Daily mean temperature and clinical kidney stone presentation in five U.S. metropolitan areas: a time-series analysis

High ambient temperature impact on the pattern of emergency-room visits due to renal colic in the Middle East

Urolithiasis has a seasonal pattern, with an established increase in incidence during the summer months. This study aims to assess the impact of high ambient temperatures on emergency room (ER) visits related to renal colic (RC) in a Middle Eastern country over the past decade. Population data were extracted using the MDClone Big Data platform. We recorded demographic and clinical data on all RC-associated ER visits from January 2012 to April 2023 and calculated the heat index (HI) that combines daily average coastal plane temperatures and humidity percentages. There was a total of 12,770 ER visits (median age 48 years, 9,236 (72%) males). The number of visits increased during the hottest months (July-October), with the highest numbers recorded during August. The number of visits remained stable throughout the study. We identified a linear association between humidity and the incidence of ER visits (p = 0.002), and a non-linear association between ambient temperature (p < 0.0001) and HI (p < 0.0001). There was a direct relationship between high temperatures and ER visits on the same day (risk ratio [RR]: 1.75, p = 0.036), with a 2-day lag (RR: 1.123, p = 0.024). In Conclusion, there is a significant relationship between temperature, humidity, HI, and the number of ER visits due to RC. Adjusted resource allocation and healthcare workforce availability are essential for managing additional cases during heat waves. Clinical implications: Increased demand is expected during heatwaves and within a 2-day lag, emphasizing the importance of proactive strategies to effectively manage RC patients.

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.

Impact of heat on emergency hospital admissions related to kidney diseases in Texas: Uncovering racial disparities

BACKGROUND AND OBJECTIVE

While impact of heat exposure on human health is well-documented, limited research exists on its effect on kidney disease hospital admissions especially in Texas, a state with diverse demographics and a high heat-related death rate. We aimed to explore the link between high temperatures and emergency kidney disease hospital admissions across 12 Texas Metropolitan Statistical Areas (MSAs) from 2004 to 2013, considering causes, age groups, and ethnic populations.

METHODS

To investigate the correlation between high temperatures and emergency hospital admissions, we utilized MSA-level hospital admission and weather data. We employed a Generalized Additive Model to calculate the association specific to each MSA, and then performed a random effects meta-analysis to estimate the overall correlation. Analyses were stratified by age groups, admission causes, and racial/ethnic disparities. Sensitivity analysis involved lag modifications and ozone inclusion in the model.

RESULTS

Our analysis found that each 1 °C increase in temperature was associated with a 1.73 % (95 % CI [1.43, 2.03]) increase in hospital admissions related to all types of kidney diseases. Besides, the effect estimates varied across different age groups and specific types of kidney diseases. We observed statistically significant associations between high temperatures and emergency hospital admissions for Acute Kidney Injury (AKI) (3.34 % (95 % CI [2.86, 3.82])), Kidney Stone (1.76 % (95 % CI [0.94, 2.60])), and Urinary Tract Infections (UTI) (1.06 % (95 % CI [0.61, 1.51])). Our research findings indicate disparities in certain Metropolitan Statistical Areas (MSAs). In Austin, Houston, San Antonio, and Dallas metropolitan areas, the estimated effects are more pronounced for African Americans when compared to the White population. Additionally, in Dallas, Houston, El Paso, and San Antonio, the estimated effects are greater for the Hispanic group compared to the Non-Hispanic group.

CONCLUSIONS

This study finds a strong link between higher temperatures and kidney disease-related hospital admissions in Texas, especially for AKI. Public health actions are necessary to address these temperature-related health risks, including targeted kidney health initiatives. More research is needed to understand the mechanisms and address health disparities among racial/ethnic groups.

The association between climate and emergency department visits for renal and urinary disease in Charlottesville, Virginia

Diseases of the kidney and urinary tract impose a significant portion of the total disease burden, and linkages to high temperature exposure suggest that this burden may increase in the near future. We examined the association between climate and daily emergency department (ED) visits for kidney and urinary disease at the University of Virginia main hospital in Charlottesville, Virginia from 2005 to 2020. Generalized additive models and distributed lag nonlinear models were used to examine these associations over a 21-day lag period. After testing a variety of weather variables from observations taken at the Charlottesville, Albemarle County Airport weather station, 1 p.m. temperature was found to have the strongest association with ED visits for renal and urinary visits while controlling for seasonal and trend factors, air quality, day of the week, and wintry weather. The relative risk of ED visits exhibited a stronger association with high temperatures compared to low temperatures. The heat response was pronounced at short lags (0-1 days) with the relative risk (RR) increasing when 1 p.m. temperatures exceeded 20°C and peaking at 29°C (RR = 1.28). By comparison, low temperatures (≤0°C) exhibited a negative association (RR = 0.80 at -10°C) at short lags (0-1 day), with evidence of a weak RR increase at lags of 2-3 and 9-14 days. These results for ED visitation are consistent with other studies linking high temperatures to acute kidney injury, chronic kidney disease, the development of kidney stones, and other associated illnesses. A better understanding of the impact of temperature extremes in generating or exacerbating existing conditions could assist medical health professionals in the prevention and management of these diseases during extreme weather events.

Climate change and kidney stones

PURPOSE OF REVIEW

Kidney stones affect an increasing proportion of the population. We suggest that these trends are in part influenced by exposure to higher temperatures as a result of climate change and urbanization. The changing epidemiology of kidney stones is a topic worthy of discussion due to the economic and healthcare burden the condition poses as well as the quality-of-life disruption faced by individuals with kidney stones.

RECENT FINDINGS

The relationship between heat and kidney stones is well supported. Exposure to high temperatures has been shown to increase risk for stone development within a short time frame. Effects are modified by factors such as sex, comorbid conditions, and population vulnerability and adaptability. Urban heat islands (UHIs) likely exaggerate the effect of increasing global surface temperature. The concentration of UHIs often coincides with historic redlining practices in the United States, potentially contributing to observed disparities in kidney health among minoritized populations. As global surface temperature increases and urbanization trends continue, a greater proportion of the world's population is exposed to significant temperature extremes each year, leading to the expectation that kidney stone prevalence will continue to increase.

SUMMARY

This work describes the effect of increasing global surface temperature as a result of climate change on kidney stone disease and kidney health. These effects may result in further perpetuation of significant kidney stone related social disparities. We suggest strategies to mitigate the effects of heat exposure on stone formation.

Short-term impact of extreme temperatures, relative humidity and air pollution on emergency hospital admissions due to kidney disease and kidney-related conditions in the Greater Madrid area (Spain)

While some studies report a possible association between heat waves and kidney disease and kidney-related conditions, there still is no consistent scientific consensus on the matter or on the role played by other variables, such as air pollution and relative humidity. Ecological retrospective time series study 01-01-2013 to 31-12-2018). Dependent variables: daily emergency hospitalisations due to kidney disease (KD), acute kidney injury (AKI), lithiasis (L), dysnatraemia (DY) and hypovolaemia (HPV). Independent variables: maximum and minimum daily temperature (Tmax, Tmin, °C), and daily relative humidity (RH, %). Other variables were also calculated, such as the daily temperature for risk of kidney disease (Theat, °C) and low daily hazardous relative humidity (HRH%). As variables of air pollution, we used the daily mean concentrations of PM10, PM2.5, NO2 and O3 in μg/m3. Based on these, we then calculated their daily excesses over World Health Organisation (WHO) guideline levels (hPM10, hPM2.5, hNO2 and hO3 respectively). Poisson family generalised linear models (GLMs) (link = log) were used to calculate relative risks (RRs), and attributable risks and attributable admissions. In the models, we controlled for the covariates included: seasonalities, trend, autoregressive component, day of the week, month and year. A statistically significant association was found between Theat and all the dependent variables analysed. The greatest AKI disease burden was attributable to Theat (2.2 % (1.7, 2.6) of attributable hospital admissions), followed by hNO2 (1.7 % (0.9, 3.4)) and HRH (0.8 (0.6, 1.1)). In the case of hypovolaemia and dysnatraemia, the greatest disease burden again corresponded to Theat, with 6.9 % (6.2, 7.6) and 5.7 (4.8, 6.6) of attributable hospital admissions respectively. Episodes of extreme heat exacerbate daily emergency hospital admissions due to kidney disease and kidney-related conditions; and attributable risks are likewise seen for low relative humidity and high ozone levels.

