Redefining the Stone Belt: Precipitation Is Associated with Increased Risk of Urinary Stone Disease

Pathophysiology and Main Molecular Mechanisms of Urinary Stone Formation and Recurrence

Kidney stone disease (KSD) is one of the most common urological diseases. The incidence of kidney stones has increased dramatically in the last few decades. Kidney stones are mineral deposits in the calyces or the pelvis, free or attached to the renal papillae. They contain crystals and organic components, and they are made when urine is supersaturated with minerals. Calcium-containing stones are the most common, with calcium oxalate as the main component of most stones. However, many of these form on a calcium phosphate matrix called Randall's plaque, which is found on the surface of the kidney papilla. The etiology is multifactorial, and the recurrence rate is as high as 50% within 5 years after the first stone onset. There is a great need for recurrence prevention that requires a better understanding of the mechanisms involved in stone formation to facilitate the development of more effective drugs. This review aims to understand the pathophysiology and the main molecular mechanisms known to date to prevent recurrences, which requires behavioral and nutritional interventions, as well as pharmacological treatments that are specific to the type of stone.

Role of Climate Change in Urologic Health: Kidney Stone Disease

Kidney stones are rising in incidence and prevalence worldwide. Given the temperature dependence of kidney stone presentations, climate change is projected to further increase the burden of disease for individuals and society. PATIENT SUMMARY: This mini-review reports current knowledge on climate change in relation to kidney stone disease. Kidney stones are more common in patients living in parts of the world that are hotter and more humid. Kidney stone problems are also more common after periods of high heat, which have a greater impact on men than on women. As temperatures rise with climate change, it is likely that the occurrence of kidney stones and the costs associated with their diagnosis and treatment will increase as well.

The relationship between patients' kidney stone type and demographics in Israel: analysis of 10 K patients

PURPOSE

To analyze urinary stone composition in Israel and assess the effects of key demographic parameters (gender, age, socioeconomic status, ethnicity, medical history and geographic region) on stone composition.

METHODS

A retrospective review was conducted of stone analysis of 10,633 patients from an HMO Israeli database analyzed by a central laboratory from 2014 to 2019 and subjected to Fourier-transform infrared spectroscopy. Associations between stone composition and different demographic parameters were determined using the Chi-square test.

RESULTS

Calcium oxalate (CaOx) monohydrate accounted for 51.9% of the stones. Of the total sample, 5776 stones had one single component (54%), whereas 4857 (46%) had mixed components. Men had a higher frequency of CaOx stones (89.6% vs. 85.6%), whereas women had a higher frequency of calcium phosphate, infection, and cystine stones (27.2%, 17.7%, and 0.9% vs. 17.2%, 7.5%, and 0.5%, respectively). Cystine stones were more abundant in Arabs (1.2% vs. 0.5% in the Jewish population). Lower socioeconomic status was associated with a higher prevalence of calcium phosphate, uric acid, and infection stones and a lower prevalence of CaOx stones. Uric acid stones were associated with medical conditions such as diabetes, hypertension, ischemic heart disease, and obesity (28.3%, 24.9%, 25.7%, and 22.6% vs. 9.6%, 8.4%, 12.3%, and 10.3%, respectively).

CONCLUSIONS

Stone types were highly influenced by patients' demographics. COM was the most common stone component in either pure or complex form. UA stone prevalence was found to increase with age and was associated with medical conditions such as diabetes, hypertension, ischemic heart disease, and obesity.

High ambient temperature increases the number of emergency visits for upper urolithiasis in Hefei City, China

Background

Few studies have examined the effect of ambient temperature on upper urolithiasis in developing countries, with even fewer considering individual factors.

Methods

The present study analyzed data on emergency department visits for upper urolithiasis from three hospital sites of a large hospital in Hefei, China, during 2016-2020. Data on environmental factors during the same period were also analyzed. A time series analysis employing a generalized Poisson regression model (GPRM) combined with a distributed lag non-linear model (DLNM) was conducted to evaluate the effect of ambient temperature on the number of emergency department visits for upper urolithiasis.

Results

We found that ambient temperatures above 9 °C were positively associated with the frequency of upper urolithiasis visits, with the relationship being most significant on the current day and with a one-day lag. In the single-day lag effect, the most significant relative risk (RR) for mild heat (75th percentile) and high heat (95th percentile) was 1.229 (95% CI: 1.100-1.373) and 1.337 (95% CI: 1.134-1.577), respectively. The cumulative lag effect was significantly higher than the single-day lag effect, with maximum relative risks (RRs) of 1.779 (95% CI: 1.356-2.335) and 2.498 (95% CI: 1.688-3.697), respectively. The maximum lag time was 7 days. RRs were also higher among women and individuals aged 30-44 years.

