Kidney Stones and Cardiovascular Risk: A Meta-analysis of Cohort Studies

Between a Rock and a Short Place-The Impact of Nephrolithiasis on Skeletal Growth and Development Across the Lifespan

PURPOSE OF REVIEW

The impact of nephrolithiasis on skeletal growth and bone health across the life span of kidney stone formers is reviewed.

MAIN FINDINGS

Bone disease is an early event among kidney stone formers (SF), with distinct phenotypes according to each age, sex, menopausal status, dietary, hormonal and genetic factors. Nephrolithiasis-associated bone disorder is characterized by reduced bone mineral density (BMD) and histologically discloses low bone formation, high bone resorption and abnormal mineralization. Although hypercalciuria has been presumed to be pathogenic for bone loss in SF, the association of BMD with urinary calcium is not uniform in all studies. Hypocitraturia, metabolic disturbances, cytokines and receptors, growth factors and acid-base status may all influence skeletal outcomes. The potential link of bone disease with vascular calcification and cardiovascular disease among SF is discussed. The unique vulnerability of the younger skeleton to the effects of nephrolithiasis on attainment of peak bone mass and strength is highlighted and the association of bone loss with kidney stone formation early in life indicate the opportunity for intervention to reduce the risk of future bone fractures.

Association Between Kidney Stone History and Cardiovascular Event Risk in US Adults

OBJECTIVE

To determine the association between kidney stone history and predicted 10-year risk of atherosclerotic cardiovascular disease (CVD) events in a nationally representative US adult sample without existing CVD.

METHODS

This was a cross-sectional study of the 2017-2020 National Health and Nutrition Examination Survey that included a nationally representative sample of 3842 adults aged 40-79 free from CVD. Kidney stone history was assessed through self-reporting. The 10-year risk of an atherosclerotic CVD event was predicted using the American College of Cardiology/American Heart Association (ACC/AHA) Pooled Cohort Equations.

RESULTS

The weighted prevalence of kidney stones was 12.2% (95% CI: 10.5% to 14.1%). In unadjusted analysis, the odds of borderline or higher (≥5%) atherosclerotic CVD risk were higher in stone formers (odds ratio=1.56; 95% CI 1.01-2.40; P = .046). This association persisted after adjustment for demographics and clinical covariates (adjusted odds ratio=1.57; 95% CI=1.02 to 2.43; P = .04). A significant interaction by biological sex was identified (P = .002), with excess risk conferred by kidney stones in males but not females.

CONCLUSION

Kidney stone history was independently associated with increased 10-year predicted atherosclerotic CVD event risk, with excess risk observed among males but not females. Intensified CVD screening may be warranted among stone formers given their increased cardiovascular risk.

Cardiovascular and Cerebrovascular Morbidity in Patients with Urolithiasis: An Epidemiological Approach Based on Hospitalization Burden Data from 1997 to 2021

Background: Patients with kidney stones (KSFs) are known to have a heightened risk of coronary heart disease (CHD) or stroke. The objective of the present study was to describe the natural history of these complications through the longitudinal analysis of the hospitalizations due to kidney stones in Spain from 1997 to 2021. Methods: A retrospective longitudinal observational study was developed based on nationwide hospitalization data (minimum basic data base). Three different analyses were carried out. In the first step, the prevalence of coronary or cerebrovascular events in kidney stone hospitalizations was compared with the hospitalization burden of CHD or strokes related to the general population. In the second step, a survival analysis of the kidney stones-hospitalized patients using the Kaplan-Meier method was conducted. In the third step, a Cox regression was used to assess the influence of the classical comorbidities in the development of the lithiasic patients-cardiovascular disease. Results: Kidney stone-hospitalized patients exhibit a significantly higher risk of CHD (OR = 14.8 CI95%: 14.7-14.9) and stroke (OR = 6.7 CI95%: 6.6-6.8) compared to the general population across in all age groups, although they had less cardiovascular risk factors. A total of 9352 KSFs (1.5%) developed a coronary event within an average time of 78.8 months. A total of 2120 KSFs (0.33%) suffered a stroke in an average time of 71.1 months. Diabetes, hypertension, hyperlipidemia, and being overweight were identified as risk factors for developing CHD and stroke using a univariate and multivariate analysis. Conclusions: Our study confirms previous studies in which kidney stones must be considered as a risk factor for developing CHD or cerebrovascular disease. Preventive strategies should target patients with kidney stones and classical risk cardiovascular factors to mitigate modifiable conditions associated with cardiovascular diseases.

Epidemiological and biological associations between cardiovascular disease and kidney stone formation: A systematic review and meta-analysis

AIMS

Previous studies find kidney stone formers (KSF) are at greater risk of developing cardiovascular disease (CVD). The underlying mechanisms are poorly understood, and many clinicians are unaware of this connection. We will: DATA SYNTHESIS: Our systematic review is registered with PROSPERO (ID CRD42021251477). We searched epidemiological and biological data. The epidemiological search generated 669 papers, narrowed down to 15. There were 4,259,869 participants (230,720 KSFs). KSF was associated with 25% higher risk of coronary artery disease (CAD) (95% confidence interval (CI): 15, 35%), 17% higher risk of stroke/transient ischemic attacks (TIA) (CI:10, 25%) and 39% higher risk of arterial disease (AD) (CI: 17 65%). Significant heterogeneity was found. Female-identifying KSFs had a higher risk of stroke (ratio = 1.10) and CAD (1.20). The biological search generated 125 papers, narrowed down to 14. Potential underlying mechanisms were extracted and discussed, including intimal/medial vascular calcification, oxidative stress via osteopontin (OPN), cholesterol-induced pathology, and endothelial dysfunction.

CONCLUSIONS

There is a significant association between KSF and CVD, supporting the consideration of KSF as a systemic, calcium-mediated disease. Clinicians will benefit from being aware of this connection.

Vascular calcification on the risk of kidney stone: a meta-analysis

BACKGROUND

The association between vascular calcification (VC) and kidney stone is still inconclusive. Therefore, we conducted a meta-analysis to estimate the risk of kidney stone disease in subjects with VC.

METHODS

To identify publications from related clinical studies, we performed a search on PubMed, Web of Science, Embase, and Cochrane Library databases from their inceptions until 1 September 2022. According to obvious heterogeneity, a random-effects model was used to calculate the odds ratios (ORs) and corresponding 95% confidence intervals (CIs). Subgroup analysis was conducted trying to dissect the effects of VC in different segments and population regions in predicting kidney stone risk.

RESULTS

Seven articles were included with a total number of 69,135 patients, of which 10,052 have vascular calcifications and 4728 have kidney stones. There was a significantly higher risk of kidney stone disease in participants with VC versus control (OR = 1.54, 95% CI: 1.13-2.10). Sensitivity analysis confirmed the stability of the results. VC can be separated into abdominal, coronary, carotid, and splenic aortic calcification while pooled analysis of abdominal aorta calcification did not indicate a significant higher kidney stone risk. An obvious higher risk of kidney stone was observed in Asian VC patients (OR = 1.68, 95% CI: 1.07-2.61).

CONCLUSION

Combined evidence of observational studies suggested patients with VC may be associated with an increased risk of kidney stone disease. Despite the predictive value was relatively low, it is still worth noting that patients with VC are under the threat of kidney stone disease.