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.

Association between air temperature and risk of hospitalization for genitourinary disorders: An environmental epidemiological study in Lanzhou, China

OBJECTIVES

The aim of this study was to investigate the relationship between air temperature and the risk of hospitalization for genitourinary disorders.

METHODS

Distributed lag non-linear models (DLNM) were used to estimate the association between air temperature and the risk of hospitalization for genitourinary disorders, with subgroup analysis by gender and age to identify the susceptible population of temperature-sensitive genitourinary system diseases.

RESULTS

Low mean temperature (MT) (RR = 2.001, 95% CI: 1.856~2.159), high MT (RR = 2.884, 95% CI: 2.621~3.173) and low diurnal temperature range (DTR) (RR = 1.619, 95% CI: 1.508~1.737) were all associated with the increased risk of hospitalization for genitourinary disorders in the total population analysis, and the high MT effect was stronger than the low MT effect. Subgroup analysis found that high MT was more strongly correlated in male (RR = 2.998, 95% CI: 2.623~3.427) and those <65 years (RR = 3.003, 95% CI: 2.670~3.344), and low DTR was more strongly correlated in female (RR = 1.669, 95% CI: 1.510~1.846) and those <65 years (RR = 1.643, 95% CI: 1.518~1.780).

CONCLUSIONS

The effect of high MT on the risk of hospitalization for genitourinary disorders is more significant than that of low MT. DTR was independently associated with the risk of hospitalization for genitourinary disorders.

The influence of climatic factors in the seasonal fluctuation of urolithiasis and the trend of stone disease management in the southern Taiwan

This study aims to analyze the effects of climate parameters on the number of urolithiasis treatments in our hospital and understand the effects of climate parameters on the prevalence of urolithiasis in southern Taiwan. We also look at trends associated with urolithiasis and treatments. Retrospectively reviewed the records of extracorporeal shockwave lithotripsy (ESWL), ureteroscopy (URS), retrograde intrarenal surgery (RIRS), and percutaneous nephrolithotripsy (PCNL) performed in our hospital from January 2012 to December 2018. Climate data for were collected from Central Weather Bureau. The monthly meteorological data included average temperatures, humidity, rainfall, sunshine hours, atmospheric pressure, and wind speed. Monthly numbers of patients undergoing stone management was positively correlated to average temperature (r = 0.657), relative humidity (r = 0.234), monthly rainfall (r = 0.261) and monthly sunshine hours (r = 0.348), while it was negatively correlated to atmospheric pressure (r = - 0.522). The multivariate linear regression model demonstrated temperature (ß = 10.682, 95% CI 6.178-14.646, p < 0.001) and Relative humidity (ß = - 95% CI - 5.233- - 1.216, p = 0.002) to be independently related to numbers of stone treatment. The data also revealed a rising prevalence of urolithiasis with an associated increase in the number of interventions, with fewer ESWL (74.0-49.4%). Temperature and relative humidity are associated with monthly numbers of stone treatment. Ambient temperature is the most critical climate factor affecting the prevalence of symptomatic urolithiasis and intention of active stone removal in southern Taiwan.

Associations between short-term temperature exposure and kidney-related conditions in New York State: The influence of temperature metrics across four dimensions

BACKGROUND

Evidence describing the relationship between short-term temperature exposure and kidney-related conditions is insufficient. It remains unclear how temperature specification affects estimation of these associations. This study aimed to assess associations between short-term temperature exposure and seven kidney-related conditions and to evaluate the influence of temperature specification.

METHODS

We obtained data on hospital encounters in New York State (2007-2016). We assessed associations with a case-crossover design using conditional logistic regression with distributed lag non-linear models. We compared model performance (i.e., AIC) and association curves using 1) five temperature spatial resolutions; 2) temperature on an absolute versus relative scale; 3) seven temperature metrics incorporating humidity, wind speed, and/or solar radiation; and 4) five intraday temperature measures (e.g., daily minimum and daytime mean).

RESULTS

We included 1,209,934 unplanned adult encounters. Temperature metric and intraday measure had considerably greater influence than spatial resolution and temperature scale. For outcomes not associated with temperature exposure, almost all metrics or intraday measures showed good model performance; for outcomes associated with temperature, there were meaningful differences in performance across metrics or intraday measures. For parsimony, we modelled daytime mean outdoor wet-bulb globe temperature, which showed good performance for all outcomes. At lag 0-6 days, we observed increased risk at the 95^th percentile of temperature versus the minimum morbidity temperature for acute kidney failure (odds ratio [OR] = 1.36, 95% confidence interval [CI]: 1.09, 1.69), urolithiasis (OR = 1.41, 95% CI: 1.16, 1.70), dysnatremia (OR = 1.26, 95% CI: 1.01, 1.59), and volume depletion (OR = 1.88, 95% CI: 1.41, 2.51), but not for glomerular diseases, renal tubulo-interstitial diseases, and chronic kidney disease.

CONCLUSIONS

High-temperature exposure over one week is a risk factor for acute kidney failure, urolithiasis, dysnatremia, and volume depletion. The differential model performance across temperature metrics and intraday measures indicates the importance of careful selection of exposure metrics when estimating temperature-related health burden.

Climate and the Nephrologist: The Intersection of Climate Change, Kidney Disease, and Clinical Care

Climate change is upon us, and it will have a major effect on both kidney disease and the nephrology practice. But the converse is also true: our treatment of kidney disease has an effect on the climate. Much attention has focused on how rising temperatures can lead to acute and CKD and health exacerbations in patients with established kidney disease. Climate change is also associated with rising air pollution from wildfires and industrial wastes and infectious diseases associated with flooding and changing habitats, all of which heighten the risk of acute and CKD. Less well recognized or understood are the ways nephrology practices, in turn, contribute to still more climate change. Hemodialysis, although lifesaving, can be associated with marked water usage (up to 600 L per dialysis session), energy usage (with one 4-hour session averaging as much as one fifth of the total energy consumed by a household per day), and large clinical wastes (with hemodialysis accounting for one third of total clinical medicine-associated waste). Of note, >90% of dialysis occurs in highly affluent countries, whereas dialysis is much less available in the poorer countries where climate change is having the highest effect on kidney disease. We conclude that not only do nephrologists need to prepare for the rise in climate-associated kidney disease, they must also urgently develop more climate-friendly methods of managing patients with kidney disease.

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.

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.