Conclusions

Increased ambient temperature is a risk factor for upper urolithiasis, and there is a hysteresis effect. Women and individuals aged 30-44 years are the most susceptible.

Ambient heat stress and urolithiasis attacks in China: Implication for climate change

BACKGROUND

Although the existing studies have suggested a significant association between high temperatures and urolithiasis, no nationwide studies have quantified the burden attributable to environmental heat stress and explored how the urolithiasis burden would vary in a warming climate.

METHODS

We collected data on urolithiasis attacks from 137 hospitals in 59 main cities from 20 provincial regions of China from 2000 to 2020. An individual-level case-crossover analysis was conducted to estimate the effect of daily wet-bulb globe temperature (WBGT), a heat stress index combining temperature and humidity, on urolithiasis attacks. Stratified analyses were performed by region, age, and sex. We further quantified the future WBGT-related burden of urolithiasis from the Coupled Model Intercomparison Project Phase 6 under three Shared Socioeconomic Pathway (SSP) scenarios.

RESULTS

In total, 118,180 urolithiasis patients were evaluated. The exposure-response curve for the association between WBGT and urolithiasis attacks was J-shaped, with a significantly increased risk for WBGT higher than 14.8 °C. The middle-aged and elderly group (≥45 years old) had a higher risk of WBGT-related urolithiasis attacks than in the younger group, while no significant sex difference was observed. The attributable fraction (AF) due to high WBGT would increase from 10.1% in the 2010s to 16.1% in the 2090s under the SSP585 scenario. Warm regions were projected to experience disproportionately higher AFs and larger increments in the future.

CONCLUSIONS

This nationwide investigation provides novel evidence on the acute effect of high WBGT on urolithiasis attacks and demonstrates the increasing disease burden in a warming climate.

The Risk Factors for Radiolucent Nephrolithiasis among Workers in High-Temperature Workplaces in the Steel Industry

Workers in high-temperature workplaces with inadequate water supply may exhibit symptoms of chronic dehydration and have increased risk of nephrolithiasis. The aim of this study was to investigate the risk of radiolucent stone formation among workers in a high-temperature workplace and the related risk factors associated with the condition. We collected data from 1681 workers in a steel factory in Southern Taiwan who underwent regular health examinations. Radiolucent stones were defined as positive findings on ultrasound with negative radiographic images. The prevalences of nephrolithiasis and radiolucent stones in this study were 12.0% and 5.1%, respectively. Heat exposure and age were two major risk factors influencing the probability of radiolucent stones. We combined the age and heat exposure into four groups (over and under 35 years of age with and without heat exposure) in a logistic regression. For workers younger than 35 years, the odds ratio of radiolucent stones was 2.695 (95% confidence interval: 1.201-6.049) in workers with heat exposure compared to workers without. Our investigation further demonstrated that heat exposure was a main risk factor for radiolucent stone formation. In conclusion, our identification of heat exposure as an independent factor for radiolucent stone development in steel workers highlights the need for attention to be paid to those working in similar environments.

Building sustainable and resilient surgical systems: A narrative review of opportunities to integrate climate change into national surgical planning in the Western Pacific region

Five billion people lack access to surgical care worldwide; climate change is the biggest threat to human health in the 21st century. This review studies how climate change could be integrated into national surgical planning in the Western Pacific region. We searched databases (PubMed, Web of Science, and Global Health) for articles on climate change and surgical care. Findings were categorised using the modified World Health Organisation Health System Building Blocks Framework. 220 out of 2577 records were included. Infrastructure: Operating theatres are highly resource-intensive. Their carbon footprint could be reduced by maximising equipment longevity, improving energy efficiency, and renewable energy use. Service delivery Tele-medicine, outreaches, and avoiding desflurane could reduce emissions. Robust surgical systems are required to adapt to the increasing burden of surgically treated diseases, such as injuries from natural disasters. Finance: Climate change adaptation funds could be mobilised for surgical system strengthening. Information systems: Sustainability should be a key performance indicator for surgical systems. Workforce: Surgical providers could change clinical, institutional, and societal practices. Governance: Planning in surgical care and climate change should be aligned. Climate change mitigation is essential in the regional surgical care scale-up; surgical system strengthening is also necessary for adaptation to climate change.

Medical Treatment and Prevention of Urinary Stone Disease

The pathophysiology underlying urinary stone formation remains an area of active investigation. There are many pharmacotherapies aimed at optimizing metabolic factors and reducing urinary supersaturation of stone components that play an important role in urinary stone prevention. In addition, medical expulsive therapy for ureteral stones and medical dissolution therapy for uric acid-based urinary stones are helpful treatment tools and are used alongside surgical treatments in the management of urinary stones.

Association of meteorological factors and ambient air pollution on medical care utilization for urolithiasis: a population-based time-series study

BACKGROUND

To identify the association of meteorological factors/ambient air pollutants with medical care utilization for urolithiasis and estimate the effect size/time lags.