Oxalate (dys)Metabolism: Person-to-Person Variability, Kidney and Cardiometabolic Toxicity

Oxalate is a metabolic end-product whose systemic concentrations are highly variable among individuals. Genetic (primary hyperoxaluria) and non-genetic (e.g., diet, microbiota, renal and metabolic disease) reasons underlie elevated plasma concentrations and tissue accumulation of oxalate, which is toxic to the body. A classic example is the triad of primary hyperoxaluria, nephrolithiasis, and kidney injury. Lessons learned from this example suggest further investigation of other putative factors associated with oxalate dysmetabolism, namely the identification of precursors (glyoxylate, aromatic amino acids, glyoxal and vitamin C), the regulation of the endogenous pathways that produce oxalate, or the microbiota's contribution to oxalate systemic availability. The association between secondary nephrolithiasis and cardiovascular and metabolic diseases (hypertension, type 2 diabetes, and obesity) inspired the authors to perform this comprehensive review about oxalate dysmetabolism and its relation to cardiometabolic toxicity. This perspective may offer something substantial that helps advance understanding of effective management and draws attention to the novel class of treatments available in clinical practice.

Proposal for pathogenesis-based treatment options to reduce calcium oxalate stone recurrence

Objective

Prevalence of kidney stone disease continues to increase globally with recurrence rates between 30% and 50% despite technological and scientific advances. Reduction in recurrence would improve patient outcomes and reduce cost and stone morbidities. Our objective was to review results of experimental studies performed to determine the efficacy of readily available compounds that can be used to prevent recurrence.

Methods

All relevant literature up to October 2020, listed in PubMed is reviewed.

Results

Clinical guidelines endorse the use of evidence-based medications, such as alkaline agents and thiazides, to reduce urinary mineral supersaturation and recurrence. However, there may be additional steps during stone pathogenesis where medications could moderate stone risk. Idiopathic calcium oxalate stones grow attached to Randall's plaques or plugs. Results of clinical and experimental studies suggest involvement of reactive oxygen species and oxidative stress in the formation of both the plaques and plugs. The renin-angiotensin-aldosterone system (RAAS), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, mitochondria, and NOD-like receptor pyrin domain containing-3 (NLRP3) inflammasome have all been implicated at specific steps during stone pathogenesis in animal models.

Conclusion

In addition to supersaturation-reducing therapies, the use of anti-oxidants, free radical scavengers, and inhibitors of NADPH oxidase, NLRP3 inflammasome, and RAAS may prove beneficial for stone prevention. Compounds such as statins and angiotensin converting enzyme inhibitors are already in use as therapeutics for hypertension and cardio-vascular disease and have previously shown to reduce calcium oxalate nephrolithiasis in rats. Although clinical evidence for their use in stone prevention in humans is limited, experimental data support they be considered along with standard evidence-based medications and clinical expertise when patients are being counselled for stone prevention.

Hospitalization Burden of Patients with Kidney Stones and Metabolic Comorbidities in Spain during the Period 2017-2020

Nephrolithiasis has become an increasing worldwide problem during the last decades. Metabolic syndrome, its components, and related dietary factors have been pointed out as responsible for the increasing incidence. The objective of this study was to evaluate the trends in the hospitalization rates of patients with nephrolithiasis, hospitalization features, costs, and how metabolic syndrome traits influence both the prevalence and complications of lithiasic patients. An observational retrospective study was conducted by analyzing hospitalization records from the minimum basic data set, including all patient hospitalizations in Spain in which nephrolithiasis has been coded as a main diagnosis or as a comorbidity during the period 2017-2020. A total of 106,407 patients were hospitalized and coded for kidney or ureteral lithiasis in this period. The mean age of the patients was 58.28 years (CI95%: 58.18-58.38); 56.8% were male, and the median length of stay was 5.23 days (CI95%: 5.06-5.39). In 56,884 (53.5%) patients, kidney or ureteral lithiasis were coded as the main diagnosis; the rest of the patients were coded mostly as direct complications of kidney or ureteral stones, such as "non-pecified renal colic", "acute pyelonephritis", or "tract urinary infection". The hospitalization rate was 56.7 (CI95%: 56.3-57.01) patients per 100,000 inhabitants, showing neither a significant increasing nor decreasing trend, although it was influenced by the COVID-19 pandemic. The mortality rate was 1.6% (CI95%: 1.5-1.7), which was higher, if lithiasis was coded as a comorbidity (3.4% CI95%: 3.2-3.6). Metabolic syndrome diagnosis component codes increased the association with kidney lithiasis when age was higher, reaching the highest in the eighth decade of life. Age, diabetes, and hypertension or lithiasis coded as a comorbidity were the most common causes associated with the mortality of lithiasic patients. In Spain, the hospitalization rate of kidney lithiasis has remained stable during the period of study. The mortality rate in lithiasic patients is higher in elderly patients, being associated with urinary tract infections. Comorbidity conditions such as diabetes mellitus and hypertension are mortality predictors.

Renal Stones and Gallstones Correlated with the Ten-Year Risk Estimation of Atherosclerotic Cardiovascular Disease Based on the Pooled Cohort Risk Assessment of Males Aged 40–79

Background: The risk of developing atherosclerotic cardiovascular disease (ASCVD) is unknown for subjects with both gallstones and renal stones, nor is it known whether there is a difference in the risk between gallstones and renal stones. This study aimed to determine the risk relationship between gallstones and renal stones and the risk of ASCVD in a male population. Methods: We recruited 6371 eligible males aged 40 to 79 years old who did not have a documented ASCVD history. The ten-year ASCVD risk was calculated using the pooled cohort equations developed by the American College of Cardiology (ACC) and the American Heart Association (AHA). The ASCVD risk score was classified as a low risk (<7.5%), an intermediate risk (7.5% to 19.9%), or a high risk (≥20%). The diagnosis of gallstones and renal stones was established based on the results of abdominal sonography. Results: Both gallstones and renal stones were associated with a high level of intermediate risk (OR = 3.21, 95% CI = 1.89–5.49, p < 0.001) and high risk (OR = 3.01, 95% CI = 1.48–6.12, p < 0.001), compared to individuals with no stones at all, after adjusting for the effects of other clinical variables. The possession of gallstones was associated with a higher level of high ASCVD risk (OR = 1.84, 95% CI = 1.31–2.59, p < 0.05) than that of renal stones. Conclusions: The ASCVD risk was higher for males with gallstones than for those with renal stones. Men with both types of stones faced a risk of ASCVD that was three times higher than that of men without stones.

Epidemiology of Kidney Stones

In the past two decades, major breakthroughs that improve our understanding of the pathophysiology and therapy of kidney stones (KS) have been lacking. The disease continues to be challenging for patients, physicians, and healthcare systems alike. In this context, epidemiological studies are striving to elucidate the worldwide changes in the patterns and the burden of the disease and identify modifiable risk factors that contribute to the development of kidney stones. Our expanding knowledge of the epidemiology of kidney stones is of paramount importance and largely upgrades the modern management of the disease. In this paper, we review the variables affecting prevalence and incidence, including age, gender, race, ethnicity, occupation, climate, geography, systemic diseases, diabetes, vascular disease, chronic kidney disease, and dietary risk factors relevant to kidney stones.

Nephrolithiasis: A Red Flag for Cardiovascular Risk

Epidemiological evidence shows that nephrolithiasis is associated with cardiovascular (CV) morbidities. The association between nephrolithiasis and CV disease is not surprising because both diseases share conditions that facilitate their development. Metabolic conditions, encompassed in the definition of metabolic syndrome (MS), and habits that promote nephrolithiasis by altering urine composition also promote clinical manifestations of CV disease. By inducing oxidative stress, these conditions cause endothelial dysfunction and increased arterial stiffness, which are both well-known predictors of CV disease. Furthermore, the subtle systemic metabolic acidosis observed in stone formers with CV disease may have a pathogenic role by increasing bone turnover and leading to reduced mineral content and osteoporosis/osteopenia. Heart valves and/or coronary artery and aortic calcifications are frequently associated with reduced mineral density. This is known as the 'calcification paradox' in osteoporosis and has also been observed in subjects with calcium nephrolithiasis. Evidence supports the hypothesis that osteoporosis/osteopenia is an independent risk factor for the development of CV calcifications. In the long term, episodes of renal stones may occur from the onset of metabolic derangements/MS to arterial stiffness/atherosclerosis and CV morbidities. These episodes should be considered a warning sign of an ongoing and silent atherosclerotic process. The evaluation of cardiometabolic risk factors and MS components should be routine in the assessment of renal stone formers. This would allow for treatment and prevention of the development of CV complications, which are much more severe for the patient and for public health.

