Long-term variations in the association between ambient temperature and daily cardiovascular mortality in Shanghai, China

The temporal variation in the effects of extreme temperature on respiratory mortality: Evidence from 136 cities in China, 2006-2019

BACKGROUND

In the context of climate change and urbanization, the temporal variation of the adverse health effect of extreme temperature has attracted increasing attention.

METHODS

The meteorological data and the daily death records of mortality from respiratory diseases of 136 Chinese cities were from 2006 to 2019. Heat wave and cold spell were selected as the indicator events of extreme high temperature and extreme low temperature, respectively. The generalized linear model and time-varying distributed lag model were used to perform a two-stage time-series analysis to evaluate the temporal variation of the mortality risk associated with extreme temperature in the total population, sub-populations (sex- and age- specific) and different regions (climatic zone and relative humidity level).

RESULTS

During the study period, relative risk (RR) of respiratory mortality associated with heat wave decreased from 1.22 (95 %CI: 1.07-1.39) to 1.13 (95 %CI: 1.01-1.26) in the total population, and RR of respiratory mortality associated with cold spell decreased from 1.30 (95 %CI: 1.14-1.49) to 1.17 (95 %CI: 1.08-1.26). The impact of heat wave reduced in the males (P = 0.044) and in the females as with cold spell (P < 0.001). The respiratory mortality risk of people over 65 associated with cold spell decreased (P = 0.040 for people aged 65-74 and P < 0.001 for people over 75). The effect of cold spell reduced in cities from tropical or arid zone (P = 0.035). The effects of both heat wave and cold spell decreased in cities with the relative humidity in the first quartile (P = 0.046 and 0.010, respectively).

CONCLUSION

The impact of heat wave on mortality of respiratory diseases decreased mainly in males and cities with the lowest relative humidity, while the impact of cold spell reduced in females, people over 65 and tropical and arid zone, suggesting adaptation to extreme temperature of Chinese residents to some extent.

Heat and Cardiovascular Mortality: An Epidemiological Perspective

As global temperatures rise, extreme heat events are projected to become more frequent and intense. Extreme heat causes a wide range of health effects, including an overall increase in morbidity and mortality. It is important to note that while there is sufficient epidemiological evidence for heat-related increases in all-cause mortality, evidence on the association between heat and cause-specific deaths such as cardiovascular disease (CVD) mortality (and its more specific causes) is limited, with inconsistent findings. Existing systematic reviews and meta-analyses of epidemiological studies on heat and CVD mortality have summarized the available evidence. However, the target audience of such reviews is mainly limited to the specific field of environmental epidemiology. This overarching perspective aims to provide health professionals with a comprehensive overview of recent epidemiological evidence of how extreme heat is associated with CVD mortality. The rationale behind this broad perspective is that a better understanding of the effect of extreme heat on CVD mortality will help CVD health professionals optimize their plans to adapt to the changes brought about by climate change and heat events. To policymakers, this perspective would help formulate targeted mitigation, strengthen early warning systems, and develop better adaptation strategies. Despite the heterogeneity in evidence worldwide, due in part to different climatic conditions and population dynamics, there is a clear link between heat and CVD mortality. The risk has often been found to be higher in vulnerable subgroups, including older people, people with preexisting conditions, and the socioeconomically deprived. This perspective also highlights the lack of evidence from low- and middle-income countries and focuses on cause-specific CVD deaths. In addition, the perspective highlights the temporal changes in heat-related CVD deaths as well as the interactive effect of heat with other environmental factors and the potential biological pathways. Importantly, these various aspects of epidemiological studies have never been fully investigated and, therefore, the true extent of the impact of heat on CVD deaths remains largely unknown. Furthermore, this perspective also highlights the research gaps in epidemiological studies and the potential solutions to generate more robust evidence on the future consequences of heat on CVD deaths.

The influence of humid heat on morbidity of megacity Shanghai in China

BACKGROUND

Increased attention has been paid to humid-heat extremes as they are projected to increase in both frequency and intensity. However, it remains unclear how compound extremes of heat and humidity affects morbidity when the climate is projected to continue warming in the future, in particular for a megacity with a large population.

METHODS

We chose the Wet-Bulb Globe Temperature (WBGT) index as the metric to characterize the humid-heat exposure. The historical associations between daily outpatient visits and daily mean WBGT was established using a Distributed Lag Non-linear Model (DLNM) during the warm season (June to September) from 2013 to 2015 in Shanghai, a prominent megacity of China. Future morbidity burden related to the combined effect of high temperature and humidity were projected under four greenhouse gases (GHGs) emission scenarios (SSP126, SSP245, SSP370 and SSP585).

RESULTS

The humid-heat weather was significantly associated with a higher risk of outpatient visits in Shanghai than the high-temperature conditions. Relative to the baseline period (2010-2019), the morbidity burden due to humid-heat weather was projected to increase 4.4 % (95 % confidence interval (CI): 1.1 %-10.1 %) even under the strict emission control scenario (SSP126) by 2100. Under the high-GHGs emission scenario (SSP585), this burden was projected to be 25.4 % (95 % CI: 15.8 %-38.4 %), which is 10.1 % (95 % CI: 6.5 %-15.8 %) more than that due to high-temperature weather. Our results also indicate that humid-hot nights could cause large morbidity risks under high-GHGs emission scenarios particularly in heat-sensible diseases such as the respiratory and cardiovascular disease by the end of this century.

CONCLUSIONS

Humid heat exposures significantly increased the all-cause morbidity risk in the megacity Shanghai, especially in humid-hot nights. Our findings suggest that the combined effect of elevated temperature and humidity is projected to have more substantial impact on health compared to high temperature alone in a warming climate.

Association between thermal stress and cardiovascular mortality in the subtropics

Hazardous thermal conditions resulting from climate change may play a role in cardiovascular disease development. We chose the Universal Thermal Climate Index (UTCI) as the exposure metric to evaluate the relationship between thermal conditions and cardiovascular mortality in Shenzhen, China. We applied quasi-Poisson regression non-linear distributed lag models to evaluate the exposure-response associations. The findings suggest that cardiovascular mortality risks were significantly increased under heat and cold stress, and the adverse effects of cold stress were stronger than heat stress. Referencing the 50th percentile of UTCI (25.4°C), the cumulative risk of cardiovascular mortality was 75% (RRlag0-21 =1.75, 95%CI: 1.32, 2.32) higher in the 1st percentile (3.5°C), and 40% (RRlag0-21=1.40, 95%CI: 1.09, 1.80) higher in the 99th percentile (34.1°C). We observed that individuals older than 65 years were more vulnerable to both cold and heat stress, and females were identified as more susceptible to heat stress than males. Moreover, increased mortality risks of hypertensive disease and cerebrovascular disease were observed under cold stress, while heat stress was related to higher risks of mortality for hypertensive disease and ischemic heart disease. We also observed a stronger relationship between cold stress and ischemic heart disease mortality during the cold season, as well as a significant impact of heat stress on cerebrovascular disease mortality in the warm season when compared to the analysis of the entire year. These results confirm the significant relationship between thermal stress and cardiovascular mortality, with age and sex as potential effect modifiers of this association. Providing affordable air conditioning equipment, increasing the amount of vegetation, and establishing comprehensive early warning systems that take human thermoregulation into account could all help to safeguard the well-being of the public, particularly vulnerable populations, in the event of future extreme weather.

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.

Temporal variation in the association between temperature and cause-specific mortality in 15 German cities

BACKGROUND

There is limited evidence of temporal changes in the association between air temperature and the risk of cause-specific cardiovascular [CVD] and respiratory [RD] mortality.

METHOD

We explored temporal variations in the association between short-term exposures to air temperature and non-accidental and cause-specific CVD and RD mortality in the 15 largest German cities over 24 years (1993-2016) using time-stratified time series analysis. We applied location-specific confounder-adjusted Poisson regression with distributed lag non-linear models with a lag period of 14 days to estimate the temperature-mortality associations. We then pooled the estimates by a multivariate meta-analytical model. We analysed the whole study period and the periods 1993-2004 and 2005-16, separately. We also carried out age- and sex-stratified analysis. Cold and heat effects are reported as relative risk [RR] at the 1st and the 99th temperature percentile, relative to the 25th and the 75th percentile, respectively.

