Evolving Non-Communicable Disease Mortality Risk Under Temperature Extremes in the Metropolitan Area of the Valley of Mexico: A Bayesian Spatiotemporal Analysis (2000–2019)

This study quantifies the spatiotemporal evolution of non-communicable disease (NCD) mortality risk associated with temperature extremes in the Metropolitan Area of the Valley of Mexico (MAVM) from 2000 to 2019. Using a Bayesian risk assessment framework, we analyzed 747,131 deaths to evaluate the impact of extreme temperature indices (Tn90p, Tn10p, TNn, Tx90p, Tx10p, TXx, DTR) across demographic and geographic dimensions. Results reveal a significant intensification of mortality risk, particularly for circulatory and metabolic diseases after 2005 and 2014. Risk expansion analysis identified 16 cases of robust relative risk (RR) intensification, predominantly among elderly populations. Females and males aged 65+ with metabolic diseases exhibited the highest thermal vulnerability. Our analysis further indicates a systematic shift in mortality risk toward higher nocturnal temperatures and reduced diurnal variability, suggesting a transition from cold-related stress to persistent nighttime heat exposure. Spatial Bayesian modeling shows a progressive homogenization of environmental risk across the metropolitan area, with high-risk thermal profiles expanding from the urban core toward peripheral municipalities, reducing the extent of previously lower-risk zones. Notably, the number of municipalities in the highest risk category for females aged 65+ with metabolic diseases increased by 550%, while for males of the same age, the expansion reached 163%. These findings indicate that vulnerability in megacities is a dynamic process driven by nocturnal warming and thermal instability. They highlight the urgent need to integrate climate-sensitive planning strategies—such as the identification and preservation of climatic refuge zones—into urban development policies, alongside continuous monitoring of temperature-related health risks.