Association between daily temperature and hospital admissions for urolithiasis in Ganzhou, China: a time-series analysis

Urolithiasis was a global disease and it was more common in southern China. This study looked into the association between daily temperature and urolithiasis hospital admissions in Ganzhou, a large prefecture-level city in southern China. In Ganzhou City from 2016 to 2019, a total of 60,881 hospitalized cases for urolithiasis from 69 hospitals and meteorological data were gathered. The effect of high ambient temperature on urolithiasis hospital admissions was estimated using a distributed lag nonlinear model. Stratified analysis was done to examine sex differences. The study found that in Ganzhou of China, the exposure-response curves approximated a "J" shape which across genders were basically similar. The maximum lag effect occurred on the second day after high temperatures for males but on the third day for females. Compared to the 10 °C reference temperature and considering the cumulative lag effect of 10 days, the relative risks of the daily mean temperature at the 95th percentile on the total, male, and female hospital admissions for urolithiasis were 2.026 (95% CI: 1.628, 2.521), 2.041 (95% CI: 1.603, 2.598), and 2.030 (95% CI: 1.552, 2.655), respectively, but the relative risks between sex were not statistically significant (p = 0.977). Urolithiasis morbidity risk in China could be exacerbated by high temperatures. The effect of high temperature on urolithiasis was similar across genders.

Redlining has led to increasing rates of nephrolithiasis in minoritized populations: a hypothesis

PURPOSE OF REVIEW

The persistent rise in kidney stone prevalence in recent decades has prompted much speculation as to the causes. There has been some discussion about the effect of heat on nephrolithiasis. Here, we review recent data and postulate that heat may play a role in stone formation on a large scale and among African-Americans in particular.

RECENT FINDINGS

African-Americans are the race/ancestry group with faster rates of increasing incidence and prevalence of kidney stones. We make the observation that urban heat islands in the United States have resulted in part from the effects of redlining, a practice of systematic segregation and racism in housing that led to the development of neighborhoods with substantial disparities in environmental conditions.

SUMMARY

In this thought experiment, we propose that the disproportionate rise in the prevalence of nephrolithiasis in minoritized populations correlates with increased temperatures specifically in neighborhoods adversely affected by the practice of redlining. We discuss phenomena in support of this hypothesis and ongoing work to test this theory.

Extreme temperature exposure and urolithiasis: A time series analysis in Ganzhou, China

Background

Ambient temperature change is a risk factor for urolithiasis that cannot be ignored. The association between temperature and urolithiasis varies from region to region. Our study aimed to analyze the impact of extremely high and low temperatures on the number of inpatients for urolithiasis and their lag effect in Ganzhou City, China.

Methods

We collected the daily number of inpatients with urolithiasis in Ganzhou from 2018 to 2019 and the meteorological data for the same period. The exposure-response relationship between the daily mean temperature and the number of inpatients with urolithiasis was studied by the distributed lag non-linear model (DLNM). The effect of extreme temperatures was also analyzed. A stratification analysis was performed for different gender and age groups.

Results

There were 38,184 hospitalizations for urolithiasis from 2018 to 2019 in Ganzhou. The exposure-response curve between the daily mean temperature and the number of inpatients with urolithiasis in Ganzhou was non-linear and had an observed lag effect. The warm effects (30.4°C) were presented at lag 2 and lag 5-lag 9 days, and the cold effects (2.9°C) were presented at lag 8 and lag 3-lag 4 days. The maximum cumulative warm effects were at lag 0-10 days (cumulative relative risk, CRR = 2.379, 95% CI: 1.771, 3.196), and the maximum cumulative cold effects were at lag 0-5 (CRR = 1.182, 95% CI: 1.054, 1.326). Men and people between the ages of 21 and 40 were more susceptible to the extreme temperatures that cause urolithiasis.

Conclusion

Extreme temperature was correlated with a high risk of urolithiasis hospitalizations, and the warm effects had a longer duration than the cold effects. Preventing urolithiasis and protecting vulnerable people is critical in extreme temperature environments.

Epidemiology of Urolithiasis with Sex and Working Status Stratification Based on the National Representative Cohort in Republic of Korea

Background

This study aimed to estimate the annual prevalence and incidence of urolithiasis stratified by work status based on a large nationwide sample.

Methods

This study used data from the National Health Insurance Service-National Sample Cohort from 2002 to 2015. The prevalence and incidence of urolithiasis were estimated based on work status and gender stratification. The risk of urolithiasis among workers was calculated using age-standardized incidence ratio with stratification of work type.

Results

The prevalence of urolithiasis was significantly higher in workers than in non-workers, especially men, during the follow-up period. The total estimated number of urolithiasis cases was 41,086 and the overall incidence of urolithiasis was 0.3%. The age-standardized incidence ratio of urolithiasis was significantly higher among the total workers (1.14; 95% confidence interval, 1.13-1.16), self-employed workers (1.08; 95% confidence interval, 1.06-1.11), and paid workers (1.19; 95% confidence interval, 1.17-1.21) than among the non-working population.

Conclusions

Workers, especially paid workers and men, were vulnerable to urolithiasis. Further studies are required to investigate the effects of working conditions on urolithiasis.

Associations Between Ambient Extreme Heat Exposure and Emergency Department Visits Related to Kidney Disease

RATIONALE & OBJECTIVE

Extreme heat exposure is associated with multiple diseases. However, our current understanding of the specific impact of extreme heat exposure on kidney disease is limited.

STUDY DESIGN

Case-crossover study.

SETTING & PARTICIPANTS

1,114,322 emergency department (ED) visits with a principal diagnosis of kidney disease were identified in New York state, 2005-2013.

EXPOSURE

Extreme heat exposure was defined as when the daily temperature exceeded the 90th percentile temperature of that month during the study period in the county.

OUTCOME

ED visits with a principal diagnosis of kidney disease and its subtypes (ICD-9 [International Classification of Diseases, Ninth Revision] codes 580-599, 788).

ANALYTICAL APPROACH

Extreme heat exposure on the ED visit days was compared with extreme heat exposure on control days using a conditional logistic regression model, controlling for humidity, air pollutants, and holidays. The excess risk of kidney disease was calculated for a week (lag days 0-6) after extreme heat exposure during the warm season (May through September). We also stratified our estimates by sociodemographic characteristics.

RESULTS

Extreme heat exposure was associated with a 1.7% (lag day 0) to 3.1% (lag day 2) higher risk of ED visits related to kidney disease; this association was stronger with a greater number of extreme heat exposure days in the previous week. The association with extreme heat exposure lasted for an entire week and was stronger in the transitional months (ie, May and September; excess rates ranged from 1.8% to 5.1%) rather than the summer months (June through August; excess rates ranged from 1.5% to 2.7%). The strength of association was greater among those with ED visits related to acute kidney injury, kidney stones, and urinary tract infections. Age and sex may modify the association between extreme heat exposure and ED visits.

LIMITATIONS

Individual exposure to heat-how long people were outside or whether they had access to air conditioning-was unknown.

CONCLUSIONS

Extreme heat exposure was significantly associated with a dose-dependent greater risk of ED visits for kidney disease.

