The influence of climate change on human cardiovascular function

The Influence of Climate Change on Vector-Borne Diseases in a Wilderness Medicine Context

The imminent climate crisis has been labeled as the biggest health threat humanity must deal with. Vector-borne disease distribution and transmission as well as the population at risk are influenced to a great degree by environmental and climactic factors affecting both the vectors themselves and the causative pathogens. Paired with an increase in worldwide travel, urbanization, and globalization, along with population displacements and migration, elucidating the effects of anthropogenic climate change on these illnesses is therefore of the essence to stave off potential negative sequelae. Outcomes on different vector-borne diseases will be diverse, but for many of them, these developments will result in a distribution shift or expansion with the possibility of (re-)introduction of vector and pathogen species in previously nonendemic areas. The consequence will be a growing likelihood for novel human, vector, and pathogen interactions with an increased risk for infection, morbidity, and mortality. Wilderness medicine professionals commonly work in close relationship to the natural environment and therefore will experience these alterations most strongly in their practice. Hence, this article attempts to bring awareness to the subject at hand in a wilderness medicine context, with a focus on malaria, the most burdensome of arthropod-borne diseases. For prevention of the potentially dire consequences on human health induced by climate change, concerted and intensified efforts to reduce the burning of fossil fuels and thus greenhouse gas emissions will be imperative on a global scale.

Short-term effects of fine particulate matter from biomass combustion and Saharan dust intrusions on emergency hospital admissions due to mental and behavioural disorders, anxiety and depression in Spain

Climate change is affecting both the frequency and scale of wildfires, as well as the increase in the number of days with Saharan dust intrusions. Traditionally, studies have focused on the extent to which the increase in fine particulate matter (PM) has had an impact on cardio-respiratory diseases, but (apart from PM) not on how the meteorological and pollution conditions in these situations affect other diseases, such as those linked to mental health. This study therefore sought to ascertain how daily mean PM10, PM 2.5, NO2, O3 concentrations and daily maximum temperature in heat waves influence daily emergency hospital admissions in Spain caused by mental and behavioural disorders, depression and anxiety on days with PM from biomass combustion and/or Saharan dust intrusions, as compared to days without such conditions, across the period 2009-2018. Our results indicate that on days on which there is biomass combustion, PM concentrations have a statistically significant effect on emergency admissions due to mental disorders, probably related with the toxicity of these particles. Yet on days with intrusions of Saharan dust rather than PM, it is the other variables considered in the analysis that are most closely linked to these types of admissions. The results of this study thus point to the need to implement public health prevention plans which take into account the joint effect of various environmental risk factors that act synergistically in given situations.

Temperature and carotid intima-medial thickness: The coronary artery risk development in young adults (CARDIA) study

BACKGROUND

Few studies have examined the role of long-term (≥1 year) ambient temperature with quantitative traits of early-stage cardiovascular disease (CVD) such as carotid intima-medial thickness (cIMT). Our objective was to examine associations between temperature and cIMT, a measure of subclinical atherosclerosis.

METHODS

This study examined data from 3257 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study, aged 18-30 years at baseline (1985-1986). We used North America Land Data Assimilation System data to derive 12 metrics of ambient daily temperature: Mean, minimum, maximum, and standard deviation temperature in summer, winter, and year-round. We examined associations with cIMT in separate cross-sectional multivariable models at CARDIA year 20 (2005-2006) as well as stratified analyses by self-reported race and sex. We also prospectively examined cumulative temperature by summing temperature variables from Y0-Y20.

RESULTS

Accounting for study center attenuated most associations between cIMT and ambient temperature exposure, but the winter standard deviation remained associated (overall β = -0.0104 mm/°C, 95 % CI: -0.0150 to -0.0059). Minimum summer temperature was also associated with cIMT in the overall study population (β = 0.0020 mm/°C, 95 % CI: 0.0005-0.0035). Associations did not differ substantially by race, but women had stronger associations than men. Cumulative temperature was not associated with cIMT.

CONCLUSIONS

Our findings suggest a role of geography, particularly ambient temperature in cIMT. Future research to address potential residual confounding is necessary, but if validated these findings have implications for policy and strategies to mitigate health impacts of climate change.

Impact of heat waves on human morbidity and hospital admissions in a city of the western mediterranean area

PURPOSE

The effect of heat waves on mortality is well known, but current evidence on morbidity is limited. Establishing the consequences of these events in terms of morbidity is important to ensure communities and health systems can adapt to them.

METHODS

We thus collected data on total daily emergency hospital admissions, admissions to critical care units, emergency department admissions, and emergency admissions for specific diagnoses to Hospital Universitario de Son Espases from 1 January 2005 to 31 December 2021. A heat wave was defined as a period of ≥ 2 days with a maximum temperature ≥ 35 °C, including a 7 day lag effect (inclusive). We used a quasi-Poisson generalized linear model to estimate relative risks (RRs; 95%CI) for heat wave-related hospital admissions.

RESULTS

Results showed statistically significant increases in total emergency admissions (RR 1.06; 95%CI 1 - 1.12), emergency department admissions (RR 1.12; 95%CI 1.07 - 1.18), and admissions for ischemic stroke (RR 1.26; 95%CI 1.02 - 1.54), acute kidney injury (RR 1.67; 95%CI 1.16 - 2.35), and heat stroke (RR 18.73, 95%CI 6.48 - 45.83) during heat waves.

CONCLUSION

Heat waves increase hospitalization risk, primarily for thromboembolic and renal diseases and heat strokes.

The trends of non-accidental mortality burden attributed to compound hot-dry events in China and its provinces in a global warming world

BACKGROUND

Global warming has provoked more co-occurrence of hot extreme and dry extreme, namely compound hot-dry events (CHDEs). However, their health impacts have seldom been investigated. This study aimed to characterize CHDEs and assess its mortality burden in China from 1990 to 2100.

METHODS

CHDEs were defined as a day when daily maximum temperature > its 90th percentile and Standardized Precipitation Index < its 50th percentile. A two-stage approach, including a distributed lag nonlinear model (DLNM) and a multivariate meta-analysis, was used to estimate exposure-response associations of CHDEs with mortality in 358 counties/districts during 2006-2017 in China, which was then applied to assess the national mortality burden attributable to CHDEs from 1990 to 2100.

FINDINGS

We observed a significant increasing trend of CHDEs in China until mid-21st century, and then flatted, while the duration and intensity of CHDEs continuously increased across the 21st century. CHDEs were much riskier (ER=17.82 %, 95 %CI: 14.17 %-21.60 %) than independent hot events (ER=5.86 %,95 %CI: -0.04 %,12.45 %) or dry events (ER=0.07 %,95 %CI: -1.22 %, 1.38 %), and there was significantly additive interaction between hot events and dry events (AP=0.10,95 %CI: 0.04, 0.16). Females (ER=24.28 %, 95 %CI: 19.21 %-29.56 %), the elderly (ER=23.28 %, 95 %CI: 18.23 %-28.55 %), and people living in humid area (ER=18.98 %, 95 %CI: 15.08 %-23.02 %) had higher mortality risks than their counterparts. Mortality burden attributed to CHDEs significantly increased during historical observation and became stable since mid-21st century in China.

INTERPRETATION

CHDEs would significantly increase mortality with higher risk for females, the elderly and people living in humid areas. Mortality burden has significantly increased during historical observation and will keep relatively steady since mid-21st century.

Long-Term Survival after Coronary Artery Surgical Revascularization-Does Ambient Temperature Matter?

Background and Objectives: The progression of global warming results in an increased exposure to extreme heat, leading to exaggeration of preexisting diseases and premature deaths. The aim of the study was to present possible risk factors for all-cause long-term mortality in patients who underwent surgical revascularization, including an assessment of the influence of ambient temperature exposure. Materials and Methods: Retrospective analysis included 153 (123 (80%) males and 30 (20%) females) patients who underwent off-pump revascularization and were followed for a median time of 2533 (1035-3250) days. The demographical, clinical data and ambient temperature exposure were taken into analysis for prediction of all-cause mortality. Individual exposure was calculated based on the place of habitation. Results: In the multivariate logistic regression model with backward stepwise elimination method, risk factors such as dyslipidaemia (p = 0.001), kidney disease (p = 0.005), age (p = 0.006), and body mass index (p = 0.007) were found to be significant for late mortality prediction. In addition to traditional factors, environmental characteristics, including tropical nights (p = 0.043), were revealed to be significant. Conclusions: High night-time ambient temperatures known as tropical nights may be regarded as additional long-term mortality risk factor after surgical revascularization.

Case discussion: The effect of extreme temperatures on an older adult

Climate change can cause high temperatures that can affect the older adult in significant ways. Older adults may not be aware of the dangers of high temperature days and may continue with old habits such as staying in the sun to garden without sunscreen or a hat as they may have done in years past. High temperatures can cause impairment of the tone and structure of blood vessels by interfering with nitric oxide synthesis and cytokine production and can cause systemic inflammation, all of which significantly contribute to dehydration in older adults, who are known to have a decreased sense of thirst, resulting in increased blood viscosity and the risk of heat induced shock and thrombotic strokes. This case discussion highlights the effects of high temperatures due to climate change on an older adult, and what nurse practitioners need to be aware of when assessing older adults who may be suffering from heat exhaustion or heat stroke, and how to manage appropriately.

