Idiopathic hypercalciuria and formation of calcium renal stones

Anti-nociceptive and antiurolithiatic activities of gum exudates from Moroccan Acacia tortilis ssp. raddiana (Savi) Brenan on ethylene glycol induced urolithiasis in rodents

ETHNOPHARMACOLOGICAL RELEVANCE

Acacia tortilis ssp. raddiana gum (G-ATR) is traditionally used in North African medicine for its various therapeutic properties. However, its potential effects on pain management and kidney stone prevention remain underexplored. This study aims to evaluate, for the first time, the antinociceptive and antiurolithiatic activities of G-ATR exudate.

AIM OF THE STUDY

This research investigates the ability of G-ATR to alleviate pain and prevent kidney stone formation. By assessing its effects on nociceptive responses in mice and its protective role against renal lithiasis in rats, the study seeks to provide scientific validation for its traditional use and explore its therapeutic potential.

MATERIALS AND METHODS

The antinociceptive activity of G-ATR was assessed in mice following oral administration of increasing doses (100, 300, and 500 mg/kg) of gum dissolved in distilled water. For the antiurolithiatic evaluation, renal lithiasis was induced in rats using ethylene glycol (0.75 %) and ammonium chloride (2 %). The animals were treated with G-ATR at doses of 200 and 500 mg/kg. Biochemical parameters were measured, and histological analyses of kidney sections were performed to assess the presence of crystals.

RESULTS

The administration of G-ATR significantly reduced pain in mice, indicating its antinociceptive potential. In the lithiasis model, G-ATR normalized altered biochemical parameters and demonstrated an antilithiasic effect by preventing the formation of kidney crystals, as confirmed by histological examination.

CONCLUSION

These findings highlight the therapeutic potential of G-ATR in pain relief and kidney stone prevention. Its ability to alleviate renal lithiasis and reduce nociception suggests that this natural exudate could serve as a promising alternative for managing urolithiasis and pain-related conditions.

An Integrative Analysis of Transcriptome Combined with Machine Learning and Single-Cell RNA-Seq for the Common Biomarkers in Crohn's Disease and Kidney Stone Disease

Background

The course of Crohn's disease (CD) is prolonged and many of them may develop kidney stone disease (KSD) with the need for surgical treatment. Therefore, finding biomarkers that can predict CD with KD become increasingly important.

Methods

We obtained three CD and one KSD dataset from GEO database. DEGs and module genes were identified utilizing Limma and WGCNA. We constructed a protein-protein interaction (PPI) network and employed machine learning algorithms to pinpoint potential hub genes (HGs) for diagnosing CD with KSD. We developed a nomogram and receiver operating characteristic (ROC) curve. Additionally, human intestinal cell and proximal tubular epithelial cell models were established to explore the HG levels. Next, we used Cytoscape to build the regulatory networks. Finally, single-cell analysis was performed to investigate specific cell types displaying these biomarkers in CD.

Results

We identified 36 common genes associated with CD and KSD. PYY, FOXA2, REG3A, REG1A, REG1B were identified as HGs utilizing the machine learning algorithm. The nomogram and all five potential HGs exhibited strong diagnostic capabilities. Cell experiments also verified that these genes were markedly expressed in cell models of CD and KSD. Meanwhile, we pinpointed four microRNAs and three transcriptional regulators intimately linked to five crucial genes. Finally, single-cell analysis indicated FOXA2, REG3A, REG1A and REG1B exhibited elevated expression in goblet cells, whereas PYY demonstrated high expression levels in coloncytes.

Conclusion

We determined five biomarkers, including PYY, FOXA2, REG3A, REG1A, REG1B. Our results offer useful perspectives for identifying CD with KSD.

Analysis of microRNA expression in patients with uric acid calculi

Uric acid calculi (UAC) account for about 10% of cases worldwide, although this varies among countries. The etiology of nephrolithiasis is multifactorial, involving both genetic and environmental factors. Kidney stones occur three times more frequently in individuals with a family history of the condition compared to those without such a history. Genetic factors also contribute to cases of UAC. Genes such as ZNF365, SLC2A9 and SLC22A12 may be associated with the development of uric acid stones. MicroRNAs (miRNAs) are small RNA molecules, that play a significant role in regulating gene expression. The aim of this study was to characterize the expression profile of miRNAs associated with the SLC2A9, SLC22A12 and ZNF365 genes in patients with uric lithiasis. Twenty-two patients with pure uric stones and 8 controls with no history of lithiasis were included, all of whom consented voluntarily. To analyze the gene expression levels of the microRNAs studied, total RNA was obtained using the miRVana®miRNA kit, following the manufacturer's guidelines. qPCR analyses were then carried out using specific probes for the selected microRNAs. When comparing clinical characteristics, patients with nephrolithiasis had significant hyperuricemia (p < 0.0001) and more acidic urine (p = 0.0012). Lower urinary citrate excretion was also observed in patients with nephrolithiasis (p = 0.0047). With regard to microRNA expression data, statistically significant under-expression was observed in patients with calculi of microRNAs 143-3p (p = 0.015), 4770 (p = 0.0194), 4750-3p (p = 0.037), 301b-5p (p = < 0.0001) and 9-5p (p = 0.0015). In addition, microRNAs 4770 and 4750-3p were underexpressed in individuals with multiple stones (p = 0.0197, p = 0.0023 respectively). In relation to miR-4750-3p, it was also overexpressed in cases with stones larger than 2 cm (p = 0.0557). With the results of our study, we can conclude that the microRNAs 143-3p, 4770, 4750-3p, 301b-5p and 9-5p may be associated with the development of uric lithiasis. In addition, under-expression of microRNAs 4770 and 4750-3p is associated with the occurrence of multiple stones, while over-expression of miR-4750-3p is related to the formation of stones larger than 2 cm.

Idiopathic Hypercalciuria: A Comprehensive Review of Clinical Insights and Management Strategies

Idiopathic hypercalciuria (IH) is a metabolic condition characterized by excessive calcium excretion in urine without identifiable secondary causes, such as hyperparathyroidism or malignancy. It is a significant clinical entity due to its association with kidney stones, nephrocalcinosis, and osteoporosis, leading to reduced quality of life and long-term complications. This comprehensive review discusses the pathophysiology, clinical manifestations, diagnostic strategies, and management approaches for IH. The disorder arises from a multifaceted interplay of renal, intestinal, and skeletal factors. Impaired renal tubular calcium reabsorption, heightened intestinal calcium absorption, and increased bone resorption are key contributors to its pathogenesis. Genetic predispositions, including mutations in calcium-regulating receptors and transporters, further complicate its etiology. Patients often present with kidney stones, bone pain, or reduced bone mineral density, although asymptomatic cases are not uncommon. Diagnosing IH requires a thorough evaluation to exclude secondary causes, with 24-hour urinary calcium excretion serving as a crucial diagnostic marker. Management focuses on mitigating complications and improving quality of life through hydration, dietary modifications, and pharmacological therapy. Thiazide diuretics are the cornerstone of treatment, effectively reducing urinary calcium levels and preventing stone formation. Adjunctive measures include citrate supplementation and lifestyle interventions such as weight management and adequate physical activity. For patients with severe nephrolithiasis or nephrocalcinosis, surgical intervention may be necessary. Despite significant advancements, IH remains a diagnostic and therapeutic challenge due to its diverse clinical presentations and underlying mechanisms. A multidisciplinary approach, incorporating tailored medical and dietary strategies, is essential for optimal management. Future research into its genetic and molecular basis holds promise for developing more targeted interventions and improving patient outcomes. This review aims to provide a practical, up-to-date guide for clinicians managing this complex yet common metabolic disorder.

Uncovering the subtle relationship between vitamin D and kidney stones: a cross-sectional NHANES-based study

OBJECTIVE

This study investigated the potential correlation between serum vitamin D levels and the risk of kidney stones. To this end, the National Health and Nutrition Examination Survey (NHANES) database resources from 2007 to 2018 were utilized. The influence of other demographic characteristics, lifestyle habits, and chronic diseases on this relationship was also assessed.

METHODS

This study included 59,842 participants from the NHANES survey, and after exclusions, 24,323 individuals with complete data were analyzed. Logistic regression modeling assessed odds ratios (OR) and 95% confidence intervals (CI) between vitamin D levels and kidney stone risk, and multivariable adjustment models were constructed to control for potential confounders. To investigate the dose-response relationship between vitamin D and kidney stones, restricted cubic spline (RCS) modeling was employed. Subgroup and interaction analyses were also conducted.

RESULTS

The preliminary analyses indicated a statistically significant positive correlation between vitamin D levels and kidney stone risk before adjustment for potential confounding variables (OR = 1.01, P < 0.001). However, after gradual adjustment for age, gender, race, and multiple lifestyle and chronic diseases, this association became non-significant (OR = 1.00, P = 0.186). Furthermore, RCS analyses demonstrated that the non-linear relationship between vitamin D levels and kidney stone risk was no longer statistically significant after adjustment for confounders. In the subgroup analyses, only slight statistical associations were observed in the subgroups of vigorous exercise and those with diabetes, with no significant differences in the remaining subgroups.