RESULT

We analysed a total of 3,159,292 non-accidental, 1,063,198 CVD and 183,027 RD deaths. Cold-related RR for CVD mortality was seen to rise consistently over time from 1.04 (95% confidence interval [95% CI] 1.02, 1.06) in the period 1993-2004 to 1.10 (95% CI 1.09, 1.11) in the period 2005-16. A similar increase in cold-related RR was also observed for RD mortality with risk increasing from 0.99 (95% CI 0.96, 1.03) to 1.07 (95% CI 1.03, 1.10). Cold-related ischemic, cerebrovascular, and heart failure mortality risk were seen to be increasing over time. Similarly, COPD, the commonly speculated driver of heat-related RD mortality was found to have a constant heat-related risk over time. Males were increasingly vulnerable to cold with time for all causes of death. Females showed increasing sensitivity to cold for CVD mortality. Our results indicated a significant increased cold and heat vulnerability of the youngest age-groups (<64) to non-accidental and RD mortality, respectively. Similarly, the older age group (>65) were found to have significantly increased susceptibility to cold for CVD mortality.

CONCLUSION

We found evidence of rising population susceptibility to both heat- and cold-related CVD and RD mortality risk from 1993 to 2016. Climate change mitigation and targeted adaptation strategies might help to reduce the number of temperature-related deaths in the future.

Have residents adapted to heat wave and cold spell in the 21st century? Evidence from 136 Chinese cities

Global climate change has increased the probability and intensity of extreme weather events. The adverse health effect of extreme temperature has gone through a temporal variation over years. Time-series data including city-level daily cardiovascular death records and meteorological data were collected from 136 Chinese cities during 2006 and 2019. A time-varying distributed lag model with interaction terms was applied to assess the temporal change of mortality risk and attributable mortality of heat wave and cold spell. The mortality effect of heat wave generally increased and that of cold spell decreased significantly in the total population during the study period. The heat wave effect increased especially among the female and people aged 65 to 74. As for the cold spell, the reduced susceptibility was detected both in the temperate and cold climatic zone. Our findings appeal for counterpart measures corresponding to sub-populations and regions responding to future extreme climate events from the public and individuals.

Extreme temperatures and circulatory mortality in a temperate continental monsoon climate city in Northeast China

Epidemiological studies have proven that extreme temperatures have a significant threat to public health. This study aimed to investigate the association between extreme temperatures and circulatory mortality from January 1, 2014, to December 31, 2016, in Harbin, a city with a cold climate in Northeast China. We set a maximum lag of 27 days to evaluate the hysteresis effects of different temperatures on circulatory mortality using a distributed lag nonlinear model (DLNM). Results indicated that daily mean temperature and circulatory mortality presented approximately an L-shaped, and the cumulative relative risks (RRs) decreased continuously as the temperature increased in both low and high temperatures. Extremely low temperature showed a hysteresis and durability on circulatory mortality, with the largest RR of 1.023 (95%CI: 1.001-1.046) at lag 26, and RR of the cumulative cold effect of 0-27 days was 1.302 (95%CI: 1.160-1.462). The effect of extremely high temperatures presented more acute and intense, with the largest RR of 1.033 (95%CI: 1.004-1.063) at lag 0. RR of the cumulative hot effect of 0-3 days was 1.056 (1.008-1.106). In addition, females were more susceptible to extremely low temperatures, while males were more vulnerable to extremely high temperatures. This study demonstrated that extremely low temperatures have a stronger effect on circulatory mortality than extremely high temperatures in Harbin.

A novel mathematical model for estimating the relative risk of mortality attributable to the combined effect of ambient fine particulate matter (PM2.5) and cold ambient temperature

Exposures to ambient fine particulate matter (PM_2.5) and cold ambient temperatures have been identified as important risk factors in contributing towards the global mortality from chronic obstructive pulmonary disease (COPD). Despite China currently being the country with the largest population in the world, previous relative risk (RR) models have considered little or no information from the ambient air pollution related cohort studies in the country. This likely provides a less accurate picture of the trend in air pollution attributable mortality in the country over time. A novel relative risk model called pollutant-temperature exposure (PTE) model is proposed to estimate the RR attributable to the combined effect of air pollution and ambient temperature in a population. In this paper, the pollutant concentration-response curve was extrapolated from the cohort studies in China, whereas the temperature response curve was extracted from a study in Yangtze River Delta (YRD) region. The performance of the PTE model was compared with the integrated exposure-response (IER) model using the data of YRD region, which revealed that the estimated relative risks of the PTE model were noticeably higher than the IER model during the winter season. Furthermore, the predictive ability of the PTE model was validated using actual data of Ningbo city, which showed that the estimated RR using the PTE model with 1-month moving average data showed a good result with the trend of actual COPD mortality, indicated by a lower root mean square error (RMSE = 0.956). By considering the combined effect of ambient air pollutant and ambient temperature, the PTE model is expected to provide more accurate relative risk estimates for the regions with high levels of ambient PM_2.5 and seasonal variation of ambient temperature.

Cardiovascular mortality risks during the 2017 exceptional heatwaves in China

Climate change has made disastrous heatwaves more frequent. Heatwave-related health impacts are much more devastating for more intense heatwaves. In the summer of 2017, exceptional heatwaves occurred in many regions, including China. This study aims to evaluate the cardiovascular mortality risk associated with the 2017 exceptional heatwaves and compare the mortality risk of the severe heatwaves with those in other years. Using daily data for a spectrum of cardiovascular mortality and temperature for 102 Chinese counties (2014-2017), we estimated the association between heatwave and mortality by generalized linear mixed-effects models. Compared with matched non-heatwave days, mortality risks on heatwaves days in 2017 increased 27.8% (95% CI, 14.8-42.3%), 26.7% (8.0-48.5%), 30.1% (10.2-53.7%), 27.3% (1.4-59.9%), 32.2% (3.4-68.4%), and 25.2% (1.0-57.7%) for total circulatory diseases, cerebrovascular disease, ischemic heart disease (IHD), acute IHD, chronic IHD, and myocardial infarction. The 2017 exceptional heatwaves impacted ischemic heart disease mortality and myocardial infarction mortality more than heatwaves in 2014-2016. Here we show that the severe heatwaves in 2017 posed catastrophic death threats for those under-studied cardiovascular diseases.

Effects of ambient temperature on mortality among elderly residents of Chengdu city in Southwest China, 2016-2020: a distributed-lag non-linear time series analysis

BACKGROUND

With complex changes in the global climate, it is critical to understand how ambient temperature affects health, especially in China. We aimed to assess the effects of temperature on daily mortality, including total non-accidental, cardiovascular disease (CVD), respiratory disease, cerebrovascular disease, and ischemic heart disease (IHD) mortality between 2016 and 2020 in Chengdu, China.

METHODS

We obtained daily temperature and mortality data for the period 2016-2020. A Poisson regression model combined with a distributed-lag nonlinear model was used to examine the association between temperature and daily mortality. We investigated the effects of individual characteristics by sex, age, education level, and marital status.

RESULTS

We found significant non-linear effects of temperature on total non-accidental, CVD, respiratory, cerebrovascular, and IHD mortality. Heat effects were immediate and lasted for 0-3 days, whereas cold effects persisted for 7-10 days. The relative risks associated with extreme high temperatures (99th percentile of temperature, 28 °C) over lags of 0-3 days were 1.22 (95% confidence interval [CI]: 1.17, 1.28) for total non-accidental mortality, 1.40 (95% CI: 1.30, 1.50) for CVD morality, 1.34 (95% CI: 1.24, 1.46) for respiratory morality, 1.33 (95% CI: 1.20, 1.47) for cerebrovascular mortality, and 1.38 (95% CI: 1.20, 1.58) for IHD mortality. The relative risks associated with extreme cold temperature (1st percentile of temperature, 3.0 °C) over lags of 0-14 days were 1.32 (95% CI: 1.19, 1.46) for total mortality, 1.45 (95% CI: 1.24, 1.68) for CVD morality, 1.28 (95% CI: 1.09, 1.50) for respiratory morality, 1.36 (95% CI: 1.09, 1.70) for cerebrovascular mortality, and 1.26 (95% CI: 0.95, 1.68) for IHD morality. We found that hot and cold affects were greater in those over 85 years of age, and that women, individuals with low education levels, and those who were widowed, divorced, or never married, were more vulnerable.

