Urine Chemistry Research Articles

Numerical characterization of astronaut CaOx renal stone incidence rates to quantify in-flight and post-flight relative risk

Changes in urine chemistry potentially alter the risk of renal stone formation in astronauts. Quantifying spaceflight renal stone incidence risk compared to pre-flight levels remains a significant challenge for assessing the appropriate vehicle, mission, and countermeasure design. A computational biochemistry model representing CaOx crystal precipitation, growth, and agglomeration is combined with a probabilistic analysis to predict the in- and post-flight CaOx renal stone incidence risk ratio (IRR) relative to pre-flight values using 1517 astronaut 24-h urine chemistries. Our simulations predict that in-flight fluid intake alone would need to increase from current prescriptions of 2.0–2.5 L/day to ~3.2 L/day to approach the CaOx IRR of the pre-flight population. Bone protective interventions would reduce CaOx risk to pre-flight levels if Ca excretion alone is reduced to <150 mg/day or if current levels are diminished to 190 mg/day in combination with increasing fluid intake to 2.5–2.7 L/day. This analysis provides a quantitative risk assessment that can influence the critical balance between engineering and astronaut health requirements.

Nephrotic Syndrome.

Nephrotic syndrome (NS) encompasses a variety of disease processes leading to heavy proteinuria and edema. Minimal change disease (MCD) remains the most common primary cause of NS, as well as the most responsive to pharmacologic treatment with often minimal to no chronic kidney disease. Other causes of NS include focal segmental glomerulosclerosis, which follows MCD, and secondary causes, including extrarenal or systemic diseases, infections, and drugs. Although initial diagnosis relies on clinical findings as well as urine and blood chemistries, renal biopsy and genetic testing are important diagnostic tools, especially when considering non-MCD NS. Moreover, biomarkers in urine and serum have become important areas for research in this disease. NS progression and prognosis are variable and depend on etiology, with corticosteroids being the mainstay of treatment. Other alternative therapies found to be successful in inducing and maintaining remission include calcineurin inhibitors and rituximab. Disease course can range from recurrent disease relapse with or without acute kidney injury to end-stage renal disease in some cases. Given the complex pathogenesis of NS, which remains incompletely understood, complications are numerous and diverse and include infections, electrolyte abnormalities, acute kidney injury, and thrombosis. Pediatricians must be aware of the presentation, complications, and overall long-term implications of NS and its treatment.

Clinical Implementation of NGAL Testing to Improve Diagnostic Assessment of AKI Episodes in a Canadian Center.

Background:The differential diagnosis of acute kidney injury (AKI) episodes is often challenging. Novel AKI biomarkers have shown their utility to improve prognostic prediction and diagnostic assessment in various research populations but their implementation in standard clinical practice is still rarely reported.Objective:To report the differential diagnostic ability and associated clinical utility of the neutrophil gelatinase-associated lipocalin (NGAL) testing in a real-life setting of a heterogeneous AKI population.Design:This is a retrospective cohort study combined with a clinical audit using questionnaires distributed to consultant nephrologists following NGAL results.Setting:The first 250 consecutive patients with a confirmed AKI where an NGAL test (plasma NGAL [pNGAL] or urine NGAL [uNGAL]) was ordered from a large academic center in Montreal, Canada from January 2021 to August 2021.Patients:Patients were classified into 3 groups based on the final AKI etiology category (functional, intrarenal, and postrenal) following definitive adjudication by 2 independent nephrologists.Methods:The ability of plasma NGAL (pNGAL), urine NGAL (uNGAL), and uNGAL-to-creatinine ratio (uNGAL/Cr) to discriminate intrarenal from functional AKI etiologies was compared to standard urine chemistry (FENa) and proteinuria. A logistic regression was used to evaluate the association between intrarenal AKI and increased biomarker levels. The overall clinical utility and appreciation of the NGAL test was evaluated using a questionnaire completed prospectively by the consultant nephrologist at the time of receiving the NGAL result. The NGAL results were prospectively available to clinicians with a median time of 2.9 (1.3-7.4) hours from the initial order.Results:A total of 214 uNGAL and 44 pNGAL were ordered from 100 functional, 139 intrarenal and 11 postrenal AKI episodes after final adjudication. The discriminative ability of FENa (AUC 0.68 [95% CI: 0.61-0.75]) was lower than uNGAL (AUC 0.80 [95% CI: 0.73-0.86]) and uNGAL/Cr (AUC 0.83 [95% CI: 0.77-0.88]) but better than pNGAL (AUC 0.66 [95% CI: 0.48-0.85]). According to consultant nephrologists, the NGAL testing has led to a change in clinical management in 42% of cases.Limitations:Data reported came from a single center and NGAL was reserved for more complex cases, which limits generalizability. No biopsy has been performed for most AKI cases as the final adjudication was based on a retrospective review of the hospitalization episode.Conclusions:Neutrophil gelatinase-associated lipocalin testing can be successfully integrated as part of the diagnostic workup for AKI in clinical practice. The integration of tubular damage biomarkers to functional biomarkers can further improve the differential diagnostic assessment. However, the impact of such biomarkers on AKI management and associated outcomes still needs further validation.

