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

Independent and synergistic effects of extreme heat and NO2 pollution on diabetic nephropathy in a type II diabetes mouse model

Extreme heat and traffic-related air pollution (TRAP) have been linked to worsening chronic health disorders, however, their combined effects on diabetic nephropathy (DN) are little understood. Type II diabetic mice were exposed to heat (40 °C) and NO2 (5 ppm) separately for 4 h per day over 6 weeks to investigate the synergistic effects on the progression of DN. We found that exposure to high temperature and NO2 elevated blood glucose levels and exacerbated histopathological changes. Additionally, there were increased oxidation indicators (ROS, MDA, 8-OHdG) and decreased antioxidant indicators (CAT, SOD, GSH-PX), along with elevated inflammation markers (TNF-α, IL-1β, IL-6). The expressions of transient receptor potential (TRP) ion channels (TRPV1, TRPV4, TRPA1, TRPM2) were also upregulated. Our findings suggest that simultaneous exposure to high temperature and NO2 impairs metabolic and autophagy pathways. Exposure to both high temperature and NO2 produces a synergistic effect, leading to more severe damage than exposure to either factor individually. This resulted in increased expression of APOA1, P62, and p-mTOR/mTOR while decreasing the expression of p-AMPKα/AMPKα and LC3-II/I. This disruption promoted the progression of DN. In contrast, capsazepine (CZP) reduced TRP expression, inflammatory markers, oxidative stress, metabolic and autophagy disorders, thereby mitigating renal damage and alleviating the progression of diabetic nephropathy. Our study provides some potential strategies for early prevention and effective reduction of DN.

The current and future temperature-related mortality burden of cause-specific kidney diseases: A national case-crossover study in China

BACKGROUND

Many studies have investigated the association of temperature with non-accidental mortality, but there is limited evidence on the temperature-related mortality burden of kidney diseases. This study aims to assess the mortality impact of temperatures on cause-specific kidney in China.

METHODS

We conducted a time-stratified case-crossover study using mortality data from kidney diseases across 2790 counties/districts in China from 2003 to 2022. We used conditional logistic regression in conjunction with distribution lag nonlinear model (DLNM) to examine the association between temperature and kidney disease mortality. Furthermore, we projected the mortality burden of kidney diseases attributed to temperature under diverse climate change scenarios in China in the future.

RESULTS

The study included 914,177 kidney disease fatalities, revealing an inversely J-shaped association between temperature and kidney disease mortality across various subgroups. Both extreme cold (Odds ratios [OR] = 1.34, 95 % CI: 1.27-1.41) and extreme heat (1.06, 95 % CI: 1.02-1.10) were linked to increased kidney mortality, with a more pronounced effect in females [1.08(95 % CI: 1.02-1.14) for extreme heat, 1.34(95 % CI: 1.24-1.46) for extreme cold], the elderly [1.07(95 % CI: 1.03-1.12) for extreme heat, 1.35(95 % CI: 1.26-1.45) for extreme cold ] and those with acute kidney disease [1.10(95 % CI: 0.96-1.26)] for extreme heat, 1.43(95 % CI: 1.19-1.73) for extreme cold]. Nationwide, temperatures accounted for 9.28 % (95 % CI: 9.17 %-9.40 %) of kidney disease mortality, with 9.15 % (95 % CI: 9.03 %-9.26 %) for cold and 0.13 % (95 % CI: 0.12 %-0.14 %) for heat, and temperature-related AF of acute kidney disease was the greatest (attributable fraction [AF] = 11.00 %,95 %CI:10.71 %-11.31 %). Projections suggest that temperature-related AFs would rise from 11.39 % (95 % CI: 8.19 %-13.89 %) in the 2050s to 15.26 % (95 % CI: 10.30 %-18.68 %) in the 2090s under SSP5-8.5, with heat-related AFs increasing from 2.82 % (95 % CI: 1.8 %-4.20 %) to 7.12 % (95 % CI: 4.23 %-10.09 %) and cold-related AFs decreasing from 8.57 % (95 % CI: 5.71 %-9.89 %) to 8.14 % (95 % CI: 5.22 %-8.81 %).