Effects of ambient temperature on hospital admissions for obstructive nephropathy in Wuhan, China: A time-series analysis

Under the background of global warming, it has been confirmed that heat exposure has a huge impact on human health. The current study aimed to evaluate the effects of daily mean ambient temperature on hospital admissions for obstructive nephropathy (ON) at the population level. A total of 19,494 hospitalization cases for ON in Wuhan, China from January 1, 2015 to December 31, 2018 were extracted from a nationwide inpatient database in tertiary hospitals according to the International Classification of Diseases (ICD)- 10 codes. Daily ambient meteorological and pollution data during the same period were also collected. A quasi-Poisson Generalized Linear Model (GLM) combined with a distributed lag non-linear model (DLNM) was applied to analyze the lag-exposure-response relationship between daily mean temperature and daily hospital admissions for ON. Results showed that there were significantly positive associations between the daily mean temperature and ON hospital admissions. Relative to the minimum-risk temperature (-3.4 ℃), the risk of hospital admissions for ON at moderate hot temperature (25 ℃, 75th percentile) occurred from lag day 4 and stayed to lag day 12 (cumulative relative risk [RR] was 1.846, 95 % confidence interval [CI]: 1.135-3.005, over lag 0-12 days). Moreover, the risk of extreme hot temperature (32 ℃, 99th percentile) appeared immediately and lasted for 8 days (RR = 2.019, 95 % CI: 1.308-3.118, over lag 0-8 days). Subgroup analyses indicated that the middle-aged and elderly (≥45 years) patients might be more susceptible to the negative effects of high temperature, especially at moderate hot conditions. Our findings suggest that temperature may have a significant impact on the acute progression and onset of ON. Higher temperature is associated with increased risks of hospital admissions for ON, which indicates that early interventions should be taken in geographical settings with relatively high temperatures, particularly for the middle-aged and elderly.

Relationships between short-term ambient temperature exposure and kidney disease hospitalizations in the warm season in Vietnam: A case-crossover study

BACKGROUND

Under a warming climate, adverse health effects of heat are an increasing concern. We evaluated associations between short-term ambient temperature exposure and hospital admission for kidney disease in Vietnam.

METHODS

We linked province-level meteorologic data with admission data from 14 province-level hospitals (2003-2015). We used a case-crossover design to evaluate associations between daily ambient temperature metrics (mean, maximum, and minimum temperature and mean heat index) and risk of hospitalization for four kidney disease subtypes: glomerular diseases, renal tubulo-interstitial diseases, chronic kidney disease, and urolithiasis, including lagged (≤lag 14 days) and cumulative (≤lag 0-6 days) associations, during the warm season. We also evaluated independent associations with extreme heat days (defined as days with daily maximum temperature >95^th percentile of the provincial daily maximum temperature distribution). Akaike's information criterion and patterns of risk estimates across cumulative exposure time windows and single-day lags informed our selection of final models.

RESULTS

We included 58,330 hospital admissions during the warm season. Daily mean temperature averaged over the same day and the previous six days (lag 0-6 days) was associated with risk of hospitalization for each kidney disease outcome with odds ratios (per 1 °C increase in daily mean temperature) of 1.07 (95% confidence interval [CI]: 0.99, 1.16) for glomerular diseases, 1.06 (95% CI: 0.96, 1.17) for renal tubulo-interstitial diseases, 1.12 (95% CI: 1.00, 1.24) for chronic kidney disease, and 1.09 (95% CI: 1.02, 1.16) for urolithiasis. We found no additional independent associations with extreme heat. Results for the four temperature metrics were similar.

CONCLUSIONS

High ambient temperature was associated with increased risk of hospitalization for each kidney disease subtype, with the most convincing associations for chronic kidney disease and urolithiasis. Further laboratory and epidemiologic research is needed to confirm the findings and disentangle the underlying mechanisms.

Association between Temperature and Inpatient Stone Admission in a Pediatric Population

BACKGROUND

Higher temperatures have been associated with increased stone formation and subsequent utilization of hospital resources, including inpatient admission. However, these observations have been derived from the adult population. We sought to examine if this purported association extends to the pediatric population.

METHODS

We used the 2016 Kids' Inpatient Database to identify nationwide pediatric inpatient admissions related to nephrolithiasis. Temperature data from the National Oceanic and Atmospheric Administration was linked to each admission. Comparative statistics analyzed patient and admission characteristics. Multivariable logistic regression analyzed associations between stone-related admissions and temperature. As a frame of reference, this analysis was replicated using the National Inpatient Sample from 2016 to evaluate associations in the adult population.

RESULTS

Of the 2,496,257 pediatric admissions, 8,453 (0.33%) were related to nephrolithiasis. Temperatures at the time of stone admission were higher than those during non-stone admission (55.9°F vs. 54.8°F, P<0.001). The stone admission group had a higher proportion of females than the non-stone admission group (64.8% vs. 55.4%, P<0.001). Stone admission was significantly associated with temperature (OR 1.025 per 10°F, 95% CI 1.003-1.049, P=0.03) and female sex (OR 1.097, 95% CI 1.027-1.171, P=0.006). In the adult population, 380,520 out of 30,000,941 patients (1.3%) were admitted with a stone. The effect of temperature on stone admissions was similar to that in the pediatric population (OR 1.020, 95% CI 1.014-1.026, P<0.001), but women were over 20% less likely to be admitted for stones than men (OR 0.770, 95% CI 0.757-0.784, P<0.001).

CONCLUSIONS

Increased temperatures were associated with an increased risk of stone-related admission in both the pediatric and adult populations. Females were at increased risk for stone-related admissions during childhood, but this trend reverses in adulthood.

Do weather parameters affect the incidence of renal colic in a predominantly warm country? A multicenter study

Purpose:

To determine whether there is any effect of weather parameters on the incidence of renal colic patients presenting to emergency rooms (ERs) during the hottest season in Israel.

Materials and Methods:

This retrospective multicenter study involved all ER admissions related to renal colic in nine centres throughout Israel between 2010 and 2017. The collected data included the date of ER visits, the patients’ age and sex, and the weather features of ambient temperature, wind velocity, noon heat index, and barometric pressure. Multivariable logistic regression analyses identified predictors of increased ER visits for renal colic.

Results:

There were 85,501 renal colic-related ER visits during the study period, involving 62,935 (74%) males and 22,566 (26%) females ( p < 0.005). The mean ± standard deviation (SD) age of the males and females was 50 ± 5.8 and 48 ± 19.6 years, respectively ( p = 0.1). Most of the ER arrivals were in the 31- to 50-year-old age group (37%, 31,508) ( p = 0.02). The maximal ambient temperature (odds ratio (OR) = 2.213, 95% confidence interval (CI) = 2.148–2.279, p < 0.0001), lower heat index (i.e. low humidity; OR = 0.880, 95% CI = 0.872–0.887, p < 0.0001) and increased wind velocity (OR = 1.165, 95% CI = 1.149–1.182, p < 0.0001) had a significant linear effect on ER visits for renal colic events.

Conclusion:

Conditions that increase sweat evaporation during the hottest months, including a decreased heat index and increased wind velocity, correlated with more ER visits for renal colic events, probably due to dehydration associated with elevated sweat evaporation.

Level of evidence:

Not applicable

Assessing proximate intermediates between ambient temperature, hospital admissions, and mortality in hemodialysis patients

BACKGROUND

Typical thermoregulatory responses to elevated temperatures among healthy individuals include reduced blood pressure and perspiration. Individuals with end-stage kidney disease (ESKD) are susceptible to systemic fluctuations caused by ambient temperature changes that may increase morbidity and mortality. We investigated whether pre-dialysis systolic blood pressure (preSBP) and interdialytic weight gain (IDWG) can independently mediate the association between ambient temperature, all-cause hospital admissions (ACHA), and all-cause mortality (ACM).

METHODS

The study population consisted of ESKD patients receiving hemodialysis treatments at Fresenius Medical Care facilities in Philadelphia County, PA, from 2011 to 2019 (n = 1981). Within a time-to-event framework, we estimated the association between daily maximum dry-bulb temperature (TMAX) and, as separate models, ACHA and ACM during warmer calendar months. Clinically measured preSBP and IDWG responses to temperature increases were estimated using linear mixed effect models. We employed the difference (c-c') method to decompose total effect models for ACHA and ACM using preSBP and IDWG as time-dependent mediators. Covariate adjustments for exposure-mediator and total and direct effect models include age, race, ethnicity, blood pressure medication use, treatment location, preSBP, and IDWG. We considered lags up to two days for exposure and 1-day lag for mediator variables (Lag 2-Lag 1) to assure temporality between exposure-outcome models. Sensitivity analyses for 2-day (Lag 2-only) and 1-day (Lag 1-only) lag structures were also conducted.