Effect of diuretics on kidney stone-forming risk – an investigation using multiple timed urine collections

Introduction: Thiazide diuretics can lower urinary calcium excretion, helping to prevent recurrent calcium kidney stones. As dietary intake and urine chemistry varies throughout the day, a 24-h urine collection may not provide sufficient information to guide the optimal management in individual patients. Using multiple timed urine collections, we sought to identify times during the day when stone-forming risk is higher, allowing for therapy to be more accurately targeted. Methods: In a prospective study, healthy adult volunteers took a 4-week course of either hydrochlorothiazide (HCTZ) 25 mg/d or indapamide 2.5 mg/d. They were assessed at baseline, and at days 7, 14 and 28. At each time point, blood samples were taken for analysis and multiple timed urine samples were collected throughout the day, together with one overnight sample. Results: Diuretic treatment was well tolerated. Daily calcium and citrate excretion decreased, while ionized calcium and phosphate excretion were unchanged. Ionized calcium-divalent phosphate and ionized calcium-oxalate products were unchanged. In the timed urine samples, calcium excretion was decreased, particularly by indapamide, in the morning. Indapamide, but not HCTZ, decreased urinary citrate excretion, most obviously in overnight and early morning urines. No changes in ionized calcium were observed. Decreased divalent phosphate excretion was observed at several time points in the indapamide group. The ionized calcium-divalent phosphate product tended to decrease at most time points in both groups but no significant changes were observed in the ionized calcium-oxalate product. Conclusions: Indapamide 2.5 mg/d has a stronger protective effect against forming calcium kidney stones than HCTZ 25 mg/d. Most of the benefits appear to be achieved during the daytime and it may therefore be beneficial to prescribe medication twice daily or in the evening to maximize the protective effects of these agents. The benefits of indapamide treatment were attenuated by a reduction in urinary citrate excretion, an effect which has not been previously described. Keywords: hydrochlorothiazide, indapamide, kidney stones, urine collection

Neglected analytes in the 24-h urine: ammonium and sulfate.

Evaluation of the kidney stone patient includes measurement of 24 h urine chemistries. This review summarizes the application of physiologic principles to the interpretation of urine chemistries, using sulfate and ammonium to estimate diet acid load, and the renal response. There has been increased recognition of the need to measure urine ammonium excretion in the clinical setting in order to understand renal acid excretion. Some 24 h urine kidney stone panels include ammonium measurements, providing an opportunity to apply this measurement to clinical practice. In order to better interpret ammonium excretion, one needs an estimate of dietary acid load to understand the driving forces for ammonium excretion. Sulfate is also included in some kidney stone panels and functions as an estimate of diet acid load. Combining these analytes with urine pH, the clinician can quickly estimate dietary stone risk as well as potential bowel disease, acidification disorders, and the presence of urease producing bacteria; all of which can affect stone risk. Measurement of ammonium and sulfate excretion along with urine pH provide important insights into the acid/alkali content of diet, presence and severity of bowel disease, presence of renal acidification disorders, and urinary infection.

C1q Nephropathy in Children with Nephrotic Syndrome: Treatment Strategies and Outcomes.