CONCLUSION

Our study indicates that temperatures are significantly associated with the mortality risk and burden of kidney diseases in China, and temperature-related mortality is expected to increase in the future, particularly from heat. Our findings indicate that kidney diseases are vulnerable to ambient temperature in the context of climate change.

Preparing for stormy weather: building VA health system resilience for dialysis emergency preparedness in the era of climate change

PURPOSE OF REVIEW

Climate change has been implicated as the driver for the increasing number, intensity, duration, and consequences of catastrophic weather events. As a result of extreme weather events, climate change has also been implicated as an important mediator of adverse kidney health outcomes, not only increasing the risk for the development of acute and chronic kidney diseases, but also disrupting the delivery of critical kidney health services. In particular, the delivery of dialysis services during major emergencies remains an ongoing and increasing problem, with a recognized need for improved emergency preparedness and disaster management (EP-DM) strategies to mitigate the increased risk of morbidity and mortality associated with missed dialysis treatment.

RECENT FINDINGS

There are increasing reports detailing the challenges of kidney dialysis care in times of crisis, to include those resulting from both man-made and natural disasters. Optimized management of the high-risk vulnerable dialysis patient population must include both facility-facing comprehensive continuity of operations and emergency response plans, and ongoing patient-facing emergency preparedness education.

SUMMARY

This review discusses the adverse impact of climate change-related natural disasters on the delivery of dialysis services, and the evolving EP-DM strategies developed and implemented by the Veterans Health Administration (VA) to optimize the care and well being of the vulnerable end stage kidney disease (ESKD) patient population.

Associations between heat waves and chronic kidney disease in China: The modifying role of land cover

The increasing frequency of heat waves under the global urbanization and climate change background poses elevating risks of chronic kidney disease (CKD). Nevertheless, there has been no evidence on associations between long-term exposures to heat waves and CKD as well as the modifying effects of land cover patterns. Based on a national representative population-based survey on CKD covering 47,086 adults and high spatial resolution datasets on temperature and land cover data, we found that annual days of exposure to heat waves were associated with increased odds of CKD prevalence. For one day/year increases in HW_975_4d (above 97.5 % of annual maximum temperature and lasting for at least 4 consecutive days), the odds ratio (OR) of CKD was 1.14 (95 %CI: 1.12, 1.15). Meanwhile, stronger associations were observed in regions with lower urbanicity [rural: 1.14 (95 %CI: 1.12, 1.16) vs urban: 1.07 (95 %CI: 1.03, 1.11), Pinteraction < 0.001], lower water body coverage [lower: 1.14 (95 %CI: 1.12, 1.16) vs higher: 1.02 (95 %CI: 0.98, 1.05), Pinteraction < 0.001], and lower impervious area coverage [lower: 1.16 (95 %CI: 1.14, 1.18) vs higher: 1.06 (95 %CI: 1.03, 1.10), Pinteraction = 0.008]. In addition, this study found disparities in modifying effects of water bodies and impervious areas in rural and urban settings. In rural regions, the associations between heat waves and CKD prevalence showed a consistent decreasing trend with increases in both proportions of water bodies and impervious areas (Pinteraction < 0.05). Nevertheless, in urban regions, we observed significant effect modification by water bodies, but not by impervious areas. Our study indicates the need for targeted land planning as part of adapting to the kidney impacts of heat waves, with a focus on urbanization in rural regions, as well as water body construction and utilization in both rural and urban regions.

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.