CONCLUSION

The present study indicates that serum vitamin D level is not an independent predictor of kidney stone risk. Rather, its effect may be co-regulated by multiple confounding factors. Further research is required to elucidate the precise mechanisms through which vitamin D contributes to kidney stone formation and to consider the combined effects of genetic polymorphisms, dose effects, and other factors.

Healthy dietary patterns, biological aging, and kidney stones: evidence from NHANES 2007-2018

Background

This study aims to investigate the comprehensive association between healthy dietary patterns, biological aging, and kidney stones in a large population-based cohort.

Methods

We analyzed data from 6 cycles of NHANES surveys from 2007 to 2018 and included a total of 26,755 participants. The association was examined using logistic regression, restricted cubic splines, and a mediation model. Machine learning with Shapley Additive Explanations (SHAP) was used to determine the relative importance of dietary factors. Sensitivity analysis was conducted to validate the stability of the results.

Results

A higher healthy dietary score was significantly associated with a reduced risk of kidney stone prevalence, as indicated by the Alternative Healthy Eating Index (AHEI) (OR = 0.76, 95% CI 0.69-0.84), the Dietary Approaches to Stop Hypertension Index (DASHI) (OR = 0.67, 95% CI 0.58-0.77), the Healthy Eating Index 2020 (HEI-2020) (OR = 0.80, 95% CI 0.72-0.89), and the Mediterranean Diet Index (MEDI) (OR = 0.81, 95% CI 0.73-0.89). Conversely, higher aging indicators were associated with an increased risk of kidney stones, including the following: Klemera-Doubal Method Age (KDMAge) (OR = 2.40, 95% CI 1.70-3.37) and Phenotypic Age (PhenoAge) (OR = 2.36, 95% CI 1.75-3.19). Mediation analyses suggested that aging indicators significantly mediated the relationship between healthy dietary patterns and kidney stones. Machine learning with SHAP revealed the relative importance of dietary patterns and specific dietary components in this association. The sensitivity analysis was largely consistent with the primary analyses.

Conclusion

These findings provide valuable insights into the complex interplay between dietary patterns, biological aging, and the risk of kidney stone. Promoting healthy dietary patterns may be an effective strategy for kidney stone prevention, potentially through the modulation of biological aging processes.

Genetic and protein structure prediction analyses identify a rare pathogenic PKD1 variant causing autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common monogenic kidney disorders. The diagnosis of ADPKD requires imaging findings showing multiple kidney cysts or genetic testing, in cases where a family history is unknown. We report a patient diagnosed with ADPKD based on the identification of a rare PKD1 variant. The patient was a 41-year-old female in whom cysts and calcification in the kidneys were incidentally detected. Whole-exome sequencing identified a rare PKD1 variant (NM_001009944.3: c.11557G > A/p.E3853K). Protein structure prediction of the PKD1-PKD2 complex showed that the variant may be pathogenic, leading to the diagnosis of autosomal dominant polycystic kidney disease. A detailed family history revealed that her relatives also had ADPKD, further supporting the diagnosis of ADPKD. Comprehensive genetic analysis and protein structure prediction led to the diagnosis of ADPKD and the identification of rare causative genes. These methods are useful for diagnosing hereditary kidney diseases of unknown etiologies.

Mechanistic studies of Ca2+-induced classical pyroptosis pathway promoting renal adhesion on calcium oxalate kidney stone formation

This study aims to investigate the role of hypercalciuria and pyroptosis in the formation of calcium oxalate kidney stones. Bioinformatics analysis was performed to compare the correlation of pyroptosis scores and cell adhesion scores between Randall's plaques and normal tissues from kidney stone patients. For the in vitro experiments, we investigated the effects of high concentrations of Ca2+ on the pyroptosis and adhesion levels of renal tubular epithelial cells and examined the adhesion levels and crystal aggregation of the cells in high Ca2+ concentrations environment by knockdown and overexpression of the key pyroptosis gene, GSDMD, and we verified the effects of Ca2+ concentration on pyroptosis and adhesion levels, kidney injury, and crystal deposition by in vivo experiments. Bioinformatic results showed that the scores of pyroptosis and cell adhesion in Randall's plaques of patients with kidney stones were significantly higher than those in normal tissues, and pyroptosis was highly positively correlated with cell adhesion. In vitro and in vivo experiments showed that high concentrations of Ca2+ activated the NLRP3/Caspase-1/GSDMD pathway of pyroptosis through ROS and up-regulated the expression of adhesion-related proteins, and GSDMD could regulate the adhesion level of renal tubular epithelial cells by mediating the level of pyroptosis, thereby affecting the adhesion and deposition of calcium oxalate crystals. Our findings reveal that the Ca2+-induced classical pyroptosis pathway may be a potential mechanism to promote calcium oxalate kidney stone formation, which provides new insights into the etiology of kidney stones.

Association between calcium and vitamin D supplementation and increased risk of kidney stone formation in patients with osteoporosis in Southwest China: a cross-sectional study

OBJECTIVES

This cross-sectional study aims to evaluate the association between calcium and vitamin D supplementation for osteoporosis treatment and the development of kidney stones while investigating the impact of urinary calcium excretion on kidney stone risk among patients receiving this supplementation treatment.

DESIGN

The study involved collecting data from 204 Chinese Han patients aged 50-89 with osteoporosis in the southwest region of China. These patients had been on daily doses of 600 mg of calcium carbonate and 0.5 µg alfacalcidol for at least 1 year. The study employed univariate analysis and multivariable logistic regression to identify risk factors for kidney stones, with independent t-tests used to compare differences between groups.

SETTING

Data were collected from patients in the southwest region of China, covering the period from July 2019 to December 2023.

PARTICIPANTS

The study included 204 patients with osteoporosis, all of whom had been receiving the specified calcium and vitamin D supplements for the duration of the study.

RESULTS

The study found that a history of recurrent kidney stones was an independent risk factor for the development of kidney stones. Patients with kidney stones who had a history of recurrent stones exhibited significantly higher levels of 24-hour urinary calcium excretion (1.00±0.62 vs 0.57±0.54, p=0.026) compared with those without such a history.

CONCLUSIONS

The results suggest that a history of recurrent kidney stones independently increases the risk of kidney stones in patients undergoing calcium and vitamin D supplementation for osteoporosis, likely due to increased urinary calcium excretion.

Metabolic dysfunction-associated fatty liver disease and risk of nephrolithiasis: a sizeable cross-sectional study

Objective

Metabolic dysfunction-associated fatty liver disease (MAFLD) and nephrolithiasis are two common metabolic diseases, but their relationship has not yet been thoroughly studied. Therefore, this study aimed to explore the association between MAFLD and nephrolithiasis and to assess the effect of MAFLD on the risk of nephrolithiasis.

Materials and methods

This cross-sectional study included 96,767 adults from China. All participants underwent medical examinations, including physical examinations, medical history tests, and laboratory tests. Based on ultrasound examination, participants were divided into MAFLD and non-MAFLD groups, and the severity of liver steatosis was determined based on ultrasound images. The relationship between MAFLD and nephrolithiasis was analyzed using a multivariate logistic regression model and subgroup analysis was performed.

Results

The proportion of participants with MAFLD was significantly higher in the nephrolithiasis group compared to the non-nephrolithiasis group (47.70% vs. 30.45%, P < 0.001). Multivariate logistic regression analysis showed a significant positive association between MAFLD and nephrolithiasis (adjusted OR=1.38, 95% CI: 1.29 to 1.47). Subgroup analyses indicated that, even after accounting for various factors such as age, diabetes, hypertension, obesity, lipid profiles, and renal function, the positive association between MAFLD and an increased risk of nephrolithiasis remained consistent. Further subgroup analysis revealed that in male patients with MAFLD, the risk of nephrolithiasis increased progressively with increasing severity of liver steatosis. The adjusted multivariable odds ratios were 1.43 (95% CI: 1.33 to 1.53) for mild, 1.48 (95% CI: 1.32 to 1.67) for moderate, and 1.94 (95% CI: 1.47 to 2.58) for severe hepatic steatosis.

Conclusions

This study found a significant positive association between MAFLD and nephrolithiasis. The risk of nephrolithiasis in males with MAFLD increased substantially with increasing severity of liver steatosis. Therefore, it is essential to strengthen prevention and screening for nephrolithiasis in individuals with MAFLD. More research is needed to elucidate the physiological and pathological mechanisms between MAFLD and nephrolithiasis.