Climate Change and Psychiatry: The Correlation between the Mean Monthly Temperature and Admissions to an Acute Inpatient Unit

BACKGROUND

Psychiatric disorders are large contributors to the global disease burden, but research on the impact of climate change on them is limited. Our aim is to investigate the correlation between temperature and exacerbations of psychiatric disorders to help inform clinical management and future public health policies.

METHODS

Temperature records for the summer months from 2013 to 2022 were obtained from the meteorological station of the Department of Physics of Turin University. Data on patients admitted to the acute psychiatric unit were extracted from registries of San Luigi Gonzaga University Hospital (Turin, Italy). Regression analyses were used to investigate the correlation between temperature and number of admissions and to test for confounding variables.

RESULTS

A total of 1600 admissions were recorded. The monthly temperature and number of admissions were directly correlated (p = 0.0020). The correlation was significant for the subgroup of admissions due to Bipolar Disorders (p = 0.0011), but not for schizophrenia or major depressive disorder. After multiple regression analyses, the effect of temperature remained significant (p = 0.0406).

CONCLUSIONS

These results confirm the impact of meteorological factors on mental disorders, particularly on BD. This can contribute to personalised follow-up and efficient resource allocation and poses grounds for studies into etiopathological mechanisms and therapeutic implications.

Impact of drought on mental and behavioral disorders, contributions of research in a climate change context. A narrative review

Mental and behavioral disorders are an important public health problem and constitute a priority for the WHO, whose recommendations include the surveillance of their risk factors. On the other hand, drought episodes have been increasing in frequency and severity in Europe since 1980. Therefore, to review the present knowledge about the impact of drought on mental and behavioral disorders, in the present climate change context, and to underline potential research gaps, could be of major interest. Thus, we performed a narrative review using online academic databases with the aim of identifying relevant literature about the impact of drought on mental and behavioral disorders. To the best of our knowledge, no study in Europe quantifies the potential association between drought and mental disorders. A limited number of studies have found significant associations between droughts (with different temporal ranges) and various measures of mental health. However, according to our review, only three of them quantified the association between drought and objective mental health outcomes, such as number of emergencies due to clinically diagnosed mental disorders or suicides. Additionally, few studies used specific indices as a measure of drought; and finally, as far as authors are aware, none of them has analyzed this relationship adjusting for various other potential environmental confounders. Moreover, the eventual association could vary between different geographical areas within the same country. Therefore, national and regional studies would be especially necessary. Thus, there is a need for specific national and regional studies, in Europe and globally, that assess the impact of specific indices of drought (with different temporal ranges) on objective mental health outcomes controlling for potential environmental confounders. Moreover, the quantification of its cost would be necessary for health prioritization, evidence-based policies and strategic health planning.

Assessment of subjective well-being of healthcare workers in response to heat and personal protective equipment under controlled conditions using a standardized protocol

BACKGROUND

Due to climate change, the increasing frequency of hot summer days and heat waves can result in occupational heat strain, especially in non-air-conditioned workplaces. Healthcare workers (HCW) engaged in patient care are particularly affected, as they are additionally exposed to physical stress. The use of personal protective equipment (PPE) can aggravate heat strain in HCW. This study aimed to examine the subjective well-being of HCW when exposed to heat and PPE under controlled conditions.

METHODS

This study was designed as a randomized crossover trial. Participants performed standardized healthcare tasks in a climatic chamber for approximately 3.5 h at different indoor temperatures (22 °C and 27 °C) and varied working conditions (with or without PPE). The effects on participants' subjective well-being, encompassing thermal, physiological and psychological stress were assessed using a customized questionnaire.

RESULTS

Heat had a greater effect than PPE on thermal, physical and psychological stress. Conversely, PPE had a greater effect on physical demand and effort. For the majority of outcomes, combined exposure to heat and PPE resulted in the highest perceived discomfort. Furthermore, the participants reported increased sweating and other discomforts when working at elevated temperatures or with PPE.

CONCLUSIONS

In this study, heat and PPE, but particularly the combination of both factors, were identified as unfavorable working environments. Although the trials were conducted in a controlled environment, the outcomes provide valuable information about the effect of heat and PPE on HCW in a real-life setting. Furthermore, the design used in this study can be beneficial in evaluating the effect of mitigation strategies.

Health impacts of a cold wave and its economic loss assessment in China's high-altitude city, Xining

OBJECTIVE

Amidst climate change, extensive research has centered on the health impacts of heatwaves, yet the consequences of cold spells, particularly in cooler, higher-altitude regions, remain under-explored.

METHODS

Analyzing climatic data and non-accidental mortality in Xining, China's second-highest provincial capital, from 2016 to 2020, this study defines cold spells as daily mean temperatures below the 10th, 7.5th, or 5th percentiles for 2-4 consecutive days. A time-stratified case-crossover approach and distributional lag nonlinear modeling were used to assess the link between cold spells and mortality, calculating attributable fractions (AFs) and numbers (ANs) of deaths. The study also examined the impact of cold spells over different periods and analyzed the value of a statistical life (VSL) loss in 2018, a year with frequent cold spells. Stratified analyses by sex, age, and education level were conducted.

RESULTS

A significant association was found between cold spells and non-accidental mortality, with a relative risk of 1.548 (95% CI: 1.300, 1.845). The AF was 33.48%, with an AN of 9,196 deaths during the study's cold period. A declining trend in mortality risk was observed from 2019-2020. The 2018 VSL was approximately 2.875 billion CNY, about 1.75% of Xining's GDP. Higher risks were noted among males, individuals aged ≥ 65, and those with lower education levels.

CONCLUSION

The findings underscore the vulnerability and economic losses of high-altitude cities to cold spells. Implementing interventions such as improved heating, educational programs, and community support is vital for mitigating these adverse health effects.

Projecting heat-related cardiovascular mortality burden attributable to human-induced climate change in China

BACKGROUND

Cardiovascular disease (CVD) has been found to be particularly vulnerable to climate change and temperature variability. This study aimed to assess the extent to which human-induced climate change contributes to future heat-related CVD burdens.

METHODS

Daily data on CVD mortality and temperature were collected in 161 Chinese communities from 2007 to 2013. The association between heat and CVD mortality was established using a two-stage time-series design. Under the natural forcing, human-induced, and combined scenarios, we then separately projected excess cause-/age-/region-/education-specific mortality from future high temperature in 2010-2100, assuming no adaptation and population changes.

FINDINGS

Under shared socioeconomic pathway with natural forcing scenario (SSP2-4.5-nat), heat-related attributable fraction of CVD deaths decreased slightly from 3.3% [95% empirical confidence interval (eCI): 0.3, 5.8] in the 2010s to 2.8% (95% eCI: 0.1, 5.2) in the 2090s, with relative change of -0.4% (95% eCI: -0.8, 0.0). However, for combined natural and human-induced forcings, this estimate would surge to 8.9% (95% eCI: 1.5, 15.7), 14.4% (95% eCI: 1.5, 25.3), 21.3% (95% eCI: -0.6, 39.4), and 28.7% (95% eCI: -3.3, 48.0) in the 2090s under SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5 scenarios, respectively. When excluding the natural forcing, the number of human-induced heat-related CVD deaths would increase from approximately eight thousand (accounting for 31% of total heat-related CVD deaths) in the 2010s to 33,052 (68%), 63,283 (80%), 101,091 (87%), and 141,948 (90%) in the 2090s under SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5 scenarios, respectively. Individuals with stroke, females, the elderly, people living in rural areas, and those with lower education level would exhibit heightened susceptibility to future high temperature. In addition, Southern and Eastern regions of China were expected to experience a faster increase in heat-related attributable fraction of CVD deaths.

INTERPRETATION

Human activities would significantly amplify the future burden of heat-related CVD. Our study findings suggested that active adaptation and mitigation measures towards future warming could yield substantial health benefits for the patients with CVD.

FUNDING

National Natural Science Foundation of China.

Cold exposure, gut microbiota and health implications: A narrative review

Temperature has been recognized as an important environmental factor affecting the composition and function of gut microbiota (GM). Although research on high-temperature impacts has been well studied, knowledge about the effect of cold exposure on GM remains limited. This narrative review aims to synthesize the latest scientific findings on the impact of cold exposure on mammalian GM, and its potential health implications. Chronic cold exposure could disrupt the α-diversity and the composition of GM in both experimental animals and wild-living hosts. Meanwhile, cold exposure could impact gut microbial metabolites, such as short-chain fatty acids. We also discussed plausible biological pathways and mechanisms by which cold-induced changes may impact host health, including metabolic homeostasis, fitness and thermogenesis, through the microbiota-gut-brain axis. Intriguingly, alterations in GM may provide a tool for favorably modulating the host response to the cold temperature. Finally, current challenges and future perspectives are discussed, emphasizing the need for translational research in humans. GM could be manipulated by utilizing nutritional strategies, such as probiotics and prebiotics, to deal with cold-related health issues and enhance well-being in populations living or working in cold environments.

Hourly Heat Exposure and Acute Ischemic Stroke

Importance

Previous studies have demonstrated the associations of daily high temperature with hospitalizations and mortality from ischemic stroke, but the hourly association of ambient heat and acute ischemic stroke (AIS) onset has been rarely examined.

Objectives

To evaluate the association between hourly high ambient temperature and the onset of AIS.

Design, Setting, and Participants

This time-stratified case-crossover study was conducted using a nationwide registry that collects data from more than 200 stroke centers in China. Participants were adult patients with AIS who were hospitalized in the warm seasons between January 1, 2019, and December 31, 2021.