Hyperoxaluria Induces Endothelial Dysfunction in Preglomerular Arteries: Involvement of Oxidative Stress

Urolithiasis is a worldwide problem and a risk factor for kidney injury. Oxidative stress-associated renal endothelial dysfunction secondary to urolithiasis could be a key pathogenic factor, similar to obesity and diabetes-related nephropathy. The aim of the present study was to characterize urolithiasis-related endothelial dysfunction in a hyperoxaluria rat model of renal lithiasis. Experimental approach: Endothelial dysfunction was assessed in preglomerular arteries isolated from control rats and in which 0.75% ethylene glycol was administered in drinking water. Renal interlobar arteries were mounted in microvascular myographs for functional studies; superoxide generation was measured by chemiluminescence and mRNA and protein expression by RT-PCR and immunofluorescence, respectively. Selective inhibitors were used to study the influence of the different ROS sources, xanthine oxidase, COX-2, Nox1, Nox2 and Nox4. Inflammatory vascular response was also studied by measuring the RNAm expression of NF-κB, MCP-1 and TNFα by RT-PCR. Results: Endothelium-dependent vasodilator responses were impaired in the preglomerular arteries of the hyperoxaluric group along with higher superoxide generation in the renal cortex and vascular inflammation developed by MCP-1 and promoted by NF-κB. The xanthine oxidase inhibitor allopurinol restored the endothelial relaxations and returned superoxide generation to basal values. Nox1 and Nox2 mRNA were up-regulated in arteries from the hyperoxaluric group, and Nox1 and Nox2 selective inhibitors also restored the impaired vasodilator responses and normalized NADPH oxidase-dependent higher superoxide values of renal cortex from the hyperoxaluric group. Conclusions: The current data support that hyperoxaluria induces oxidative stress-mediated endothelial dysfunction and inflammatory response in renal preglomerular arteries which is promoted by the xanthine oxidase, Nox1 and Nox2 pathways.

Modification effect of changes in cardiometabolic traits in association between kidney stones and cardiovascular events

Backgrounds

Whether longitudinal changes in metabolic status influence the effect of kidney stones on cardiovascular disease (CVD) remains unclarified. We investigated the modification effect of status changes in metabolic syndrome (MetS) in the association of kidney stones with risk of incident CVD events.

Methods

We performed a prospective association and interaction study in a nationwide cohort including 129,172 participants aged ≥ 40 years without CVDs at baseline and followed up for an average of 3.8 years. Kidney stones information was collected by using a questionnaire and validated by medical records. The repeated biochemical measurements were performed to ascertain the metabolic status at both baseline and follow-up.

Results

4,017 incident total CVDs, 1,413 coronary heart diseases (CHDs) and 2,682 strokes were documented and ascertained during follow-up. Kidney stones presence was significantly associated with 44%, 70% and 31% higher risk of CVDs, CHDs and stroke, respectively. The stratified analysis showed significant associations were found in the incident and sustained MetS patients, while no significant associations were found in the non-MetS at both baseline and follow-up subjects or the MetS remission ones, especially in women. For the change status of each single component of the MetS, though the trends were not always the same, the associations with CVD were consistently significant in those with sustained metabolic disorders, except for the sustained high blood glucose group, while the associations were consistently significant in those with incident metabolic disorders except for the incident blood pressure group. We also found a significant association of kidney stone and CVD or CHD risk in the remain normal glucose or triglycerides groups; while the associations were consistently significant in those with incident metabolic disorders except for the incident blood pressure group. We also found a significant association of kidney stone and CVD or CHD risk in the remain normal glucose or triglycerides groups.

Conclusions

A history of kidney stones in women with newly developed MetS or long-standing MetS associated with increased risk of CVD. The mechanisms link kidney stones and CVD risk in the metabolic and non-metabolic pathways were warranted for further studies.

Vascular Calcification Is Associated with Fetuin-A and Cortical Bone Porosity in Stone Formers

Background: Nephrolithiasis has been associated with bone loss and vascular calcification (VC), reflecting abnormal extraosseous calcium deposition. Fetuin-A (Fet-A) acts as a potent inhibitor of ectopic mineralization. The aim of the present study was to evaluate the prevalence of VC in stone formers (SF) and non-stone formers (NSF) and to investigate potential determinants of VC among SF, including circulating levels of Fet-A and bone microarchitecture parameters. Methods: Abdominal aortic calcification (AAC) was assessed using available computed tomography in SF and in age-, sex-, and BMI-matched NSF (potential living kidney donors). Serum Fet-A was measured in stored blood samples from SF. Bone microarchitecture parameters were obtained as a post hoc analysis of a cross-sectional cohort from young SF evaluated by high-resolution peripheral quantitative computed tomography (HR-pQCT). Results: A total of 62 SF (38.0 [28.0−45.3] years old) and 80 NSF (40.0 [37.0−45.8] years old) were included. There was no significant difference in AAC scores between SF and NSF. However, when dividing SF according to mean AAC score, below <5.8% (n = 33) or above ≥5.8% (n = 29), SF with higher AAC presented significantly higher BMI and tibial cortical porosity (Ct.Po) and significantly lower serum HDL, klotho, Fet-A, and eGFR. Urinary calcium did not differ between groups, but fractional excretion of phosphate was higher in the former. Upon multivariate regression, BMI, serum Fet-A, and tibial Ct.Po remained independently associated with AAC. Conclusions: This study suggests an association between reduced circulating Fet-A levels and increased bone Ct.Po with VC in SF.

Why is diagnosis, investigation and improved management of kidney stone disease important? Non-pharmacological and pharmacological treatments for nephrolithiasis

INTRODUCTION

Progress in the medical treatment and management of nephrolithiasis has been limited to date and continues to depend on urinary metabolic screening to assess excretion of the main stone constituents, factors determining stone solubility and precipitation, and on dietary and lifestyle recommendations.

AREAS COVERED

In this review, we try to highlight some of the broader aspects of kidney stone disease in relation to recent epidemiological and pathophysiological findings, and emerging new treatments. Specifically, this review will cover recent evidence on the association between metabolic risk factors and kidney stone disease, dietary risk factors and dietary interventions to prevent kidney stones, and how genomics, metabolomics and proteomics may improve diagnosis and treatment of this troublesome, if rarely fatal, condition. PubMed was used to identify the most suitable references according to our search strategy; only full manuscripts were included.

EXPERT OPINION

What is emerging is that kidney stone disease is not an isolated disorder, but is systemic in nature with links to important and common co-morbidities such as diabetes, hypertension, cardiovascular disease, and chronic kidney disease. These associations support the need to take nephrolithiasis seriously as a medical condition and to adopt a more holistic approach to its investigation and treatment.