RESULTS

Based on Lag 2- Lag 1 temporal ordering, 1 °C increase in daily TMAX was associated with increased hazard of ACHA by 1.4% (adjusted hazard ratio (HR), 1.014; 95% confidence interval, 1.007-1.021) and ACM 7.5% (adjusted HR, 1.075, 1.050-1.100). Short-term lag exposures to 1 °C increase in temperature predicted mean reductions in IDWG and preSBP by 0.013-0.015% and 0.168-0.229 mmHg, respectively. Mediation analysis for ACHA identified significant indirect effects for all three studied pathways (preSBP, IDWG, and preSBP + IDWG) and significant indirect effects for IDWG and conjoined preSBP + IDWG pathways for ACM. Of note, only 1.03% of the association between temperature and ACM was mediated through preSBP. The mechanistic path for IDWG, independent of preSBP, demonstrated inconsistent mediation and, consequently, potential suppression effects in ACHA (-15.5%) and ACM (-6.3%) based on combined pathway models. Proportion mediated estimates from preSBP + IDWG pathways achieved 2.2% and 0.3% in combined pathway analysis for ACHA and ACM outcomes, respectively. Lag 2 discrete-time ACM mediation models exhibited consistent mediation for all three pathways suggesting that 2-day lag in IDWG and preSBP responses can explain 2.11% and 4.41% of total effect association between temperature and mortality, respectively.

CONCLUSION

We corroborated the previously reported association between ambient temperature, ACHA and ACM. Our results foster the understanding of potential physiological linkages that may explain or suppress temperature-driven hospital admissions and mortality risks. Of note, concomitant changes in preSBP and IDWG may have little intermediary effect when analyzed in combined pathway models. These findings advance our assessment of candidate interventions to reduce the impact of outdoor temperature change on ESKD patients.

The impact of heat on kidney stone presentations in South Carolina under two climate change scenarios

The risk of kidney stone presentations increases after hot days, likely due to greater insensible water losses resulting in more concentrated urine and altered urinary flow. It is thus expected that higher temperatures from climate change will increase the global prevalence of kidney stones if no adaptation measures are put in place. This study aims to quantify the impact of heat on kidney stone presentations through 2089, using South Carolina as a model state. We used a time series analysis of historical kidney stone presentations (1997–2014) and distributed lag non-linear models to estimate the temperature dependence of kidney stone presentations, and then quantified the projected impact of climate change on future heat-related kidney stone presentations using daily projections of wet-bulb temperatures to 2089, assuming no adaptation or demographic changes. Two climate change models were considered—one assuming aggressive reduction in greenhouse gas emissions (RCP 4.5) and one representing uninibited greenhouse gas emissions (RCP 8.5). The estimated total statewide kidney stone presentations attributable to heat are projected to increase by 2.2% in RCP 4.5 and 3.9% in RCP 8.5 by 2085–89 (vs. 2010–2014), with an associated total excess cost of ~ $57 million and ~ $99 million, respectively.

Performance intensification of CO2 absorption and microalgae conversion (CAMC) hybrid system via low temperature plasma (LTP) treatment

CO₂ absorption and microalgae conversion (CAMC) hybrid system is a promising alternative for simultaneous carbon capture and utilization. It can not only overcome the challenge of high energy consumption solvent thermal regeneration in chemical CO₂ absorption, but also enhance the carbon conversion efficiency in biological conversion process. However, the discordance between CO₂ absorption and bio-conversion rate has become the key to limiting the development of CAMC system. Therefore, in this study, low temperature plasma (LTP) mutation breeding technology was used to training Chlorella strains by combining undirected mutagenesis and directional screening. Then, the mutagenic microalgae were cultivated and evaluated in CAMC system. It was found that compared with original Chlorella L166, the OD₆₈₀ of mutant strain L166-M₃ in CAMC system increased 7.8%, and the maximum specific growth rate improved 27.5%. The carbon sequestration rate of wild Chlorella L166 increased from 82.9% to 93.7% after mutation treatment, the activity of RubisCO, and the content of NADPH produced by photoreaction increased 37.2% and 17.2%. In addition, lipid production of L166-M₃ increased to 6.89 mg/L, which was 15.4% higher than original Chlorella L166. It could be observed that LTP mutation breeding could be used as a potential method for training algae species and improve the overall performance of CAMC system.

Hot weather as a risk factor for kidney disease outcomes: A systematic review and meta-analysis of epidemiological evidence

BACKGROUND

The occurrence or exacerbation of kidney disease has been documented as a growing problem associated with hot weather. The implementation of effective prevention measures requires a better understanding of the risk factors that increase susceptibility. To fill gaps in knowledge, this study reviews the current literature on the effects of heat on kidney-disease outcomes (ICD-10 N00-N39), including morbidity and mortality.

METHODS

Databases were systematically searched for relevant literature published between 1990 and 2020 and the quality of evidence evaluated. We performed random effects meta-analysis to calculate the pooled relative risks (RRs) of the association between high temperatures (and heatwaves) and kidney disease outcomes. We further evaluated vulnerability concerning contextual population characteristics.

RESULTS

Of 2739 studies identified, 91 were reviewed and 82 of these studies met the criteria for inclusion in a meta-analysis. Findings showed that with a 1 °C increase in temperature, the risk of kidney-related morbidity increased by 1% (RR 1.010; 95% CI: 1.009-1.011), with the greatest risk for urolithiasis. Heatwaves were also associated with increased morbidity with a trend observed with heatwave intensity. During low-intensity heatwaves, there was an increase of 5.9% in morbidity, while during high-intensity heatwaves there was a 7.7% increase. There were greater RRs for males, people aged ≤64 years, and those living in temperate climate zones. Similarly, for every 1 °C temperature increase, there was a 3% (RR 1.031; 95% CI: 1.018-1.045) increase in the risk of kidney-related mortality, which also increased during heatwaves.

CONCLUSIONS

High temperatures (and heatwaves) are associated with an elevated risk of kidney disease outcomes, particularly urolithiasis. Preventive measures that may minimize risks in vulnerable individuals during hot spells are discussed.

Attributable risks of hospitalizations for urologic diseases due to heat exposure in Queensland, Australia, 1995-2016

BACKGROUND

Heat exposure is a risk factor for urologic diseases. However, there are limited existing studies that have examined the relationship between high temperatures and urologic disease. The aim of this study was to examine the associations between heat exposure and hospitalizations for urologic diseases in Queensland, Australia, during the hot seasons of 1995-2016 and to quantify the attributable risks.

METHODS

We obtained 238 427 hospitalized cases with urologic diseases from Queensland Health between 1 December 1995 and 31 December 2016. Meteorological data were collected from the Scientific Information for Land Owners-a publicly accessible database of Australian climate data that provides daily data sets for a range of climate variables. A time-stratified, case-crossover design fitted with the conditional quasi-Poisson regression model was used to estimate the associations between temperature and hospitalizations for urologic diseases at the postcode level during each hot season (December-March). Attributable rates of hospitalizations for urologic disease due to heat exposure were calculated. Stratified analyses were performed by age, sex, climate zone, socio-economic factors and cause-specific urologic diseases.