CONCLUSIONS

This study showed that exposure to hot and cold temperatures in Chengdu was associated with increased mortality, with people over 85 years old, women, those with low education levels, and unmarried individuals being more affected by hot and cold temperatures.

Association between ambient temperature and cardiovascular diseases related hospital admissions in Lanzhou, China

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality worldwide, ranking first in the global disease burden. Evidence on association between temperature and cardiovascular disease is insufficient and inconsistent in developing countries. In this study, a distributed lag nonlinear model (DLNM) was used to determine the association between daily mean temperature and cardiovascular diseases (CVD) related admission in Lanzhou 2015-2019. We included 41,389 patients with CVD in this study. The relative risk (RR) of CVD admission increased significantly with temperature in lag 5-10 days, and we found harvesting effect of temperature in the study, shown as decreased RR in lag 15-30 days. The maximum RR was 1.15 (95% confidence interval [CI]: 1.03-1.30), corresponding to 24 °C. Both cold and heat effects of temperature could impact the CVD admission. Compared with the 25th percentile of temperature (2 °C), the cumulative relative risk (cumRR) of extreme cold (-5 °C, the 2.5th percentile of the temperature) was 0.69 (95% CI: 0.51-0.94) in lag 0-14, whereas the cumRR of moderate cold (-2 °C, the 10th percentile) was 0.83 (95% CI:0.71-0.97). Compared with the 75th percentile of temperature (20-°C), the cumRR of extreme heat (27 °C, the 97.5th percentile) was 0.93 (95% CI: 0.78-1.10) in lag 0, whereas the cumRR of moderate heat (24 °C, the 90th percentile) was 1.01 (95% CI: 0.94-1.08). In the stratified analysis, cold decreased RR significantly in female and ≥65 years, whereas heat increased it more obviously in male and ≥65 years. Ambient temperature and CVD admissions were positively associated, with the harvesting effect. Our findings demonstrate the adaption of residents in Lanzhou to cold temperature. Public and environmental policies and measures aimed at moderate heat may minimize CVD burden effectively.

Heat-induced health impacts and the drivers: implications on accurate heat-health plans and guidelines

Urban heat challenges are increasingly severe, along with climate change and urbanisation. Despite significant environmental, economic, and social consequences, limited actions have been conducted to address urban heat challenges. To support the formulation of heat-health plans and guidelines at the city and community scale, this study presented results, through a questionnaire survey among 584 respondents in Shanghai, China, on heat-induced physiological and psychological impacts and analysed the variability of them with demographic characteristics. The results indicate that psychological impacts were more severe than physiological impacts in severity and susceptible people. Skin heat damage and digestive system diseases were ignored in previous studies, compared with fatal cardiovascular and respiratory diseases. Emotional irritability and difficulty in controlling temper were the two most prominent psychological symptoms. The elderly and health-vulnerable groups were more susceptible to heat-induced physiological and psychological impacts than other groups. Among different demographic groups, the most critical physiological and psychological symptoms could vary significantly. Afterwards, suggestions for heat-health plans or guidelines have been proposed. Overall, this study provides a reference for the understanding of heat-induced impacts and enhancing the capacity to cope with urban heat challenges.

Global Population Exposure to Extreme Temperatures and Disease Burden

The frequency and duration of extreme temperature events continues to increase worldwide. However, the scale of population exposure and its quantitative relationship with health risks remains unknown on a global scale, limiting our ability to identify policy priorities in response to climate change. Based on data from 171 countries between 2010 and 2019, this study estimated the exposure of vulnerable populations to extreme temperatures, and their contemporary and lag associations with disease burden attributed to non-optimal temperatures. Fixed-effects models and dynamic panel models were applied. Increased vulnerable population exposure to extreme temperatures had adverse contemporary effects on the burden of disease attributed to non-optimal temperature. Health risks stemming from extreme cold could accumulate to a greater extent, exhibiting a larger lag effect. Population exposure to extreme cold was mainly distributed in high-income countries, while extreme heat occurred more in low-income and middle-income countries. However, the association between population exposure to extreme cold and burden of disease was much stronger in low-income and middle-income countries than in high-income countries, whereas the effect size of population exposure to extreme heat was similar. Our study highlighted that differential strategies should be determined and implemented according to the characteristics in different countries.

Acute effects of black carbon on mortality in nine megacities of China, 2008-2016: a time-stratified case-crossover study

Black carbon (BC) may have more adverse effects on human health than other constituents of PM_2.5. The daily mean concentrations of BC in China are much higher than those in developed countries and are estimated to account for more than a quarter of global anthropogenic BC emissions. However, reports on the health effects of BC in China have been limited. Thus, a time-stratified case-crossover study was conducted to evaluate the impacts of BC on daily mortality risk in nine Chinese megacities from 2008-2016. Our results show that for all-cause mortality, when compared to the interquartile range (IQR) of BC concentration increased, odds ratios (ORs) were in the range of 1.01-1.06 (95% CIs: 0.99-1.10). For cardiovascular mortality, ORs were in the range of 1.02-1.07 (95% CIs: 1.003-1.12), and for respiratory mortality, ORs were in the range of 1.01-1.15 (95% CIs: 1.00-1.18). The effects of BC in the nine cities were robust after adjusting for PM_2.5, or even became more prominent. Furthermore, BC had stronger effects in spring and winter in northern cities, whereas in mid-latitude cities, BC had stronger effects in the warm seasons. In southern cities, BC had stronger effects in the cool and dry seasons. Our findings support an association between residential exposure to BC and mortality and thus provide further evidence that BC negatively impacts human health and is helpful for decision-making.

Impact of ozone exposure on heart rate variability and stress hormones: A randomized-crossover study

The biological mechanisms underlying the associations between atmospheric ozone exposure and adverse cardiometabolic outcomes are yet to be identified. Imbalanced autonomic nervous system (ANS) as well as activations of the sympatho-adrenomedullary (SAM) and hypothalamic-pituitary-adrenal (HPA) axes are among possible early biological responses triggered by ozone, and may eventually lead to cardiometabolic abnormalities. To determine whether acute ozone exposure causes ANS imbalance and increases the secretion of neuroendocrine stress hormones, we conducted a randomized, double-blind, crossover trial, under controlled 2-hour exposure to either ozone (200 ppb) or clean air with intermittent exercise among 22 healthy young adults. Here we found that, compared to clean air exposure, acute ozone exposure significantly decreased the high-frequency band of heart rate variability, even after adjusting for heart rate and pre-exposure to ambient air pollutants and meteorological factors. Ozone exposure also significantly increased the serum levels of stress hormones, including corticotrophin-releasing factor, adrenocorticotropic hormone, adrenaline, and noradrenaline. Metabolomics analysis showed that acute ozone exposure led to alterations in stress hormones, systemic inflammation, oxidative stress, and energy metabolism. Our results suggest that acute ozone exposure may trigger ANS imbalance and activate the HPA and SAM axes, offering potential biological explanations for the adverse cardiometabolic effects following acute ozone exposure.

Sensors for Context-Aware Smart Healthcare: A Security Perspective

The advances in the miniaturisation of electronic devices and the deployment of cheaper and faster data networks have propelled environments augmented with contextual and real-time information, such as smart homes and smart cities. These context-aware environments have opened the door to numerous opportunities for providing added-value, accurate and personalised services to citizens. In particular, smart healthcare, regarded as the natural evolution of electronic health and mobile health, contributes to enhance medical services and people's welfare, while shortening waiting times and decreasing healthcare expenditure. However, the large number, variety and complexity of devices and systems involved in smart health systems involve a number of challenging considerations to be considered, particularly from security and privacy perspectives. To this aim, this article provides a thorough technical review on the deployment of secure smart health services, ranging from the very collection of sensors data (either related to the medical conditions of individuals or to their immediate context), the transmission of these data through wireless communication networks, to the final storage and analysis of such information in the appropriate health information systems. As a result, we provide practitioners with a comprehensive overview of the existing vulnerabilities and solutions in the technical side of smart healthcare.