The association between urinary lead concentration and the likelihood of kidney stones in US adults: a population-based study

The negative effects of lead exposure on human health have attracted widespread attention. Our present study focused on assessing the relationship between urinary lead levels (ULL) and the risk of kidney stones in US adults. We used data from NHANES 2007-2018 for this cross-sectional study, where participants had complete data on ULL and kidney stones. The correlation between ULL and kidney stones was explored by weighted multiple logistic regression analysis. In addition, we also performed subgroup analysis and interaction tests. A total of 8325 subjects were included, and the prevalence of kidney stones was 9.90%. In the fully adjusted model, we observed a positive association between ULL and the risk of kidney stones (OR:1.07, 95% CI: 1.01-1.14, p = 0.03). Participants in the highest quartile of ULL had a 64% higher risk of kidney stones than those in the lowest quartile of ULL (OR:1.64, 95% CI: 1.05-2.57, p = 0.03). Subgroup analysis and interaction test indicated that the association between ULL and the risk of kidney stones was similar in different population settings. The findings of this study indicate a positive correlation between urine lead concentration and the risk of kidney stones. The potential prognostic value of the urine lead concentration for kidney stone outcomes was another new area investigated in this study. However, further prospective clinical trials are needed to confirm the role of urine lead in the pathogenesis of kidney disease and to validate urine lead as a reliable predictor of kidney stone risk.

Pectolinarigenin alleviates calcium oxalate-induced renal inflammation and oxidative stress by binding to HIF-1α

Calcium oxalate (CaOx) crystals are the main constituents of renal crystals in humans and induce tubular lumen damage in renal tubules, leading to renal calcium deposition and kidney stone formation. Oxidative stress and inflammation play important roles in regulating calcium oxalate-induced injury. Here, we evaluated the efficacy in inhibiting oxidation and inflammation of pectinolinarigenin, a biologically active natural metabolite, in CaOx nephrocalcinosis and further explored its targets of action. First, we developed cellular and mouse models of calcium oxalate renal nephrocalcinosis and identified the onset of oxidative stress and inflammation according to experimental data. We found that pectolinarigenin inhibited this onset while reducing renal crystal deposition. Network pharmacology was subsequently utilized to screen for hypoxia-inducible factor-1α (HIF-1α), a regulator involved in the body's release and over-oxidation of inflammatory factors. Finally, molecular docking, cellular thermal shift assay, and other experiments to detect HIF-1α expression showed that pectolinarigenin directly combined with HIF-1α and prevented downstream reactive oxygen species activation and release. Our results indicate that pectolinarigenin can target and inhibit HIF-1α-mediated inflammatory responses and oxidative stress damage and be a novel drug for CaOx nephrocalcinosis treatment.

Machine Learning Models Decoding the Association Between Urinary Stone Diseases and Metabolic Urinary Profiles

Background: Employing advanced machine learning models, we aim to identify biomarkers for urolithiasis from 24-h metabolic urinary abnormalities and study their associations with urinary stone diseases. Methods: We retrospectively recruited 468 patients at Peking Union Medical College Hospital who were diagnosed with urinary stone disease, including renal, ureteral, and multiple location stones, and had undergone a 24-h urine metabolic evaluation. We applied machine learning methods to identify biomarkers of urolithiasis from the urinary metabolite profiles. In total, 148 (34.02%) patients were with kidney stones, 34 (7.82%) with ureter stones, and 163 (34.83%) with multiple location stones, all of whom had detailed urinary metabolite data. Our analyses revealed that the Random Forest algorithm exhibited the highest predictive accuracy, with AUC values of 0.809 for kidney stones, 0.99 for ureter stones, and 0.775 for multiple location stones. The Super Learner Ensemble Method also demonstrated high predictive performance with slightly lower AUC values compared to Random Forest. Further analysis using multivariate logistic regression identified significant features for each stone type based on the Random Forest method. Results: We found that 24-h urinary magnesium was positively associated with both kidney stones and multiple location stones (OR = 1.195 [1.06-1.3525] and 1.3258 [1.1814-1.4949]) due to its high correlation with urinary phosphorus, while 24-h urinary creatinine was a protective factor for kidney stones and ureter stones, with ORs of 0.9533 [0.9117-0.996] and 0.8572 [0.8182-0.8959]. eGFR was a risk factor for ureter stones and multiple location stones, with ORs of 1.0145 [1.0084-1.0209] and 1.0148 [1.0077-1.0223]. Conclusion: Machine learning techniques show promise in revealing the links between urological stone disease and 24-h urinary metabolic data. Enhancing the prediction accuracy of these models leads to improved dietary or pharmacological prevention strategies.

Association between magnesium depletion score and the prevalence of kidney stones in the low primary income ratio: a cross-sectional study of NHANES 2007-2018

INTRODUCTION

To explore the association between magnesium depletion score (MgDS) and the prevalence of kidney stones in the low primary income ratio (PIR).

METHOD

A cross-sectional study was conducted using data from the National Health and Nutrition Examination Survey 2007-2018. Within the low PIR, people aged ≥20 years with complete information on MgDS and kidney stones questionnaires were enrolled. Multivariable logistic regression and stratified logistic regression analyses were performed to examine the association between MgDS and the prevalence of kidney stones and the recurrence of kidney stones by confounding factors adjusted. Stratified and interaction analysis was conducted to find whether some factors modified the association. In addition, sensitive analyses were also conducted to observe the stability. The work has been reported in line with the strengthening the reporting of cohort, cross-sectional, and case-control studies in surgery (STROCSS) criteria (Supplemental Digital Content 1, http://links.lww.com/JS9/C781 ).

RESULT

A total of 7600 adults were involved in the study, and the individuals were classified into four groups: 0 points for MgDS ( n =3814), 1 point for MgDS ( n =2229), 2 points for MgDS ( n =1020), and ≥3 points for MgDS ( n =537). The multivariable logistic regression suggested that a positive association between MgDS and the prevalence of kidney stones (OR=1.123, 95% CI: 1.019-1.238) in the fully adjusted model. Compared with the lowest group, people with ≥3 points of MgDS had a significant relationship with kidney stones (OR=1.417, 95% CI: 1.013-1.983). No significant association was observed between the recurrence of kidney stones and MgDS. The result of the sensitive analysis showed the robustness of the main analysis.

CONCLUSION

The prevalence of kidney stones is positively correlated with MgDS, which suggests that maintaining a higher MgDS is accompanied by higher prevalence rates of kidney stones in the low PIR.

Metabolic Alkalemia in Hypercalciuria Stone Formers: Does It Matter?

INTRODUCTION

The literature lacks whether metabolic alkalemia occurs in outpatients with hypercalciuric nephrolithiasis. Thus, we aim to investigate it because these patients are often treated with thiazides to reduce urinary calcium excretion. However, thiazides induce chloride losses due to the inhibition of Na-Cl cotransporter expressed in the renal distal tubule cells. Besides thiazide prescription, many of these patients are also supplemented with potassium citrate, which is an addition of alkali source in their bodies.

METHODS

We collected clinical, demographic characteristics, and laboratory data from electronic medical charts of outpatients with calcium kidney stones followed in our institution from January 2013 to July 2021. We diagnosed those cases as metabolic alkalemia, in which the venous blood gas tests showed pH ≥7.46 and bicarbonate concentration >26 mEq/L. Then, we applied statistical analysis to compare distinct categories between patients with and without metabolic alkalemia.

RESULTS

We diagnosed metabolic alkalemia in 4.3% of hypercalciuric nephrolithiasis outpatients, and we verified that thiazides had been used in all of them except in one case. Furthermore, we observed that the amount of thiazide taken daily was higher in patients with metabolic alkalemia than in those without this imbalance. Additionally, hypokalemia was present in 37% of patients who developed metabolic alkalemia. We also found lower chloride, magnesium and ionic calcium serum concentrations in patients with metabolic alkalemia than in those without an acid-base disequilibrium.

CONCLUSION

Despite the low prevalence of metabolic alkalemia in hypercalciuric kidney stone formers, it is important to monitor these patients due to the high incidence of hypokalemia and the potential presence of other electrolyte disorders.

Targeting protein receptors and enzymes for precision management of urolithiasis: A comprehensive review

Urolithiasis, characterized by the formation of solid crystalline structures within the urinary tract, presents a significant global health burden with high recurrence rates and limited treatment efficacy. Recent research has identified various protein receptors and enzymes implicated in the pathogenesis of urolithiasis, offering potential targets for therapeutic intervention. Protein receptors such as the calcium-sensing receptor and vasopressin V2 receptor play crucial roles in regulating urinary calcium excretion and water reabsorption, respectively, influencing stone formation. Additionally, modulation of receptors like the angiotensin II receptor and aldosterone receptor can impact renal function and electrolyte balance, contributing to stone prevention. Furthermore, enzymes such as urease inhibitors and xanthine oxidase inhibitors offer targeted approaches to prevent the formation of specific stone types. This review discusses the potential of targeting these receptors and enzymes for the treatment of urolithiasis, exploring associated drugs and their mechanisms of action. Despite promising avenues for personalized and precision medicine approaches, challenges such as the need for robust clinical evidence and ensuring cost-effectiveness must be addressed for the translation of these interventions into clinical practice. By overcoming these challenges, receptor-targeted therapies and enzyme inhibitors hold promise for revolutionizing the management of urolithiasis and reducing its global burden.