Exposures

Hourly temperature and single-hour temperature exposure lag up to 24 hours before the AIS onset (lag 0 hours to lag 24 hours).

Main Outcomes and Measures

The main outcome was onset of AIS. Associations between hourly mean temperatures and AIS onset were analyzed using conditional logistic regression integrated with the distributed lag nonlinear model. Stratification analyses were applied to examine potential association modifiers. Several sensitivity analyses were conducted to examine the robustness of the results.

Results

A total of 82 455 patients with AIS (mean [SD] age, 65.8 [11.9] years; 52 267 males [63.4%]) were included in the final analysis. A monotonically increasing risk of AIS onset was associated with higher temperatures. The excess AIS risk occurred immediately at lag 0 hours and persisted for 10 hours. Compared with the reference temperature (12.1 °C), the cumulative odds ratio (OR) over lag 0 to 10 hours of AIS onset associated with extremely high temperature (33.3 °C) was 1.88 (95% CI, 1.65-2.13) nationwide. The exposure-response curve was steeper in the north than in the south (OR, 1.80 [95% CI, 1.53-2.11] vs 1.57 [95% CI, 1.31-1.87]). The ORs were greater for males and patients with a history of dyslipidemia or atrial fibrillation, but the differences were not significant.

Conclusions and Relevance

Results of this study suggest that hourly heat exposure is associated with increased risk of AIS onset. This finding may benefit the formulation of public health strategies to reduce cerebrovascular risk associated with high ambient temperature under global warming.

The Impact of Climate Change and Extreme Weather Conditions on Cardiovascular Health and Acute Cardiovascular Diseases

Climate change is widely recognized as one of the most significant challenges facing our planet and human civilization. Human activities such as the burning of fossil fuels, deforestation, and industrial processes release greenhouse gases into the atmosphere, leading to a warming of the Earth's climate. The relationship between climate change and cardiovascular (CV) health, mediated by air pollution and increased ambient temperatures, is complex and very heterogeneous. The main mechanisms underlying the pathogenesis of CV disease at extreme temperatures involve several regulatory pathways, including temperature-sympathetic reactivity, the cold-activated renin-angiotensin system, dehydration, extreme temperature-induced electrolyte imbalances, and heat stroke-induced systemic inflammatory responses. The interplay of these mechanisms may vary based on individual factors, environmental conditions, and an overall health background. The net outcome is a significant increase in CV mortality and a higher incidence of hypertension, type II diabetes mellitus, acute myocardial infarction (AMI), heart failure, and cardiac arrhythmias. Patients with pre-existing CV disorders may be more vulnerable to the effects of global warming and extreme temperatures. There is an urgent need for a comprehensive intervention that spans from the individual level to a systemic or global approach to effectively address this existential problem. Future programs aimed at reducing CV and environmental burdens should require cross-disciplinary collaboration involving physicians, researchers, public health workers, political scientists, legislators, and national leaders to mitigate the effects of climate change.

Short-term effects of heatwaves on clinical and subclinical cardiovascular indicators in Chinese adults: A distributed lag analysis

AIMS

Previous studies have related heat waves to morbidity and mortality of cardiovascular diseases; however, potential mechanisms remained limited. Our aims were to investigate the short-term effects of heat waves on a series of clinical/subclinical indicators associated with cardiovascular health.

METHODS

Our study used 80,574 health examination records from the Health Management Center of Nanjing Zhongda Hospital during the warm seasons of 2019-2021, including 62,128 participants. A total of 11 recognized indicators of cardiovascular risk or injury were assessed. Air pollution and meteorological data were obtained from the Nanjing Ecological Environment Bureau and the China Meteorological Data Network, respectively. Heat waves were defined as a daily average temperature over the 95th percentile for three or more consecutive days from May to September. We used a combination of linear mixed effects models and distributed lag nonlinear models to assess the lagged effects of heat waves on clinical and subclinical cardiovascular indicators. Stratified analyses based on individuals' characteristics, including gender, age, body mass index (BMI), diabetes, and hypertension, were also performed.

RESULTS

Heat waves were related to significant changes in most indicators, with the magnitude of effects generally peaking at a lag of 0 to 3 days. Moreover, the cumulative percentage changes over lag 0-7 days were -0.82 % to -2.55 % in blood pressure, 1.32 % in heart rate, 0.20 % to 2.66 % in systemic inflammation markers, 0.36 % in a blood viscosity parameter, 9.36 % in homocysteine, and 1.35 % to 3.25 % in injuring myocardial enzymes. Interestingly, females and males showed distinct susceptibilities in different indicators. Stronger effects were also found in participants aged 50 years or over, individuals with abnormal BMI status, and patients with diabetes.

CONCLUSION

Short-term exposure to heat waves could significantly alter clinical/subclinical cardiovascular indicator profiles, including blood pressure changes, increased heart rate, acute systemic inflammation, elevated blood viscosity, and myocardial injury.

Effects of heat and personal protective equipment on thermal strain in healthcare workers: part B-application of wearable sensors to observe heat strain among healthcare workers under controlled conditions

PURPOSE

As climate change accelerates, healthcare workers (HCW) are expected to be more frequently exposed to heat at work. Heat stress can be exacerbated by physical activity and unfavorable working requirements, such as wearing personal protective equipment (PPE). Thus, understanding its potential negative effects on HCW´s health and working performance is becoming crucial. Using wearable sensors, this study investigated the physiological effects of heat stress due to HCW-related activities.

METHODS

Eighteen participants performed four experimental sessions in a controlled climatic environment following a standardized protocol. The conditions were (a) 22 °C, (b) 22 °C and PPE, (c) 27 °C and (d) 27 °C and PPE. An ear sensor (body temperature, heart rate) and a skin sensor (skin temperature) were used to record the participants´ physiological parameters.

RESULTS

Heat and PPE had a significant effect on the measured physiological parameters. When wearing PPE, the median participants' body temperature was 0.1 °C higher compared to not wearing PPE. At 27 °C, the median body temperature was 0.5 °C higher than at 22 °C. For median skin temperature, wearing PPE resulted in a 0.4 °C increase and higher temperatures in a 1.0 °C increase. An increase in median heart rate was also observed for PPE (+ 2/min) and heat (+ 3/min).

CONCLUSION

Long-term health and productivity risks can be further aggravated by the predicted temperature rise due to climate change. Further physiological studies with a well-designed intervention are needed to strengthen the evidence for developing comprehensive policies to protect workers in the healthcare sector.

Spatiotemporal distribution characteristics and influencing factors of the rate of cardiovascular hospitalization in Ganzhou city of China

Aims

The objective of this study was to analyze hospitalization rates for cardiovascular diseases (CVD) in Ganzhou City, Jiangxi Province of China from 2015 to 2020 and to uncover the spatiotemporal distribution characteristics and influencing factors, and thus to provide reference for the prevention and control of CVD and public health resources planning.

Methods

The hospitalization data for CVDs from 2016 to 2020 was obtained from the First Affiliated Hospital of Gannan Medical University, and ArcGIS 10.8, SaTScan 9.5, and Matlab 20.0 were used to analyze the spatial autocorrelation, spatiotemporal scan statistics, and potential affecting factors of the hospitalization rates.

Results

The hospitalization rate for CVDs in Ganzhou City showed a slightly increasing trend from 2016 to 2020, with higher rates in winter and summer than that in spring and autumn, and the individuals aged 61 and above constitute a higher proportion compared to other age groups. Additionally, there was a positive correlation between hospitalization rates for CVDs and the counties and districts in Ganzhou City, with high-high aggregation areas mainly distributed in Nankang District, the western urban area of Ganzhou City. The spatial scan analysis identified three different types of significant aggregation areas: high-risk, low-risk, and middle-risk areas. The high-risk area was mainly centered around Zhanggong District or Shangyu County in the central and western regions, with a disease hospitalization rate 2-3 times higher than the rest areas. The study also found that environmental meteorological factors such as the annual average concentration of NO2, O3, average annual temperature, and annual maximum temperature diurnal range had a significant positive effect on hospitalization rates for CVDs in Ganzhou City, with O3 concentration and average annual temperature having significant positive indirect spatial spillover effects.

Conclusion

Winter and summer are the seasons with high hospitalization rate of cardiovascular diseases. County residents aged 61 and above are the higher-risk population that needs to pay more attention on for prevention and control of CVD in Ganzhou City, which exhibits significant spatiotemporal clustering. The urban areas of Zhanggong and Nankang in Ganzhou City are the key areas for prevention and control of CVD. The hospitalization rate of CVD in Ganzhou City is influenced by the aforementioned four environmental meteorological factors, with the annual maximum temperature diurnal range showing the most significant positive direct effect.

Climate Change, Summer Temperature, and Heat-Related Mortality in Finland: Multicohort Study with Projections for a Sustainable vs. Fossil-Fueled Future to 2050

BACKGROUND

Climate change scenarios illustrate various pathways in terms of global warming ranging from "sustainable development" (Shared Socioeconomic Pathway SSP1-1.9), the best-case scenario, to 'fossil-fueled development' (SSP5-8.5), the worst-case scenario.

OBJECTIVES

We examined the extent to which increase in daily average urban summer temperature is associated with future cause-specific mortality and projected heat-related mortality burden for the current warming trend and these two scenarios.