Pediatric Mineral and Bone Disorder of Chronic Kidney Disease and Cardiovascular Disease

Chronic kidney disease is common and causes significant morbidity including shortened lifespans and decrease in quality of life for patients. The major cause of mortality in chronic kidney disease is cardiovascular disease. Cardiovascular disease within the chronic kidney disease population is closely tied with disordered calcium and phosphorus metabolism and driven in part by renal bone disease. The complex nature of renal, bone, and cardiovascular diseases was renamed as mineral and bone disorder of chronic kidney disease to encompass how bone disease drives vascular calcification and contributes to the development of long-term cardiovascular disease, and recent data suggest that managing bone disease well can augment and improve cardiovascular disease status. Pediatric nephrologists have additional obstacles in optimal mineral and bone disorder of chronic kidney disease management such as linear growth and skeletal maturation. In this article, we will discuss cardiovascular and bone diseases in chronic kidney disease and end-stage kidney disease patients with a focus on pediatric issues and concerns.

Association of stone surgery with patient-reported complications after spinal cord injury

AIMS

To determine if a history of urinary stone surgery in individuals with spinal cord injury (SCI) is associated with an increased incidence of SCI-related complications and lower quality of life (QOL).

METHODS

The Neurogenic Bladder Research Group (NBRG) registry is a multicenter, prospective, observational study which measures QOL after acquired SCI. Over 1.5 years, 1479 participants were enrolled and grouped according to history of stone surgery. We evaluated SCI-related complications, QOL, and associations between patient factors and prior stone surgery using multivariable regression.

RESULTS

Participants were a median of 11 years post-SCI and 189 (12.8%) reported prior bladder or kidney stone surgery; 95.8% of these occurred after the SCI. Median time between SCI and first stone was 5.6 years (IQR: 1.8-12.8). Hospitalizations were higher for those with prior stone surgery, with common reasons including UTIs, blood clots, pressure ulcers, and pneumonia (p < 0.001). During the year of observation, the incidence of stone surgery was 17% in those with a prior history of stone surgery and 2% per year in those without prior stone surgery (p < 0.001). Controlling for covariates, bladder management strategy, age, BMI, and years since SCI were associated with history of stone surgery.

CONCLUSIONS

People with SCI and a history of surgical stone disease are at high risk for episodes of recurrent stones and increased hospitalizations, particularly those with kidney stones and indwelling catheter use. Identification of high-risk patients may guide tailored surveillance for complications and stone prevention strategies.

Endothelial Dysfunction: An Intermediate Clinical Feature between Urolithiasis and Cardiovascular Diseases

An epidemiological relationship between urolithiasis and cardiovascular diseases has extensively been reported. Endothelial dysfunction is an early pathogenic event in cardiovascular diseases and has been associated with oxidative stress and low chronic inflammation in hypertension, coronary heart disease, stroke or the vascular complications of diabetes and obesity. The aim of this study is to summarize the current knowledge about the pathogenic mechanisms of urolithiasis in relation to the development of endothelial dysfunction and cardiovascular morbidities.

METHODS

A non-systematic review has been performed mixing the terms "urolithiasis", "kidney stone" or "nephrolithiasis" with "cardiovascular disease", "myocardial infarction", "stroke", or "endothelial dysfunction".

RESULTS

Patients with nephrolithiasis develop a higher incidence of cardiovascular disease with a relative risk estimated between 1.20 and 1.24 and also develop a higher vascular disease risk scores. Analyses of subgroups have rendered inconclusive results regarding gender or age. Endothelial dysfunction has also been strongly associated with urolithiasis in clinical studies, although no systemic serum markers of endothelial dysfunction, inflammation or oxidative stress could be clearly related. Analysis of urine composition of lithiasic patients also detected a higher expression of proteins related to cardiovascular disease. Experimental models of hyperoxaluria have also found elevation of serum endothelial dysfunction markers.

CONCLUSIONS

Endothelial dysfunction has been strongly associated with urolithiasis and based on the experimental evidence, should be considered as an intermediate and changeable feature between urolithiasis and cardiovascular diseases. Oxidative stress, a key pathogenic factor in the development of endothelial dysfunction has been also pointed out as an important factor of lithogenesis. Special attention must be paid to cardiovascular morbidities associated with urolithiasis in order to take advantage of pleiotropic effects of statins, angiotensin receptor blockers and allopurinol.

The safety of continued low dose aspirin therapy during Complete Supine Percutaneous Nephrolithotomy (csPCNL)

OBJECTIVE

Using anticoagulants and antiplatelet drugs in patients with cardiovascular and medical comorbidities is prevalent. Because of hyper vascular nature of kidney, physicians tend to stop using aspirin before percutaneous nephrolithotomy (PCNL). We have shown the effects of remaining on low dose aspirin in complete supine PCNL (csPCNL).

MATERIAL AND METHODS

The records of 643 patients who underwent csPCNL between 2012 and 2018 were analyzed. Surgical outcomes and complications of patients who were on aspirin therapy and continued it daily (group A) were compared with those not taking aspirin (group B).

RESULTS

Of the 643 csPCNLs, 40 (6%) were performed in patients of group A and the rest of 603 (94%) cases were in group B. The differences between the mean age of groups were statistically significant (60.08±9.45, group A and 48.66±12.32, group B) (P<0.001). Thirty-nine (97.5%) of patients in group A and 548 (90.9%) of group B were stone free by the end of the study which was not statistically significant (P=0.118). The mean operative time between groups A and B (43.20±21.37 and 44.83±16.83, respectively) was not considered significant (P=0.561). There was also no significant difference between 2 groups in any types of complications. Multivariate analysis showed that, perioperative aspirin use was not a significant predictor of transfusion, Hb drop, operative time and other complications.

CONCLUSIONS

Remaining on aspirin does not increase the risk of bleeding, transfusionand other complications. Consequently, continuing aspirin prioperatively in csPCNL appears safe. There is no fear for continuing aspirin in csPCNL.

LEVEL OF EVIDENCE

3.

Association between kidney stones and risk of developing stroke: a meta-analysis

Background

Many studies have described the relationship between kidney stones and stroke, but the results are controversial, so we conducted this meta-analysis to estimate the relationship between kidney stones and the risk of developing stroke.

Methods

Studies were marked with a comprehensive search of PubMed, EMBASE, Google, and ISI Web of Science databases through 25 March 2020. Hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted, and a random-effects model or fix-effects model was used to compute the pooled combined risk estimate. Heterogeneity was reported as I². We performed subgroup and sensitivity analysis to assess potential sources of heterogeneity.

Results

Eight studies of seven articles involving 3,526,808 participants were included in the meta-analysis. Overall, kidney stones were associated with a moderate risk of stroke incidence (HR, 1.24; 95% CI, 1.11–1.40; I²=79.6%; p=0.000). We conducted a sensitivity analysis by removing the studies that had a high risk of bias. Heterogeneity subsequently decreased significantly, while an increased risk of stroke in patient with kidney stones was again demonstrated (HR, 1.16; 95% CI, 1.11–1.23; I²=28.7%; p=0.000). Stratifying analysis showed that the results were more pronounced for ischemic stroke (HR, 1.14; 95% CI, 1.08–1.22; I²=15.6%; p=0.00) and the follow-up duration ≥10 years (HR, 1.18; 95% CI, 1.10–1.27; I²=31.6%; p=0.003).

Conclusions

Our meta-analysis suggests that patients with kidney stones may have a modestly increased risk of developing stroke, especially in ischemic stroke. More large-scaled and clinical trials should be done to identify the relative impact of kidney stones on stroke outcomes in the future.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-021-05113-5.

