Climate change is expected to lead to an increase in cardiovascular deaths in China

Climate change is expected to lead to an increase in cardiovascular deaths in China

A new study was published in the journaleBioMedicineaims to predict the extent to which climate change may affect cardiovascular disease (CVD) mortality risk in China.

Climate change and cardiovascular disease

Current estimates suggest that around 19 million people die from cardiovascular disease every year, five million of whom live in China. In addition, cardiovascular disease causes over 390 million disability-adjusted life years (DALYs) worldwide.

Due to climate change, the global temperature on the earth's surface has risen by 1.15 °C compared to pre-industrial times. Previous studies have reported negative impacts of climate change on all-cause mortality, which varies by age, gender and cause of death, as well as deaths from cardiovascular disease.

Heat affects the cardiovascular system in a variety of ways, including excretion of salt and water in the form of sweat, higher cholesterol levels, and hemodynamic stress. In addition, climate change-related heat can increase the risk of atherosclerotic thrombosis of the heart and cerebral vessels and thus the rate of strokes and heart attacks.

About the study

The present study attempted to predict climate change-related CVD mortality in a Chinese setting. Current temperatures were measured at 161 Disease Monitoring Points (DSPs).

These forecasts were based on the Coupled Model Intercomparison Project Phase 6 (CMIP6), which runs as part of the World Climate Research Program (WCRP). WCRP examines natural climate change and the combined scenario with both natural and anthropogenic impacts on the climate.

A total of 22 General Climate Models (GCMs) were used to determine projected temperatures from 2010 to 2100 in both human-caused and natural scenarios. Man-made scenarios were calculated based on the difference between the combined and natural impacts.

Recognizing that economic and social change is closely linked to climate change, the Intergovernmental Panel on Climate Change (IPCC) has presented a series of integrated scenarios that combine both common socio-economic pathways (SSPs) and climate representative concentration pathways (RCPs).

Study results

The mean annual temperature at the DSPs varied between 12.6 and 28.4 °C. During this period, there were around 330,000 deaths from cardiovascular diseases.

Under natural conditions, summer temperatures in China would not change significantly. Similarly, in this scenario, the proportion of heat-related deaths from cardiovascular disease would decrease by 0.5% in the 2090s compared to mortality rates from cardiovascular disease in 2010.

Conversely, summer temperatures increased by 5-6°C depending on the region in the combined scenarios. The projected proportion of CVD mortality in the 2090s increased from 10% to 30%, depending on the modeled scenario.

The mortality rate in CVD patients followed a J-shaped curve above a critical minimum temperature. The largest increase compared to the base temperature was recorded in the south and east of China.

The proportion of heat-related deaths from cardiovascular disease associated with human-caused climate change continued to increase in each decade, from about 31% in the 2010s to an estimated 70–90% in the 2090s under various scenarios.

Those considered most vulnerable to heat-related cardiovascular mortality included people living in rural areas, people with lower levels of education, stroke patients, women, older adults and people residing in southern and eastern China. Importantly, those with lower levels of education are more likely to engage in outdoor work, have unequal access to healthcare, and suffer from chronic illnesses.

Conclusions

“This study provides evidence that human activities will increase the heat-related cardiovascular mortality burden in the future.”.”

Human-caused climate change leading to deaths from cardiovascular disease could account for up to 90% of excess mortality from excessive heat by 2090. At the same time, the burden of cardiovascular disease associated with natural climate change is unlikely to change significantly. Nevertheless, the study results underline the importance of limiting carbon emissions to ultimately prevent further global warming.

“Active adaptation and mitigation measures for future warming could provide significant health benefits for patients with cardiovascular disease.”.”

Future studies are needed to identify populations and groups at greatest risk of climate-related health impacts, as well as the different types of risks that may be associated with global climate change. These data will help implement integrated and sensitive public health policies to ultimately achieve environmental goals.

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