METHODS

We did an observational cohort study of 363,754 participants living in six cities in Finland. Using residential addresses, participants were linked to daily temperature records and electronic death records from national registries during summers (1 May to 30 September) 2000 to 2018. For each day of observation, heat index (average daily air temperature weighted by humidity) for the preceding 7 d was calculated for participants' residential area using a geographic grid at a spatial resolution of 1 km × 1 km . We examined associations of the summer heat index with risk of death by cause for all participants adjusting for a wide range of individual-level covariates and in subsidiary analyses using case-crossover design, computed the related period population attributable fraction (PAF), and projected change in PAF from summers 2000-2018 compared with those in 2030-2050.

RESULTS

During a cohort total exposure period of 582,111,979 summer days (3,880,746 person-summers), we recorded 4,094 deaths, including 949 from cardiovascular disease. The multivariable-adjusted rate ratio (RR) for high (≥ 21 ° C ) vs. reference (14 - 15 ° C ) heat index was 1.70 (95% CI: 1.28, 2.27) for cardiovascular mortality, but it did not reach statistical significance for noncardiovascular deaths, RR = 1.14 (95% CI: 0.96, 1.36), a finding replicated in case-crossover analysis. According to projections for 2030-2050, PAF of summertime cardiovascular mortality attributable to high heat will be 4.4% (1.8%-7.3%) under the sustainable development scenario, but 7.6% (3.2%-12.3%) under the fossil-fueled development scenario. In the six cities, the estimated annual number of summertime heat-related cardiovascular deaths under the two scenarios will be 174 and 298 for a total population of 1,759,468 people.

DISCUSSION

The increase in average urban summer temperature will raise heat-related cardiovascular mortality burden. The estimated magnitude of this burden is > 1.5 times greater if future climate change is driven by fossil fuels rather than sustainable development. https://doi.org/10.1289/EHP12080.

Effects of weather conditions on endovascular treatment case volume for patients with ischemic stroke

BACKGROUND

Weather conditions have been shown to influence the occurrence of cardiovascular events. We tested the hypothesis that weather parameters may be associated with variations of case volume of endovascular treatment (EVT) for acute ischemic stroke.

METHODS

Individual data from the ETIS (Endovascular Treatment in Ischemic Stroke) French national registry were matched to local weather stations. Meteorological parameters (rainfall, humidity, atmospheric pressure, air temperature) were gathered from national online resources. Weather readings and EVT case volumes were annually standardized per weather station and EVT center, and their associations tested with non-parametric univariable and generalized linear statistical models.

RESULTS

Between 2015 and 2021, 9913 EVT procedures addressed by 135 primary stroke units were matched to weather conditions. The mean daily case volume per center was 0.41 [StDev 0.33], and there was a median of 0.84 procedures daily linked to a weather station [StDev 0.47]. We found lower atmospheric pressure (β estimate -0.04; 95%CI[-0.07;-0.03], p<0.001), higher humidity (β estimate 0.07; 95%CI [0.05;0.09], p<0.001) and lower temperatures (β estimate -0.08; 95%CI[-0.10;-0.06], p<0.001) to be associated with higher standardized EVT daily case volumes. These associations were stable when testing them across strata of binned EVT standardized case volumes.

CONCLUSIONS

Our study suggests that lower ambient temperature, lower atmospheric pressure, and higher air humidity are associated with significantly more daily EVT cases in a European temperate country. These results may provide insight into both system of care optimization at times of climate change and intracranial LVO pathophysiology. REGISTRATION-URL: https://clinicaltrials.gov/ct2/show/NCT03776877.

Urban heat island impacts on heat-related cardiovascular morbidity: A time series analysis of older adults in US metropolitan areas

Many United States (US) cities are experiencing urban heat islands (UHIs) and climate change-driven temperature increases. Extreme heat increases cardiovascular disease (CVD) risk, yet little is known about how this association varies with UHI intensity (UHII) within and between cities. We aimed to identify the urban populations most at-risk of and burdened by heat-related CVD morbidity in UHI-affected areas compared to unaffected areas. ZIP code-level daily counts of CVD hospitalizations among Medicare enrollees, aged 65-114, were obtained for 120 US metropolitan statistical areas (MSAs) between 2000 and 2017. Mean ambient temperature exposure was estimated by interpolating daily weather station observations. ZIP codes were classified as low and high UHII using the first and fourth quartiles of an existing surface UHII metric, weighted to each have 25% of all CVD hospitalizations. MSA-specific associations between ambient temperature and CVD hospitalization were estimated using quasi-Poisson regression with distributed lag non-linear models and pooled via multivariate meta-analyses. Across the US, extreme heat (MSA-specific 99th percentile, on average 28.6 °C) increased the risk of CVD hospitalization by 1.5% (95% CI: 0.4%, 2.6%), with considerable variation among MSAs. Extreme heat-related CVD hospitalization risk in high UHII areas (2.4% [95% CI: 0.4%, 4.3%]) exceeded that in low UHII areas (1.0% [95% CI: -0.8%, 2.8%]), with upwards of a 10% difference in some MSAs. During the 18-year study period, there were an estimated 37,028 (95% CI: 35,741, 37,988) heat-attributable CVD admissions. High UHII areas accounted for 35% of the total heat-related CVD burden, while low UHII areas accounted for 4%. High UHII disproportionately impacted already heat-vulnerable populations; females, individuals aged 75-114, and those with chronic conditions living in high UHII areas experienced the largest heat-related CVD impacts. Overall, extreme heat increased cardiovascular morbidity risk and burden in older urban populations, with UHIs exacerbating these impacts among those with existing vulnerabilities.

Mediation of daily ambient ozone concentration on association between daily mean temperature and mortality in 7 metropolitan cities of Korea

BACKGROUND

Climate change is suspected to cause adverse health effects, and increased ozone concentration is one of the proposed pathways. We examined the mediation of ozone on the association between temperature and daily mortality and estimated excess mortality due to climate change.

METHODS

Daily mean temperature, 8-hour maximum ozone concentration, and daily number of non-accidental deaths from 7 metropolitan cities in Korea (Seoul, Busan, Daegu, Incheon, Daejeon, Gwangju, and Ulsan) between January 1, 2006 and December 31, 2019 were analyzed. A mediation analysis using a linear regression model for temperature and ozone and a Poisson regression model for temperature and mortality adjusting for ozone was conducted on days with temperature higher than or lower than city specific minimum mortality temperature. We calculated excess mortality due to direct and indirect effects of daily temperature exceeding average daily temperature from 1960 to 1990.

RESULTS

The daily mean temperature from 2006 to the end of 2019 was 1.15 ± 2.94 °C higher than the average daily temperature from 1960 to 1990. The pooled relative risk (for a 1 °C increment) of indirect effects through increased ozone were 1.0002 [95% confidence interval (CI): 0.9999, 1.0004] and 1.0003 (95% CI: 1.0002, 1.0005) in days with higher than or lower than minimum mortality temperature, respectively. The numbers of excess deaths during the study period were 2072.5 (95% CI: 1957.1, 2186.5) due to direct effects in days with higher than minimal mortality temperature, and 94.6 (95% CI: 84.3, 101.7) and 268.5 (95% CI: 258.4, 289.1) due to indirect effects in days with higher than and lower than minimal mortality temperature, respectively.

CONCLUSION

We observed a mediating effect of ozone between temperature and daily mortality. There has been excess deaths due direct effect of temperature and indirect effects through ozone.

Short-term impact of diurnal temperature range on cardiovascular diseases mortality in residents in northeast China

It has been reported that cardiovascular disease (CVD) has become one of the major threats to global public health and is associated with climate change. Several previous studies have shown the influence of ambient temperature on CVD, but lack some evidence for the short-term effect of diurnal temperature range (DTR) on CVD mortality in northeast China. This is the first study to assess the correlation between DTR and CVD mortality in Hulunbuir located in northeast China. Daily CVD mortality data and meteorological data were collected from 2014 to 2020. A quasi-Poisson generalized linear regression with a distributed lag non-linear model (DLNM) was applied to exploring the short-term impact of DTR on CVD mortality. Stratified analyses by gender, age, and season were conducted and the short-term impacts of extremely high DTR on CVD mortality were investigated. In this study, a total of 21,067 CVD mortality cases were recorded in Hulunbuir, China from 2014 to 2020. Compared to the reference value (11.20 [Formula: see text]C, 50[Formula: see text] percentile), a "U-shaped" non-linear relationship between DTR and CVD mortality was observed, and extremely high DTR increased the risk of CVD mortality. The short-term effect of extremely high DTR occurred immediately and lasted up to 6 days. In addition, the male and the age [Formula: see text] 65 groups were more likely to be affected by extremely high DTR compared with the female and the age < 65 groups, respectively. The results also showed that extremely high DTR in cold season had a more adverse effect on CVD mortality than warm season. This study suggests that extremely high DTR for cold season should be paid enough attention to for residents in northeast China. The male and the age [Formula: see text] 65 groups were more vulnerable to the impacts of DTR. The study results may provide some suggestions for decision-making by local public health authorities to avoid the adverse impacts of high DTR, and improve the health of residents, especially vulnerable groups in cold season.