Short-term exposure to extreme temperature and risk of hospital admission due to cardiovascular diseases

Objective: Numerous epidemiological studies have reported relevance of morbidity and mortality from cardiovascular diseases with short-term exposure to environmental temperature. In this study, we examined the hypothesis between temperature indices and hospital admission because of cardiovascular diseases. Methods: The daily number of CVDs was obtained from all hospitals of the Sabzevar city. A semi-parametric generalized additive model (GAM) following a quasi-Poisson distribution with distributed lag non-linear model (dlnm) was selected as a modeling framework for time-series analysis. Results: The overall CVD risk comparing the 1st percentile and the 99th percentile relative to the mean temperature (at lag 0) was 1.33 (95% CI, 1.11: 1.61), and 1.34 (95% CI, 1.10: 1.64), respectively. For all indicators, the extremely cold effects persisted for the initial 7 days. Conclusions: Our results suggest that extremely cold and extremely hot temperatures increase the relative risk of cardiovascular diseases.

Air Conditioning and Heat-related Mortality: A Multi-country Longitudinal Study

BACKGROUND

Air conditioning has been proposed as one of the key factors explaining reductions of heat-related mortality risks observed in the last decades. However, direct evidence is still limited.

METHODS

We used a multi-country, multi-city, longitudinal design to quantify the independent role of air conditioning in reported attenuation in risk. We collected daily time series of mortality, mean temperature, and yearly air conditioning prevalence for 311 locations in Canada, Japan, Spain, and the USA between 1972 and 2009. For each city and sub-period, we fitted a quasi-Poisson regression combined with distributed lag non-linear models to estimate summer-only temperature-mortality associations. At the second stage, we used a novel multilevel, multivariate spatio-temporal meta-regression model to evaluate effect modification of air conditioning on heat-mortality associations. We computed relative risks and fractions of heat-attributable excess deaths under observed and fixed air conditioning prevalences.

RESULTS

Results show an independent association between increased air conditioning prevalence and lower heat-related mortality risk. Excess deaths due to heat decreased during the study periods from 1.40% to 0.80% in Canada, 3.57% to 1.10% in Japan, 3.54% to 2.78% in Spain, and 1.70% to 0.53% in the USA. However, increased air conditioning explains only part of the observed attenuation, corresponding to 16.7% in Canada, 20.0% in Japan, 14.3% in Spain, and 16.7% in the USA.

CONCLUSIONS

Our findings are consistent with the hypothesis that air conditioning represents an effective heat adaptation strategy, but suggests that other factors have played an equal or more important role in increasing the resilience of populations.

Ambient Temperature and Years of Life Lost: A National Study in China

Although numerous studies have investigated premature deaths attributable to temperature, effects of temperature on years of life lost (YLL) remain unclear. We estimated the relationship between temperatures and YLL, and quantified the YLL per death caused by temperature in China. We collected daily meteorological and mortality data, and calculated the daily YLL values for 364 locations (2013–2017 in Yunnan, Guangdong, Hunan, Zhejiang, and Jilin provinces, and 2006–2011 in other locations) in China. A time-series design with a distributed lag nonlinear model was first employed to estimate the location-specific associations between temperature and YLL rates (YLL/100,000 population), and a multivariate meta-analysis model was used to pool location-specific associations. Then, YLL per death caused by temperatures was calculated. The temperature and YLL rates consistently showed U-shaped associations. A mean of 1.02 (95% confidence interval: 0.67, 1.37) YLL per death was attributable to temperature. Cold temperature caused 0.98 YLL per death with most from moderate cold (0.84). The mean YLL per death was higher in those with cardiovascular diseases (1.14), males (1.15), younger age categories (1.31 in people aged 65–74 years), and in central China (1.34) than in those with respiratory diseases (0.47), females (0.87), older people (0.85 in people ≥75 years old), and northern China (0.64) or southern China (1.19). The mortality burden was modified by annual temperature and temperature variability, relative humidity, latitude, longitude, altitude, education attainment, and central heating use. Temperatures caused substantial YLL per death in China, which was modified by demographic and regional characteristics.

•

Years of life lost (YLL) is used to estimate the effects of temperature

•

Both low and high temperatures can increase the YLLs

•

Average 1.02 YLL per death is attributed to temperature exposure

•

Temperature causes larger YLLs per death in males, younger people, and central China

Extreme temperatures and cardiovascular mortality: assessing effect modification by subgroups in Ganzhou, China

Background

Many people die from cardiovascular diseases each year, and extreme temperatures are regarded as a risk factor for cardiovascular deaths. However, the relationship between temperature and cardiovascular deaths varies in different regions because of population density, demographic inequality, and economic situation, and the evidence in Ganzhou, China is limited and inconclusive.

Objective

This study aimed to assess extreme temperature-related cardiovascular mortality and identify the potential vulnerable people.

Methods

After controlling other meteorological measures, air pollution, seasonality, relative humidity, day of the week, and public holidays, we examined temperature-related cardiovascular mortality along 21 lag days by Poisson in Ganzhou, China.

Results

A J-shaped relationship was observed between mean temperature and cardiovascular mortality. Extremely low temperatures substantially increased the relative risks (RR) of cardiovascular mortality. The effect of cold temperature was delayed by 2–6 days and persisted for 4–10 days. However, the risk of cardiovascular mortality related to extremely high temperatures was not significant (p > 0.05). Subgroup analysis indicated that extremely low temperatures had a stronger association with cardiovascular mortality in people with cerebrovascular diseases (RR: 1.282, 95% confidence interval [CI]: 1.020–1.611), males (RR: 1.492, 95% CI: 1.175–1.896), married people (RR: 1.590, 95% CI: 1.224–2.064), and people above the age of 65 years (RR: 1.641, 95% CI: 1.106–2.434) than in people with ischemic heart disease, females, unmarried people, and the elderly (≥65 years old), respectively.

Conclusions

The type of cardiovascular disease, sex, age, and marital status modified the effects of extremely low temperatures on the risk of cardiovascular mortality. These findings may help local governments to establish warning systems and precautionary measures to reduce temperature-related cardiovascular mortality.

Modelling climate change impacts on attributable-related deaths and demographic changes in the largest metropolitan area in Portugal: A time-series analysis

Previous studies have consistently analyzed the impact that extreme temperatures will have on human health. However, there are very few data on temperature-related mortality burden considering future demographic changes in a context of climate change in Portugal. This study aims to quantify the impact of climate change on heat-, cold-, and net change mortality burdens, taking into account the future demographic changes in Lisbon Metropolitan Area, Portugal. We applied a time-series generalized linear model with a quasi-Poisson model via a distributed lag nonlinear model to project temperature-related mortality burden for two climatological scenarios: a present (or reference, 1986-2005) scenario and a future scenario (2046-2065), in this case the Representative Concentration Pathway RCP8.5, which reflects the worst set of expectations (with the most onerous impacts). The results show that the total attributable fraction due to temperature, extreme and moderate cold, is statistically significant in the historical period and the future projected scenarios, while extreme and moderate heat were only significant in the projected future summer period. Net differences were attributed to moderate cold in the future winter months. Projections show a consistent and significant increase in future heat-related mortality burden. The attributable fraction due to heat in the future period, compared to the historical period, ranges from 0 to 1.5% for moderate heat and from 0 to 0.5% for extreme heat. Adaptation should be implemented at the local level, so as to prevent and diminish the effects on citizens and healthcare services, in a context of climate change.

Comparison of life loss per death attributable to ambient temperature among various development regions: a nationwide study in 364 locations in China

BACKGROUND

Several studies have investigated the associations between ambient temperature and years of life lost (YLLs), but few focused on the difference of life loss attributable to temperature among different socioeconomic development levels.

OBJECTIVES

We investigated the disparity in temperature-YLL rate relationships and life loss per death attributable to nonoptimal temperature in regions with various development levels.

METHODS

Three hundred sixty-four Chinese counties or districts were classified into 92 high-development regions (HDRs) and 272 low-development regions (LDRs) according to socioeconomic factors of each location using K-means clustering approach. We used distributed lag non-linear models (DLNM) and multivariate meta-analysis to estimate the temperature-YLL rate relationships. We calculated attributable fraction (AF) of YLL and temperature-related average life loss per death to compare mortality burden of temperature between HDRs and LDRs. Stratified analyses were conducted by region, age, sex and cause of death.