Introduction:There is a paucity of clinical data on C1q nephropathy (C1qN) in children in India and Southeast Asia. This is the first detailed analysis conducted to elucidate the prevalence, clinicopathological profile, and response to different immunosuppressives in children with C1qN in India.Materials and Methods:Detailed demographic profile, clinical features, urine and blood chemistries, kidney biopsy, and response to different immunosuppressives of the study participants were analyzed between August 2015 and October 2020 for steroid-dependent/-resistant nephrotic syndrome (NS).Results:C1qN was diagnosed in 16 (14.13%) of 113 children who underwent biopsy for steroid-dependent/-resistant NS. The mean age was 44 months (range 18–99 months) and male and female number was 12 (75%) and four (25%), respectively, and mean follow-up was 3.5 years. Eight (50%) had coexistent minimal-change nephrotic syndrome (MCNS) pattern, seven (43.7%) had focal segmental glomerulosclerosis (FSGS), and one (6.2%) had diffuse mesangial hypercellularity. Thirteen children had complete follow-up, of which eight (61.5%) and four (30.7%) cases presented as steroid-dependent and primary steroid-resistant NS, respectively, whereas one (7.6%) had joint pain with rashes. At presentation, seven (53.8%) had hypertension, 12 (92.3%) had nephrotic range proteinuria, and six cases (46.1%) had hematuria. Nine (75%) of 12 cases achieved complete remission with calcineurin inhibitor (CNI) therapy, and two were non responders, one was a partial responder, and one responded to mycophenolate. Of six FSGS cases, four had complete remission, one had partial remission, and one was in non-remission. Of six cases with MCNS, five had complete remission and one was in non-remission. Renal functions remained normal in all except one case who had progression to chronic kidney disease Stage 3.Conclusion:One out of seven children with difficult NS can have underlying C1qN. CNIs are most beneficial to attain and maintain remission. Renal functions remain normal in the majority. Along with C1q deposits, MCNS and FSGS patterns are seen equally and respond almost similarly to CNIs.

Collecting Duct-Specific CR6-Interacting Factor-1-Deletion Aggravates Renal Inflammation and Fibrosis Induced by Unilateral Ureteral Obstruction.

Although inflammation and fibrosis, which are key mechanisms of chronic kidney disease, are associated with mitochondrial damage, little is known about the effects of mitochondrial damage on the collecting duct in renal inflammation and fibrosis. To generate collecting duct-specific mitochondrial injury mouse models, CR6-interacting factor-1 (CRIF1) flox/flox mice were bred with Hoxb7-Cre mice. We evaluated the phenotype of these mice. To evaluate the effects on unilateral ureteral obstruction (UUO)-induced renal injury, we divided the mice into the following four groups: a CRIF1flox/flox (wild-type (WT)) group, a CRIF1flox/flox-Hob7 Cre (CRIF1-KO) group, a WT-UUO group, and a CRIF1-KO UUO group. We evaluated the blood and urine chemistries, inflammatory and fibrosis markers, light microscopy, and electron microscopy of the kidneys. The inhibition of Crif1 mRNA in mIMCD cells reduced oxygen consumption and membrane potential. No significant differences in blood and urine chemistries were observed between WT and CRIF1-KO mice. In UUO mice, monocyte chemoattractant protein-1 and osteopontin expression, number of F4/80 positive cells, transforming growth factor-β and α-smooth muscle actin staining, and Masson’s trichrome staining were significantly higher in the kidneys of CRIF1-KO mice compared with the kidneys of WT mice. In sham mice, urinary 8-hydroxydeoxyguanosine (8-OHDG) was higher in CRIF1-KO mice than in WT mice. Moreover, CRIF1-KO sham mice had increased 8-OHDG-positive cell recruitment compared with WT-sham mice. CRIF1-KO-UUO kidneys had increased recruitment of 8-OHDG-positive cells compared with WT-UUO kidneys. In conclusion, collecting duct-specific mitochondrial injury increased oxidative stress. Oxidative stress associated with mitochondrial damage may aggravate UUO-induced renal injury.

Effect of Hydroxycitrate (HCA) on Urine Chemistry in Calcium Kidney Stone Formers

Effect of Hydroxycitrate (HCA) on Urine Chemistry in Calcium Kidney Stone Formers

The syndrome of inappropriate antidiuresis after vaccination against COVID-19: case report