Development of a screening tool for assessment of climate change-related heat illness in the clinical setting

ABSTRACT

Extreme heat contributes to heat-related illnesses resulting from heat intolerance, which is the inability to maintain a thermal balance to tolerate heat stress. In the United States, heat-related mortality for older persons has almost doubled in the past 20 years. Other populations at risk for heat-related illness (HRI) include children, pregnant people, those who work outside, young people participating in outdoor sports, and at-risk populations such as Black, indigenous, and populations of color. The classic heat tolerance test used for decades monitoring physiological responses to repetitive motions is impractical across large and potentially health challenged populations and does not identify environmental or social factors or specific vulnerable populations. To address this issue, we developed a heat-related illness screening tool (HIST) to identify individuals at risk for HRI morbidity and mortality based on their physical, environmental, and social vulnerabilities with an emphasis on populations of concern. The HIST has the potential to be used as routine clinical screening in the same way as other commonly used screening tools. Heat intolerance affects patient outcomes and quality of life; therefore, early screening with a simple, easy-to-administer screening tool such as the HIST can identify people at risk and refer them to services that address heat exposure and/or create safety nets to prevent heat-related illnesses.

The effects of heat exposure on tropical farm workers in Malaysia: six-month physiological health monitoring

Farmers in tropical countries have been impacted by slow-onset heat stress. By comparing the nature of farming activities performed by conventional farmworkers and agroecological farmers, this study examined the changes in physiological health in responses to heat exposure through a six-month longitudinal study. Throughout the six-month follow-up period, the heat stress index (HSI), physiological strain indices (PSI), and physiological health parameters (BMI, blood glucose level, blood cholesterol level, uric acid level) were measured and repeated every two-month. Physiological parameters were recorded twice daily, before and during their first lunch break. This study found that slow-onset heat stress affects farmers differently. The health of agroecological farmers is more resistant to slow-onset extreme temperatures. Pre-existing metabolic health effects from pesticide exposure make conventional farmers more susceptible to extreme temperatures, delaying their bodies' adaptation to rising temperatures.

Predicting fatal heat and humidity using the heat index model

A unique wet-bulb temperature of 35°C is often used as the threshold for human survivability, but recent experiments have shown that a person's core temperature starts to rise at a wide range of critical wet-bulb temperatures. Here, it is shown that the model underlying the heat index correctly predicts those critical wet-bulb temperatures, explaining 95% of the variance in the values observed in laboratory heat-stress experiments. This is the first time the heat-index model has been validated against physiological data from laboratory experiments. For light and moderate exertion in an indoor setting, the heat index model predicts that the critical wet-bulb temperature ranges from 20°C to 32°C, depending on the relative humidity, consistent with experimental results. For the same setting and exertion, the heat index model predicts fatal wet-bulb temperatures ranging from 24°C to 37°C.NEW & NOTEWORTHY Recent experiments have identified the critical combinations of heat and humidity, in an indoor setting, above which an individual is unable to maintain a standard core temperature, indicating severe heat stress. It is shown here why this state of severe heat stress cannot be predicted using the wet-bulb temperature. Instead, it is shown that the recently extended heat index model can explain nearly all of the variance in the observed critical combinations of temperature and humidity, and can be used to calculate fatal combinations.

Inflammation, coagulation, and cellular injury in heat-induced shock

BACKGROUND

The number of heatstroke victims hit record numbers in 2022 as global warming continues. In heat-induced injuries, circulatory shock is the most severe and deadly complication. This review aims to examine the mechanisms and potential approaches to heat-induced shock and the life-threatening complications of heatstroke.

METHODS

A computer-based online search was performed using the PubMed database and Web of Science database for published articles concerning heatstroke, shock, inflammation, coagulopathy, endothelial cell, cell death, and heat shock proteins.

RESULTS

Dehydration and heat-induced cardiomyopathy were reported as the major causes of heat-induced shock, although other heat-induced injuries are also involved in the pathogenesis of circulatory shock. In addition to dehydration, the blood volume decreases considerably due to the increased vascular permeability as a consequence of endothelial damage. Systemic inflammation is induced by factors that include elevated cytokine and chemokine levels, dysregulated coagulation/fibrinolytic responses, and the release of damage-associated molecular patterns (DAMPs) from necrotic cell death that cause distributive shock. The cytoprotective heat shock proteins can also facilitate circulatory disturbance under excess heat stress.

CONCLUSIONS

Multiple mechanisms are involved in the pathogenesis of heat-induced shock. In addition to dehydration, heat stress-induced cardiomyopathy due to the thermal damage of mitochondria, upregulated inflammation via damage-associated molecular patterns released from oncotic cells, unbalanced coagulation/fibrinolysis, and endothelial damage are the major factors that are related to circulatory shock.

Abnormal ambient temperature change increases the risk of out-of-hospital cardiac arrest: A systematic review and meta-analysis of exposure types, risk, and vulnerable populations

BACKGROUND

There is growing evidence in support of a short-term association between ambient temperature and cardiac arrest attacks that is a serious manifestation of cardiovascular disease and has a high incidence and low survival rate. However, it remains unrecognized about the hazardous temperature exposure types, exposure risk magnitude, and vulnerable populations.

OBJECTIVES

We comprehensively summarize prior epidemiological studies looking at the short-term associations of out-of-hospital cardiac arrest (OHCA) with various temperature exposures among different populations.

METHODS

We searched PubMed and Web of Science databases from inception to October 2021 for eligible English language. Temperature exposure was categorized into three types: heat (included high temperature, extreme heat, and heatwave), cold (included low temperature and extreme cold), and temperature variation (included diurnal temperature range and temperature change between two adjacent days). Meta-analysis weighted by inverse variance was used to pool effect estimates.

RESULTS

This study included 15 studies from 8 countries, totaling around 1 million OHCA events. Extreme heat and extreme cold were significantly associated with an increased risk of OHCA, and the pooled relative risks (RRs) were 1.071 [95 % confidence interval (CI): 1.019-1.126] and 1.662 (95%CI: 1.138-2.427), respectively. The risk of OHCA was also elevated by heatwaves (RR = 1.248, 95%CI: 1.091-1.427) and more intensive heatwaves had a greater effect. Notably, the elderly and males seemed to be more vulnerable to the effects of heat and cold. However, we did not observe a significant association between temperature variation and the risk of OHCA (1.005, 95%CI: 0.999-1.012).

CONCLUSION

Short-term exposure to heat and cold may be novel risk factors for OHCA. Considering available studies in limited regions, the temperature effect on OHCA should be urgently confirmed in different regions.

Effect modification by temperature on the association between O3 and emergency ambulance dispatches in Japan: A multi-city study

Numerous epidemiological studies have reported that ozone (O₃) and temperature are independently associated with health outcomes, but modification of the effects of O₃ on health outcomes by temperature, and vice versa, has not been fully described. This study aimed to investigate effect modification by temperature on the association between O₃ and emergency ambulance dispatches (EADs) in Japan. Data on daily air pollutants, ambient temperature, and EADs were obtained from eight Japanese cities from 2007 to 2015. A distributed lag non-linear model combined with Poisson regression was performed with temperature as a confounding factor and effect modifier to estimate the effects of O₃ on EADs at low (<25th percentile), moderate (25th-75th percentile), and high (>75th percentile) temperature for each city. The estimates obtained from each city were pooled by random-effects meta-analysis. When temperature was entered as a confounder, the estimated effects of O₃ on EADs for all acute, cardiovascular, and respiratory illnesses were largest at lag 0 (current-day lag). Therefore, this lag was used to further estimate the effects of O₃ on EADs in each temperature category. The estimated effects of O₃ on EADs for all acute, cardiovascular, and respiratory illnesses in all eight Japanese cities increased with increasing temperature. Specifically, a 10 ppb increase in O₃ was associated with 0.80 % (95 % CI: 0.25 to 1.35), 0.19 % (95 % CI: -0.85 to 1.25), and 1.14 % (95 % CI: -0.01 to 2.31) increases in the risk of EADs for all acute, cardiovascular, and respiratory illnesses, respectively, when city-specific daily temperature exceeded the 75th percentile. Our findings suggest that the association between O₃ and EADs for all acute, cardiovascular, and respiratory illnesses is the highest during high temperature. Finding of this study can be used to develop potential mitigation measures against O₃ exposure in high temperature environment to reduce its associated adverse health effects.

The joint and interaction effect of high temperature and humidity on mortality in China

BACKGROUND

Although many studies have reported the mortality effect of temperature, there were few studies on the mortality risk of humidity, let alone the joint effect of temperature and humidity. This study aimed to investigate the joint and interaction effect of high temperature and relative humidity on mortality in China, which will deepen understanding the health risk of mixture climate exposure.

METHODS

The mortality and meteorological data were collected from 353 locations in China (2013-2017 in Jilin, Hunan, Guangdong and Yunnan provinces, 2009-2017 in Zhejiang province, and 2006-2011 in other Provinces). We defined location-specific daily mean temperature ≥ 75th percentile of distribution as high temperature, while minimum mortality relative humidity as the threshold of high relative humidity. A time-series model with a distributed lag non-linear model was first employed to estimate the location-specific associations between humid-hot events and mortality, then we conducted meta-analysis to pool the mortality effect of humid-hot events. Finally, an additive interaction model was used to examine the interactive effect between high temperature and relative humidity.

RESULTS

The excess rate (ER) of non-accidental mortality attributed to dry-hot events was 10.18% (95% confidence interval (CI): 8.93%, 11.45%), which was higher than that of wet-hot events (ER = 3.21%, 95% CI: 0.59%, 5.89%). The attributable fraction (AF) of mortality attributed to dry-hot events was 10.00% (95% CI: 9.50%, 10.72%) with higher burden for females, older people, central China, cardiovascular diseases and urban city. While for wet-hot events, AF was much lower (3.31%, 95% CI: 2.60%, 4.30%). We also found that high temperature and low relative humidity had synergistic additive interaction on mortality risk.