RESULTS

We found that non-optimal temperatures increased YLL rates in both HDRs and LDRs, but all subgroups in LDRs were more vulnerable. The disparity of cold effects between HDRs and LDRs was significant, while the difference in heat effect was insignificant. The overall AF of non-optimal temperature in LDRs [AF = 12.2, 95% empirical confidence interval (eCI):11.0-13.5%] was higher than that in HDRs (AF = 8.9, 95% eCI: 8.3-9.5%). Subgroups analyses found that most groups in LDRs had greater AFs than that in HDRs. The average life loss per death due to non-optimal temperature in LDRs (1.91 years, 95% eCI: 1.72-2.10) was also higher than that in HDRs (1.32 years, 95% eCI: 1.23-1.41). Most of AFs and life loss per death were caused by moderate cold in both HDRs and LDRs.

CONCLUSIONS

Mortality burden caused by temperature was more significant in LDRs than that in HDRs, which means that more attention should be paid to vulnerable populations in LDRs in planning adaptive strategies.

Temporal variations in the triggering of myocardial infarction by air temperature in Augsburg, Germany, 1987-2014

AIMS

The association between air temperature and mortality has been shown to vary over time, but evidence of temporal changes in the risk of myocardial infarction (MI) is lacking. We aimed to estimate the temporal variations in the association between short-term exposures to air temperature and MI in the area of Augsburg, Germany.

METHODS AND RESULTS

Over a 28-years period from 1987 to 2014, a total of 27 310 cases of MI and coronary deaths were recorded. Daily meteorological parameters were measured in the study area. A time-stratified case-crossover analysis with a distributed lag non-linear model was used to estimate the risk of MI associated with air temperature. Subgroup analyses were performed to identify subpopulations with changing susceptibility to air temperature. Results showed a non-significant decline in cold-related MI risks. Heat-related MI relative risk significantly increased from 0.93 [95% confidence interval (CI): 0.78-1.12] in 1987-2000 to 1.14 (95% CI: 1.00-1.29) in 2001-14. The same trend was also observed for recurrent and non-ST-segment elevation MI events. This increasing population susceptibility to heat was more evident in patients with diabetes mellitus and hyperlipidaemia. Future studies using multicentre MI registries at different climatic, demographic, and socioeconomic settings are warranted to confirm our findings.

CONCLUSION

We found evidence of rising population susceptibility to heat-related MI risk from 1987 to 2014, suggesting that exposure to heat should be considered as an environmental trigger of MI, especially under a warming climate.

Temperature and cardiovascular mortality in Rio de Janeiro, Brazil: effect modification by individual-level and neighbourhood-level factors

BACKGROUND

Many factors related to susceptibility or vulnerability to temperature effects on mortality have been proposed in the literature. However, there is limited evidence of effect modification by some individual-level factors such as occupation, colour/race, education level and community-level factors. We investigated the effect modification of the temperature-cardiovascular mortality relationship by individual-level and neighbourhood-level factors in the city of Rio de Janeiro, Brazil.

METHODS

We used a case-crossover study to estimate the total effect of temperature on cardiovascular mortality in Rio de Janeiro between 2001 and 2018, and the effect modification by individual-level and neighbourhood-level factors. Individual-level factors included sex, age, colour/race, education, and place of death. Neighbourhood-level characteristics included social development index (SDI), income, electricity consumption and demographic change. We used conditional Poisson regression models combined with distributed lag non-linear models, adjusted for humidity and public holidays.

RESULTS

Our results suggest a higher vulnerability to high temperatures among the elderly, women, non-hospitalised deaths, and people with a lower education level. Vulnerability to low temperatures was higher among the elderly, men, non-white people, and for primary education level. As for neighbourhood-level factors, we identified greater vulnerability to low and high temperatures in places with lower SDI, lower income, lower consumption of electricity, and higher demographic growth.

CONCLUSION

The effects of temperature on cardiovascular disease mortality in Rio de Janeiro vary according to individual-level and neighbourhood-level factors. These findings are valuable to inform policymakers about the most vulnerable groups and places, in order to develop more effective and equitable public policies.

Spatio-Temporal Mechanism Underlying the Effect of Urban Heat Island on Cardiovascular Diseases

Background:

We explored the spatio-temporal characteristics of urban heat island (UHI) effect on cardiovascular diseases (CVDs).

Methods:

The land surface temperatures (LST) were retrieved from four Landsat remote-sensing images’ data, the temperature data from 95 meteorological stations, and analysis data on CVDs mortality. Based on these data, landscape pattern indexes were used to analyze the pattern-process-function and the mechanism.

Results:

During 1984–2017, the effects of UHI on CVDs increased, thereby increased the mortality by 28.8%. The affected areas gradually expand from the central area of the city and undergo three evolution stages; the highly affected areas are mainly distributed in central and southern regions, and patches increase in number. The areas and ratio of high-level patches also show an upward tendency, increasing dominance in the overall landscape. Patches of the overall landscape become more complicated in shape, whereas those of high-level ones become less complicated. Concentration degree of the overall landscape decreases gradually with the types of landscapes patches increasing, reaching a rather even space distribution.

Conclusion:

Increased temperatures exacerbated by UHI lead to increased CVD mortality. As cities expand, the effects of UHI on CVDs increase in terms of both intensity and areas, with the overall landscape in uneven distribution, high-level affected areas in point distribution, and low-level ones in large-area concentration.

Association between ambient temperature and daily emergency hospitalizations for acute coronary syndrome in Yancheng, China

Acute coronary syndrome (ACS) is a major public health concern worldwide. Few studies have directly evaluated the associations between ambient temperature and ACS incidence. To explore the association between ambient temperature and ACS emergency hospitalizations in the area of subtropical monsoon climate, data on ACS emergency hospitalizations were collected from two highest-ranking hospitals in the central urban area of Yancheng, China, from January 1, 2013, to December 31, 2018. We applied the time-series method to investigate the potentially lagged and non-linear effects of ambient temperature on ACS using the generalized linear model combined with the distributed lag non-linear model after adjusting for time trend, day of the week, holiday, and relative humidity. We identified a total of 5303 cases of ACS emergency hospitalizations during the study period. The exposure-response curves between ambient temperature and ACS hospitalizations were inverse "J-shaped." The effects of extreme low temperature on ACS hospitalizations occurred on the present day and lasted for 3 days, followed by the harvesting effect. The effects of extreme high temperature occurred on the present day and lasted for 5 days. The cumulative relative risks of ACS were 2.14 [95% confident interval (CI): 1.32 to 3.47] for extremely low temperature and 1.66 (95% CI: 1.33 to 2.06) for extremely high temperature over the lag of 0-5 days, compared with the reference temperature (25.0 °C). Both low and high temperatures were significantly associated with higher risks of emergency hospital admissions for ACS in Yancheng, China.

The effect of ambient temperature on cardiovascular mortality in 27 Brazilian cities

BACKGROUND

There is limited evidence on the relationship between temperature and cardiovascular mortality in middle and low-income countries, particularly in Latin America. In this study, we investigated the total effect of temperature on cardiovascular mortality in 27 Brazilian cities, and the effect modification by geographic, socioeconomic, demographic and infrastructure characteristics within cities.

METHODS

In the city-specific analysis, we used time-series analyses to estimate the relationship between mean temperature and daily cardiovascular mortality using quasi-Poisson generalized linear models combined with distributed lag non-linear models. In the second stage, a meta-analysis was used to pool the effects of temperature on cardiovascular mortality for Brazil and its five regions (Central-West, North, Northeast, South, and Southeast). We used a meta-regression to examine the effect modification of city-specific geographic, socioeconomic, demographic and infrastructure-related variables.

RESULTS

The risks associated with temperature varied across the locations. Higher cardiovascular mortality was associated with low and high temperatures in most of the cities, Brazil and the Central-West, North, South, and Southeast regions. The overall relative risk (RR) for Brazil was 1.26 (95% confidence interval [CI]: 1.17-1.35) for the 1st percentile of temperature and 1.07 (95% CI: 1.01-1.13) for the 99th percentile of temperature versus the 79th percentile (27.7 °C), where RR was lowest. The temperature range was the variable that best explained the variation in effects among the cities, with greater effects in locations having a broader range.