The complex relationship between vitamin D and kidney stones: balance, risks, and prevention strategies

The association between vitamin D and kidney stones is characterized by a remarkable multi-dimensional complexity involving numerous physiological and metabolic pathways. Vitamin D is pivotal in maintaining calcium-phosphorus metabolic homeostasis and bone health. However, fluctuations in its intake, whether excessive or insufficient, May potentially increase the risk of kidney stones. Vitamin D exerts its influence on kidney stone formation indirectly by increasing the efficiency of intestinal calcium absorption and regulating renal calcium excretion. Moreover, there is a robust correlation between various states of vitamin D, particularly its active form, 1,25-dihydroxyvitamin D, and the development of numerous kidney stones. This finding underscores the necessity of individualized medical treatment in vitamin D supplementation and kidney stone prevention. When developing treatment strategies, it is essential to consider the patient's genetic background, lifestyle, environmental factors, and overall health. To prevent the formation of kidney stones, it is recommended that patients adopt a comprehensive approach, which May include measures such as moderate sun exposure, dietary modification, moderate exercise, and weight management. These preventive measures are designed to maintain healthy calcium and phosphorus metabolism and reduce kidney stone formation risk. Future studies should aim to elucidate the detailed mechanisms of vitamin D metabolism, individual differences, and the role of genes in this process. Furthermore, the role of lifestyle interventions in preventing kidney stones requires greater attention. Moreover, the implementation of large-scale, long-term prospective studies and randomized controlled trials will facilitate the assessment of the actual effects of diverse vitamin D supplementation strategies, thereby providing a robust scientific foundation for advancing more precise prevention strategies and clinical guidelines.

A high-calcium environment induced ectopic calcification of renal interstitial fibroblasts via TFPI-2-DCHS1-ALP/ENPP1 axis to participate in Randall's plaque formation

Randall's plaques (RP) serve as anchoring sites for calcium oxalate (CaOx) stones, but the underlying mechanism remains unclear. Renal interstitium with a high-calcium environment is identified as pathogenesis of RP formation where the role of human renal interstitial fibroblasts (hRIFs) was highlighted. Our study aims to elucidate the potential mechanism by which a high-calcium environment drives ectopic calcification of hRIFs to participate in RP formation. Alizarin Red staining demonstrated calcium nodules in hRIFs treated with high-calcium medium. Utilizing transcriptome sequencing, tissue factor pathway inhibitor-2 (TFPI-2) was found to be upregulated in high-calcium-induced hRIFs and RP tissues, and TFPI-2 promoted high-calcium-induced calcification of hRIFs. Subsequently, the downstream regulator of TFPI2 was screened by transcriptome sequencing analysis of hRIFs with TFPI-2 knockdown or overexpressed. Dachsous Cadherin Related 1 (DCHS1) knockdown was identified to suppress the calcification of hRIFs enhanced by TFPI-2. Further investigation revealed that TFPI-2/DCHS1 axis promoted high-calcium-induced calcification of hRIFs via disturbing the balance of ENPP1/ALP activities, but without effect on the canonical osteogenic markers, such as osteopontin (OPN), osteogenic factors runt-related transcription factor 2 (RUNX2), bone morphogenetic protein 2 (BMP2). In summary, our study mimicked the high-calcium environment observed in CaOx stone patients with hypercalciuria, and discovered that the high-calcium drove ectopic calcification of hRIFs via a novel TFPI-2-DCHS1-ALP/ENPP1 pathway rather than adaption of osteogenic phenotypes to participate in RP formation.

Correlation analysis between renal papillae Hounsfield density (PHD) and endoscopic papillary description in stone formers

We aimed to evaluate the correlation between endoscopic papillary abnormalities (PA) and high renal papilla Hounsfield density (PHD) on CT scan in patients who underwent flexible ureteroscopic treatment (fURS) for renal stones. We retrospectively assessed patients from a prospectively collected database who were treated with fURS for renal stones between May 2016 and October 2020. PHD was measured on preoperative CT-scan by a radiologist blinded from the intraoperative aspect of the papillae. Correlation was examined between high PHD (≥ 43 HU) and PA described in fURS, stone composition, metabolic abnormalities, … Out of 159 consecutive cases, 131 were eligible for analysis with available preoperative CT-scan. Median age was 55 years (IQR 43-67) and median PHD was 40 (IQR 36-45). Eighty patients (61%) had PHD < 43, and 51 patients (39%) had PHD ≥ 43. In univariate and multivariate analysis, only young age (p-value = 0.017) and insufficient diuresis (p-value = 0.008) were correlated with high PHD. No significant correlation was found with PA described during endoscopy, including the intensity of Randall's plaques. In this study, high PHD appears to be only a sign of insufficient diuresis, with no significant correlation with potential PA.

Baicalin attenuated oxidative stress and inflammation in ethylene glycol-induced urolithiasis in adult male SD rats

AIMS

Baicalin is a flavonoid derived from the root of the medicinal plant Scutellaria baicalensis Georgi (S. baicalensis) and is known for its various pharmacological properties. This study aimed to investigate the impact of baicalin (BAI) on the occurrence of kidney calcium oxalate crystal formation induced by ethylene glycol in male SD rats.

MAIN METHODS

A rat model of renal stones was created and various concentrations of baicalin were used for intervention. Samples of urine, blood, and kidney tissue were taken from the rats, and they were euthanized for biochemical and histopathological examinations.

KEY FINDINGS

Our results show that baicalin treatment improved the weight loss induced by ethylene glycol (EG) and ammonium chloride (AC) in rats. Baicalin also reduced the formation of calcium oxalate crystals and protected kidney function in rats with urolithiasis. Furthermore, it lowered the level of malondialdehyde (MDA) and elevated the activity of antioxidant enzymes compared to the stone control group. Additionally, baicalin notably alleviated renal inflammation in rats with urolithiasis.

SIGNIFICANCE

The present study attributed clinical evidence first time that claiming the significant antiurolithic effect of baicalin and could be a cost-effective candidate for the prevention and treatment of urolithiasis.

A Novel Machine-Learning Algorithm to Predict Stone Recurrence with 24-Hour Urine Data

Objectives: The absence of predictive markers for kidney stone recurrence poses a challenge for the clinical management of stone disease. The unpredictability of stone events is also a significant limitation for clinical trials, where many patients must be enrolled to obtain sufficient stone events for analysis. In this study, we sought to use machine learning methods to identify a novel algorithm to predict stone recurrence. Subjects/Patients and Methods: Patients enrolled in the Registry for Stones of the Kidney and Ureter (ReSKU), a registry of nephrolithiasis patients collected between 2015-2020, with at least one prospectively collected 24-hour urine test (Litholink 24-hour urine test; Labcorp) were included in the training set. A validation set was obtained from chart review of stone patients not enrolled in ReSKU with 24-hour urine data. Stone events were defined as either an office visit where a patient reports symptomatic passage of stones or a surgical procedure for stone removal. Seven prediction classification methods were evaluated. Predictive analyses and receiver operator characteristics (ROC) curve generation were performed in R. Results: A training set of 423 kidney stone patients with stone event data and 24-hour urine samples were trained using the prediction classification methods. The highest performing prediction model was a Logistic Regression with ElasticNet machine learning model (area under curve [AUC] = 0.65). Restricting analysis to high confidence predictions significantly improved model accuracy (AUC = 0.82). The prediction model was validated on a validation set of 172 stone patients with stone event data and 24-hour urine samples. Prediction accuracy in the validation set demonstrated moderate discriminative ability (AUC = 0.64). Repeat modeling was performed with four of the highest scoring features, and ROC analyses demonstrated minimal loss in accuracy (AUC = 0.63). Conclusion: Machine-learning models based on 24-hour urine data can predict stone recurrences with a moderate degree of accuracy.

Dietary Sodium and Potassium Intakes and Kidney Stone Prevalence: The National Health and Nutrition Examination Survey 2011-2018

The associations between dietary sodium intake (DSI), dietary potassium intake (DPI), and kidney stone disease (KSD) are not clear. We examined The National Health and Nutrition Examination Survey 2011-2018 to determine the independent associations between daily DSI, DPI, DSI/DPI, and KSD prevalence. In total, 19,405 participants were included for analysis, of which 1,895 had KSD. Higher DSI was not associated with increased odds of KSD in regression analysis when DSI was modeled as a continuous variable (OR = 0.99, 95% CI: 0.99-1.00, p = 0.2), or when comparing highest quartile of DSI to lowest quartile (OR = 0.84, 95% CI: 0.68-1.04, p = 0.1). Unlike DSI, higher DPI was strongly associated with reduced odds of KSD in regression analysis when DPI was modeled as a continuous variable (OR = 0.99, 95% CI: 0.99-0.99, p = 0.02), or when comparing highest quartile of DPI to lowest quartile (OR = 0.75, 95% CI: 0.60-0.94, p = 0.01). Lastly, higher DSI/DPI was also strongly associated with increased odds of KSD in regression analysis when DSI/DPI was modeled as a continuous variable (OR = 1.1, 95% CI: 1.01-1.20, p = 0.03), or when comparing highest quartile of DPI to lowest quartile (OR = 1.30, 95% CI: 1.10-1.70, p = 0.008). All the observed relationships were independent of total calorie intake. In conclusion, both lower DPI and higher DSI/DPI are associated with an increased risk of KSD. Future prospective studies are needed to clarify these causal relationships.