RESULTS

We found that a 1°C increase in temperature was associated with a 3.3% [95% confidence interval (CI): 2.9%, 3.7%] increase in hospitalization for the selected urologic diseases during the hot season. Hospitalizations for renal failure showed the strongest increase 5.88% (95% CI: 5.25%, 6.51%) among the specific causes of hospital admissions considered. Males and the elderly (≥60 years old) showed stronger associations with heat exposure than females and younger groups. The sex- and age-specific associations with heat exposure were similar across specific causes of urologic diseases. Overall, nearly one-fifth of hospitalizations for urologic diseases were attributable to heat exposure in Queensland.

CONCLUSIONS

Heat exposure is associated with increased hospitalizations for urologic disease in Queensland during the hot season. This finding reinforces the pressing need for dedicated public health-promotion campaigns that target susceptible populations, especially for those more predisposed to renal failure. Given that short-term climate projections identify an increase in the frequency, duration and intensity of heatwaves, this public health advisory will be of increasing urgency in coming years.

Temperatures and health costs of emergency department visits: A multisite time series study in China

BACKGROUND

Evidence is limited regarding the association between temperatures and health costs.

OBJECTIVES

We tried to investigate the association between temperatures and emergency department visits (EDVs) costs in China.

METHODS

Daily data on EDVs costs, weather, air pollution were collected from 17 sites in China during 2014-2018. A quasi-Poisson generalized additive regression with distributed lag nonlinear model was applied to assess the temperature-EDVs cost association. Random-effect meta-analysis was used to pool the estimates from each site. Attributable fractions and national attributable EDVs costs due to heat and cold were calculated.

RESULTS

Relative risk (RR) due to extreme heat over 0-7 lag days was 1.14 [95% confidence intervals (CI): 1.08-1.19] and 1.11 (95% CI: 1.07-1.16) for EDVs examination (including treatment) and medicine cost, respectively. People aged 18-44 and those with genitourinary diseases were at higher risk from heat. 0.72% of examination cost and 0.57% of medicine cost were attributed to extreme heat, costing 274 million Chinese Yuan annually. Moderate heat had lower RR but higher attributable fraction of EDVs costs. Exposure to extreme cold over 0-21 lag days increased the risk of medicine cost for people aged 18-44 [RR: 1.30 (95% CI: 1.10-1.55)] and those with respiratory diseases [RR: 1.56 (95% CI: 1.14-2.14)], but had non-statistically significant attributable fraction of the total EDVs cost.

CONCLUSIONS

Exposure to heat and cold resulted in remarkable health costs. More resources and preparedness are needed to tackle such a challenge as our climate is rapidly changing.

A single day fasting may increase emergency room visits due to renal colic

We aimed to explore whether a single-day of fasting (SDF) increase emergency room (ER) visits due to renal colic (RC). We elected to concentrate on Yom-Kippur (i.e.: SDF), the holiest day in Judaism. Food and liquid consumption is prohibited during this day for 25 h, and an estimated 50–70% fasting rate is observed. SDF always takes place between mid-September and mid-October during which the temperature in the Middle-East ranges between 19 and 30 °C. ER visits for RC between 01/2012 and 11/2019 were reviewed, and the Gregorian days on which SDF occurred were retrieved. The number of ER visits for RC was compared between SDF and the surrounding days/months as well as to another single-day "standard" holiday (SDSH) that precedes SDF in 10 days and is not associated with fasting. Of 11,717 ER visits for RC, 8775 (74.9%) were males. Male:Female ratio was 3:1. The mean daily number of ER visits for RC during the 3 days following SDF was 6.66 ± 2.49, significantly higher compared with the mean annual daily visits (4.1 ± 2.27, p < 0.001), the mean daily visits during the week prior to SDF (5.27 ± 2.656, p = 0.032), and the mean daily visits during September (5.06 ± 2.659, p = 0.005), and October (4.78 ± 2.23, p < 0.001). The mean number of ER daily visits for RC during the 3 days following SDSH, 5.79 ± 2.84, did not differ compared with the mean daily visits during September and October (p = 0.207; p = 0.13, respectively). It was lower compared to SDF, however statistically insignificant (p = 0.285). A single-day fasting may increase ER visits for RC. The mechanism underlying this phenomenon is unknown.

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.

Influence of socioeconomic disparities, temperature and humidity in kidney stone composition

INTRODUCTION

Large variations in demographic, economic and environmental factors might influence the worldwide distribution of urolithiasis, but scarce data are available concerning their associations with stone composition. We aimed to evaluate the frequency and composition of kidney stones and their associations with temperature, humidity, and human development index (HDI).

MATERIALS AND METHODS

A total of 1,158 stones from distinct patients (47±14 years old, male/female 2:1) were included. The mean annual temperature and relative humidity of each town were considered separately.

RESULTS

Calcium oxalate monohydrate (COM) was disclosed in 38.8% of patients, calcium oxalate dihydrate (COD) in 22.1%, mixed COD/apatite in 9.4%, pure apatite in 1.9%, brushite in 1.8%, struvite in 8.3%, pure uric acid in 11.1%, mixed uric acid/COM in 5.6%, and cystine/rare types in 0.8%. Mean HDI of all pooled cities was 0.780±0.03. However, people living in HDI<0.800 regions had twice the odds of having a struvite stone versus those living in HDI>0.800 (OR=2.14, 95% CI 1.11-4.11). Furthermore, a progressive increase in the struvite stones frequency from 4.5 to 22.8% was detected from HDI>0.800 through HDI<0.700. No significant difference for other stone types was disclosed. Separate logistic regression models assessed the association of each stone composition with gender, temperature, humidity and HDI as covariates.

CONCLUSION

Patients living in low HDI areas are more prone to develop struvite stones, possibly due to lower access to healthcare. Temperature and humidity did not represent a specific risk factor for any stone type in the present sample.

Association of Social Distancing, Population Density, and Temperature With the Instantaneous Reproduction Number of SARS-CoV-2 in Counties Across the United States

IMPORTANCE

Local variation in the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) across the United States has not been well studied.

OBJECTIVE

To examine the association of county-level factors with variation in the SARS-CoV-2 reproduction number over time.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included 211 counties, representing state capitals and cities with at least 100 000 residents and including 178 892 208 US residents, in 46 states and the District of Columbia between February 25, 2020, and April 23, 2020.

EXPOSURES

Social distancing, measured by percentage change in visits to nonessential businesses; population density; and daily wet-bulb temperatures.

MAIN OUTCOMES AND MEASURES

Instantaneous reproduction number (Rt), or cases generated by each incident case at a given time, estimated from daily case incidence data.

RESULTS

The 211 counties contained 178 892 208 of 326 289 971 US residents (54.8%). Median (interquartile range) population density was 1022.7 (471.2-1846.0) people per square mile. The mean (SD) peak reduction in visits to nonessential business between April 6 and April 19, as the country was sheltering in place, was 68.7% (7.9%). Median (interquartile range) daily wet-bulb temperatures were 7.5 (3.8-12.8) °C. Median (interquartile range) case incidence and fatality rates per 100 000 people were approximately 10 times higher for the top decile of densely populated counties (1185.2 [313.2-1891.2] cases; 43.7 [10.4-106.7] deaths) than for counties in the lowest density quartile (121.4 [87.8-175.4] cases; 4.2 [1.9-8.0] deaths). Mean (SD) Rt in the first 2 weeks was 5.7 (2.5) in the top decile compared with 3.1 (1.2) in the lowest quartile. In multivariable analysis, a 50% decrease in visits to nonessential businesses was associated with a 45% decrease in Rt (95% CI, 43%-49%). From a relative Rt at 0 °C of 2.13 (95% CI, 1.89-2.40), relative Rt decreased to a minimum as temperatures warmed to 11 °C, increased between 11 and 20 °C (1.61; 95% CI, 1.42-1.84) and then declined again at temperatures greater than 20 °C. With a 70% reduction in visits to nonessential business, 202 counties (95.7%) were estimated to fall below a threshold Rt of 1.0, including 17 of 21 counties (81.0%) in the top density decile and 52 of 53 counties (98.1%) in the lowest density quartile.2.