CONCLUSIONS

The results indicate effects of low and high temperatures on the risk of cardiovascular mortality in most of Brazil's capital cities, besides a pooled effect for Brazil and the Central-West, North, South, and Southeast regions. These findings can help inform public policies addressing the health impact of temperature extremes, especially in the context of climate change.

A systematic review and meta-analysis of the association between daily mean temperature and mortality in China

PURPOSE

We summarized the evidence on the effects of heat and cold exposures on mortality in China. We included studies published on this topic in both Chinese and English, thereby filling a gap in knowledge using data from a country that consists of one-fifth of the world's population.

METHODS

We conducted a systematic search of peer-reviewed studies on the association between daily mean temperature and mortality published from 2001 up to July 2018. We searched one Chinese database (China National Knowledge infrastructure, http://www.cnki.net) and three English databases (PubMed, Scopus, Web of Science). We converted the effect estimates of heat/cold to rate ratios (RRs) associated with 1° increase/decrease beyond the heat/cold reference temperatures. For studies that provided lag-specific estimates, we used both the maximum and minimum of RR estimates. We calculated summary effect estimates for all-cause and cause-specific mortalities, as well as RRs stratified by sex, age, and socioeconomic status. We also investigated patterns of heat and cold adaptation at different latitudes, and at different reference temperatures.

RESULTS

In total, 45 articles were included in this systematic review. For every 1° temperature increase/decrease beyond reference points, the rate of non-accidental mortality increased by 2% (RR, 1.02; 95% confidence interval (95% CI [1.01-1.02]) for heat and 4% (RR, 1.04; 95% CI [1.03-1.04]) for cold, respectively; the rate of cardiovascular mortality increased 3% (RR, 1.03; 95% CI [1.03-1.04]) for heat and 6% (RR, 1.06; 95% CI [1.04-1.07]) for cold; the rate of respiratory mortality increased 2% (RR, 1.02; 95% CI [1.01-1.03]) for heat and 2% (RR, 1.02; 95% CI [1.00-1.04]) for cold; the rate of cerebrovascular mortality increased 2% (RR, 1.02; 95% CI [1.02-1.03]) for heat and 3% (RR, 1.03; 95% CI [1.02-1.04]) for cold. We identified a variation in optimal temperature range related to latitude of the residential area, and differences in people's capability to adapt to heat versus cold.

CONCLUSION

We found consistent evidence of the association between temperature and mortality, as well as evidence of patterns in human adaptation, and we discussed the implications of our findings.

Long-term exposure to ambient fine particulate matter and incidence of diabetes in China: A cohort study

BACKGROUND

Diabetes caused substantial economic and health burden worldwide. However, the associations between air pollution and diabetes incidence were rarely reported in the developing countries, especially in China with relatively high PM_2.5 concentrations.

OBJECTIVES

A cohort-based study was conducted to assess the diabetes incidence associated with long-term exposure to ambient PM_2.5.

METHODS

We collected individual health data and risk factors from the project of Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR Project) from 15 provinces over China. Diabetes was defined as fasting glucose levels ≥7.0 mmol/L at the follow-ups and/or the use of insulin or oral hypoglycemic agents and/or diagnosed medical history of diabetes during 2004 to 2015. Individual-level PM_2.5 exposures were estimated from satellite-based PM_2.5 concentrations (10 km spatial resolution) during the study period. Cox proportional hazards models with random intercepts of each cohort and region were employed to estimate the diabetes incidence attributable to PM_2.5, after the adjustment for age, gender, body mass index, smoking status, education, work-related physical activity level, hypertension, urbanicity, county-level averaged years of education, and long-term levels of temperature and relative humidity.

RESULTS

A total of 88,397 subjects were analyzed with 580,928 person-years of follow-up after 2004, among which 6439 new cases of diabetes were observed. The mean age of the subjects was 51.7 years at baseline. For an increase of 10 μg/m³ in long-term PM_2.5 exposure, the multivariable-adjusted percent increase in the diabetes incidence was estimated to be 15.66% (95% confidence interval: 6.42%, 25.70%). The adverse effects of PM_2.5 were larger among females, rural subjects, non-smokers, normotensives, subjects younger than 65 years and subjects with body mass index <25 kg/m².

CONCLUSIONS

Our findings provided evidence for the association of long-term exposure to PM_2.5 with diabetes incidence in China. A sustained improvement of air quality will benefit the reduction for diabetes epidemic in China.

Impact of heat on mortality and morbidity in low and middle income countries: A review of the epidemiological evidence and considerations for future research

Heat waves and high air temperature are associated with increased morbidity and mortality. However, the majority of research conducted on this topic is focused on high income areas of the world. Although heat waves have the most severe impacts on vulnerable populations, relatively few studies have studied their impacts in low and middle income countries (LMICs). The aim of this paper is to review the existing evidence in the literature on the impact of heat on human health in LMICs. We identified peer-reviewed epidemiologic studies published in English between January 1980 and August 2018 investigating potential associations between high ambient temperature or heat waves and mortality or morbidity. We selected studies according to the following criteria: quantitative studies that used primary and/or secondary data and report effect estimates where ambient temperature or heat waves are the main exposure of interest in relation to human morbidity or mortality within LMICs. Of the total 146 studies selected, eighty-two were conducted in China, nine in other countries of East Asia and the Pacific, twelve in South Asia, ten in Sub-Saharan Africa, eight in the Middle East and North Africa, and seven in each of Latin America and Europe. The majority of studies (92.9%) found positive associations between heat and human morbidity/mortality. Additionally, while outcome variables and study design differed greatly, most utilized a time-series study design and examined overall heath related morbidity/mortality impacts in an entire population, although it is notable that the selected studies generally found that the elderly, women, and individuals within the low socioeconomic brackets were the most vulnerable to the effects of high temperature. By highlighting the existing evidence on the impact of extreme heat on health in LMICs, we hope to determine data needs and help direct future studies in addressing this knowledge gap. The focus on LMICs is justified by the lack of studies and data studying the health burden of higher temperatures in these regions even though LMICs have a lower capacity to adapt to high temperatures and thus an increased risk.

A new method to estimate the temperature-CVD mortality relationship

Few detailed, individual-focused studies have researched the added effect of temperature on cardiovascular disease (CVD), particularly in China. Moreover, no prior studies have explored the exposure-response relationship among all populations and different sub-sociodemographic groups. A distributed lag nonlinear model (DLNM) was applied to evaluate the adverse health effects of temperature on CVD mortality for all populations and different sub-sociodemographic groups (by age, sex, educational level, living arrangement, and occupation) in Beijing. Based on the exposure-response relationships, firstly, we proposed a new model (COCKTAIL, Code Of Climate Key To An Ill) for revealing the split-and-merge relationships of the temperature-CVD mortality curve. This method could be used to apply the CVD deaths in a studied area to forecast the exposure-response relationships in the same area in the future. Secondly, this is the most detailed study to analyze the relationship between temperature and CVD mortality for different subgroups among the existing researches for developed and developing countries. We found that the cold temperature (at - 14 °C) was the risk factor for people with low socioeconomic status, especially for single people (including unmarried, divorced, and widowed), for indoor workers, and for people with low education, compared with the minimum mortality temperature, with a cumulative increase of 3.9 (80%CI, 2.9-5.4), 3.8 (80%CI, 2.8-5.1), and 4.5 (80%CI, 3.1-6.3) times respectively. Meanwhile, the hot temperature (at 35 °C) was the risk factor for CVD death, with a cumulative increase of 2.6 (80%CI, 2.0-3.4) for females, and 3.1 (80%CI, 2.4-4.2) for single people. The varying CVD vulnerability in terms of CVD mortality among various groups may assist governments in preparing health resources and taking measures to prevent or reduce temperature-related deaths.