Effects of thiazides and new findings on kidney stones and dysglycemic side effects

Thiazide and thiazide-like diuretics (thiazides) belong to the most frequently prescribed drugs worldwide. By virtue of their natriuretic and vasodilating properties, thiazides effectively lower blood pressure and prevent adverse cardiovascular outcomes. In addition, through their unique characteristic of reducing urine calcium, thiazides are also widely employed for the prevention of kidney stone recurrence and reduction of bone fracture risk. Since their introduction into clinical medicine in the early 1960s, thiazides have been recognized for their association with metabolic side effects, particularly impaired glucose tolerance, and new-onset diabetes mellitus. Numerous hypotheses have been advanced to explain thiazide-induced glucose intolerance, yet underlying mechanisms remain poorly defined. Regrettably, the lack of understanding and unpredictability of these side effects has prompted numerous physicians to refrain from prescribing these effective, inexpensive, and widely accessible drugs. In this review, we outline the pharmacology and mechanism of action of thiazides, highlight recent advances in the understanding of thiazide-induced glucose intolerance, and provide an up-to-date discussion on the role of thiazides in kidney stone prevention.

Establishment of an artificial urine model in vitro and rat or pig model in vivo to evaluate urinary crystal adherence

The current study aimed to establish an experimental model in vitro and in vivo of urinary crystal deposition on the surface of ureteral stents, to evaluate the ability to prevent crystal adhesion. Non-treated ureteral stents were placed in artificial urine under various conditions in vitro. In vivo, ethylene glycol and hydroxyproline were administered orally to rats and pigs, and urinary crystals and urinary Ca were investigated by Inductively Coupled Plasma-Optical Emission Spectrometer. in vitro, during the 3- and 4-week immersion periods, more crystals adhered to the ureteral stent in artificial urine model 1 than the other artificial urine models (p < 0.01). Comparing the presence or absence of urea in the composition of the artificial urine, the artificial urine without urea showed less variability in pH change and more crystal adhesion (p < 0.05). Starting the experiment at pH 6.3 resulted in the highest amount of crystal adhesion to the ureteral stent (p < 0.05). In vivo, urinary crystals and urinary Ca increased in rat and pig experimental models. This experimental model in vitro and in vivo can be used to evaluate the ability to prevent crystal adhesion and deposition in the development of new ureteral stents to reduce ureteral stent-related side effects in patients.

Role of Nutrition in the Management of Patients with Multiple Endocrine Neoplasia Type 1

Multiple endocrine neoplasia type 1 (MEN1) is a rare syndrome caused by inactivating mutations in the MEN1 tumor suppressor gene. The three main clinical manifestations of MEN1 are primary hyperparathyroidism (PHPT), duodenal-pancreatic neuroendocrine tumors (DP-NETs) and anterior pituitary tumors. Endocrine tumors in patients with MEN1 differ from sporadic tumors because of their younger age at onset, common multiple presentations and the different clinical course. MEN1 is characterized by a complex clinical phenotype; thus, patients should be followed by a multidisciplinary team of experts that includes an endocrinologist, a surgeon, a oncologist, a radiotherapist, and not least, a nutritionist. It is important to remember the fundamental role that diet plays as a primary prevention tool, together with a healthy and active lifestyle in preventing osteoporosis/osteopenia and reducing the risk of developing kidney stones due to hypercalciuria, two frequent clinical complications in MEN1 patients. Is very important for MEN1 patients to have an adequate intake of calcium, vitamin D, magnesium and phosphate to maintain good bone health. The intake of foods containing oxalates must also be kept under control because in combination with calcium they concur to form calcium oxalate crystals, increasing the risk of nephrolithiasis. Another aspect to consider is the management of patients with pancreatic neuroendocrine tumors undergoing major surgical resections of the pancreas that can lead to alterations in digestion and absorption mechanisms due to partial or total reduction in pancreatic enzymes such as amylase, lipase, and protease, resulting in malabsorption and malnutrition. Therefore, the nutritionist's aim should be to devise a dietary plan that takes into consideration each single patient, educating them about a healthy and active lifestyle, and accompanying them through various life stages by implementing strategies that can enhance their quality of life.

Protein phosphorylation and kinases: Potential therapeutic targets in necroptosis

Necroptosis is a pivotal contributor to the pathogenesis of various human diseases, including those affecting the nervous system, cardiovascular system, pulmonary system, and kidneys. Extensive investigations have elucidated the mechanisms and physiological ramifications of necroptosis. Among these, protein phosphorylation emerges as a paramount regulatory process, facilitating the activation or inhibition of specific proteins through the addition of phosphate groups to their corresponding amino acid residues. Currently, the targeting of kinases has gained recognition as a firmly established and efficacious therapeutic approach for diverse diseases, notably cancer. In this comprehensive review, we elucidate the intricate role of phosphorylation in governing key molecular players in the necroptotic pathway. Moreover, we provide an in-depth analysis of recent advancements in the development of kinase inhibitors aimed at modulating necroptosis. Lastly, we deliberate on the prospects and challenges associated with the utilization of kinase inhibitors to modulate necroptotic processes.

Proton pump inhibitors use is associated with a higher prevalence of kidney stones: NHANES 2007-2018

BACKGROUND

Proton pump inhibitors (PPIs) are widely used throughout the world as an effective gastrointestinal drug. Nevertheless, according to the existing literature, PPIs can reduce the excretion of magnesium, calcium and other components in urine, which may promote the formation of kidney stones. We used the National Health and Nutrition Examination Survey (NHANES) database to further investigate the association between the use of PPIs and the prevalence of kidney stones.

METHODS

We performed a cross-sectional analysis using data from 2007 to 2018 NHANES. PPIs use information of 29,910 participants was obtained by using prescription medications in the preceding month, and kidney stones were presented by a standard questionnaire. Multiple regression analysis and stratified analysis were used to estimate the association between PPIs use and kidney stones after an adjustment for potential confounders.

RESULTS

The multiple logistic regression indicated that the PPIs exposure group (P1) had a significantly higher risk of nephrolithiasis than the PPIs non-exposure group (P0) in Model 3 (OR 1.24, 95% CI 1.10-1.39, P < 0.001). The stratified analyses indicated there were significant statistical differences between PPIs use and kidney stones among females (OR 1.36, 95% CI 1.15-1.62, P < 0.001), non-Hispanic whites (OR 1.27, 95% CI 1.09-1.48, P = 0.002), individuals with an education level than 11th grade (OR 1.41, 95% CI 1.13-1.76, P = 0.002) and individuals with an annual family income of $0 to $19,999 (OR 1.32, 95% CI 1.06-1.65, P = 0.014) and $20,000 to $44,999 (OR 1.25, 95% CI 1.02-1.54, P = 0.033) in Model 3.

CONCLUSIONS

Our study revealed that PPIs use is associated with a higher prevalence of kidney stones for the US population, primarily among women, non-Hispanic whites, individuals with low education levels and individuals with low household income levels. Further studies are required to confirm our findings.

Sex-specific Stone-forming Phenotype in Mice During Hypercalciuria/Urine Alkalinization

Sex differences in kidney stone formation are well known. Females generally have slightly acidic blood and higher urine pH when compared with males, which makes them more vulnerable to calcium stone formation, yet the mechanism is still unclear. We aimed to examine the role of sex in stone formation during hypercalciuria and urine alkalinization through acetazolamide and calcium gluconate supplementation, respectively, for 4 weeks in wild-type (WT) and moderately hypercalciuric [TRPC3 knockout [KO](-/-)] male and female mice. Our goal was to develop calcium phosphate (CaP) and CaP+ calcium oxalate mixed stones in our animal model to understand the underlying sex-based mechanism of calcium nephrolithiasis. Our results from the analyses of mice urine, serum, and kidney tissues show that female mice (WT and KO) produce more urinary CaP crystals, higher [Ca2+], and pH in urine compared to their male counterparts. We identified a sex-based relationship of stone-forming phenotypes (types of stones) in our mice model following urine alkalization/calcium supplementation, and our findings suggest that female mice are more susceptible to CaP stones under those conditions. Calcification and fibrotic and inflammatory markers were elevated in treated female mice compared with their male counterparts, and more so in TRPC3 KO mice compared with their WT counterparts. Together these findings contribute to a mechanistic understanding of sex-influenced CaP and mixed stone formation that can be used as a basis for determining the factors in sex-related clinical studies.

Genetic susceptibility of urolithiasis: comprehensive results from genome-wide analysis

BACKGROUND

The pathogenesis of urolithiasis is multi-factorial and genetic factors have been shown to play a significant role in the development of urolithiasis. We tried to apply genome-wide Mendelian randomization (MR) analysis and figure out reliable gene susceptibility of urolithiasis from the largest samples to date in two independent genome-wide association studies (GWAS) database of European ancestry.