CONCLUSIONS AND RELEVANCE

In this cohort study, social distancing, lower population density, and temperate weather were associated with a decreased Rt for SARS-CoV-2 in counties across the United States. These associations could inform selective public policy planning in communities during the coronavirus disease 2019 pandemic.

Prevention of recurrent urinary stone disease

PURPOSE OF REVIEW

Urinary stone disease (USD) is increasing in prevalence and recurrence is common. In pediatrics, most stones are composed primarily of calcium with the highest incidence observed in adolescents. Given the morbidity associated with USD, an in depth review of current management strategies is of paramount importance to highlight the data supporting the recommended treatments and the knowledge gaps which still exist.

RECENT FINDINGS

Several interventions for the management of recurrent calcium USD in children have been recommended based on primarily adult studies. These interventions include modification of diet and fluid intake in addition to the utilization of medications such as thiazide diuretics and citrates when supportive care is inadequate. Overall there is conflicting data in the adult literature which is further complicated by our attempts to extrapolate these data to children.

SUMMARY

Based on the currently available literature the management of USD in pediatrics should be individualized to each patient and focused on the particular metabolic risk factors that are identified during the course of their evaluation. Several interventions may be required or trialed in a particular patient to show an effect. Well designed trials to assess the efficacy of each intervention in the pediatric population are needed.

Associations between ambient temperature and hepatobiliary and renal hospitalizations in California, 1999 to 2009

BACKGROUND

High ambient temperature has been linked to a number of types of morbidity, such as cardiovascular disease and dehydration. Fewer studies have explored specifically the relationship between ambient temperature and liver, kidney, and urinary system morbidity despite known biological impacts of extreme high temperatures on those systems.

OBJECTIVE

We assessed the relationship between temperature and hospitalizations related to selected renal system (urinary stones, urinary tract infections, septicemia, chronic kidney disease, and a composite of selected kidney diseases) and hepatobiliary (biliary tract disease, other liver diseases [e.g. cirrhosis], non-diabetic pancreatic disorders) ailments.

METHODS

We compiled data on daily hospitalization counts for hepatobiliary and renal system diseases in California for 1999 through 2009, and matched it with meteorological data. Relationships between temperature and admissions during the warm season (May-October) were assessed at the climate zone-level cumulative over 14 days following exposure using distributed lag non-linear models, with adjustment for time trends and relative humidity, then combined using random-effects meta-regression to create statewide estimates.

RESULTS

Higher mean temperatures in the warm season were associated with significant increases in renal admissions for urinary tract infection [% change per 10 °F: 7.3, 95% CI: 5.6, 9.1], septicemia [% increase: 2.9; 95% CI: 1.5, 4.3], urinary stones [% increase: 15.2; 95% CI: 10.3, 20.4], and composite kidney disease. Additionally, increased temperatures were linked to increased admissions for biliary tract disease, but lower risk of other liver diseases. Some differences in association by race/ethnicity and regional meteorology were observed.

CONCLUSIONS

Exposure to higher temperatures was associated with increased risk of multiple renal system hospitalization types, with additional links to specific hepatobiliary morbidities observed.

The heat exposure risk to outdoor workers in Brazil

Heat exposure is a major cause of health issues in outdoor workers. The aim of this study is to show a macro analysis of the heat exposure risk (HER) countrywide through the WBGT index. The index estimates are conducted from 50 years of meteorological observations. The HER takes into account the light, moderate, and heavy workloads, and the HER maps are separately generated decade by decade and season by season. It was found that HER has stronger effect on heavy workload workers during summer. It is even more critical in the Northern, Northeastern, and in part of Midwestern Brazil. There was HER increase in the last two decades, showing the need of applying control measures. It is very important taking continuous actions such as environmental and physiological monitoring, light clothing, and flexible work shifts.

Endocrine regulation of MFS2 by branchless controls phosphate excretion and stone formation in Drosophila renal tubules

How inorganic phosphate (Pi) homeostasis is regulated in Drosophila is currently unknown. We here identify MFS2 as a key Pi transporter in fly renal (Malpighian) tubules. Consistent with its role in Pi excretion, we found that dietary Pi induces MFS2 expression. This results in the formation of Malpighian calcium-Pi stones, while RNAi-mediated knockdown of MFS2 increases blood (hemolymph) Pi and decreases formation of Malpighian tubule stones in flies cultured on high Pi medium. Conversely, microinjection of adults with the phosphaturic human hormone fibroblast growth factor 23 (FGF23) induces tubule expression of MFS2 and decreases blood Pi. This action of FGF23 is blocked by genetic ablation of MFS2. Furthermore, genetic overexpression of the fly FGF branchless (bnl) in the tubules induces expression of MFS2 and increases Malpighian tubule stones suggesting that bnl is the endogenous phosphaturic hormone in adult flies. Finally, genetic ablation of MFS2 increased fly life span, suggesting that Malpighian tubule stones are a key element whereby high Pi diet reduces fly longevity previously reported by us. In conclusion, MFS2 mediates excretion of Pi in Drosophila, which is as in higher species under the hormonal control of FGF-signaling.

Using the excess heat factor to indicate heatwave-related urinary disease: a case study in Adelaide, South Australia

The excess heat factor (EHF) is being adopted nationally for heatwave forecasting in Australia, but there is limited research utilizing it as a predictor for heat-related morbidity from diseases of the urinary system (urinary diseases). In this study, the incidence of eight temperature-prone specific urinary disease categories was analyzed in relation to the EHF. Daily data for maximum and minimum temperature and data for metropolitan hospital emergency department presentations and inpatient admissions for urinary disease were acquired in Adelaide, South Australia, from 1 July 2003 to 31 March 2014. An increased incidence for urolithiasis, acute kidney injury (AKI), chronic kidney disease, and lower urinary tract infections was associated with the EHF. Using the Australian national heatwave definition with the EHF, emergency department presentations increased on heatwave days compared to non-heatwave days for total urinary disease (IRR 1.046, 95% CI 1.016-1.076), urolithiasis (IRR 1.106, 95% 1.046-1.169), and acute kidney injury (AKI) (IRR 1.416, 95% CI 1.258-1.594). Likewise, inpatient admissions increased for total urinary disease (IRR 1.090, 95% CI 1.048-1.133) and AKI (IRR 1.335, 95% CI 1.204-1.480). The EHF is a reliable metric for predicting heat-induced morbidity from urinary disease. Climate change-related elevations in temperature can increase morbidity from urinary disease, especially AKI and urolithiasis. Diseases of the urinary system should be highlighted when providing public health guidance during heatwaves indicated by the EHF.

