Mortality burden of protein-energy malnutrition associated with ambient temperature in China: a nationwide...

In the context of global warming, the health effects of non-optimum temperatures have attracted increasing attention. Studies have shown that high temperatures increase risk of hospitalization for protein-energy malnutrition (PEM), yet the impact of non-optimum temperatures on PEM mortality is unknown.

This study aims to quantitatively assess risk and burden of PEM-related mortality associated with short-term temperature exposure across 31 provinces in China.

We collected mortality and meteorological data from 1 January, 2013, to 31 December, 2022, in 31 provinces of mainland China. Based on time-stratified case-crossover design, we integrated logistic model with distributed lag nonlinear model to assess the association between non-optimum temperatures and PEM-related mortality. Subgroup analyses were performed by age, sex, type of PEM, and province to identify vulnerable populations.

A total of 197,406 PEM-related deaths were recorded during 2013-2022. The exposure-response curves were inversely J-shaped with higher effect for low temperature than high temperature. Nationally, we estimated that 17.03% [95% empirical confidence intervals (eCI): 14.59%, 19.17%] of PEM mortality was attributable to non-optimum temperatures. Subgroup analyses suggested that the attributable fraction of PEM mortality resulting from non-optimum temperatures was more prominent in males (17.69%; 95% eCI: 13.57%, 21.48%), the older adults ≥65 y (17.44%; 95% eCI: 14.84%, 19.80%), and non-severe PEM (17.45%; 95% eCI: 14.30%, 20.56%). In terms of spatial disparities, the top provinces with higher AFs were Anhui (27.63%; 95% eCI: 20.31%, 33.80%), Xinjiang (22.73%; 95% eCI: -0.14%, 39.55%), and Hubei (22.05%; 95% eCI: 12.36%, 29.87%).

Findings from this nationwide study suggest that both heat and cold are associated with increased risks and burden of PEM-related deaths. These findings underscore the necessity of targeted interventions to reduce the PEM-related mortality burden associated with ambient temperature.