[Chronic kidney disease among adults in Rio Branco, State of Acre: a population-based survey]

The scope of this study was to establish the prevalence of CKD and associated factors among young adults (18-59 years of age) from Rio Branco in the State of Acre. It involved a population-based survey conducted in 2014, in the urban and rural areas of the municipality and CKD was defined as the glomerular filtration rate (GFR) < 60ml/min/1.73m², estimated by the CKD-EPI, and the presence of albuminuria > 29 mg/g. Association measures were estimated by logistic regression, with a confidence level of 95%. The overall prevalence of CKD was 6.2%. The presence of CKD was higher among women, aged 40 to 59 years, with non-white skin color, with lower schooling, and of sedentary disposition. There were statistically significant differences in the distribution according to the presence of CKD in the hypertension, diabetes and hospitalization variables over the past 12 months. CKD among adults was associated with the female sex (OR: 2.41, 95%CI: 1.14-5.12), diabetes (OR: 4.67, 95%CI: 1.28-17.03) and arterial hypertension (OR: 1.98; 95%CI: 1.16-3.37). CKD reveals a high prevalence and is associated with chronic diseases, calling for the need for public health measures for early detection and prevention of its progression.

Association of nephrolithiasis with the risk of cardiovascular diseases: a longitudinal follow-up study using a national health screening cohort

OBJECTIVES

The aim of this study was to explore the associations of stroke and ischaemic heart disease in patients with nephrolithiasis.

DESIGN

A longitudinal follow-up study.

SETTING

Data from the Korean National Health Insurance Service-Health Screening Cohort (2002-2013) were retrieved to identify the occurrence of nephrolithiasis.

PARTICIPANTS AND INTERVENTIONS

In total, 19 103 patients with nephrolithiasis were matched at a 1:4 ratio with control participants for age, sex, income and region of residence.

PRIMARY AND SECONDARY OUTCOME MEASURES

The occurrence of stroke and ischaemic heart disease was analysed in both patients with nephrolithiasis and control participants. The primary outcome was HRs of stroke and ischaemic heart disease in a stratified Cox proportional hazards model. Smoking, alcohol consumption, obesity and Charlson Comorbidity Index were adjusted for as covariates. Subgroup analyses according to age and sex were also performed.

RESULTS

Eight per cent (1615/19 103) of patients with nephrolithiasis and 7.2% (5476/76 412) of control participants had stroke. Nine per cent (1879/19 103) of patients with nephrolithiasis and 7.7% (5895/76 412) of control participants had ischaemic heart disease. Patients with nephrolithiasis had risks of stroke and ischaemic heart disease that were 1.18 times (95% CI=1.11 to 1.24) and 1.24 times (95% CI=1.18 to 1.31) those of the control participants, respectively. The age and sex subgroups showed consistent results.

CONCLUSIONS

Nephrolithiasis was associated with increased risks of stroke and ischaemic heart disease.

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

Aim: Evidence is lacking about whether urinary stones are associated with the subsequent risk of cardiovascular diseases. Herein, we investigated the association between history of urinary stones and the risk of coronary heart disease (CHD) and stroke among middle-aged Japanese.

Methods: This cohort study included 89,037 Japanese men and women (45–74 years) registered in the Japan Public Health Center-based prospective study. Cox proportional hazard models were used to calculate the hazard ratios (HRs) and their 95% confidence intervals (CIs) for incident CHD and stroke among Japanese adults with a self-reported history of urinary stones compared with those without it. The following covariates were included in the regression models: age, sex, area, body mass index, and histories of hypertension, diabetes, hyperlipidemia, smoking habit, alcohol intake, and physical activity.

Results: In total, 1.31% of Japanese adults reported a positive history of urinary stones. Throughout a median follow-up period of 12 years, 1.16% of Japanese adults developed CHD, and 4.96% developed stroke. No associations were detected between history of urinary stones and the risk of CHD (HR 1.04; 95% CI: 0.64–1.67), stroke (HR 0.92; 95% CI: 0.71–1.20), or total CVD (HR 0.95; 95% CI: 0.75–1.19). Younger urinary stone formers (45–59 years) tended to have a higher, though statistically insignificant, risk of CHD than older urinary stone formers (60–74 years): [(HR 1.15; 95% CI: 0.61–2.15) versus (HR 0.83; 95% CI: 0.40–1.76)], respectively.

Conclusion: The history of urinary stones was shown to be not associated with the risk of CVD among Japanese adults.

Racial Differences in Risk Factors for Kidney Stone Formation

BACKGROUND AND OBJECTIVES

Incidence of kidney stone disease is rising. It is not known whether mechanisms of stone formation differ across racial groups. Our objective was to identify differing lithogenic risk factors across racial groups in idiopathic nephrolithiasis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a retrospective cohort study evaluating metabolic risk factors in black and age-matched white idiopathic stone formers at our tertiary referral center. We compared serum and urine metabolic risk factors pre- and post-treatment across racial groups using analysis of covariance. Generalized linear modeling was used to build regression models for risk of stone formation in both groups.

RESULTS

Among 117 black and 172 white stone formers, urine volume was lower in black stone formers (1.4±0.8 versus 2.0±0.8 L/d, P<0.001). Urine calcium was lower in black stone formers (116±70 versus 217±115 mg/d, P<0.001). Supersaturations for calcium oxalate were similar among the groups, whereas calcium phosphate supersaturation was higher in white stone formers, and uric acid supersaturation was higher in black stone formers. Electrolyte free water clearance was significantly lower in black stone formers (207±780 versus 435±759 ml/d, P=0.02). In the subgroup of 77 black patients and 107 white patients with post-treatment evaluations, urine volume rose significantly and similarly in both groups. Urine sodium was unchanged in whites but increased in blacks by 40 mmol/d (95% confidence interval, 32 to 48 mmol/d). Electrolyte free water clearance remained lower in black stone formers (385±891 versus 706±893 ml/d, P=0.02). Post-treatment supersaturations were similar across the groups except for calcium phosphate, which improved with treatment in whites.

CONCLUSIONS

Black stone formers have lower 24-hour urine calcium excretion and urine volume. Increases in urine volume with treatment were associated with increased solute, but not free water, excretion in black stone formers.

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

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

Sex differences in the therapy of kidney and ureteral stones

PURPOSE OF REVIEW

Better understanding of sex differences affecting urolithiasis may help us offer tailored treatment strategies to our patients.

RECENT FINDINGS

The incidence of urolithiasis is increasing and the male-to-female ratio has decreased from 3 : 1 to 1.3 : 1 between 1970 and 2000. In women, obesity has a larger effect on the risk of developing urolithiasis [odds ratio (OR) 1.35; 95% confidence interval (CI): 1.33-1.37] compared with men (OR 1.04; 95% CI: 1.02-1.06). Urolithiasis is a risk factor for coronary artery disease in men (risk ratio = 1.23; 95% CI: 1.02-1.49) and for stroke in women (risk ratio = 1.12; 95% CI: 1.03-1.21). Women tolerate cystoscopic stent removal and shock wave lithotripsy better than men. For shock wave lithotripsy menopaused women have reported lower visual analog scale scores than menstruating women (P < 0.001). Female sex was an independent predictor of stone impaction (OR 1.15; 95% CI: 1.03-1.27) and postoperative sepsis after ureteroscopy (OR 2.31; 95% CI: 1.14-4.37).

SUMMARY

The sex gap in urolithiasis is closing. The changing role of women in society and dietary habits can be responsible for this epidemiologic shift. Women show a higher threshold for pain during urologic procedures, but they suffer from infectious complications more than men. Urolithiasis is a risk factor for cardiovascular events in both sexes.

Educational review: role of the pediatric nephrologists in the work-up and management of kidney stones

BACKGROUND

The incidence of nephrolithiasis in children and adolescents is increasing and appears to double every 10 years. The most important role of the pediatric nephrologist is to diagnose and modify various metabolic and non-metabolic risk factors, as well as prevent long-term complications especially in the case of recurrent nephrolithiasis.