BackgroundThe Syndrome of Inappropriate Antidiuresis (SIADH) has been described to be associated with a multitude of conditions and medications, including the severe acute respiratory syndrome coronavirus 2. We describe the case of a patient with newly diagnosed and symptomatic SIADH after receiving the second COVID-19 vaccination not explained otherwise.Case presentationA 79-year-old male person was admitted to the emergency department due to a worsening of his general health state expressed by weakness, fatigue and anorexia. Vital signs and clinical findings were normal, in particular the patient was considered to be euvolemic. Laboratory investigations revealed a serum sodium of 117 mmol/L, a serum osmolality of 241 mosm/kg and a urea of 1.2 mmol/L with creatinine within normal range. Urine chemistry showed a urine osmolality of 412 mosm/kg and urine sodium of 110 mmol/L. TSH, C-reactive protein, and basal cortisol levels were normal. Under therapy with balanced crystalloid fluids, hyponatremia worsened and in absence of diuretic medications, diagnosis of SIADH was made. Since fluid restriction was not sufficiently effective, oral urea was administered. Under this therapy regimen hyponatremia resolved.ConclusionsLocal as well as systemic reactions have been described for the new mRNA-based vaccines including pain and fever. Therefore, it is imaginable that the vaccine might trigger SIADH in some patients.

PD21-07 EFFECT OF A HIGH CITRATE BEVERAGE ON URINE CHEMISTRY IN KIDNEY STONE FORMERS

You have accessJournal of UrologyStone Disease: Medical & Dietary Therapy (PD21)1 Sep 2021PD21-07 EFFECT OF A HIGH CITRATE BEVERAGE ON URINE CHEMISTRY IN KIDNEY STONE FORMERS Lama Nazzal, Frank Modersitzki, John Asplin, and David Goldfarb Lama NazzalLama Nazzal More articles by this author , Frank ModersitzkiFrank Modersitzki More articles by this author , John AsplinJohn Asplin More articles by this author , and David GoldfarbDavid Goldfarb More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002010.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Moonstone is a high citrate, over-the-counter beverage designed to prevent recurrent kidney stones. Popular lore has promoted citrus juice for stone prevention, but the amount required to have meaningful benefits (increased urine citrate and pH) is not well-established. Thus, there are no evidence-based beverages that serve as an alternative to water, designed to increase urine volume and alter urine chemistry, in order to achieve stone prevention. We sought to demonstrate the effects of Moonstone on urine chemistry in a group of stone formers of various compositions. METHODS: Participants mixed 1 packet of powder in water and drank it twice a day for one week. Patients temporarily discontinued alkali supplements but continued other meds. Total Moonstone dose comprised 9.2 meq Na, 11.3 meq K, 32 meq Mg, 30 calories, and 66 meq net alkali. We compared 24h urine chemistry to the result of a similar amount of water only. 16 patients participated: 11 with calcium, 2 with uric acid, 3 with cystine stones. Participants replicated self-selected diets on days 6 and 7 of the week, and performed 24h urine collection on day 7. Urine was sent to and analyzed by Litholink. We surveyed participants about preferences for a stone prevention regimen, comparing Moonstone to water alone or K-citrate if patients had previously taken that (12/16). RESULTS: Compared to water (table; *=p<0.05) Moonstone caused an increase in 24h urine citrate from 469.1 +231.9 mg/d to 635.4 +349.1 mg/day (delta 166.3 mg/day; P<0.05 by paired t test). 24h urine pH went up from 6.21 +0.78 to 6.61 +0.69 (delta 0.40, P<0.05). Patients expressed a preference for Moonstone compared to water alone or Urocit-K (Figure). CONCLUSIONS: 2 packets of Moonstone caused increases in 24h urine citrate and urine pH. In table, we compare the result to that of 60 meq of K-Mg-citrate which was associated with an 85% reduction in kidney stone recurrence in 3 years in patients with calcium stones (Ettinger et al, J Urol 158:2069, 1997; PMID 9366314). The effect on pH would also be expected to benefit patients with uric acid and cystine stones. Patients preferred Moonstone as a stone prevention regimen. Source of Funding: NYU Langone discretionary research funds © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e377-e377 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Lama Nazzal More articles by this author Frank Modersitzki More articles by this author John Asplin More articles by this author David Goldfarb More articles by this author Expand All Advertisement Loading ...