Modification Effects of Population Expansion, Ageing, and Adaptation on Heat-Related Mortality Risks Under Different Climate Change Scenarios in Guangzhou, China

(1) Background: Although the health effects of future climate change have been examined in previous studies, few have considered additive impacts of population expansion, ageing, and adaptation. We aimed to quantify the future heat-related years of life lost (YLLs) under different Representative Concentration Pathways (RCP) scenarios and global-scale General Circulation Models (GCMs), and further to examine relative contributions of population expansion, ageing, and adaptation on these projections. (2) Methods: We used downscaled and bias-corrected projections of daily temperature from 27 GCMs under RCP2.6, 4.5, and 8.5 scenarios to quantify the potential annual heat-related YLLs in Guangzhou, China in the 2030s, 2060s, and 2090s, compared to those in the 1980s as a baseline. We also explored the modification effects of a range of population expansion, ageing, and adaptation scenarios on the heat-related YLLs. (3) Results: Global warming, particularly under the RCP8.5 scenario, would lead to a substantial increase in the heat-related YLLs in the 2030s, 2060s, and 2090s for the majority of the GCMs. For the total population, the annual heat-related YLLs under the RCP8.5 in the 2030s, 2060s, and 2090s were 2.2, 7.0, and 11.4 thousand, respectively. The heat effects would be significantly exacerbated by rapid population expansion and ageing. However, substantial heat-related YLLs could be counteracted by the increased adaptation (75% for the total population and 20% for the elderly). (4) Conclusions: The rapid population expansion and ageing coinciding with climate change may present an important health challenge in China, which, however, could be partially counteracted by the increased adaptation of individuals.

Temporal Trends in Heat-Related Mortality: Implications for Future Projections

High temperatures have large impacts on premature mortality risks across the world, and there is concern that warming temperatures associated with climate change, and in particular larger-than-expected increases in the proportion of days with extremely high temperatures, may lead to increasing mortality risks. Comparisons of heat-related mortality exposure-response functions across different cities show that the effects of heat on mortality risk vary by latitude, with more pronounced heat effects in more northerly climates. Evidence has also emerged in recent years of trends over time in heat-related mortality, suggesting that in many locations, the risk per unit increase in temperature has been declining. Here, I review the emerging literature on these trends, and draw conclusions for studies that seek to project future impacts of heat on mortality. I also make reference to the more general heat-mortality literature, including studies comparing effects across locations. I conclude that climate change projection studies will need to take into account trends over time (and possibly space) in the exposure response function for heat-related mortality. Several potential methods are discussed.

A new look at weather-related health impacts through functional regression

A major challenge of climate change adaptation is to assess the effect of changing weather on human health. In spite of an increasing literature on the weather-related health subject, many aspect of the relationship are not known, limiting the predictive power of epidemiologic models. The present paper proposes new models to improve the performances of the currently used ones. The proposed models are based on functional data analysis (FDA), a statistical framework dealing with continuous curves instead of scalar time series. The models are applied to the temperature-related cardiovascular mortality issue in Montreal. By making use of the whole information available, the proposed models improve the prediction of cardiovascular mortality according to temperature. In addition, results shed new lights on the relationship by quantifying physiological adaptation effects. These results, not found with classical model, illustrate the potential of FDA approaches.

Effects of Consecutive Moderately Cold Days on Cardiovascular Disease Mortality in Shenzhen, China: A Preliminary Study

Despite traditional risk factors such as aging and hyperlipemia for cardiovascular disease (CVD) mortality, many studies have also confirmed that both hot and cold ambient temperatures are associated with CVD mortality. This paper aims to explore the effects of consecutive moderately cold days on CVD mortality in the warm city Shenzhen during relatively cold months from 2011 to 2015. In this study, totally there were 4589 CVD death cases among the residents during a total of 24 relatively cold months. Effects of consecutive cold days on CVD mortality was evaluated by the daily percent increase of CVD mortality. Three temperature thresholds were selected, which were 15°, 14°, and 13°, respectively. The results showed that when the cold weather lasted 5 days and onwards, CVD mortality showed a continuous increment. When the temperature thresholds were 15°, 14°, or 13°, percent increase of CVD mortality at the consecutive 6th cold day reached 22%, 21%, and 24% respectively, and 26%, 38%, 33% at the consecutive 10th cold day, respectively. Thus, the consecutive moderately cold days in warm regions had continuous and accumulative negative effects on CVD mortality. The study may help local government to take timely prevention measures for moderately cold temperatures and thus to protect the wellbeing for the public.

Aggregating the response in time series regression models, applied to weather-related cardiovascular mortality

In environmental epidemiology studies, health response data (e.g. hospitalization or mortality) are often noisy because of hospital organization and other social factors. The noise in the data can hide the true signal related to the exposure. The signal can be unveiled by performing a temporal aggregation on health data and then using it as the response in regression analysis. From aggregated series, a general methodology is introduced to account for the particularities of an aggregated response in a regression setting. This methodology can be used with usually applied regression models in weather-related health studies, such as generalized additive models (GAM) and distributed lag nonlinear models (DLNM). In particular, the residuals are modelled using an autoregressive-moving average (ARMA) model to account for the temporal dependence. The proposed methodology is illustrated by modelling the influence of temperature on cardiovascular mortality in Canada. A comparison with classical DLNMs is provided and several aggregation methods are compared. Results show that there is an increase in the fit quality when the response is aggregated, and that the estimated relationship focuses more on the outcome over several days than the classical DLNM. More precisely, among various investigated aggregation schemes, it was found that an aggregation with an asymmetric Epanechnikov kernel is more suited for studying the temperature-mortality relationship.

The Effects of Apparent Temperature on Cardiovascular Mortality Using a Distributed Lag Nonlinear Model Analysis: 2005 to 2014

The relationship between apparent temperature and cardiovascular disease (CVD) mortality was studied in Rasht, Iran, from 2005 to 2014. The effects of apparent temperature on CVD mortality were investigated using the distributed lag nonlinear model. Data on all types of cardiovascular mortality cases according to the International Classification of Diseases were collected from the only cardiovascular hospital in Rasht, and the meteorological variables were obtained from Rasht Meteorological Center during the period of study. Our findings showed that low temperatures had significant impacts on CVD mortality, and a reverse J-shaped temperature-mortality relationship was found. Moreover, immediate effects of hot temperatures on CVD mortality with the strongest effects on the same day but delayed effects of cold temperature was observed. This study showed that exposure to both hot and cold apparent temperatures was associated with increased cardiovascular mortality in Rasht.

EMD-regression for modelling multi-scale relationships, and application to weather-related cardiovascular mortality

In a number of environmental studies, relationships between nat4ural processes are often assessed through regression analyses, using time series data. Such data are often multi-scale and non-stationary, leading to a poor accuracy of the resulting regression models and therefore to results with moderate reliability. To deal with this issue, the present paper introduces the EMD-regression methodology consisting in applying the empirical mode decomposition (EMD) algorithm on data series and then using the resulting components in regression models. The proposed methodology presents a number of advantages. First, it accounts of the issues of non-stationarity associated to the data series. Second, this approach acts as a scan for the relationship between a response variable and the predictors at different time scales, providing new insights about this relationship. To illustrate the proposed methodology it is applied to study the relationship between weather and cardiovascular mortality in Montreal, Canada. The results shed new knowledge concerning the studied relationship. For instance, they show that the humidity can cause excess mortality at the monthly time scale, which is a scale not visible in classical models. A comparison is also conducted with state of the art methods which are the generalized additive models and distributed lag models, both widely used in weather-related health studies. The comparison shows that EMD-regression achieves better prediction performances and provides more details than classical models concerning the relationship.

Ambient temperature and cardiovascular mortality: a systematic review and meta-analysis

INTRODUCTION

Our study aims at identifying and quantifying the relationship between the cold and heat exposure and the risk of cardiovascular mortality through a systematic review and meta-analysis.

MATERIAL AND METHODS

A systematic review and meta-analysis were conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Peer-reviewed studies about the temperature and cardiovascular mortality were retrieved in the MEDLINE, Web of Science, and Scopus databases from January 2000 up to the end of 2015. The pooled effect sizes of short-term effect were calculated for the heat exposure and cold exposure separately. Also, we assessed the dose-response relationship of temperature-cardiovascular mortality by a change in units of latitudes, longitude, lag days and annual mean temperature by meta-regression.

