Acute Impact of Nonoptimal Ambient Temperatures on Plasma Levels of 3000 Proteins in Chinese Adults

Nonoptimal ambient temperatures (i.e., cold and heat) are leading environmental determinants of major diseases worldwide, but the underlying pathological mechanisms are still poorly understood. We used distributed-lag nonlinear models to examine the associations of cold (5^th percentile: -2.1 °C) and heat (95^th percentile: 29.5 °C) with 2923 plasma proteins in 3926 adults from 10 areas across China. Overall, 949 proteins were significantly (5% false discovery rate) associated with ambient temperature, including 387 (216/171 down/upregulated) with cold, 770 (656/114 down/upregulated) with heat, and 208 with both cold and heat. Above the median reference temperature (17.7 °C), the associations were largely linear, while below it, they were nonlinear with attenuation below 5 °C, potentially reflecting mediation by heating. Among the 949 proteins, >80% were also associated with systolic blood pressure and incident ischemic heart disease risk and enriched in relevant pathological pathways (e.g., inflammation, immunity, and platelet aggregation). Our study provided a novel atlas of plasma proteins associated with nonoptimal temperatures in Chinese adults.