OBJECTIVE

The purpose of this review is to summarize the existing literature on the etiology and management of pediatric nephrolithiasis.

RESULTS

The incidence of kidney stones is increasing; dietary and environmental factors are probably the main causes for this increased incidence. In most pediatric patients, the etiology for the kidney stones can be identified. Metabolic factors, such as hypercalciuria and hypocitraturia, urinary tract infection, and urinary stasis, constitute leading causes. Herein, we review the etiologies, diagnostic work-up, and treatment options for the most prevalent causes of kidney stones. The detrimental effects of excessive dietary sodium, reduced fluid intake, and the benefits of plant-based over animal-based protein consumption on urinary crystal formation are discussed. We also review the long-term complications.

CONCLUSIONS

Pediatric nephrologists have an important role in the diagnostic work-up and prevention of recurring nephrolithiasis.

Lead-induced oxidative damage in rats/mice: A meta-analysis

BACKGROUND

Lead (Pb) is ubiquitous in the environment and is an environmental genotoxic metal. Pb accumulation in the body could cause the oxidative stress.

OBJECTIVE

This meta-analysis aimed to perform a systematic evaluation of the extent of oxidative damage in rats/mice induced by lead.

METHODS

All relevant articles in English or Chinese were retrieved from Embase, PubMed, Web of Science, Medline, China National Knowledge Infrastructure, and Chinese Biological Medicine databases from their inception date until July 22, 2018.

RESULTS

A total of 108 eligible articles were included in this study. The indicators of oxidative stress included malondialdehyde (MDA), glutathione disulfide (GSSG), reactive oxygen species (ROS), hydrogen peroxide (H₂O₂), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), reduced glutathione (GSH), superoxide dismutase (SOD), and glutathione-s-transferase (GST). The meta-analysis showed that lead significantly increased oxidants levels, such as MDA, GSSG, ROS, and H₂O₂ (P < 0.05), and significantly reduced the level of antioxidants, such as CAT, GPx, GR, GSH, SOD, and GST (P < 0.05). The intraperitoneal mode was more effective than water drinking mode in reducing the levels of CAT, GPx, GSH, and SOD (P < 0.05). Other factors that influenced the overall oxidative stress, including species of animals, type of tissues, and intervention dosage and time, were comprehensively evaluated.

CONCLUSION

The results of meta-analysis indicated that mice were more sensitive to lead than rats, and intraperitoneal mode was an effective intervention mean. High doses and long periods of lead treatment can cause serious oxidative damage. Moreover, testicular was more vulnerable to lead than other tissues. These results provided scientific evidence for preventing and treating lead toxicity.

Kidney Stone History and Adverse Outcomes After Percutaneous Coronary Intervention

OBJECTIVE

To determine whether kidney stone history is associated with adverse outcomes after percutaneous coronary intervention (PCI). Kidney stone formers have an increased risk of developing coronary artery disease; however, whether these patients have worse cardiac outcomes is unknown.

MATERIALS AND METHODS

We identified adult patients who underwent first-time PCI in Vanderbilt University Medical Center (VUMC) Synthetic Derivative from 2008 to 2016 (n = 11,289) and in a nationwide database of Taiwan (NHIRD) from 2005 to 2012 (n = 155,762). Odds ratios (ORs) of 30-day in-hospital mortality and hazard ratios (HRs) of 1-year and 3-year adverse outcomes associated with kidney stone history were estimated using a propensity score approach.

RESULTS

Overall, 294 and 12,286 stone formers undergoing PCI were identified in the VUMC and NHIRD, respectively. After matching, stone formers at VUMC were at higher risks of 30-day in-hospital mortality (OR 2.79, 95% CI 1.15-6.69) and 1-year (HR 1.59, 95% CI 1.13-2.24) and 3-year (HR 1.36, 95% CI 1.02-1.81) myocardial infarction. In the NHIRD, kidney stone history was associated with 1-year (HR 1.12, 95% CI 1.03-1.21) and 3-year (HR 1.14, 95% CI 1.06-1.22) myocardial infarction. In a sensitivity analysis, stone formers undergoing kidney stone surgery were marginally associated with 30-day in-hospital mortality (OR 1.21, 95% CI 0.99-1.48) and were associated with 3-year myocardial infarction (HR 1.13, 95% CI 1.02-1.25).

CONCLUSION

Kidney stone history is associated with poorer cardiac outcomes after PCI. Improving secondary cardiac prevention strategies after PCI may be necessary for patients with a history of kidney stone disease.

Oxalates, urinary stones and risk of cardiovascular diseases

Increased level of oxalates in urine and plasma can be attributed to endogenous overproduction, increased ingestion or excessive intestinal absorption. When a supersaturation status is reached, oxalates combine with calcium and crystallize to form 80% of the urinary stones. Several cardiovascular diseases such as coronary heart disease and stroke are thought to be associated with the formation of urinary stones via sharing the same pathogenesis and/or risk factors. This review investigated the evidence linking oxalates/urinary stones to cardiovascular diseases. Eventually, two theories can explain the possible association between urinary stones and cardiovascular diseases: the theory of common origin and the theory of common risk factors. While the first theory is based on the common vascular pathophysiology of urinary stones and cardiac events, the later suggests that metabolic syndrome traits increase the risk of urinary stones and cardiovascular diseases independently. A few cohort studies showed a higher risk of coronary heart disease and stroke among people with history of urinary stones than people without it while other cohort studies did not. These studies had different definitions for cardiovascular diseases, used various methods to assess urinary stones, and some of them did not control for potential confounders. When they were pooled together in meta-analyses, a significant heterogeneity across studies was observed. In conclusion, although there is some evidence indicating that urinary stones could increase the risk of cardiovascular diseases, a substantial causal relationship cannot be settled.

Nephrotoxic metals of cadmium, lead, mercury and arsenic and the odds of kidney stones in adults: An exposure-response analysis of NHANES 2007-2016

BACKGROUND

Nephrotoxic metals of arsenic, cadmium, lead and mercury exposures are common environmental pollutants. The associations between arsenic, cadmium, lead and mercury exposures and the risk of kidney stones are unclear.

OBJECTIVE

To explore the associations between biomarkers of arsenic, cadmium, lead and mercury exposures and the odds of kidney stones.

METHODS

Adult participants (≥20 years) from the 2007-2016 NHANES were included. Restricted cubic splines were adopted.

RESULTS

The odds ratio (95% confidence interval) of kidney stones increased with increasing blood cadmium and reached the maximum at 1.00 μg/L [1.38 (1.02-1.88) overall, 1.62 (1.11-2.32) for women and 1.53 (1.06-2.22) for non-Hispanic white]. The odds of kidney stones increased with increasing urinary cadmium and reached the maximum at 1.50 μg/L [2.56 (1.17-5.59) overall, 5.57 (1.88-16.49) for women, 4.31 (1.75-10.63) for obese individuals and 3.75 (1.60-8.78) for non-Hispanic white]. The odds of kidney stones increased with increasing total urinary arsenic and urinary dimethylarsinic acid in women, and reached the maximum of 1.69 (1.08-2.67) at 40 μg/L and 1.71 (1.07-2.72) at 10.00 μg/L, respectively. Inverse associations were found between the odds of kidney stones and blood lead within 5.00 μg/dL [0.64 (0.46-0.90) overall, 0.53 (0.33-0.84) for men and 0.58 (0.37-0.92) for non-Hispanic white], methyl mercury within 3.00 μg/L [non-obese individuals: 0.71 (0.51-0.99)] and urinary arsenous acid within 1.20 μg/L [individuals other than non-Hispanic white: 0.63 (0.41-0.95)]. No association was found with other biomarkers.