RESULT

After screening the titles, abstracts and full texts, a total of 26 articles were included in the meta-analysis. The risk of cardiovascular mortality increased by 5% (RR, 1.055; 95% CI [1.050-1.060]) for the cold exposure and 1.3% (RR, 1.013; 95% CI [1.011-1.015]) for the heat exposure. The short-term effects of cold and heat exposure on the risk of cardiovascular mortality in males were 3.8% (RR, 1.038; 95% CI [1.034-1.043]) and 1.1%( RR, 1.011; 95% CI [1.009-1.013]) respectively. Moreover, the effects of cold and heat exposure on risk of cardiovascular mortality in females were 4.1% (RR, 1.041; 95% CI [1.037-1.045]) and 1.4% (RR, 1.014; 95% CI [1.011-1.017]) respectively. In the elderly, it was at an 8.1% increase and a 6% increase in the heat and cold exposure, respectively. The greatest risk of cardiovascular mortality in cold temperature was in the 14 lag days (RR, 1.09; 95% CI [1.07-1.010]) and in hot temperatures in the seven lag days (RR, 1.14; 95% CI [1.09-1.17]). The significant dose-response relationship of latitude and longitude in cold exposure with cardiovascular mortality was found. The results showed that the risk of cardiovascular mortality increased with each degree increased significantly in latitude and longitude in cold exposure (0.2%, 95% CI [0.006-0.035]) and (0.07%, 95% CI [0.0003-0.014]) respectively. The risk of cardiovascular mortality increased with each degree increase in latitude in heat exposure (0.07%, 95% CI [0.0008-0.124]).

CONCLUSION

Our findings indicate that the increase and decrease in ambient temperature had a relationship with the cardiovascular mortality. To prevent the temperature- related mortality, persons with cardiovascular disease and the elderly should be targeted. The review has been registered with PROSPERO (registration number CRD42016037673).

How Does Ambient Air Temperature Affect Diabetes Mortality in Tropical Cities?

Diabetes is well-known as one of the many chronic diseases that affect different age groups. Currently, most studies that evaluated the effects of temperature on diabetes mortality focused on temperate and subtropical settings, but no study has been conducted to assess the relationship in a tropical setting. We conducted the first multi-city study carried out in tropical cities, which evaluated the temperature–diabetes relationship. We collected daily diabetes mortality (ICD E10–E14) of four Philippine cities from 2006 to 2011. Same period meteorological data were obtained from the National Oceanic and Atmospheric Administration. We used a generalized additive model coupled with a distributed lag non-linear model (DLNM) in determining the relative risks. Results showed that both low and high temperatures pose greater risks among diabetics. Likewise, the study was able to observe the: (1) high risk brought about by low temperature, aside from the largely observed high risks by high temperature; and (2) protective effects in low temperature percentile. These results provide significant policy implications with strategies related to diabetes risk groups in relation to health service and care strategies.

Ambient Temperature and Early Delivery of Singleton Pregnancies

BACKGROUND

Extreme temperature is associated with adverse birth outcomes but it is unclear whether it increases early delivery risk.

OBJECTIVES

We aimed to determine the association between ambient temperature and early delivery.

METHODS

Medical records from 223,375 singleton deliveries from 12 U.S. sites were linked to local ambient temperature. Exposure to hot (> 90th percentile) or cold (< 10th percentile) using site-specific and window-specific temperature distributions were defined for 3-months preconception, 7-week periods during the first two trimesters, 1 week preceding delivery, and whole pregnancy. Poisson regression with generalized estimating equations calculated the relative risk (RR) and 95% confidence interval for early deliveries associated with hot/cold exposures, adjusting for conception month, humidity, site, sex, maternal demographics, parity, insurance, prepregnancy body mass index, pregnancy complications, and smoking or drinking during pregnancy. Acute temperature associations were estimated separately for warm (May-September) and cold season (October-April) in a case-crossover analysis using conditional logistic regression.

RESULTS

Compared with mild temperature (10-90th percentile), exposure to hot or cold during weeks 1-7 increased risk for early preterm (< 34 weeks) [RRhot: 1.11 (95% CI: 1.01, 1.21); RRcold: 1.20 (95% CI: 1.11, 1.30)], late preterm (34-36 weeks) [RRcold: 1.09 (95% CI: 1.04, 1.15)], and early term (37-38 weeks) [RRhot: 1.04 (95% CI: 1.02, 1.07); RRcold: 1.03 (95% CI: 1.00, 1.05)] delivery. Findings were similar for hot exposures during weeks 15-21. Examining deliveries at each week from 23 through 38, whole-pregnancy hot exposures increased delivery risk by 6-21% at weeks 34 and 36-38. In the case-crossover analysis, a 5°F increase during the week preceding delivery was associated with 12-16% higher and 4-5% lower early delivery risk during warm and cold season, respectively.

CONCLUSIONS

Both acute and chronic ambient temperature extremes may affect early delivery risk. Citation: Ha S, Liu D, Zhu Y, Kim SS, Sherman S, Mendola P. 2017. Ambient temperature and early delivery of singleton pregnancies. Environ Health Perspect 125:453-459; http://dx.doi.org/10.1289/EHP97.

The effects of Sulphur dioxide on acute mortality and years of life lost are modified by temperature in Chengdu, China

The effect modification of meteorological factors on the association between ambient Sulphur dioxide (SO₂) and mortality is critical for designing intervention policy. Existing studies did not result in consistent conclusions on the effect modification, and Years of life lost (YLLs) was rarely used as a health impact indicator to examine the modifying effect. This study aims to estimate the mean air temperature and relative humidity modification effects on the impact of SO₂ on daily mortality and YLLs in Chengdu, China. Mortality, YLLs, air pollution and meteorological data were collected for 2011-2014. Three analytical approaches based on generalized additive models (GAMs) were used, including bivariate response surface model, product term model, and stratification model. We found that the effects of SO₂ on mortality and YLLs depended on temperature at various lags, but did not depend on relative humidity. SO₂ exhibited larger adverse effects on mortality in high temperature level (22.8-29.4°C) days than in low temperature level (-0.3-9.3°C) days, with a 10μg/m³ increment in SO₂, non-accidental death increased by 0.8% (0.001, 0.015)at low temperature level, but increased by 1.4% (0.005, 0.024) at high temperature level. On the contrary, SO₂ showed greater adverse effects on YLLs in low temperature days than in high temperature days, with a 10μg/m³ increment in SO₂, non-accidental YLL increased by 40.580 (31.478, 49.682) at high temperature level, but increased by -2.703 (-14.668, 9.261) at low temperature level. We concluded that the effect of SO₂ on mortality and YLLs may depend on temperature in Chengdu, China. Our results highlight the importance of considering the interaction between SO₂ and temperature on health outcomes in future research. Also, policy makers should enhance the emission control of SO₂ in extreme temperature days in Chengdu.

The association between ambient temperature and out-of-hospital cardiac arrest in Guangzhou, China

Out-of-hospital cardiac arrest (OHCA) is becoming a considerable public health burden worldwide. The seasonal variation of OHCA has been observed, but the potential effects of ambient temperature on OHCA were rarely investigated. We, therefore, aimed to evaluate the association between ambient temperature and OHCA in Guangzhou, China. We collected daily emergency ambulance dispatches for OHCA from the Guangzhou Emergency Center from January 1, 2008 to December 31, 2012. We analyzed the associations using the time-series method. We applied the generalized linear model combined with the distributed lag non-linear model to estimate the potentially non-linear and lagged effects of temperature on OHCA. Time trends, day of the week, and air pollutants were controlled as covariates. We identified a total of 4369 cases of OHCD. The associations between daily mean temperature and OHCA were generally J-shaped. Both low and high temperatures could increase the risk of OHCA. The effects were strongest on the concurrent day (lag 0) and lasted for 6 or 7days. The cumulative risks of extreme cold (1st percentile of temperature) and extreme heat (99th percentile of temperature) over lags 0-21days were 3.75 (95% confidence interval [CI]: 1.63, 8.63) and 2.45 (95%CI: 1.15, 5.33), respectively, compared with the referent temperature (28°C)·This study suggested that both cold and hot temperatures could significantly increase the risk of OHCA in Guangzhou, China. Our results might have important public health implications for the prevention of OHCA.