CONCLUSION

Dry-hot events may have a higher risk of mortality than wet-hot events, and the joint effect of high temperature and low relative humidity may be greater than the sum of their individual effects.

Ability to adapt to seasonal temperature extremes among atrial fibrillation patients. A nation-wide study of hospitalizations in Israel

BACKGROUND

In recent years, temperature fluctuations and adverse weather events have become major concerns, influencing overall mortality and morbidity. While the association between extreme temperatures and atrial fibrillation (AF) has been supported by research, there is limited evidence on the ability of AF patients to adapt to the changing temperatures. We explored this question among AF patients in Israel featured by extreme temperature conditions.

METHODS

We examined the association between exposure to extreme temperatures and hospitalizations related to AF in a nationwide cohort in Israel. A case-crossover design with a distributed nonlinear model (DLNM) was applied to assess possible effects of temperature fluctuations during each season. We considered the 7 days prior to the event as the possible window period.

RESULTS

During 2004-2018 we recorded a total of 54,909 hospitalizations for AF. Low temperatures in winter and high in summer adversely affected AF-related hospitalizations. The effect recorded for the first few weeks of each season was of higher magnitude and decreased or faded off completely as the seasons progressed (OR in winter: from 1.14, 95%CI 0.98, 1.32 to 0.90, 95%CI: 0.77, 1.06;OR in summer: from 1.95, 95%CI: 1.51, 2.52 to 1.22, 95%CI: 0.90, 1.65). Patients living in the south region and patients with low socioeconomic status were more susceptible to extreme temperatures.

CONCLUSIONS

Although extreme hot and cold temperatures are associated with an increased risk of hospitalization for AF, the patients are likely to adapt to temperature change over the course of the first weeks of the season.

Health effect of temperature change on respiratory diseases in opposite phase in semi-arid region

The impact of temperature variation on health has attracted increasing attention under global climate change. A distributed lag non-linear model (DLNM) was performed to estimate the risk of two indicators of temperature change (diurnal temperature range (DTR) and temperature change between neighboring days (TCN)) on respiratory hospital visits in Lanzhou, a semi-arid climate city in western China from 2012 to 2018. The whole year is divided into two different temperature change periods according to the TCN of each solar term. The results showed that extreme high DTR can apparently enlarge respiratory risk, and it indicated strong cumulative relative risk (RR) in the temperature drop period. Extreme low TCN had strong adverse effects on respiratory diseases especially in temperature rise period, with the greatest RR of 1.068 (95% CI 1.004, 1.136). The effect of extreme high TCN was more obvious in temperature drop period, with a RR of 1.082 (95% CI 1.021, 1.148) at lag 7. Females were more affected by extreme temperature changes. Young people were more vulnerable to DTR, while TCN has a greater impact on the elderly.

Neurodegenerative Diseases: Implications of Environmental and Climatic Influences on Neurotransmitters and Neuronal Hormones Activities

Neurodegenerative and neuronal-related diseases are major public health concerns. Human vulnerability to neurodegenerative diseases (NDDs) increases with age. Neuronal hormones and neurotransmitters are major determinant factors regulating brain structure and functions. The implications of environmental and climatic changes emerged recently as influence factors on numerous diseases. However, the complex interaction of neurotransmitters and neuronal hormones and their depletion under environmental and climatic influences on NDDs are not well established in the literature. In this review, we aim to explore the connection between the environmental and climatic factors to NDDs and to highlight the available and potential therapeutic interventions that could use to improve the quality of life and reduce susceptibility to NDDs.

The Impact of Meteorological Factors and Air Pollutants on Acute Coronary Syndrome

Purpose of Review

Several studies have found that air pollution and climate change can have an impact on acute coronary syndromes (ACS), the leading cause of death worldwide. We synthesized the latest information about the impact of air pollution and climate change on ACS, the latest data about the pathophysiological mechanisms of meteorological factors and atmospheric pollutants on atherosclerotic disease, and an overall image of air pollution and coronary heart disease in the context of the COVID-19 pandemic.

Recent Findings

The variation of meteorological factors in different seasons increased the risk of ACS. Both the increase and the decrease in apparent temperature were found to be risk factors for ACS admissions. It was also demonstrated that exposure to high concentrations of air pollutants, especially particulate matter, increased cardiovascular morbidity and mortality.

Summary

Climate change as well as increased emissions of air pollutants have a major impact on ACS. The industrialization era and the growing population cause a constant increase in air pollution worldwide. Thus, the number of ACS favored by air pollution and the variations in meteorological factors is expected to increase dramatically in the next few years.

Does air pollution modify temperature-related mortality? A systematic review and meta-analysis

INTRODUCTION

There is an increasing interest in understanding whether air pollutants modify the quantitative relationships between temperature and health outcomes. The results of available studies were, however, inconsistent. This study aims to sum up the current evidence and provide a comprehensive understanding of this topic.

METHODS

We conducted an electronic search in PubMed (MEDLINE), EMBASE, Web of Science Core Collection, and ProQuest Dissertations and Theses. The modified Navigation Guide was applied to evaluate the quality and strength of evidence. We calculated pooled temperature-related mortality at low and high pollutant levels respectively, using the random-effects model.

RESULTS

We identified 22 eligible studies, eleven of which were included in the meta-analysis. Significant effect modification was observed on heat effects for all-cause and non-accidental mortality by particulate matter with an aerodynamic diameter of <10 μm (PM₁₀) and ozone (O₃) (p < 0.05). The excess risks (ERs) for all-cause and non-accidental mortality were 5.4% (4.4%, 6.4%) and 6.3% (4.8%, 7.8%) at the low PM₁₀ level, 8.8% (7.5%, 10.1%) and 11.4% (8.7%, 14.2%) at the high PM₁₀ level, respectively. As for O₃, the ERs for all-cause and non-accidental mortality were 5.1% (3.9%, 6.3%) and 3.6% (0.1%, 7.2%) at the low O₃ level, 7.6% (6.3%, 9.0%) and 12.5% (4.7%, 20.9%) at the high O₃ level, respectively. Surprisingly, the heat effects on cardiovascular mortality were found to be lower at high carbon monoxide (CO) levels [ERs = 5.4% (3.9%, 6.9%)] than that at low levels [ERs = 9.4% (7.0%, 11.9%)]. The heterogeneity varied, but the results of sensitivity analyses were generally robust. Significant effect modification by air pollutants was not observed for heatwave or cold effects.

CONCLUSIONS

PM₁₀ and O₃ modify the heat-related all-cause and non-accidental mortality, indicating that policymakers should consider air pollutants when establishing heat-health warning systems. Future studies with comparable designs and settings are needed.

Impact of temperature changes between neighboring days on cardiovascular disease hospital admissions among suburban farmers in Qingyang, Northwest China

BACKGROUND

No studies focused on impact of temperature changes between neighboring days (TCN) on cardiovascular disease (CVD) hospital admissions among suburban farmers although CVD has been the main cause to global mortality and disability especially in undeveloped and developing countries/areas.

METHOD

Daily data of CVD hospital admissions on suburban farmers and daily data of meteorology in Qingyang (China) were collected during 2011-2015. A distributed lag non-linear model (DLNM) was applied to explore the exposure-response relations and lagged effects between TCN and CVD hospital admissions with stratified analyses by age and gender. Extreme low TCN effects and burden analysis were conducted.

RESULTS

Based on 25,984 cases in Qingyang (China) during 2011-2015 among suburban farmers, we found that, first, nonlinear relationship was observed between TCN and CVD hospital admissions and adverse impact in negative TCN (temperature dropping between neighboring days) while protective effect in positive TCN (temperature rising between neighboring days) were discovered; third, during lag0-27, the cumulative relative risk (RR) for extreme low TCN (5th percentile, - 3.5 °C) and extreme high TCN (95th percentile, 3 °C) was 29.55 (95% CI 4.709-185.436) and 0.040 (95% CI 0.009-0.169), respectively; fourth, the age < 65 and females were more vulnerable to negative TCN than the age ≥ 65 and males among suburban farmers, respectively; last, moderate low TCN contributed the most fractions and numbers on CVD hospital admissions.

CONCLUSIONS

Among Qingyang suburban farmers in Northwest China, negative TCN should be paid more attention.

Plasma Proteins as Occupational Hazard Risk Monitors for Populations Working in Harsh Environments: A Mendelian Randomization Study

Harsh work environments can include very cold, hot, dusty, and noisy workplaces, as well as exposure in the workplace with chemicals and other fumes, cigarette smoke, and diesel exhaust. Although working in these harsh environments can have a negative effect on health, there are no effective biomarkers for monitoring health conditions until workers develop disease symptoms. Plasma protein concentrations, which reflect metabolism and immune status, have great potential as biomarkers for various health conditions. Using a Mendelian-randomization (MR) design, this study analyzed the effects of these harsh environments on plasma proteins to identify proteins that can be used as biomarkers of health status. Preliminary analysis using inverse variance weighted (IVW) method with a p-value cutoff of 0.05 showed that workplace environments could affect the concentrations of hundreds of plasma proteins. After filtering for sensitivity via MR-Egger, and Weighted Median MR approaches, 28 plasma proteins altered by workplace environments were identified. Further MR analysis showed that 20 of these plasma proteins, including UNC5D, IGFBP1, SCG3, ST3GAL6, and ST3GAL2 are affected by noisy workplace environments; TFF1, RBM39, ACYP2, STAT3, GRB2, CXCL1, EIF1AD, CSNK1G2, and CRKL that are affected by chemical fumes; ADCYAP1, NRSN1, TMEM132A, and CA10 that are affected by passive smoking; LILRB2, and TENM4 that are affected by diesel exhaust, are associated with the risk of at least one disease. These proteins have the potential to serve as biomarkers to monitor the occupational hazards risk of workers working in corresponding environments. These findings also provide clues to study the biological mechanisms of occupational hazards.