MP54-19 MACHINE LEARNING MODELS TO PREDICT 24-HOUR URINE ABNORMALITIES FROM ELECTRONIC HEALTH RECORD-DERIVED FEATURES

You have accessJournal of UrologyStone Disease: Epidemiology & Evaluation II (MP54)1 Sep 2021MP54-19 MACHINE LEARNING MODELS TO PREDICT 24-HOUR URINE ABNORMALITIES FROM ELECTRONIC HEALTH RECORD-DERIVED FEATURES Nicholas Kavoussi, Abin Abraham, Wilson Sui, Cosmin Bejan, John Capra, and Ryan Hsi Nicholas KavoussiNicholas Kavoussi More articles by this author , Abin AbrahamAbin Abraham More articles by this author , Wilson SuiWilson Sui More articles by this author , Cosmin BejanCosmin Bejan More articles by this author , John CapraJohn Capra More articles by this author , and Ryan HsiRyan Hsi More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002084.19AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: To enable earlier preventative interventions or guide empiric therapy for kidney stone disease, our objective was to demonstrate feasibility of predicting 24-hour urine abnormalities using several machine learning methods. METHODS: We trained machine learning models (XGBoost [XG] and Ensemble [EN]) to predict 24-hour urine abnormalities from electronic health record-derived demographic, laboratory, stone composition, and comorbidity data, including age, BMI, comorbidities (n=1,296). The machine learning models were compared to a logistic regression model [LR]. Models predicted binary (normal vs high) 24-hour urine values for sodium, oxalate, calcium, and uric acid; and (normal vs low) for citrate; as well as a multiclass prediction of pH (low, normal, high). We evaluated performance using area under the receiver operating curve (ROC-AUC) and accuracy and identified predictors for each task. RESULTS: Both XG and EN were able to discriminate 24-hour urine abnormalities with fair performance, with comparable performance to LR (see Figure). EN most accurately predicted abnormalities of oxalate (accuracy=65%, ROC-AUC=0.70) and citrate (65%, 0.69), while XG most accurately predicted abnormalities of uric acid (69%, 0.73) and sodium (71%, 0.70). Both models had similar accuracy for the prediction of pH (45%, 0.57) and calcium (55%, 0.59) abnormalities. Body mass index, age, and gender were the three most important features for training the models for all outcomes. CONCLUSIONS: Urine chemistry prediction for kidney stone disease appears to be feasible with machine learning methods with acceptable discrimination for several urinary parameters modifiable with diet. Further optimization of the performance could facilitate earlier pharmacologic preventative therapy. Source of Funding: none © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e957-e957 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Nicholas Kavoussi More articles by this author Abin Abraham More articles by this author Wilson Sui More articles by this author Cosmin Bejan More articles by this author John Capra More articles by this author Ryan Hsi More articles by this author Expand All Advertisement Loading ...

Vasodilation and blood pressure-lowering effect mediated by 5,6-EEQ lactone in 5/6 nephrectomy hypertensive rats

Microvascular dysfunction is a key contributor to vascular hypertension, one of the most common chronic diseases in the world. Microvascular dysfunction leads to the loss of nitric oxide-mediated endothelial dilation and the subsequent compensatory function of endothelium-derived hyperpolarizing (EDH) factors in the regulation of vascular tone. Previously, we showed that lactone metabolite derived from arachidonic acid induces endothelial-dependent vasodilation in isolated human microvessels. Based on structural similarities, we hypothesize that additional lactone metabolites formed from eicosapentaenoic fatty acid (EPA) may bear EDH properties. AimTo elucidate the vasodilatory and blood pressure (BP)-reducing characteristics of the 5,6-EEQ (5,6-epoxyeicosatetraenoic acids) lactone (EPA-L) in hypertensive 5/6 nephrectomy (5/6Nx) rats. Methods5/6Nx hypertensive rats intravenously administrated with EPA-L for five days. BP, blood and urine chemistry, and kidney function were detected and analyzed. Vascular dilation was detected using a pressure myograph with or without Ca2+ − activated K+ (KCa) endothelial channel inhibitors. KCNN3 and KCNN4 gene expression (mRNA) detected in mesenteric arteries from 5/6Nx and NT rats. ResultsEPA-L administration to 5/6Nx rats significantly (p < 0.05) reduced BP and heart rate without affecting kidney function. 5/6Nx rat mesenteric arterioles exhibited a lower dilation response to acetylcholine (10-7 mol/l) than normotensive (NT) vessels, while EPA-L administration restored the vessel relaxation response. The EPA-L-driven relaxation of mesenteric arteries was significantly reduced by pretreatment with TRAM-34 and apamin. However, KCa channel expression did not significantly differ between 5/6Nx and NT mesenteric arteries. ConclusionEPA-L reduces BP by improving microvessel dilation involving calcium-dependent potassium endothelial channels.