METHODS

This is a population-based time-series analysis of 300,000 urolithiasis cases from eight large metropolitan areas in Korea. Seventeen meteorological factors and ambient air pollutants were measured daily during 2002-2017 for each metropolis. Data on daily medical utilization owing to urolithiasis were collected. A generalized additive model was used while factoring in the nonlinear relationship between meteorological factors/ambient air pollutants and urolithiasis and a time lag of ≤10 days. A multivariate analysis was performed. Backward elimination with an Akaike information criterion was used for fitting the multivariate model.

RESULTS

Urolithiasis was significantly associated with average temperature, diurnal temperature range, sunshine duration, particulate matter (PM) ≤2.5 μm, and carbon monoxide (CO) levels. The incidence of ureteral stones was positively correlated with average temperature, PM ≤2.5 μm level, and CO level (time lags 0-9, 2-4, and 0-9 days, respectively). The incidence of renal stones was positively correlated with PM ≤2.5 μm and CO levels (time lags 2-4 and 0-9 days, respectively). PM ≤2.5 μm (0.05 and 0.07% per 10 μg/m³⁾ and CO (2.05 and 2.25% per 0.1 ppm) conferred the highest excess risk on ureteral and renal stones.

CONCLUSIONS

Urolithiasis is affected by various meteorological factors and ambient air pollutants, PM ≤2.5 μm, and CO levels may be novel potential risk factors for this condition.

THE FUNCTIONAL STATE OF THE RENAL PARENCHYMA AFTER VARIOUS VIDEO ENDOSURGICAL METHODS OF TREATMENT OF PATIENTS WITH LARGE AND COMPLEX KIDNEY STONES

The work is based on the analysis of literature data devoted to the problem of preserving the functional state of the kidneys with various video endoscopic methods of surgical treatment of large and complex kidney stones. The purpose of the review is to highlight the likelihood of deterioration in the functional state of the kidneys in the postoperative period. A detailed analysis of postoperative outcomes in various minimally invasive methods of treatment of patients with large and complex kidney stones was carried out, with an overview of the possibility of using dynamic nephroscintigraphy as a method of objectively assessing the functional state of the kidneys.

The stone crescent of Anatolia

OBJECTIVES

To assess the largest stone composition data available and to present the variations in the stone composition according to gender and different climatic environments in Turkey.

METHODOLOGY

Data for a total of 24 768 urinary stone patients from the Turkish Mineral Research and Exploration Institute were evaluated. X-ray diffraction crystallography was used for analysis and the Köppen-Trewartha classification was used to assess the climatic features of the cities. After the assessment, the cities were divided into two groups-those with a continental climate (Dc) were defined as inland areas and the others (Non-Dc) were defined as coastal areas.

RESULTS

The male-to-female ratio was 2.2:1. Amongst the patients, 53.7% had pure stones, while 46.3% had mixed-type stones. The most common type of stone was calcium oxalate in both pure and mixed stone groups. Given the climate patterns, the stone ratio between regions with a Dc climate and a Non-Dc climate was approximately 2:3. Cystine and uric acid stones were observed more frequently in inland regions, while calcium oxalate, whewellite, and struvite stones were observed more frequently in coastal areas (P = .005, P < .001, P < .001, P = .002, P = .002, respectively). Calcium oxalate stones were found at a higher rate in men, while cysteine, struvite, and calcium phosphate stones were more common in women (P < .001, P = .003, P < .001, P < .001, respectively).

CONCLUSION

This study provides the most comprehensive data on the stone disease in Turkey. Considering the distribution of stone disease in Turkey, the frequency of analysed stones had parallels with the temperature averages and climate features, presenting crescent-like distribution.

Role of core body temperature in nephrolithiasis

OBJECTIVES

To assess the role of core body temperature in urinary stone formation using a large clinical dataset.

PATIENTS AND METHODS

We retrospectively collected 14 519 039 individual temperature measurements from 580 416 patients with medical history, laboratory values and medication history between 2013 and 2018 at a single institution. After exclusions and matching 2:1 (controls:cases) to account for confounding variables, 7104 patients with a history of urinary stones were identified.

RESULTS

Patients with a history of urinary stones (cases) had an elevated mean (SD) oral temperature compared to matched controls, at 36.666 (0.17) vs 36.659 (0.20)°C (P = 0.012). Logistic regression of matched samples showed that higher core body temperature was predictive of a history of nephrolithiasis (odds ratio 1.21, 95% confidence interval 1.04-1.4; P = 0.015).

CONCLUSION

Core body temperature was significantly higher in patients with a history of urinary stones compared to matched controls, contrary to the anticipated thermodynamic considerations leading to crystal aggregation. Given that the core body temperature is elevated, rather than decreased, thermodynamic process driving stone formation is unlikely.

