Rising heatwaves—growing in frequency, duration, and intensity—are increasingly recognized as a threat to human health, especially for older adults whose thermoregulation and physiological resilience are declining. At the same time, the global population is aging rapidly, raising urgent questions about how environmental stressors shape long-term aging trajectories beyond what chronological age alone can explain. Against this backdrop, researchers examined whether recurrent heatwave exposure accelerates biological aging and which metabolic mechanisms may connect heat stress to system-wide deterioration.
Biological age acceleration, estimated as the difference between biological and chronological age, can integrate multi-system wear-and-tear reflected in biomarker patterns. Unlike acute heat illness, this work focuses on longer-term signals of aging, asking whether repeated heat exposure can push the body onto a faster aging pathway. “It remains unclear whether recurrent heatwaves accelerate systemic biological aging and what biological mechanisms may underlie this association,” said author Dengyong Xu of Zhejiang University.
Using data from the China Health and Retirement Longitudinal Study (CHARLS), the team followed 2,318 participants aged 45 and over across baseline (2011) and follow-up (2015). Biological age was calculated with the Klemera–Doubal method, integrating eight clinical biomarkers spanning inflammation, metabolic control, renal function, platelet parameters, and blood pressure. Biological age acceleration was then computed as biological age minus chronological age.
Heatwave exposure was derived from city-level meteorological records, focusing on heatwave event counts and heatwave days during the 12 months preceding each biological-age assessment. To test robustness, the researchers applied 12 heatwave definitions based on different temperature percentile thresholds and event-duration criteria. A difference-in-differences approach evaluated whether within-person changes in heatwave exposure corresponded to changes in biological age acceleration.
Across the cohort, biological age increased from an average of 57.3 years in 2011 to 62.3 years in 2015, and 58.8% of participants showed biological age acceleration during follow-up. In the difference-in-differences analyses, higher heatwave exposure consistently aligned with greater acceleration, with the relationship strengthening under stricter definitions. Under the strictest heatwave definition (HW12; at least four consecutive days above the local 97.5th percentile), each additional heatwave event corresponded to a 0.531-year increase in biological age acceleration, and each additional heatwave day to a 0.057-year increase.
Subgroup results suggested vulnerability was not uniform: stronger associations appeared among individuals with higher BMI (≥23 kg/m²), urban residents, and those living in southern China or subtropical monsoon regions. Biomarker shifts offered clues, showing heatwave exposure linked to higher total cholesterol and glycated hemoglobin, pointing toward disrupted lipid and glucose metabolism.
To probe mechanisms, the study combined human epidemiology with transcriptomic evidence. Liver tissue from aged mice exposed to heatwave-like conditions was analyzed to identify heatwave-induced differentially expressed genes, which were then integrated with aging-related genes from the AgeAnno database. Protein–protein interaction and functional enrichment analyses highlighted pathways related to lipid metabolism, atherosclerosis, and insulin resistance.
Overall, the findings indicate that recurrent heatwave exposure may accelerate biological aging by promoting metabolic dysregulation, transforming heat from an acute hazard into a potential driver of faster physiological aging. The authors caution that the study is observational and that exposure estimates rely on city-level data; nonetheless, they argue the results support targeted heat-health warning systems and urban cooling interventions aimed at high-risk groups. They also plan longer-term follow-up and more precise individual exposure monitoring to validate mechanisms with molecular aging clocks and multi-omics approaches.
Subject of Research: Heatwave exposure and biological aging; metabolic dysregulation mechanisms
Article Title: Heatwave Exposure Accelerates Biological Aging via Metabolic Dysregulation
News Publication Date: Jul 15, 2026
Web References: Not provided
References: Not provided
Image Credits: Dengyong Xu, Zhejiang University
Keywords: heatwaves, biological age acceleration, Klemera–Doubal method, difference-in-differences, metabolic dysregulation, lipid metabolism, insulin resistance, liver transcriptomics