METHODS

We extracted summary statistics of expression quantitative trait locus (eQTL) from eQTLGen consortium. Urolithiasis phenotype information was obtained from both FinnGen Biobank and UK Biobank. Multiple two-sample MR analysis with a Bonferroni-corrected P threshold (P < 2.5e-06) was conducted. The primary endpoint was the causal effect calculated by random-effect inverse variance weighted (IVW) method. Sensitivity analysis, volcano plots, scatter plots, and regional plots were also performed and visualized.

RESULTS

After multiple MR tests between 19942 eQTLs and urolithiasis phenotype from both cohorts, 30 common eQTLs with consistent effect size direction were found to be causally associated with urolithiasis risk. Finally only one gene (LMAN2) was simultaneously identified among all top significant eQTLs from both FinnGen Biobank (beta = 0.6758, se = 0.0327, P = 6.775e-95) and UK Biobank (beta = 0.0044, se = 0.0009, P = 2.417e-06). We also found that LMAN2 was with the largest beta effect size on urolithiasis phenotype from the two cohorts.

CONCLUSION

We for the first time implemented genome-wide MR analysis to investigate the genetic susceptibility of urolithiasis in general population of European ancestry. Our results provided novel insights into common genetic variants of urinary stone disease, which was of great help to subsequent researches.

Understanding formation processes of calcareous nephrolithiasis in renal interstitium and tubule lumen

Kidney stone, one of the oldest known diseases, has plagued humans for centuries, consistently imposing a heavy burden on patients and healthcare systems worldwide due to their high incidence and recurrence rates. Advancements in endoscopy, imaging, genetics, molecular biology and bioinformatics have led to a deeper and more comprehensive understanding of the mechanism behind nephrolithiasis. Kidney stone formation is a complex, multi-step and long-term process involving the transformation of stone-forming salts from free ions into asymptomatic or symptomatic stones influenced by physical, chemical and biological factors. Among the various types of kidney stones observed in clinical practice, calcareous nephrolithiasis is currently the most common and exhibits the most intricate formation mechanism. Extensive research suggests that calcareous nephrolithiasis primarily originates from interstitial subepithelial calcified plaques and/or calcified blockages in the openings of collecting ducts. These calcified plaques and blockages eventually come into contact with urine in the renal pelvis, serving as a nidus for crystal formation and subsequent stone growth. Both pathways of stone formation share similar mechanisms, such as the drive of abnormal urine composition, involvement of oxidative stress and inflammation, and an imbalance of stone inhibitors and promoters. However, they also possess unique characteristics. Hence, this review aims to provide detailed description and present recent discoveries regarding the formation processes of calcareous nephrolithiasis from two distinct birthplaces: renal interstitium and tubule lumen.

Monogenic features of urolithiasis: A comprehensive review

Objective

Urolithiasis formation has been attributed to environmental and dietary factors. However, evidence is accumulating that genetic background can contribute to urolithiasis formation. Advancements in the identification of monogenic causes using high-throughput sequencing technologies have shown that urolithiasis has a strong heritable component.

Methods

This review describes monogenic factors implicated in a genetic predisposition to urolithiasis. Peer-reviewed journals were evaluated by a PubMed search until July 2023 to summarize disorders associated with monogenic traits, and discuss clinical implications of identification of patients genetically susceptible to urolithiasis formation.

Results

Given that more than 80% of urolithiases cases are associated with calcium accumulation, studies have focused mainly on monogenetic contributors to hypercalciuric urolithiases, leading to the identification of receptors, channels, and transporters involved in the regulation of calcium renal tubular reabsorption. Nevertheless, available candidate genes and linkage methods have a low resolution for evaluation of the effects of genetic components versus those of environmental, dietary, and hormonal factors, and genotypes remain undetermined in the majority of urolithiasis formers.

Conclusion

The pathophysiology underlying urolithiasis formation is complex and multifactorial, but evidence strongly suggests the existence of numerous monogenic causes of urolithiasis in humans.

Association of Urine (pH < 5.5) with Community Periodontal Index (CPI) and the Number of Remaining Teeth in Korean Adults: A Cross-Sectional Study Using Data from Korea National Health and Nutrition Examination Survey 2016-2018

This study aims to determine the association between UpH (<5.5), Community Periodontal Index (CPI), and the number of remaining teeth-cumulative indicators of oral health-using data from the 7th Korea National Health and Nutrition Examination Survey (KNHANES, 2016-2018), which represents the Korean population. Data from 12,689 adults aged 19 years and older who had periodontal examinations were analyzed. Logistic regression analysis was performed after adjusting for demographic, health, and health-related behavioral factors as covariates to determine the association between UpH, CPI, and the number of remaining teeth. This study found that UpH (<5.5) was associated with CPI and the number of remaining teeth. For UpH (<5.5), the odds ratio for CPI (≥4 mm) was 1.19 times (95% CI: 1.06-1.33). The risk of tooth loss was 1.25 times (95% CI: 1.06-1.48) for those with 0-19 remaining teeth and 1.20 times (95% CI: 1.07-1.34) for those with 20-27 teeth. The results revealed an association between UpH, CPI, and the number of remaining teeth. However, further longitudinal research on UpH and oral status is necessary.

Establishment and application of a nomogram diagram for predicting calcium oxalate stones in patients with urinary tract stones

This retrospective study aims to examine the correlation between calcium oxalate (CaOx) stones and common clinical tests, as well as urine ionic composition. Additionally, we aim to develop and implement a personalized model to assess the accuracy and feasibility of using charts to predict calcium oxalate stones in patients with urinary tract stones. A retrospective analysis was conducted on data from 960 patients who underwent surgery for urinary stones at the First Affiliated Hospital of Soochow University from January 1, 2010, to December 31, 2022. Among these patients, 447 were selected for further analysis based on screening criteria. Multivariate logistic regression analysis was then performed to identify the best predictive features for calcium oxalate stones from the clinical data of the selected patients. A prediction model was developed using these features and presented in the form of a nomogram graph. The performance of the prediction model was assessed using the C-index, calibration curve, and decision curve, which evaluated its discriminative power, calibration, and clinical utility, respectively. The nomogram diagram prediction model developed in this study is effective in predicting calcium oxalate stones which is helpful in screening and early identification of high-risk patients with calcium oxalate urinary tract stones, and may be a guide for urologists in making clinical treatment decisions.

Contrasting Response of Urine Stone Risk to Medical Treatment in Calcium Oxalate versus Calcium Phosphate Stone Formers

Key Points

Thiazide treatment successfully lowered urine calcium and both calcium oxalate and calcium phosphate supersaturations in both types of stone formers (SFs). Alkali therapy may not confer the same benefits on calcium phosphate SFs as it does on calcium oxalate SFs.

Background

Randomized controlled trials have shown that both thiazide diuretics and potassium citrate (K-Cit) can prevent calcium stone recurrence, but most participants formed calcium oxalate (CaOx) stones. While thiazides are expected to lower risk of calcium phosphate (CaP) stone formation, the effect of K-Cit on risk of CaP stone formation is unclear.

Methods

To study the effect of common calcium stone treatments, we analyzed the 24-hour urines of CaOx and CaP stone formers (SFs) by four treatment types: Lifestyle, K-Cit, Thiazide, or Both medications.

Results

Patients treated with thiazides reduced urine calcium in both CaOx (M =−74.4, SD =94.6 mg/d) and CaP (M =−102, SD =99.7 mg/d) SFs while those on K-Cit had no change in urine calcium. Among CaOx SFs, urine citrate rose in patients administered K-Cit with or without thiazide, but citrate did not rise significantly in CaP SFs. Urine pH rose in all CaOx SFs, but among CaP SFs, only rose in patients receiving K-Cit. CaOx supersaturation (SS) decreased in all patients who received Thiazide, and decreased among CaOx SFs treated with K-Cit. CaP SS decreased in both CaOx SFs (M =−0.46, SD =0.86) and CaP SFs (M =−0.76, SD =0.85) treated with Thiazide, except CaOx SFs who received Both. Patients treated with K-Cit alone increased CaP SS in CaOx SFs (M =0.25, SD =0.79).

Conclusions

Patients treated with Thiazide lowered urine calcium and SS in both stone groups. Patients treated with K-Cit had no significant changes in urine calcium and had a decrease in CaOx SS in CaOx SFs. The study raises questions about the best preventive treatment for patients with CaP stones and suggests that K-Cit may not confer the same benefits on CaP SFs as it does on CaOx SFs.

Magnesium Decreases Urine Supersaturation but Not Calcium Oxalate Stone Formation in Genetic Hypercalciuric Stone-Forming Rats

BACKGROUND/AIMS

Hypercalciuria is the most common identifiable risk factor predisposing to CaOx stone formation. Increased oral magnesium intake may lead to decreased CaOx stone formation by binding intestinal Ox leading to decreased absorption and/or binding urinary Ox to decrease urinary supersaturation. This study assessed the effect of oral magnesium on 24-h urine ion excretion, supersaturation, and kidney stone formation in a genetic hypercalciuric stone-forming (GHS) rat model of human idiopathic hypercalciuria.