Clinical safety of robenacoxib in cats with chronic musculoskeletal disease.

BackgroundEvaluate the clinical safety of robenacoxib in cats with chronic musculoskeletal disease (CMSD).AnimalsFour hundred forty‐nine client‐owned cats with CMSD.MethodsPooled analysis of safety variables from 4 prospective randomized blinded clinical trials of robenacoxib (n = 222) versus placebo (n = 227), administered orally once daily for 4 to 12 weeks. Safety was evaluated from reported adverse events (AEs) and abnormalities detected on hematology and serum and urine chemistry analyses.ResultsThe number of cats with at least 1 AE was not significantly different (P = .15) with robenacoxib (n = 106, 47.8%) compared to placebo (n = 93, 41.0%). The relative risk of at least 1 AE (incidence robenacoxib/placebo) was 1.15 (95% confidence interval 0.93‐1.43). There was no significant difference between groups in the number of clinical signs (range, 0‐9) per cat (P = .23). Serum creatinine concentrations were higher during robenacoxib administration compared to placebo (+4.36 μmol/L, 95% confidence interval 0.21‐8.50), but no related adverse clinical effects were detected. In the subgroup of 126 cats with evidence of chronic kidney disease, the relative risk of at least 1 AE (robenacoxib/placebo) was 1.09 (95% confidence interval 0.78‐1.52, P = .61).Conclusions and Clinical ImportanceRobenacoxib was not associated with increased risk of AEs compared to placebo when administered for 4 to 12 weeks to cats with CMSD. The generalizability of the results to general practice is limited by the fact that cases with severe and uncontrolled concomitant diseases were not included.

PROFIL KIMIA AIR KENCING GAJAH SUMATRA (ELEPHAS MAXIMUS SUMATRANUS) DALAM PENANGKARAN DI BALI ELEPHANT CAMP) DI CARANG SARI, PETANG, BADUNG, BALI

Sumatran elephant (Elephas maximus sumatranus) is the biggest land mammals in Indonesia in criteria A2c category Critically Endangered (CR) dan Appendix I in Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES). Considering the importance of conservation and health maintenance of Sumatran elephants, various diagnostic tests must be carried out to determine the health status of elephants ranging from physical examination to blood chemistry tests and urinalysis. This study aimed to obtain the urine chemistry profile of the Sumatran elephant (Elephas maximus sumatranus) held captive in Bali Elephant Camp, Carangsari, Petang, Badung Regency, Bali. The urine sample taken is midstream (middle emission) urine. Sampling was carried out 5 times for 2 weeks with 2-3 days distance between samples taken and the dipstick test was carried out twice in one sample. Based on the results of this study, it can be concluded that out of the 8 Sumatran elephants maintained at the Bali Elephant Camp were all 100% negative for glucose. Protein, blood, bilirubin, ketones, and nitrite traces were found in deviant values in few individuals whereas it should be negative. Urobilinogen is found to be normal in most individuals at 0.2 mg/dL. pH in the range 6-9 while specific gravity is in the range of 1-1.020. Leucocytes value found in most individuals were 70 Leu/μL. It is important to note that a dipstick kit is used to indicate components in urine but it can not be used as a standard to diagnose a disease. Further examinations need to be carried out to find the definite value of the components found in urine.

The Effect of Urine Collection with a Novel External Catheter Device on Common Urine Chemistry and Urinalysis Results.

Urine collection from incontinent individuals can be challenging. Various methods have been devised to collect the sample without catheterization. Recently the PureWick external catheter was developed to draw the sample gently away from external female genitalia. While the primary purpose of the device is to prevent moisture and maintain skin integrity, the urine that is collected may be sent for laboratory analysis. We sought to validate the use of this collection method for common urine chemistry assays and urinalysis. Twenty pools of residual urine samples were separated into "control" and "PureWick" treated samples. The control samples were maintained at room temperature while 15 mL of urine was added to the PureWick device which was connected to a vacuum line through a collection canister. The urine collected in the canister and the controls samples were all subject to urine chemistry strip, microscopic, and automated urine chemistry analysis. Results were compared between pairs of treated and control samples. No clear affect was noted on urine strip semi-quantitative or automated chemistry analysis from the PureWick collection. There was a statistically significant decrease in microscopic measurements of white blood cells and crystals in the PureWick urine samples. This study supports the use of the PureWick external catheter for collection of samples for most urinalysis and urine chemistry tests.