Tracking the impacts of climate change on human health via indicators: lessons from the Lancet Countdown

BACKGROUND

In the past decades, climate change has been impacting human lives and health via extreme weather and climate events and alterations in labour capacity, food security, and the prevalence and geographical distribution of infectious diseases across the globe. Climate change and health indicators (CCHIs) are workable tools designed to capture the complex set of interdependent interactions through which climate change is affecting human health. Since 2015, a novel sub-set of CCHIs, focusing on climate change impacts, exposures, and vulnerability indicators (CCIEVIs) has been developed, refined, and integrated by Working Group 1 of the "Lancet Countdown: Tracking Progress on Health and Climate Change", an international collaboration across disciplines that include climate, geography, epidemiology, occupation health, and economics.

DISCUSSION

This research in practice article is a reflective narrative documenting how we have developed CCIEVIs as a discrete set of quantifiable indicators that are updated annually to provide the most recent picture of climate change's impacts on human health. In our experience, the main challenge was to define globally relevant indicators that also have local relevance and as such can support decision making across multiple spatial scales. We found a hazard, exposure, and vulnerability framework to be effective in this regard. We here describe how we used such a framework to define CCIEVIs based on both data availability and the indicators' relevance to climate change and human health. We also report on how CCIEVIs have been improved and added to, detailing the underlying data and methods, and in doing so provide the defining quality criteria for Lancet Countdown CCIEVIs.

CONCLUSIONS

Our experience shows that CCIEVIs can effectively contribute to a world-wide monitoring system that aims to track, communicate, and harness evidence on climate-induced health impacts towards effective intervention strategies. An ongoing challenge is how to improve CCIEVIs so that the description of the linkages between climate change and human health can become more and more comprehensive.

Impact of ambient temperature on life loss per death from cardiovascular diseases: a multicenter study in central China

BACKGROUND

In the context of global climate change, studies have focused on the ambient temperature and mortality of cardiovascular diseases (CVDs). However, little is known about the effect of ambient temperature on year of life lost (YLL), especially the life loss per death caused by ambient temperature. In this study, we aimed to assess the relationship between ambient temperature and life loss and estimate the impact of ambient temperature on life loss per death.

METHODS

We collected daily time series of mortality and meteorological data from 70 locations in Hunan province, central China, in periods ranging from Jan. 1, 2013, to Dec. 31, 2017. Crude rates of YLL were calculated per 100,000 people per year (YLL/100,000 population) for each location. A distributed lag nonlinear model and multivariate meta-regression were used to estimate the associations between ambient temperature and YLL rates. Then, the average life loss per death attributable to ambient temperature was calculated.

RESULTS

There were 711,484 CVD deaths recorded within the study period. The exposure-response curve between ambient temperature and YLL rates was inverted J or U-shaped. Relative to the minimum YLL rate temperature, the life loss risk of extreme cold temperature lasted for 10 to 12 days, whereas the risk of extreme hot temperature appeared immediately and lasted for 3 days. On average, the life loss per death attributable to non-optimum ambient temperatures was 1.89 (95% CI, 1.21-2.56) years. Life loss was mainly caused by cold temperature (1.13, 95% CI, 0.89‑1.37), particularly moderate cold (1.00, 95% CI, 0.78‑1.23). For demographic characteristics, the mean life loss per death was relatively higher for males (2.07, 95% CI, 1.44‑2.68) and younger populations (3.72, 95% CI, 2.06‑5.46) than for females (1.88, 95% CI, 1.21-2.57) and elderly people (1.69, 95% CI, 1.28-2.10), respectively.

CONCLUSIONS

We found that both cold and hot temperatures significantly aggravated premature death from CVDs. Our results indicated that the whole range of effects of ambient temperature on CVDs should be given attention.

Heat Adaptive Capacity: What Causes the Differences Between Residents of Xiamen Island and Other Areas?

Extreme heat events caused by climate change have serious adverse effects on residents' health in many coastal metropolises in southeast China. Adaptive capacity (AC) is crucial to reduce heat vulnerability in the human-environment system. However, it is unclear whether changes in individual characteristics and socioeconomic conditions likely amplify or attenuate the impacts of residents' heat adaptive capacity (HAC) changes. Moreover, which public policies can be implemented by the authorities to improve the HAC of vulnerable groups remains unknown. We conducted a questionnaire survey of 630 residents of Xiamen, a typical coastal metropolis, in 2018. The effects of individual and household characteristics, and government actions on the residents' HAC were examined by using ordinal logistic regression analysis. Results show that the majority (48.10%) of Xiamen residents had a "medium" HAC level, followed by a "high" level (37.14%). On Xiamen Island, residents who settled locally for one-three years and spent less than one hour outdoors might report weaker HAC, and their HAC would not improve with increased air conditioning units in household. In other areas of Xiamen, residents with more rooms in their households, no educational experience, and building areas <50 m2 might report better HAC. Further, vulnerable groups, such as local residents and outdoor workers on Xiamen Island, people lacking educational experience and renters in other areas of Xiamen, showed better AC to hot weather than those in previous studies. Low-income groups should be given more attention by local governments and community groups as monthly household income played a positive role in improving Xiamen residents' HAC. Rational green spaces planning and cooling services, such as street sprinkling operations, provided by municipal departments can effectively bring benefits to Xiamen residents. Identification of basic conditions of AC has significant implications for practical promoting targeted measures or policies to reduce health damages and livelihood losses of urban residents during extreme heat events.

Impacts of Environmental Insults on Cardiovascular Aging

PURPOSE OF REVIEW

With cardiovascular disease (CVD) being the top cause of deaths worldwide, it is important to ensure healthy cardiovascular aging through enhanced understanding and prevention of adverse health effects exerted by external factors. This review aims to provide an updated understanding of environmental influences on cardiovascular aging, by summarizing epidemiological and mechanistic evidence for the cardiovascular health impact of major environmental stressors, including air pollution, endocrine-disrupting chemicals (EDCs), metals, and climate change.

RECENT FINDINGS

Recent studies generally support positive associations of exposure to multiple chemical environmental stressors (air pollution, EDCs, toxic metals) and extreme temperatures with increased risks of cardiovascular mortality and morbidity in the population. Environmental stressors have also been associated with a number of cardiovascular aging-related subclinical changes including biomarkers in the population, which are supported by evidence from relevant experimental studies. The elderly and patients are the most vulnerable demographic groups to majority environmental stressors. Future studies should account for the totality of individuals' exposome in addition to single chemical pollutants or environmental factors. Specific factors most responsible for the observed health effects related to cardiovascular aging remain to be elucidated.

Airborne particles and cardiovascular morbidity in severe inherited hypercholesterolemia: Vulnerable endothelium under multiple attacks

Despite recent advances in the research related to air pollution and associated adverse cardiovascular events, the combined effects of air pollution, climate change, and SARS-CoV-2 infection on cardiovascular health need to be researched further. This Commentary addresses their impacts on cardiovascular health in the approximately 25 million people with a severe form of inherited hypercholesterolemia, called familial hypercholesterolemia (FH). The arterial endothelium in these individuals is potentially under multiple attacks caused by particles of both endogenous and exogenous origin. Thus, they have a lifelong highly elevated level of circulating low density lipoprotein (LDL) cholesterol which drives premature atherosclerosis. The high levels of LDL particles, often associated with an elevated level of circulating lipoprotein(a) particles, are both capable of inducing and maintaining endothelial dysfunction. Such pre-existing endothelial dysfunction can be exacerbated by exposure to SARS-CoV-2 viral particles, by exposure to fine particulate matter generated by climate change-associated wildfires, and by dehydration during deadly heatwaves linked to the globally rising temperatures. The external factors can severely worsen the pre-existing endothelial dysfunction, and thereby significantly increase the risk of a cardiovascular event in the exposed FH patients.

Effects of diurnal temperature range on cardiovascular disease hospital admissions in farmers in China's Western suburbs

Cardiovascular disease (CVD), reported to relate with climate change, is the leading cause of global mortality and morbidity. Since the relevant information is quite limited from suburbs and countryside in developing and underdeveloped countries, there are no studies that focused on morbidity through diurnal temperature range (DTR) for these regions. This is the first study to evaluate the short-term effect of DTR on CVD hospital admission in suburban farmers, as well as to identify vulnerable subpopulations. Daily time series data of CVD hospital admissions on suburban farmers of Qingyang, China, and meteorological data from 2011 to 2015 were collected, and a distributed lag non-linear model (DLNM) combined with a quasi-Poisson generalized additive regression model (GAM) was used to examine the exposure-response relationship and delayed effect between DTR and CVD hospital admissions. Stratified analyses by age and gender were performed and extreme DTR effects were examined. Non-linear relation between DTR and CVD hospital admissions was observed, and whether DTR lower or higher than the reference (13 °C, 50^th percentile) had adverse effect while lower DTR have slightly higher impact. Also, both extreme low and extreme high DTR had adverse effect. Besides, adults (age < 65) and males were more vulnerable to the effects of DTR compared with the old (age ≥ 65) and females, respectively. This study provides evidence that not only high DTR but also low DTR had adverse effects on CVD which should be paid attention to. Adults and males were more vulnerable among suburban farmers. The results are inconsistent with the studies from urban and indicate differences between urban and suburban residents. Multiple factors such as occupations, risk awareness, and lifestyles could have a significant influence on CVD morbidity, and further study is needed to explore more evidence.