METHODS

When fed the oxalate precursor, hydroxyproline, every GHS rat develops CaOx stones. The GHS rats, fed a normal calcium and phosphorus diet supplemented with hydroxyproline to induce CaOx, were divided into three groups of ten rats per group: control diet with 4.0 g/kg MgO, low MgO diet (0.5 g/kg), and high MgO diet (8 g/kg). At 6 weeks, 24-h urines were collected, and urine chemistry and supersaturation were determined. Stone formation was quantified.

RESULTS

The GHS rats fed the low and high Mg diets had a significant reduction and increase, respectively, in urinary Mg compared to those fed the control diet. Dietary Mg did not alter urine Ca excretion while the low Mg diet led to a significant fall in urinary Ox. Urine supersaturation with respect to CaOx was significantly increased with low Mg, whereas urine supersaturation was significantly decreased with high Mg. There was no effect of dietary Mg on stone formation within 6 weeks of treatment.

CONCLUSION

Dietary magnesium decreases urine supersaturation but not CaOx stone formation in GHS rats.

Is Kidney Stone Associated with Thyroid Disease? The United States National Health and Nutrition Examination Survey 2007-2018

BACKGROUND

Kidney stones and thyroid disease are two common diseases in the general population, with multiple common risk factors. The associations between kidney stones and thyroid disease are unclear.

AIM

This study aims to assess the association between 'once had a thyroid disease' and the odds of kidney stones.

METHODS

Adult participants from the National Health and Nutrition Examination Survey (NHANES) 2007-2018 with reliable kidney stone and thyroid disease data were included. Adjusting for age, gender, race, education level, and marital status, diabetes, hypertension, gout, angina pectoris, stroke, and asthma, logistic regression was used to examine the relationship between kidney stones and thyroid illness.

RESULTS

Using stratified analysis, the association between thyroid illness and kidney stones was investigated further. Among the participants, 4.9% had kidney stones, and 10.1% had thyroid disease. Kidney stone was associated with thyroid disease (OR=1.441, (95% CI:1.294-1.604), p <0.01), which remained significant (OR=1.166, (95% CI:1.041-1.305), p <0.01) after adjustments with age, gender, race, education level and marital status, diabetes, hypertension, gout, angina pectoris, stroke, and asthma. Stratified by blood lead, blood cadmium, and blood urea nitrogen levels in the human body, the odds of kidney stones still increased with once having a previous thyroid disease.

CONCLUSIONS

In this large nationally representative survey over 10 years, kidney stone was strongly associated with thyroid disease. In this cross-sectional study, we explored the association between thyroid disease and kidney stones, which may help clinicians intervene in them early.

The intricate role of annexin A2 in kidney: a comprehensive review

Annexin A2 (Anxa2) is a calcium (Ca2+)-regulated phospholipid binding protein composed of a variable N-terminus and a conserved core domain. This protein has been widely found in many tissues and fluids, including tubule cells, glomerular epithelial cells, renal vessels, and urine. In acute kidney injury, the expression level of this protein is markedly elevated in response to acute stress. Moreover, Anxa2 is a novel biomarker and potential therapeutic target with prognostic value in chronic kidney disease. In addition, Anxa2 is associated not only with clear-cell renal cell carcinoma differentiation but also the formation of calcium-related nephrolithiasis. In this review, we discuss the characteristics and functions of Anxa2 and focus on recent reports on the role of Anxa2 in the kidney, which may be useful for future research.

Awareness of Urinary Stone Risk Factors Among the Adult Population of Jazan, Saudi Arabia: A Cross-Sectional Study

BACKGROUND

Urolithiasis, a common clinical condition, has seen a global increase in prevalence in recent years. Urinary stones are common in hot climate areas like Saudi Arabia. This study aimed to assess the prevalence and awareness of risk factors for urinary stones in Jazan, Saudi Arabia.

METHODS

A cross-sectional study was conducted among 1000 Jazan adults between January and June 2022. A questionnaire was used to collect data on sociodemographics, urinary stone diagnosis, and awareness of risk factors.

RESULTS

The overall prevalence of diagnosed urinary stones was 140 (14.0%). The prevalence was higher among patients who were older, married, had higher education, and were employees (all P<0.001). Participants who believed that hot weather (p = 0.012), sleeve gastrectomy (p = 0.049), and Saxenda injections (p = 0.000) increased the risk of stones had a higher prevalence. No association was found between stones and other sociodemographic factors or dietary habits. The main sources of knowledge were the internet (426, 42.6%) and education (155, 15.5%).

CONCLUSIONS

The prevalence of urinary stones in Jazan is considerable (14.0%). Certain sociodemographic factors and beliefs about risk factors were associated with higher prevalence. Improving public awareness about the prevention and risk factors for urinary stones is crucial to controlling this health problem in high-risk communities.

Kidney Stone Pathophysiology, Evaluation and Management: Core Curriculum 2023

Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a disorder in which urinary solutes precipitate to form aggregates of crystalline material in the urinary space. The incidence of nephrolithiasis has been increasing, and the demographics have been evolving. Once viewed as a limited disease with intermittent exacerbations that are simply managed by urologists, nephrolithiasis is now recognized as a complex condition requiring thorough evaluation and multifaceted care. Kidney stones are frequently manifestations of underlying systemic medical conditions such as the metabolic syndrome, genetic disorders, or endocrinopathies. Analysis of urine chemistries and stone composition provide a window into pathogenesis and direct ancillary studies to uncover underlying diseases. These studies allow providers to devise individualized strategies to limit future stone events. Given its complexity, kidney stone disease is best addressed by a team led by nephrologists and urologists with input from multiple other health professionals including dietitians, endocrinologists, interventional radiologists, and endocrine surgeons. In this installment of AJKD's Core Curriculum in Nephrology, we provide a case-based overview of nephrolithiasis, divided by the individual stone types. The reader will gain a pragmatic understanding of the pathophysiology, evaluation, and management of this condition.

2022 Recommendations of the AFU Lithiasis Committee: Endoscopic description of renal papillae and stones

Endoscopic observation is performed during treatments by flexible ureteroscopy to differentiate in situ between renal papillary abnormalities and stones based on their concordance with Daudon's morphological/composition descriptions adapted to endoscopy. These intraoperative visual analyses are now an integral part of the urinary stone disease diagnostic approach in addition to the morphological/structural and spectrophotometric analysis that remains the reference exam, but that loses information on the stone component representativeness due to the development of in situ laser lithotripsy. These are the first practical recommendations on the endoscopic description of renal papillae and stones. METHODOLOGY: These recommendations were developed using two methods: the Clinical Practice Recommendations (CPR) and the ADAPTE method, depending on whether the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis [EAU Guidelines on urolithiasis. 2022]) and their adaptability to the French context.

Protective Effect of Alkaline Mineral Water on Calcium Oxalate-Induced Kidney Injury in Mice

Background

Kidney stone disease induces chronic renal insufficiency by crystal-induced renal tubular epithelial cell injury. It has been reported that the prevalence of kidney stone disease is increasing, accompanied by the high recurrence rate. Alkaline mineral water has been reported to possess beneficial effects to attenuate inflammation. Here, we explored the potential protective effects and underlying mechanisms of alkaline mineral water against calcium oxalate-induced kidney injury.

Methods

We performed the mice kidney stone model by administering glyoxylate at 100 mg/kg once daily for 7 days. To assess the effects of alkaline mineral water on oxalate-induced kidney injury, mice drank different water (distilled water, natural mineral water at pH = 8.0, as well as natural mineral water at pH = 9.3) for 7 days, respectively, followed by glyoxylate exposure. After collection, crystal formation, kidney injury and cell apoptosis, fibrosis, oxidative stress, as well as inflammation were measured.

Results

Our results showed that glyoxylate treatment led to kidney crystal formation and fibrosis, which can be attenuated by drinking alkaline mineral water. Furthermore, alkaline mineral water also reduced kidney injury and cell apoptosis, oxidative stress, and inflammation.

Conclusion

Alkaline mineral water supplement prevents progression of glyoxylate-induced kidney stones through alleviating oxidative stress and inflammation.

Increased risk of chronic kidney disease in uric acid stone formers with high neutrophil-to-lymphocyte ratio

Urolithiasis is associated with an increased risk of chronic kidney disease (CKD), irrespective of stone compositions. Chronic inflammation is an important factor for CKD progression. Neutrophil-to-lymphocyte ratio (NLR) has been recognized as a reliable biomarker of inflammation, yet its use in predicting renal deterioration in patients with urolithiasis remains limited. We aimed to explore whether the combination of stone composition and NLR could be useful as a predictor for CKD risk. A total of 336 stone formers with at least one stone submission for analysis were enrolled in the retrospective study. Stones were classified into uric acid and calcium groups. Renal functions were assessed at least one month after stone treatment. Uric acid stone formers had significantly lower estimated glomerular filtration rate (eGFR) compared with calcium stone formers (p < 0.001). NLR was significantly higher in uric acid stone formers (p = 0.005), and a significantly negative correlation (p < 0.001) between NLR and eGFR had been observed only in uric acid stone group. Univariate and multivariate logistic regression analyses showed that higher proportion of uric acid stone composition and higher NLR were both significantly associated with CKD risks. A nomogram integrating independent predictors was generated for CKD prediction, yielding an AUC of 0.811 (0.764-0.858). In conclusion, our study demonstrated that stone formers with higher proportion of uric acid composition and higher NLR levels were associated with higher CKD risk.

