Associations between meteorological factors and acute myocardial infarction mortality risk in Hefei, China: evidence from a subtropical city

Acute myocardial infarction (AMI) remains a leading cause of cardiovascular mortality worldwide. Although meteorological factors have been increasingly linked to health outcomes, evidence of their short-term effects in rapidly urbanizing regions is still limited. Therefore, this study aimed to evaluate the short-term effects of meteorological factors – including daily mean temperature (Tmean), relative humidity (RH), and diurnal temperature range (DTR) – on AMI mortality in Hefei, China, from 2015 to 2020. We applied a generalized additive model (GAM) combined with a distributed lag non-linear model (DLNM) to assess the associations between meteorological factors and AMI mortality, based on daily mortality and meteorological data. The results showed that extremely high Tmean and low DTR significantly increased the AMI mortality risk. Low RH was identified as a risk factor, whereas high RH had a protective effect. Stratified analyses indicated that elderly individuals and women were particularly vulnerable to adverse meteorological conditions. Sensitivity analyses confirmed the results’ robustness. This study provides novel insights into the climate-sensitive risk of AMI mortality amid rapid urbanization and climate change. By identifying key meteorological risk factors and vulnerable subpopulations, our findings offer scientific evidence to support targeted public health interventions and climate-adaptive strategies to reduce AMI-related mortality.