Sex differences in the temperature dependence of kidney stone presentations: a population-based aggregated case-crossover study

Previous studies assumed a uniform relationship between heat and kidney stone presentations. Determining whether sex and other characteristics modify the temperature dependence of kidney stone presentations has implications for explaining differences in nephrolithiasis prevalence and improving projections of the effect of climate change on nephrolithiasis. We performed an aggregated case-crossover study among 132,597 children and adults who presented with nephrolithiasis to 68 emergency departments throughout South Carolina from 1997 to 2015. We used quasi-Poisson regression with distributed lag non-linear models to estimate sex differences in the cumulative exposure and lagged response between maximum daily wet-bulb temperatures and emergent kidney stone presentations, aggregated at the ZIP-code level. We also explored interactions by age, race, payer, and climate. Compared to 10 °C, daily wet-bulb temperatures at the 99th percentile were associated with a greater increased relative risk (RR) of kidney stone presentations over 10 days for males (RR 1.73; 95% CI 1.56, 1.91) than for females (RR 1.15; 95% CI 1.01, 1.32; interaction P < 0.001). The shape of the lagged response was similar for males and females, with the greatest risk estimated for the 2 days following high temperatures. There were weak differences by age, race, and climatic zone, and no differences by payer status. The estimated risk of presenting emergently with kidney stones within 10 days of high daily wet-bulb temperatures was substantially greater among men than women, and similar between patients with public and private insurance. These findings suggest that the higher risk among males may be due to sexually dimorphic physiologic responses rather than greater exposure to ambient temperatures.

Global Environmental Change and Noncommunicable Disease Risks

Multiple global environmental changes (GECs) now under way, including climate change, biodiversity loss, freshwater depletion, tropical deforestation, overexploitation of fisheries, ocean acidification, and soil degradation, have substantial, but still imperfectly understood, implications for human health. Noncommunicable diseases (NCDs) make a major contribution to the global burden of disease. Many of the driving forces responsible for GEC also influence NCD risk through a range of mechanisms. This article provides an overview of pathways linking GEC and NCDs, focusing on five pathways: ( a) energy, air pollution, and climate change; ( b) urbanization; ( c) food, nutrition, and agriculture; ( d) the deposition of persistent chemicals in the environment; and ( e) biodiversity loss.

Priority focus areas for a sub-national response to climate change and health: A South African provincial case study

INTRODUCTION

The intersection of health and climate change is often absent or under-represented in sub-national government strategies. This analysis of the literature, using a new methodological framework, highlights priority focus areas for a sub-national government response to health and climate change, using the Western Cape (WC) province of South Africa as a case study.

METHODS

A methodological framework was created to conduct a review of priority focus areas relevant for sub-national governments. The framework encompassed the establishment of a Project Steering Group consisting of relevant, sub-national stakeholders (e.g. provincial officials, public and environmental health specialists and academics); an analysis of local climatic projections as well as an analysis of global, national and sub-national health risk factors and impacts.

RESULTS

Globally, the discussion of health and climate change adaptation strategies in sub-national, or provincial government is often limited. For the case study presented, multiple health risk factors were identified. WC climatic projections include a warmer and potentially drier future with an increased frequency and intensity of extreme weather events. WC government priority focus areas requiring further research on health risk factors include: population migration and environmental refugees, land use change, violence and human conflict and vulnerable groups. WC government priority focus areas for further research on health impacts include: mental ill-health, non-communicable diseases, injuries, poisonings (e.g. pesticides), food and nutrition insecurity-related diseases, water- and food-borne diseases and reproductive health. These areas are currently under-addressed, or not addressed at all, in the current provincial climate change strategy.

CONCLUSIONS

Sub-national government adaptation strategies often display limited discussion on the health and climate change intersect. The methodological framework presented in this case study can be globally utilized by other sub-national governments for decision-making and development of climate change and health adaptation strategies. Additionally, due to the broad range of sectoral issues identified, a primary recommendation from this study is that sub-national governments internationally should consider a "health and climate change in all policies" approach when developing adaptation and mitigation strategies to address climate change.

Strengthened scientific support for the Endangerment Finding for atmospheric greenhouse gases

We assess scientific evidence that has emerged since the U.S. Environmental Protection Agency’s 2009 Endangerment Finding for six well-mixed greenhouse gases and find that this new evidence lends increased support to the conclusion that these gases pose a danger to public health and welfare. Newly available evidence about a wide range of observed and projected impacts strengthens the association between the risk of some of these impacts and anthropogenic climate change, indicates that some impacts or combinations of impacts have the potential to be more severe than previously understood, and identifies substantial risk of additional impacts through processes and pathways not considered in the Endangerment Finding.

Systemic analysis of urinary stones from the Northern, Eastern, Central, Southern and Southwest China by a multi-center study

BACKGROUND

To provide some basis for the prevention of urinary stones in general population, we did a systemic analysis of urinary stones from Northern, Eastern, Central, Southern and Southwest China by a multi-center study.

METHODS

A total of 11,157 urinary stones from Northern, Eastern, Central, Southern and Southwest China were obtained and analyzed by Fourier transform infrared spectroscopy. Combined with scanning electron microscopy and X-ray energy spectrometer, urinary stones were classified into different types. Furthermore, the correlation between stone types and clinical characteristics, as well as their regional distribution were elucidated.

RESULTS

Calcium oxalate stones were the most common type in each region, followed by calcium oxalate-calcium phosphate mixed stones, uric acid stones and calcium phosphate stones. The distribution of calcium oxalate stones were highest prevalence in Southwest China (67.9%, P < 0.05), followed by Eastern and Northern China. Anhydrous uric acid stones, with a constituent ratio of 19.3% in Southern China, and 13.7% in Central China, were significantly higher than that in other regions (P < 0.05). Elements analysis indicated varieties among stone types as well as distribution regions. Moreover, the clinical characteristics were highly correlated with stone types and anatomical locations but not their distribution regions.

CONCLUSIONS

The material and elements composition of urinary stones among different regions showed some varieties. Calcium oxalate stone has the highest constituent ratio in Southwest China, while anhydrous uric acid stone has the highest constituent ratio in Southern China. Moreover, the clinical characteristics were highly correlated with stone types and anatomical locations but not their distribution regions.

High Temperatures and Kidney Disease Morbidity: A Systematic Review and Meta-analysis

Objectives

In recent years, serious concerns have been raised regarding the impacts of rising temperatures on health. The present study was conducted to investigate the relationship between elevated temperatures and kidney disease through a systematic review and meta-analysis.

Methods

In October 2017, 2 researchers independently searched related studies in PubMed and Embase. A meta-analysis was conducted using a random-effects model, including only studies that presented odds ratios, relative risks, or percentage changes, along with 95% confidence intervals (CIs). The characteristics of each study were summarized, and the Egger test and funnel plots were used to evaluate publication bias.

Results

Eleven studies that met the criteria were included in the final analysis. The pooled results suggest an increase of 30% (95% CI, 20 to 40) in kidney disease morbidity with high temperatures. In a disease-specific subgroup analysis, statistically significant results were observed for both renal colic or kidney stones and other renal diseases. In a study design–specific subgroup analysis, statistically significant results were observed in both time-series analyses and studies with other designs. In a temperature measure–specific subgroup analysis, significant results were likewise found for both studies using mean temperature measurements and studies measuring heat waves or heat stress.

Conclusions

Our results indicate that morbidity due to kidney disease increases at high temperatures. We also found significant results in subgroup analyses. However, further time-series analyses are needed to obtain more generalizable evidence.

Pediatric Stone Disease

Once considered rare, pediatric nephrolithiasis has become a critical field of study in the last decade due to the rapid increase in incidence. Understanding the changing epidemiology and lifelong implications of pediatric stone disease is critically important to effectively manage the individual patient as well as identify risk factors for childhood onset that could be modified. Determining the role of diagnostic imaging in children is a unique challenge as limiting radiation and imaging stewardship should be priorities. Approaches to management have also changed, as technology continues to evolve and both medical and surgical options expand.