Abnormal ambient temperatures and CVD: What is the link?

Nonoptimal ambient temperatures affect plasma levels of 949 proteins in Chinese adults, with >80 percent of these proteins linked to increased systolic blood pressure and a higher risk of ischaemic heart disease, a study conducted jointly by researchers from the Chinese University of Hong Kong (CUHK), the University of Oxford, Fudan University and the London School of Hygiene and Tropical Medicine has shown.

Nonoptimal ambient temperatures take a toll on proteins

Prior studies primarily focused on the influence of long-term average temperatures on Western populations, often overlooking daily temperature fluctuations that can lead to acute health effects, especially in individuals from low- and middle-income countries, where access to central heating or air conditioning is often limited. [Environ Sci Technol 2025;59:4868-4882]

“To our knowledge, this is the first study to assess the acute impact of nonoptimal ambient temperatures on large-scale plasma proteome in an East Asian population,” said the researchers.

The researchers used distributed-lag nonlinear models to examine the associations of nonoptimal ambient temperatures with 2,923 plasma proteins in 3,926 adults (median age, 58 years; female, 53.8 percent) from 10 geographically diverse areas in China, ranging from Harbin to Hainan. Temperatures recorded in the study areas were categorized into two levels: cold (5^th percentile, -2.1 °C) and heat (95^th percentile, 29.5 °C), with a median temperature of 17.7 °C.

Overall, 949 proteins were consistently shown to be associated with temperature, including 387 with cold, 770 with heat, and 208 with both cold and heat.

Below the median reference temperature, most proteins exhibited nonlinear relationships with ambient temperature, showing attenuation below 5°C. In contrast, the associations tended to be linear above the median reference temperature. “The lack of air-conditioning may explain the broadly linear associations between heat and plasma proteins,” added the researchers.

Among the 949 proteins, >80 percent were associated with increased systolic blood pressure and incident ischaemic heart disease risk. These proteins are enriched by pathological pathways including inflammation, platelet activation, and endothelial dysfunction.

“These proteins may serve as important biomarkers for developing protein-specific drugs that can reduce the risk of temperature-related diseases,” pointed out Dr Yitong Guo of the Jockey Club School of Public Health and Primary Care, CUHK. “The study uncovers new insights into the health risks linked to climate change, including an increased incidence of cardiovascular disease during winter, potentially related to elevated levels of inflammatory proteins triggered by colder temperatures.”

New insights

“This innovative interdisciplinary study provides a temperature-protein map that reveals how climate and environment affect health,” said Professor Kin-Fai Ho of the Jockey Club School of Public Health and Primary Care, CUHK.

“Identifying specific proteins influenced by temperature can help us better understand how temperature affects human bodies and formulate strategies to mitigate these effects,” added Dr Peter Ka-Kung Chan of the Nuffield Department of Population Health, the University of Oxford.