Effect of age, BMI, and gender on urinary risk factors in pediatric idiopathic stone formers

The incidence of pediatric urolithiasis has been increasing over the years; however, the etiology of this increase is not well understood. Age, body mass index, and gender have been examined as possible risk factors for stone disease, but with inconsistent and variable associations. We aim to investigate the urine chemistry factors, as assessed by 24-h urinary parameters, in pediatric stone formers at a large volume tertiary referral center in the highest areas in the United States, the Southeast, based on age, body mass index, and gender. We retrospectively reviewed all pediatric stone formers who completed a 24-h study between 2005 and 2016. Patients were stratified by age (3-10 versus 11-18 years of age), overweight status (above versus below the 85th percentile for body mass index), and gender (male versus female) (Summary Figure). Statistical analysis included analysis of variance and logistic regression. 243 patients were included in our analysis. Patients in the first decade of life were found to have greater numbers of urinary risk factors than those in the second decade. Non-overweight patients were more likely to have hyperoxaluria and hyperuricosuria, while overweight patients were more likely to have hypocitraturia. Female patients were more likely to have higher hyperoxaluria, while male patients were more likely to have hypercalciuria. In contrast to prior publications, obesity is not linked to increased risk of urolithiasis with non-overweight individuals having a greater number of risk factors than the overweight cohort. Despite stone disease being more prevalent in adolescents, the greatest number of risk factors were present in the first decade of life. Lastly, female children had more urinary risk factors than males. Further understanding of the underlying causes of stone disease in various pediatric populations is warranted. While more urinary risk factors were identified in younger, non-overweight, and female patients, there remains no consensus on the urinary risk factors for pediatric urolithiasis. Further study is needed to elucidate the risk factors and pathophysiology of pediatric stone disease.

A retrospective study on sex difference in patients with urolithiasis: who is more vulnerable to chronic kidney disease?

BackgroundUrolithiasis is considered a vital public health issue with a substantial burden on kidney function. Additionally, only few reports focused on the gender difference in patients with urolithiasis. Therefore, this study aimed to compare the clinical characteristics of sex difference and their potential risk for chronic kidney disease (CKD) in patients with urolithiasis.MethodsPatients diagnosed with stone disease from 2013 to 2018 were retrospectively reviewed and divided into two groups by gender. Clinical demographic characteristics, stone location, stone composition, urine chemistries, and renal function were investigated. Univariate and multivariate analyses were used to assess the relationship and potential risk of CKD between sex groups.ResultsA total of 1802 patients were included: 1312 from men and 490 from women. Female patients had a higher rate of hypertension, diabetes, and dyslipidemia. Male patients predominantly had calcium-containing stones, especially calcium oxalate stone, uric acid stone, and struvite stone. Carbonate apatite stone was more frequently found in women. Complex surgeries such as percutaneous nephrolithotomy (PCNL) and ureteroscopic lithotripsy (URSL) were more frequently performed in women than that in men. Multivariate analysis confirmed that age > 60 years (odds ratios [ORs] = 6.36; 95% confidence interval [CI], 3.8–10.8), female sex (ORs = 5.31; 95% CI 3.3–8.4), uric acid stone (ORs = 3.55; 95% CI 2.0–6.4), hypertension (OR = 7.20; 95% CI 3.8–13.7), and diabetes (OR = 7.06; 95% CI 3.1–16.2) were independent predictors of poor prognoses in CKD.ConclusionsThe female gender is significantly associated with a higher prevalence of CKD among patients with urolithiasis. Therefore, women with stone disease may need close renal function monitoring during follow-up.

Plant-Based Milk Alternatives and Risk Factors for Kidney Stones and Chronic Kidney Disease

