone formation. This greater risk is primarily due to raised U.UA and U.Na, lower U.pH and higher prevalence of hypercalciuria, along with unchanged levels of the commonly measured urinary lithogenesis inhibitors. Moreover, our study established a higher incidence of uric acid, but not calcium, stones in OW KSF. Thus, appropriate evaluation and follow-up may be warranted even in OW patients who are at risk of increased stone formation. Whether modest weight loss in OW KSF will have a favourable impact on their metabolic urinary profiles and thereby diminish the risk of further stone formation needs exploring.