Association between urinary phthalate metabolites and nephrolithiasis in adults: A cross-sectional analysis with NHANES 2007-2018

Nephrolithiasis is highly prevalent and brings health and economic burdens to patients. The augmentation of nephrolithiasis may be associated with exposure to phthalate metabolites. However, few studies investigated the effect of various phthalates exposure on nephrolithiasis. We analyzed data from 7139 participants aged 20 years or above from the National Health and Nutrition Examination Survey (NHANES) 2007-2018. Serum calcium level-stratified univariate and multivariate linear regression analyses were performed to explore the relationship between urinary phthalate metabolites and nephrolithiasis. As a result, the prevalence of nephrolithiasis was approximately 9.96%. After adjusting for confounding factors, associations were found between serum calcium concentration with monoethyl phthalate (P = 0.012) and mono-isobutyl phthalate (P = 0.003) compared with tertile 1 (T1). In adjusted analysis, nephrolithiasis was positively associated with middle and high tertiles of mono benzyl phthalate (P < 0.05) compare with low tertile group. Furthermore, high-level exposure to mono-isobutyl phthalate had a similar positive association with nephrolithiasis (P = 0.028). Our findings provide evidence that exposure to certain phthalate metabolites (i.e. MiBP and MBzP) may be associated with a high risk of nephrolithiasis depending on serum calcium level.

Urinary Calcium Is Associated with Serum Sclerostin among Stone Formers

BACKGROUND

Sclerostin plays an important role in bone metabolism and adipose tissue. Animal studies suggest that sclerostin influences urinary calcium (UCa), but this relationship has not been evaluated in stone formers (SFs). We aimed to investigate the association of UCa with serum sclerostin, bone mineral density (BMD), and body composition among SFs.

METHODS

Clinical and laboratorial data were retrieved from medical records. Determinants of UCa were studied using linear regression.

RESULTS

A total of 107 SFs (35.8 ± 9.3 years, 54% male) with eGFR 99.8 ± 14.5 mL/min/1.73 were studied. Subjects were split by sex and grouped into tertiles of UCa levels. Men in the highest UCa tertile had higher body mass index (BMI) and serum sclerostin, lower lean mass, and a trend towards higher fat mass. Women in the highest tertile had higher BMI and a trend towards higher serum sclerostin. Hypertension and metabolic syndrome, but not lower BMD, were more prevalent in the highest UCa tertile for both sexes. Sclerostin was positively correlated with fat mass and inversely correlated with lean mass among men, but not among women. BMD corrected for BMI at lumbar spine was inversely associated with UCa in a univariate analysis, but only serum sclerostin, hypertension, and NaCl intake were independent determinants of UCa in the multivariate model.

CONCLUSION

The present findings disclose that in addition to hypertension and salt intake, serum sclerostin is associated with urinary calcium in stone formers, suggesting that in addition to the hormones traditionally thought to alter calcium reabsorption in the kidney, sclerostin may play a significant additional role, warranting further investigation.

Characterizations of annexin A1-interacting proteins in apical membrane and cytosolic compartments of renal tubular epithelial cells

Annexin A1 (ANXA1) is a multifunctional calcium-binding protein that can bind to membrane phospholipids. Under high-calcium condition, ANXA1 expression increases on renal epithelial cell surface, leading to enhanced adhesion of calcium oxalate (CaOx) crystal (stone material) onto the cells. To regulate various cellular processes, ANXA1 interacts with many other intracellular protein partners. However, components of the ANXA1-interacting protein complex remain unclear. Herein, we characterized the interacting complexes of apical membrane (ApANXA1) and cytosolic (cyANXA1) forms of ANXA1 in apical membrane and cytosolic compartments, respectively, of renal epithelial cells under high-calcium condition using proteomic and bioinformatic approaches. After fractionation, the ApANXA1- and CyANXA1-interacting partners were identified by immunoprecipitation followed by nanoLC‑ESI‑Qq-TOF tandem mass spectrometry (IP-MS/MS). The ANXA1-interacting partners that were common in both apical membrane and cytosolic compartments and those unique in each compartment were then analyzed for their physico-chemical properties (molecular weight, isoelectric point, amino acid contents, instability index, aliphatic index, and grand average of hydropathicity), secondary structure (α-helix, β-turn, random coil, and extended strand), molecular functions, biological processes, reactome pathways and KEGG pathways. The data demonstrated that each set of these interacting proteins exhibited common and unique characteristics and properties. The knowledge from this study may lead to better understanding of the ApANXA1 and CyAXNA1 biochemistry and functions as well as the pathophysiology of CaOx kidney stone formation induced by high-calcium condition.

Risk Factors for Common Kidney Stones Are Correlated with Kidney Function Independent of Stone Composition

INTRODUCTION

Kidney stone type varies with age, sex, season, and medical conditions. Lower estimate glomerular filtration rate (eGFR) leads to changes in urine chemistry, and risk factors for kidney stones are thought to vary by stone type. We explore the association between eGFR, urine risk factors, and common stone compositions.

METHODS

This was a retrospective cohort study of 811 kidney stone patients seen at Yale Medicine between 1994 and 2021 with serum chemistries and 24-h urine chemistries matched within 1 year of baseline stone analysis. Patients' eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2021 equation. Demographics and medical history were compared by χ2 tests. 24-h urine chemistries and stone analyses were analyzed by one-way ANOVA. Linear regressions were performed to control for demographics, comorbidities, and stone composition.

RESULTS

With lower eGFR, the proportion of calcium stones declined while uric acid (UA) stones increased. On univariable analysis, lower eGFR was associated with lower urine pH, calcium, citrate, UA, magnesium, phosphorus, and ammonium. On multivariable analysis, controlling for age, sex, ethnicity, body mass index, comorbidities, and stone type, these factors remained significant. Stone formers with lower eGFR had elevated supersaturation for UA, but reduced supersaturations for calcium-containing stones. Though urine oxalate was significant on univariable analysis, it was not on multivariable analysis.

CONCLUSION

Changes in urine parameters are strongly correlated with eGFR regardless of stone type. Renal function may play a key role in modulating kidney stone risk factors. Strategies to mitigate stone risk may need to vary with kidney function, especially when patient urine or stone composition data are unavailable.

Could METS-VF provide a clue as to the formation of kidney stones?

Objective

The lifetime occurrence rate of kidney stones is 14%, making it one of the most prevalent urological conditions. Other contributing elements, such as obesity, diabetes, diet, and heredity, are also taken into account. Our research sought to explore the potential link between high visceral fat scores (METS-VF) and the occurrence of kidney stones, as a means of understanding how to prevent them.

Methods

This research utilized data from the National Health and Nutrition Examination Survey (NHANES), mirroring the demographics of the United States. We carried out an in-depth analysis of the connection between METS-VF and kidney stones, based on data from 29,246 participants in the National Health and Nutrition Examination Survey spanning 2007 to 2018, involving logistic regression, segmentation, and dose-response curve analysis.

Results

Our study of 29,246 potential participants found that METS-VF was positively associated with the prevalence and progression of kidney stones. After subgroup analysis by gender, race, blood pressure, and blood glucose, our results showed that the ORs for METS-VF and kidney stones were (1.49, 1.44) in males and females, respectively; while in Mexicans, whites, blacks, and In other populations, the OR values were (1.33, 1.43, 1.54, 1.86); in hypertensive and normal populations, the OR values were (1.23, 1.48); in diabetic patients and normoglycemic patients were (1.36,1.43). This proves that it works for all groups of people.

Summary

Our studies demonstrate a strong connection between METS-FV and the emergence of kidney stones. It would be beneficial to investigate METS-VF as a marker for kidney stone development and progression in light of these findings.

Vitamin D and Calcium Supplementation and Urolithiasis: A Controversial and Multifaceted Relationship

Patients with urolithiasis, and particularly those with hypercalciuria, frequently have a marked reduction of bone mineral content up to the levels of osteoporosis, with a significant increase in bone fracture risk. For these reasons, the indication to prescribe vitamin D and/or calcium supplementations is very frequent in such patients. On the other hand, both calcium supplementation, and even more vitamin D therapy, can worsen the risk of developing urolithiasis by increasing calcium, phosphate, and oxalate urinary excretion. Despite the clinical and practical relevance of this issue, the evidence on this topic is scarce and contradictory. Therefore, some concerns exist about how and whether to prescribe such supplements to a patient with a history of kidney stones. In this narrative review, we resume some pivotal pathophysiological concepts strictly related to the dealt topic, and we draw some considerations and personal opinions on the pros and cons of such prescriptions. Finally, we share with the reader our pragmatic algorithm for handling the urolithiasis risk in patients who have strong indications to be prescribed vitamin D and calcium supplementations.