Patients with kidney stones are counseled to eat a diet low in animal protein, sodium, and oxalate and rich in fruits and vegetables, with a modest amount of calcium, usually from dairy products. Restriction of sodium, potassium, and oxalate may also be recommended in patients with chronic kidney disease. Recently, plant-based diets have gained popularity owing to health, environmental, and animal welfare considerations. Our objective was to compare concentrations of ingredients important for kidney stones and chronic kidney disease in popular brands of milk alternatives. Sodium, calcium, and potassium contents were obtained from nutrition labels. The oxalate content was measured by ion chromatography coupled with mass spectrometry. The calcium content is highest in macadamia followed by soy, almond, rice, and dairy milk; it is lowest in cashew, hazelnut, and coconut milk. Almond milk has the highest oxalate concentration, followed by cashew, hazelnut, and soy. Coconut and flax milk have undetectable oxalate levels; coconut milk also has comparatively low sodium, calcium, and potassium, while flax milk has the most sodium. Overall, oat milk has the most similar parameters to dairy milk (moderate calcium, potassium and sodium with low oxalate). Rice, macadamia, and soy milk also have similar parameters to dairy milk. As consumption of plant-based dairy substitutes increases, it is important for healthcare providers and patients with renal conditions to be aware of their nutritional composition. Oat, macadamia, rice, and soy milk compare favorably in terms of kidney stone risk factors with dairy milk, whereas almond and cashew milk have more potential stone risk factors. Coconut milk may be a favorable dairy substitute for patients with chronic kidney disease based on low potassium, sodium, and oxalate. Further study is warranted to determine the effect of plant-based milk alternatives on urine chemistry.

Critical Reappraisal of Methods for Measuring Urine Saturation with Calcium Salts.

Background: Metabolic and physicochemical evaluation is recommended to manage the condition of patients with nephrolithiasis. The estimation of the saturation state (β values) is often included in the diagnostic work-up, and it is preferably performed through calculations. The free concentrations of constituent ions are estimated by considering the main ionic soluble complexes. It is contended that this approach is liable to an overestimation of β values because some complexes may be overlooked. A recent report found that β values could be significantly lowered upon the addition of new and so far neglected complexes, [Ca(PO4)Cit]4− and [Ca2H2(PO4)2]. The aim of this work was to assess whether these complexes can be relevant to explaining the chemistry of urine. Methods: The Ca–phosphate–citrate aqueous system was investigated by potentiometric titrations. The stability constants of the parent binary complexes [Cacit]− and [CaPO4]−, and the coordination tendency of PO43− toward [Ca(cit)]− to form the ternary complex, were estimated. βCaOx and βCaHPO4 were then calculated on 5 natural urines by chemical models, including or not including the [CaPO4]− and [Ca(PO4)cit]4− species. Results: Species distribution diagrams show that the [Ca(PO4)cit]4− species was only noticeable at pH > 8.5 and below 10% of the total calcium. β values estimated on natural urine were slightly lowered by the formation of [CaPO4]− species, whereas [Ca(PO4)cit]4− results were irrelevant. Conclusions: While [CaPO4]− species have an impact on saturation levels at higher pHs, the existence of ternary complex and of the dimer is rejected.

L-Leucine Supplementation for Preserving Lean Mass During Low Calorie Diet in Sarcopenic Obese Women: A Pilot Study

Background: In sarcopenic obese subjects it is essential to reduce body weight and to preserve lean mass, in order to avoid a worsening of muscle function (1). Several studies have shown that leucine supplementation can be useful to improve skeletal muscle mass in sarcopenic patients (2). Aim: Evaluate the effectiveness of a short-term low calorie diet (LCD) combined with combined supplementation with whey protein, leucine and vitamin D on weight loss, lean mass and muscle strength in sarcopenic, obese, hyperinsulinemic and menopause women. Materials and methods: 16 female with mean age: 58.1 years (range: 47–69 years), BMI 37.6 Kg/m2 (range: 31,7 - 44,1 Kg/m2), HOMA-index ≥ 2.5, were assigned to an LCD regimen (1000 kcal/day) with supplementation of 18 g protein, 4 g leucine and 5 mcg vitamin D for 45 days. Anthropometric indexes, blood and urine chemistry, body composition by DEXA, muscle strength by handgrip test and Short Physical Performance Battery (SPPB) were assessed at baseline and at the end of the treatment. Results: A significant reduction of BMI (35,7 vs 37,6 Kg/m2), waist circumference (102,4 vs 107 cm), HOMA index (2,3 vs 4,8) and fasting insulin (10,4 vs 17,4 μIU/ml) was observed in all patients. Women preserved total lean body mass (57 vs 55 %) and improved significantly muscle strength, as measured by handgrip (22,2 vs 18,6 Kg) and SPPB (8,9 vs 7,5). Conclusion: We conclude that LCD with adequate protein intake and a supplementation with whey protein, leucine and vitamin D should be promoted to maintain muscle mass and improve muscle strength in menopause women with sarcopenic obesity.