Extreme Heat and Cardiovascular Health: What a Cardiovascular Health Professional Should Know

As global temperatures continue to rise, extreme heat events are becoming more frequent and intense. Extreme heat affects cardiovascular health as it is associated with a greater risk of adverse cardiovascular events, especially for adults with preexisting cardiovascular diseases. Nonetheless, the pathophysiology underlying the association between extreme heat and cardiovascular risk remains understudied. Furthermore, specific recommendations to mitigate the effects of extreme heat on cardiovascular health remain limited to guide clinical practice within the context of a warming climate. The overall objective of this review article is to raise awareness that extreme heat poses a risk for cardiovascular health. Specifically, the review discusses why cardiovascular healthcare professionals should care about extreme heat, how extreme heat affects cardiovascular health, and recommendations to minimise the cardiovascular consequences of extreme heat. Future research directions are also provided to further our understating of the cardiovascular health consequences of extreme heat. A better awareness and understanding of the cardiovascular consequences of extreme heat will help cardiovascular health professionals assess the risk and optimise the care of their patients exposed to an increasingly warm climate.

Regulation of free radical processes in healthy volunteers during experimental hyperthermia and in patients with coronary artery disease during summer heat waves

Background. In view of the worsening forecast for global temperature rise worldwide, it seems relevant to study the effects of abnormal heat waves on systemic regulatory processes in people with chronic diseases, in particular coronary artery disease (CAD).

Aims. This study aimed to investigate the effect of hyperthermia on oxidative stress parameters in patients with various severity of CAD and in healthy subjects.

Materials and methods. We studied the level of malonic dialdehyde (MDA) and the activity of Cu,Zn-containing superoxide dismutase (Cu,Zn-SOD) in healthy subjects under conditions of 30-day long simulated hyperthermia and in patients with different severity of CAD after the summer heat waves

Results. We revealed signs of oxidative stress in healthy volunteers during model hyperthermia that manifested as an increase in content of MDA in blood plasma. At the  same time we observed increasing activity of Cu,Zn-SOD in erythrocytes that  utilizes reactive oxygen species. The increase of Cu,Zn-SOD activity started with a certain latency what also can be explained by de novo enzyme biosynthesis induction. We also studied oxidative stress parameters in patients at high and moderate cardiovascular risk according to the SCORE risk chart with uncomplicated CAD course and in patients with complicated CAD with severe coronary damage according to angiography during the summer heat waves. We observed accumulation of MDA in blood plasma and increasing activity of erythrocyte Cu,Zn-SOD in patients with uncomplicated CAD. At the same time we noted that accumulation of MDA in blood plasma was not followed by any increase in activity of red blood cell Cu,Zn-SOD in patients with severe complicated CAD. This fact indicates dysregulation of free radical processes in patients with severe course of CAD during the heat waves.

Conclusions. The dysregulation of free-radical processes in patients with a severe clinical course of CAD has been revealed. 

Temperature-related effects on respiratory medical prescriptions in Spain

BACKGROUND

The increased risk of mortality during periods of high and low temperatures has been well established. However, most of the studies used daily counts of deaths or hospitalisations as health outcomes, although they are the ones at the top of the health impact pyramid reflecting only a limited proportion of patients with the most severe cases.

OBJECTIVES

This study evaluates the relationship between short-term exposure to the daily mean temperature and medication prescribed for the respiratory system in five Spanish cities.

METHODS

We fitted time series regression models to cause-specific medical prescriptions, including different respiratory subgroups and age groups. We included a distributed lag non-linear model with lags up to 14 days for daily mean temperature. City-specific associations were summarised as overall-cumulative exposure-response curves.

RESULTS

We found a positive association between cause-specific medical prescriptions and daily mean temperature with a non-linear inverted J- or V-shaped relationship in most cities. Between 0.3% and 0.6% of all respiratory prescriptions were attributed to cold for Madrid, Zaragoza and Pamplona, while in cities with only cold effects the attributable fractions were estimated as 19.2% for Murcia and 13.5% for Santander. Heat effects in Madrid, Zaragoza and Pamplona showed higher fractions between 8.7% and 17.2%. The estimated costs are in general higher for heat effects, showing annual values ranging between €191,905 and €311,076 for heat per 100,000 persons.

CONCLUSIONS

This study provides novel evidence of the effects of the thermal environment on the prescription of medication for respiratory disorders in Spain, showing that low and high temperatures lead to an increase in the number of such prescriptions. The consumption of medication can reflect exposure to the environment with a lesser degree of severity in terms of morbidity.

Climate change and neurodegenerative diseases

The climate change induced global warming, and in particular the increased frequency and intensity of heat waves, have been linked to health problems. Among them, scientific works have been reporting an increased incidence of neurological diseases, encompassing also neurodegenerative ones, such as Dementia of Alzheimer's type, Parkinson's Disease, and Motor Neuron Diseases. Although the increase in prevalence of neurodegenerative diseases is well documented by literature reports, the link between global warming and the enhanced prevalence of such diseases remains elusive. This is the main theme of our work, which aims to examine the connection between high temperature exposure and neurodegenerative diseases. Firstly, we evaluate the influence of high temperatures exposure on the pathophysiology of these disorders. Secondly, we discuss its effects on the thermoregulation, already compromised in affected patients, and its interference with processes of excitotoxicity, oxidative stress and neuroinflammation, all of them related with neurodegeneration. Finally, we investigate chronic versus acute stressors on body warming, and put forward a possible interpretation of the beneficial or detrimental effects on the brain, which is responsible for the incidence or progression of neurological disorders.

Short-Term Effect of Temperature Change on Non-Accidental Mortality in Shenzhen, China

Temperature change is an important meteorological indicator reflecting weather stability. This study aimed to examine the effects of ambient temperature change on non-accidental mortality using diurnal temperature change (DTR) and temperature change between neighboring days (TCN) from two perspectives, intra-day and inter-day temperature change, and further, to explore seasonal variations of mortality, identify the susceptible population and investigate the interaction between temperature change and apparent temperature (AT). We collected daily data on cause-specific mortality, air pollutants and meteorological indicators in Shenzhen, China, from 1 January 2013 to 29 December 2017. A Quasi-Poisson generalized linear regression combined with distributed lag non-linear models (DLNMs) were conducted to estimate the effects of season on temperature change-related mortality. In addition, a non-parametric bivariate response surface model was used to explore the interaction between temperature change and AT. The cumulative effect of DTR was a U-shaped curve for non-accidental mortality, whereas the curve for TCN was nearly monotonic. The overall relative risks (RRs) of non-accidental, cardiovascular and respiratory mortality were 1.407 (95% CI: 1.233-1.606), 1.470 (95% CI: 1.220-1.771) and 1.741 (95% CI: 1.157-2.620) from exposure to extreme large DTR (99th) in cold seasons. However, no statistically significant effects were observed in warm seasons. As for TCN, the effects were higher in cold seasons than warm seasons, with the largest RR of 1.611 (95% CI: 1.384-1.876). The elderly and females were more sensitive, and low apparent temperature had a higher effect on temperature change-related non-accidental mortality. Temperature change was positively correlated with an increased risk of non-accidental mortality in Shenzhen. Both female and elderly people are more vulnerable to the potential adverse effects, especially in cold seasons. Low AT may enhance the effects of temperature change.

Long-term exposure to ambient PM2.5 and stroke mortality among urban residents in northern China

Evidence is still limited for the role of long-term PM_2.5 exposure in cerebrovascular diseases among residents in high pollution regions. The study is aimed to investigate the long-term effects of PM_2.5 exposure on stroke mortality, and further explore the effect modification of temperature variation on the PM_2.5-mortality association in northern China. Based on a cohort data with an average follow-up of 9.8 years among 38,435 urban adults, high-resolution estimates of PM_2.5 derived from a satellite-based model were assigned to each participant. A Cox regression model with time-varying exposures and strata of geographic regions was employed to assess the risks of stroke mortality associated with PM_2.5, after adjusting for individual risk factors. The cross-product term of PM_2.5 exposure and annual temperature range was further added into the regression model to test whether the long-term temperature variation would modify the association of PM_2.5 with stroke mortality. Among the study participants, the annual mean level of PM_2.5 concentration was 66.3 μg/m³ ranging from 39.0 μg/m³ to 100.6 μg/m³. For each 10 μg/m³ increment in PM_2.5, the hazard ratio (HR) was 1.31 (95% CI: 1.04-1.65) for stroke mortality after multivariable adjustment. In addition, the HRs of PM_2.5 decreased gradually as the increase of annual temperature range with the HRs of 1.95 (95% CI: 1.36-2.81), 1.53 (95% CI: 1.06-2.22), and 1.11 (95% CI: 0.75-1.63) in the low, middle, and high group of annual temperature range, respectively. The findings provided further evidence of long-term PM_2.5 exposure on stroke mortality in high-exposure settings such as northern China, and also highlighted the view that assessing the adverse health effects of air pollution might not ignore the role of temperature variations in the context of climate change.