CONCLUSIONS

Several biomarkers of arsenic, cadmium, lead and mercury exposures were associated with the odds of kidney stones in adults.

Association of dipstick hematuria with all-cause mortality in the general population: results from the specific health check and guidance program in Japan

Background

Dipstick urine tests are used for general health screening in Japan. The effects of this screening on mortality have not been examined, especially with regard to hematuria.

Methods

Subjects were those who participated in the 2008 Tokutei-Kenshin (nationwide specific health check and guidance program) in six districts in Japan. Using the national database of death certificates from 2008 to 2012, we identified subjects who might have died. We verified the candidates in collaboration with the regional National Health Insurance agency and public health nurses. Data were released to the research team supported by the Ministry of Health, Labor, and Welfare of Japan. Dipstick results of 1+ and higher were defined as hematuria (+). Hazard ratio (HR) [95% confidence interval (CI)] was calculated using the Cox proportional hazard analysis.

Results

Among 112 115 subjects, we identified that 1290 had died by the end of 2012. In hematuria (-) subjects, the crude mortality rates were 1.2% (1.8% in men, 0.7% in women), whereas in hematuria (+) subjects, they were 1.1% (2.9% in men, 0.7% in women). After adjusting for age, body mass index, estimated glomerular filtration rate, proteinuria, comorbid condition (diabetes mellitus, hypertension and dyslipidemia), past history (stroke, heart disease and kidney disease) and lifestyle (smoking, drinking, walking and exercise), the HR (95% CI) for dipstick hematuria (+) in men was 1.464 (1.147-1.846; P = 0.003), whereas that for hematuria (-) was 0.820 (0.617-1.073; P = 0.151).

Conclusions

Dipstick hematuria is significantly associated with mortality in men among Japanese community-based screening participants.

Adolescents with urinary stones have elevated urine levels of inflammatory mediators

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

Klotho gene polymorphisms are associated with healthy aging and longevity: Evidence from a meta-analysis

Klotho gene polymorphisms have been implicated in healthy aging, but inconsistences in findings from previous case-control studies have raised concerns regarding the associations between KLOTHO gene polymorphisms and susceptibility to aging-related diseases and longevity. Hence, this meta-analysis was performed. We assessed the associations between two polymorphisms (G-395 A/rs1207568 and F352 V/rs9536314) and five parameters (urolithiasis, cognitive impairment, cardiovascular disease, cancer, and longevity) by calculating pooled odds ratios with 95% confidence intervals. According to the pooled results, the G allele of the G-395 A polymorphism conferred a significantly higher risk of urolithiasis; G-395 A was related to the susceptibility to cardiovascular disease under allele, dominant, and recessive models. There was no significant association between the G-395 A polymorphism and cognitive impairment among the elderly. The F allele of the F352 V polymorphism protected against breast and ovarian cancer susceptibility. Interestingly, based on the results of the subgroup analysis, the F352 V polymorphism was associated with the overall risk of neoplasms in BRCA1 mutation carriers but not in BRCA2 mutation carriers. Moreover, the F allele played a protective role in determining human longevity. In conclusion, Klotho G-395 A polymorphisms were associated with urolithiasis and cardiovascular disease but not with cognitive impairment. Additionally, Klotho F352 V polymorphisms were associated with cancers and longevity.

Nephrolithiasis predicts ischemic stroke: A longitudinal follow-up study using a national sample cohort

This study sought to evaluate associations between nephrolithiasis and hemorrhagic and ischemic stroke using a national sample cohort from Korea. Data from 2002 to 2013 were collected for individuals ≥ 20 years of age in the Korean National Health Insurance Service (NHIS)-National Sample Cohort. We extracted nephrolithiasis patients (n = 22,636) and 1:4 matched controls (n = 90,544) and analyzed the occurrence of stroke. Matching was performed based on age, sex, income, region of residence, hypertension, diabetes mellitus, and dyslipidemia history. Crude and adjusted hazard ratios (HRs) were calculated using Cox proportional hazard models, and 95% confidence intervals (CIs) were determined. We performed subgroup analyses according to age, sex, and follow-up period. The adjusted HR of ischemic stroke was 1.13 (95% CI = 1.06-1.21) in the nephrolithiasis group (P < 0.001). The relationship between nephrolithiasis and ischemic stroke remained present for the young women and middle-aged men as well as during a follow-up period of ≤ 1 year. The HR for hemorrhagic stroke did not reach statistical significance. The risk of ischemic stroke was higher in the nephrolithiasis patients.

Heavy Metal Components in Blood and Urinary Stones of Urolithiasis Patients

Lifestyle, food intake, and exposure to chemicals are potential risk factors for the development of calcium urolithiasis. Pb, Cd, and Hg have been proved to cause renal illness, and urinary tract stones might be caused by exposure to metals. Therefore, this study aimed to measure the concentration of metals in urinary tract stones and blood simultaneously in urolithiasis patients. Moreover, we intended to determine whether urinary tract stones can be regarded as a biomarker of exposure or an effect marker in a population with environmental exposure to metals. Thirty-five urolithiasis patients (case) and 34 healthy inhabitants (control) were recruited in this study. The contents of Pb, Cd, Cr, Cu, Ni, As, Zn, and Hg were determined in urinary stones and blood in the case and control groups. The most abundant metals were Zn and Cu in blood and Zn and Ni in urinary stones. Significantly higher levels of Zn, Ni, and As were found in calcium phosphate stones than in calcium oxalate or uric acid stones. The majority of metals were not present at consistent levels in both blood and urinary stones, except for Zn. Urinary stones might be explained as providing another metabolic pathway for metal contamination. Moreover, as the metals with the highest content in urinary stones were Ni and Zn, and Ni content was very much higher than in other countries, contamination by Ni should be further taken into consideration if there is any serious contamination in Taiwan.

Cross-talk between renal lithogenesis and atherosclerosis: an unveiled link between kidney stone formation and cardiovascular diseases

The prevalence of kidney stones and cardiovascular diseases (CVDs) are increasing throughout the world. Both diseases are chronic and characterized by accumulation of oxidized proteins and lipids in the renal tissue and arterial wall, respectively. Emerging studies have revealed a positive association between nephrolithiasis and CVDs. Based on preclinical and clinical evidences, this review discusses: (i) stone forming risk factors, crystal nucleation, aggregation, injury-induced crystal retention, and stone formation, (ii) CVD risk factors such as dyslipidemia, perturbation of gut microbiome, obesity, free radical-induced lipoprotein oxidation, and retention in the arterial wall, subsequent foam cell formation, and atherosclerosis, (iii) mechanism by which stone forming risk factors such as oxalate, calcium, uric acid, and infection contribute toward CVDs, and (iv) how CVD risk factors, such as cholesterol, phospholipids, and uric acid, contribute to kidney stone formation are described.

Association between chronic pancreatitis and urolithiasis: A population-based cohort study

Purpose

Chronic pancreatitis (CP) can cause fat or bile acid malabsorption due to exocrine insufficiency. Fat or bile acid malabsorption has been reported to increase the risk of urolithiasis through increased intestinal oxalate absorption. However, no studies have reported an association between CP and urolithiasis.

Methods

We identified 15,848 patients (age: ≥20 years) diagnosed as having CP between 2000 and 2010 from the National Health Insurance Research Database as the study cohort. Beneficiaries without a history of CP were randomly selected and propensity-matched with the study cohort in a 1:4 ratio according to age; sex; comorbidities of hyperlipidemia, diabetes, obesity, hypertension, chronic obstructive pulmonary disease, alcohol-related illness, stroke, and coronary artery disease; and the index date. The prevalence of inflammatory bowel disease (0.44%), hyperparathyroidism (0.10%), or end stage renal disease (1.55%) in CP patients was low, but these comorbidities were also considered in the analysis. All patients were followed until the end of 2011 or withdrawal from the National Health Insurance program to determine the incidence of urolithiasis.