Factors Associated with Regional Adoption of Ureteroscopy in California from 2005 to 2016

PURPOSE

To explore regional adoption of ureteroscopy (URS) over extracorporeal shockwave lithotripsy (SWL) in the state of California (CA) and to identify factors associated with this adoption over time.

MATERIALS AND METHODS

We used the California Office of Statewide Health Planning and Development (OSHPD) public data to identify URS and SWL procedures performed for renal and ureteral stones from 2005 to 2016. The level of analysis was the region wherein each procedure was performed, defined by the 19 CA labor market regions. OSHPD data were supplemented with the Area Health Resource File to provide information on regional characteristics. Generalized linear regression was used to determine procedural rates adjusted for age, gender and race. Choropleth time series maps were used to illustrate adoption of URS by region over time.

RESULTS

A total of 328,795 URS and SWL procedures were identified from 2005 to 2016. The number of URS procedures surpassed the number of SWL procedures in 2011. Fourteen regions became URS predominant by 2016 and were characterized as having a higher per capita income, higher percentages with a college education and lower percentage of female heads-of-household (all p-values <0.05). A higher percentage of patients in these regions were male and had private or Medicare insurance (p = 0.03 for both).

CONCLUSIONS

From 2005 to 2016, most CA regions adopted URS as the primary renal and ureteral stone management strategy. These regions demonstrated characteristics of higher socioeconomic status compared to regions that remained SWL predominant. A better understanding of such differences in practice patterns will allow urologists to better negotiate for the capital expenditures required to conform to evolving standards of care and allow patients the ability to make more informed decisions on where they receive care.

Study on the prevalence and incidence of urolithiasis in Korea over the last 10 years: An analysis of National Health Insurance Data

Purpose

We aimed to analyze the incidence and prevalence of urolithiasis in Korea over the last decade using the National Health Insurance (NHI) sample cohort data.

Materials and Methods

From January 2002 to December 2013, we enrolled sample cohort data from the NHI. Patients diagnosed with international classification of diseases code N20 or N13.2 were included. The incidence and prevalence rate was counted from the same period and patients previously diagnosed with urolithiasis were excluded. We compared the incidence and prevalence of urolithiasis by region, age, and sex, and identified the changes.

Results

Total 1,111,828 subjects were included. Of these subjects, 36,857 had urolithiasis. The male-to-female ratio was 1.57:1, and total incidence rate was 3.27 per 1,000 person-years (1,000p-yrs). The annual incidence was lowest in 2013 (3,138 patients) and highest in 2005 (3,751 patients). Incidence rate by diagnostic code was highest in ureter stone only (2.49 per 1,000p-yrs) and was lowest in kidney and ureter stone both (0.17 per 1,000p-yrs). Prevalence gradually increased from 3,172 in 2002 and 5,758 in 2013. Jeollanam-do had the highest incidence rate of 3.70 persons per 1,000p-yrs, and Jeju had the lowest rate of 2.84 persons per 1,000p-yrs. In gender analysis, Daegu had the highest incidence (4.56) in males, Jeollanam-do had the highest incidence (3.20) in females.

Conclusions

Annual incidence remained stable, whereas prevalence gradually increased. The incidence in male was 1.57 times higher than female, and the peak incidence age was 45–49 years, with the highest incidence occurring in Jeollanam-do and the lowest in Jeju.

Unplanned Emergency Department Visits and Hospital Admissions Following Ureteroscopy: Do Ureteral Stents Make a Difference?

OBJECTIVE

To evaluate unplanned medical visits within the early postoperative period after ureteroscopy in patients with and without ureteral stent placement.

MATERIALS AND METHODS

We identified all ureteroscopic procedures for urinary stone disease in the California Office of Statewide Health Planning and Development database from 2010 to 2012. The primary outcome was any emergency department visit or inpatient hospital admission in the first 7 days following ureteroscopy. Patients were subcategorized by type of ureteroscopy (ie, laser lithotripsy vs basket retrieval) and were analyzed for significant differences between stented and unstented patients. Multivariable logistic regression was performed to determine if ureteral stent placement was independently associated with unplanned visits.

RESULTS

Our analytic cohort included 16,060 patients undergoing 17,716 ureteroscopy procedures. A ureteral stent was placed in 86.2% of patients undergoing laser lithotripsy and in 70.5% of patients receiving basket retrieval. In the 7 days following ureteroscopy, 6.6% of patients were seen in the emergency department and 2.2% of patients were admitted to a hospital. In a fully adjusted model, the utilization of a ureteral stent was not associated with emergency department visits or inpatient admissions.

CONCLUSION

Ureteral stent placement during ureteroscopy is not associated with an increased odds of emergency department visits and inpatient admissions in the early postoperative period.