Associations between short-term exposure to PM2.5, NO2 and O3 pollution and kidney-related conditions and the role of temperature-adjustment specification: A case-crossover study in New York state

Epidemiologic evidence on the relationship between air pollution and kidney disease remains inconclusive. We evaluated associations between short-term exposure to PM_2.5, NO₂ and O₃ and unplanned hospital visits for seven kidney-related conditions (acute kidney failure [AKF], urolithiasis, glomerular diseases [GD], renal tubulo-interstitial diseases, chronic kidney disease, dysnatremia, and volume depletion; n = 1,209,934) in New York State (2007-2016). We applied a case-crossover design with conditional logistic regression, controlling for temperature, dew point temperature, wind speed, and solar radiation. We used a three-pollutant model at lag 0-5 days of exposure as our main model. We also assessed the influence of model adjustment using different specifications of temperature by comparing seven temperature metrics (e.g., dry-bulb temperature, heat index) and five intraday temperature measures (e.g., daily mean, daily minimum, nighttime mean), according to model performance and association magnitudes between air pollutants and kidney-related conditions. In our main models, we adjusted for daytime mean outdoor wet-bulb globe temperature, which showed good model performance across all kidney-related conditions. We observed the odds ratios (ORs) for 5 μg/m³ increase in daily mean PM_2.5 to be 1.013 (95% confidence interval [CI]: 1.001, 1.025) for AKF, 1.107 (95% CI: 1.018, 1.203) for GD, and 1.027 (95% CI: 1.015, 1.038) for volume depletion; and the OR for 5 ppb increase in daily 1-hour maximum NO₂ to be 1.014 (95% CI; 1.008, 1.021) for AKF. We observed no associations with daily 8-hour maximum O₃ exposure. Association estimates varied by adjustment for different intraday temperature measures: estimates adjusted for measures with poorer model performance resulted in the greatest deviation from estimates adjusted for daytime mean, especially for AKF and volume depletion. Our findings indicate that short-term exposure to PM_2.5 and NO₂ is a risk factor for specific kidney-related conditions and underscore the need for careful adjustment of temperature in air pollution epidemiologic studies.

Heat-related first cardiovascular event incidence in the city of Madrid (Spain): Vulnerability assessment by demographic, socioeconomic, and health indicators

While climate change and population ageing are expected to increase the exposure and vulnerability to extreme heat events, there is emerging evidence suggesting that social inequalities would additionally magnify the projected health impacts. However, limited evidence exists on how social determinants modify heat-related cardiovascular morbidity. This study aims to explore the association between heat and the incidence of first acute cardiovascular event (CVE) in adults in Madrid between 2015 and 2018, and to assess how social context and other individual characteristics modify the estimated association. We performed a case-crossover study using the individual information collected from electronic medical records of 6514 adults aged 40-75 living in Madrid city that suffered a first CVE during summer (June-September) between 2015 and 2018. We applied conditional logistic regression with a distributed lag non-linear model to analyse the heat-CVE association. Estimates were expressed as Odds Ratio (OR) for extreme heat (at 97.5th percentile of daily maximum temperature distribution), compared to the minimum risk temperature. We performed stratified analyses by specific diagnosis, sex, age (40-64, 65-75), country of origin, area-level deprivation, and presence of comorbidities. Overall, the risk of suffering CVE increased by 15.3% (OR: 1.153 [95%CI 1.010-1.317]) during extreme heat. Males were particularly more affected (1.248, [1.059-1.471]), vs 1.039 [0.810-1.331] in females), and non-Spanish population (1.869 [1.28-2.728]), vs 1.084 [0.940-1.250] in Spanish). Similar estimates were found by age groups. We observed a dose-response pattern across deprivation levels, with larger risks in populations with higher deprivation (1.228 [1.031-1.462]) and almost null association in the lowest deprivation group (1.062 [0.836-1.349]). No clear patterns of larger vulnerability were found by presence of comorbidity. We found that heat unequally increased the risk of suffering CVE in adults in Madrid, affecting mainly males and deprived populations. Local measures should pay special attention to vulnerable populations.