Results

The cumulative incidence of urolithiasis was higher in the CP cohort than that in the non-CP cohort (log-rank test, P < 0.001) with a 1.89-fold risk of urolithiasis (95% confidence interval [CI] = 1.74–2.06). The prevalence of CP was higher in men (81.9%) and in patients younger than 49 years (63.5%; mean age: 48.5 ± 15.3 years). CP was associated with the development of urolithiasis in each age group (≤49 years: aHR = 2.00, 95% CI = 1.81–2.22; 50–64 years: aHR = 1.71, 95% CI = 1.40–2.09; ≥65 years: aHR = 1.54, 95% CI = 1.20–1.98) and each sex (women: aHR = 2.10, 95% CI = 1.67–2.66; men; aHR = 1.86, 95% CI = 1.70–2.04). Among the patients without comorbidities, the rate of urolithiasis increased from 2.93/1,000 person-years in non-CP patients to 8.28/1,000 person-years in CP patients. Among the patients with comorbidities, the rate of urolithiasis increased from 6.12/1,000 person-years in non-CP patients to 10.9/1,000 person-years in CP patients. The contribution of CP to the relative risk of urolithiasis was greater in patients without comorbidities (without comorbidities: aHR = 2.81, 95% CI = 2.30–3.44) than in those with comorbidities (aHR = 1.76, 95% CI = 1.61–1.94).

Conclusion

CP is associated with urolithiasis in this population-based cohort study. The contribution of CP to the relative risk of urolithiasis was even greater in patients with a lower risk of urolithiasis, such as those without other comorbidities. Our findings warrant a survey and education on urolithiasis for patients with CP.

Kidney stones may increase the risk of coronary heart disease and stroke: A PRISMA-Compliant meta-analysis

BACKGROUND

We aimed to quantitatively assess the potential relationship between kidney stones and coronary heart disease or stroke.

METHODS

A meta-analysis was conducted on eligibly studies published before 31 May 2016 in PubMed or Embase. The data were pooled, and the relationship was assessed by the random-effect model with inverse variance-weighted procedure. The results were expressed as relative risk (RR) with 95% confidence intervals (95%CI).

RESULTS

Eight studies of 11 cohorts (n = 11) were included in our analysis with 3,658,360 participants and 157,037 cases. We found that a history of kidney stones was associated with increased risk of coronary heart disease (CHD) (RR = 1.24; 95%CI: 1.14-1.36; I = 79.0%, n = 11); similar effect on myocardial infarction, a serious condition of CHD, was observed (RR = 1.24; 95%CI: 1.10-1.40; I = 80.4%, n = 8). We also found that a history of kidney stones may increase the risk of stroke (RR = 1.21, 95%CI: 1.06-1.38; I = 54.7%, n = 4). In subgroup analysis, the risk of coronary heart disease was higher in men (RR = 1.23, 95%CI: 1.02-1.49) while the risk for stroke was higher in women (RR = 1.12; 95%CI: 1.03-1.21). No obvious publications bias was detected (Egger test: P = .47).

CONCLUSION

Kidney stones are associated with increased risk of coronary heart disease and stroke, and the effect may differ by sex.

Renal Calcium Oxalate Deposits Induce a Pro-Atherosclerotic and Pro-Osteoporotic Response in Mice

Urinary stone disease (USD) is increasing in adult and pediatric populations. Adult and pediatric studies have demonstrated decreased bone mineral density and increased fracture rates. USD has also been independently linked to increased rates of myocardial infarction and cerebral vascular accidents. Although USD is a multisystem disorder involving the kidneys, bone, and vasculature, the molecular mechanisms linking these three organs remain unknown. Calcium oxalate nephropathy was induced in C57BL/6J mice with intra-peritoneal (ip) injection of sodium glyoxolate. Half of each kidney underwent Pizzalato staining and half was snap frozen for RNA extraction. RT² Profiler Mouse Atherosclerosis, Osteoporosis, and Calcium Signaling PCR Arrays (Qiagen) were performed. Only results that passed quality checks in PCR array reproducibility and genomic DNA contamination were included. Genes had to show at least fourfold differential expression and P < 0.01 to be considered significant. Atherosclerosis array showed upregulation of 19 genes by fourfold, 10 of which were ≥10-fold. All 19 had P ≤ 0.002. The Osteoporosis array showed fourfold upregulation of 10 genes, five showed >10-fold increase. All 10 have P ≤ 0.003. The calcium signaling array showed significant fourfold upregulation of 10 genes, four of which were ≥10-fold. All 10 have P ≤ 0.03. We have demonstrated that calcium oxalate nephropathy can induce upregulation of atherosclerotic, metabolic bone, and calcium homeostasis genes in a murine model. This may be and initial step in identifying the molecular mechanisms linking stone, bone, and cardiovascular disease. J. Cell. Biochem. 118: 2744-2751, 2017. © 2017 Wiley Periodicals, Inc.

Renal tubular injury induced by ischemia promotes the formation of calcium oxalate crystals in rats with hyperoxaluria

Hyperoxaluria and cell injury are key factors in urolithiasis. Oxalate metabolism may be altered by renal dysfunction and therefore, impact the deposition of calcium oxalate (CaOx) crystals. We investigated the relationship of renal function, oxalate metabolism and CaOx crystal deposition in renal ischemia. One hundred male Sprague-Dawley rats were randomly divided into four groups. Hyperoxaluria model (Group A and B) was established by feeding rats with 0.75 % ethylene glycol (EG). The left renal pedicle was clamped for 30 min to establish renal ischemia Groups (B and C), while Groups A and D underwent sham operation. Then, serum and urine oxalate (Ox), creatinine (Cr) and urea nitrogen (UN) levels were evaluated by liquid chromatography mass spectrometry (LCMS) and ion mass spectrum (IMS) at days 0, 2, 4, 7, and 14. CaOx crystallization was assessed by transmission electron microscope (TEM). A temporal and significant increase of serum Cr and UN levels was observed in Groups B and C compared to values obtained for Groups A and D (P < 0.05). Ox levels in serum and urine were significantly higher in Groups A and B than in the other two groups from day 7 (P < 0.05). In addition, CaOx crystallization was observed in both Groups A and B, but Group B showed earlier and more pronounced crystal deposition in the renal tissue. Our results indicated that renal tubular injury induced by renal ischemia might not affect Ox levels but could promote CaOx crystal retention under hyperoxaluria.

Pediatric Origins of Nephrolithiasis-Associated Atherosclerosis

OBJECTIVES

To determine if nephrolithiasis-associated atherosclerosis has pediatric origins and to consider possible association between kidney stones and atherosclerosis-related proteins.

STUDY DESIGN

We matched children aged 12-17 years with kidney stones and without kidney stones. Carotid artery intima-media thickness (cIMT) was measured by ultrasound. Participants' urine was investigated by enzyme-linked immunosorbent assay for the atherosclerosis-related proteins fibronectin 1, macrophage scavenger receptor 1, osteopontin, and vascular cell adhesion molecule 1 levels, and normalized to urine creatinine levels.

RESULTS

Subjects with nephrolithiasis had higher cIMT in the right common carotid artery and overall mean measurement. Urine osteopontin and fibronectin 1 were significant predictors of cIMT.

CONCLUSIONS

We have provided initial preliminary evidence that nephrolithiasis-associated atherosclerosis has pediatric origins and performed studies that begin to identify potential reasons for the association of nephrolithiasis and vascular disease.