Objective To investigate the distribution of cardio/cerebrovascular disease deaths in residents in Ningxia Hui Autonomous Region (Ningxia) and explore the exposure-response relationship between ambient temperature and cardio/cerebrovascular disease deaths and associated lag effects.

Methods Data of acute cardio/cerebrovascular disease deaths, concurrent meteorological parameters (including temperature, atmospheric pressure, wind speed) and air quality indices (AQI) were collected from Yinchuan, Wuzhong, and Zhongwei in Ningxia from January 1, 2015 to December 31, 2024. A distributed lag non-linear model (DLNM) was applied to analyze the impact of extreme temperature on CVD mortality and its lag effects.

Results A total of 106797 cardio/cerebrovascular disease deaths were recorded in the three cities during this period, with a daily average of 29.24 deaths. The mean daily AQI, temperature, atmospheric pressure, and wind speed were 110.79, 11.04℃, 101.70 kPa, and 1.94 m/s, respectively. After adjusting for daily atmospheric pressure, wind speed, and AQI, the DLNM results demonstrated a significant lag effect of ambient temperature on cardio/cerebrovascular disease mortality risk. For extreme low temperature (−11℃), the mortality risk reached the peak on the same day (lag 0 day) relative risk (RR)=1.01, 95% confidence interval (CI): 1.00～1.03, P<0.05. In contrast, extreme high temperature (29℃) exerted the strongest effect on the same day (lag 0 day), with the highest mortality risk (RR=1.05, 95% CI: 1.01−1.09, P<0.05). Subgroup analysis showed that extreme low temperature was significantly associated with elevated cumulative risks of overall cardio/cerebrovascular disease mortality (RR=1.23, 95% CI: 1.08−1.39, P<0.05) and cerebrovascular disease mortality (RR=1.30, 95% CI: 1.10−1.54, P<0.05), as well as mortality risk for ischemic stroke (RR=1.35, 95% CI: 1.09−1.67, P<0.05). Such adverse effects were also observed in men (RR=1.40, 95% CI: 1.17−1.68, P<0.05), those aged ≥65 years (RR=1.32, 95% CI: 1.12−1.57, P<0.05) and those living in Wuzhong (RR=1.94, 95% CI: 1.41−2.68, P<0.05) . On the other hand, extreme high temperature was significantly associated with increased cumulative risks for cardio/cerebrovascular disease mortality (RR=1.81, 95%CI: 1.19−2.75, P<0.05) and cardiovascular disease mortality (RR=1.94, 95% CI: 1.16−3.23, P<0.05), as well as mortality risk for rheumatic heart disease (RR=1.60, 95% CI: 1.06−2.43, P<0.05). Significant associations were also found in women (RR=2.69, 95% CI: 1.52−4.76, P<0.05), those aged ≥65 years (RR=2.21, 95%CI: 1.40−3.48, P<0.05) and those living in Yinchuan (RR=2.89, 95% CI: 1.64−5.07, P<0.05), Wuzhong (RR=3.27, 95% CI: 1.67−6.40, P<0.05) and Zhongwei (RR=0.41, 95% CI: 0.22−0.77, P<0.05).

Conclusions Extreme temperature exhibited significant effects on cardio/cerebrovascular disease mortality risk in residents in the three cities of Ningxia, with obvious lag effects. It is suggested to strengthen the protection of the population at high-risk by advising them to reduce outdoor activity on low-temperature day, improving centralized heating; taking area specific cardio/cerebrovascular disease prevention and control measures when ambient temperature is high, timely early warning of high temperature, establishing a dynamic monitoring and early warning mechanism for temperature and cardio/cerebrovascular disease and allocating medical resources rationally.