Effect of Meteorological Factors, Air Pollutants on Daily Hospital Admissions for Ischemic Heart Disease in Lanzhou, China

Background: Meteorological factors and air pollutants are believed to be associated with cardiovascular disease. Ischemic heart disease (IHD) is a major public health issue worldwide. Few studies have investigated the associations among meteorological factors, air pollutants and IHD daily hospital admissions in Lanzhou, China. Methods: We conducted a distributed lag non-linear model (DLNM) on the basis of five years data, aiming at disentangling the impact of meteorological factors and air pollutants on IHD hospital admissions. All IHD daily hospital admissions recorded from January 1, 2015 and December 31, 2019 were obtained from three hospitals in Lanzhou, China. Daily air pollutant concentrations and meteorological data were synchronously collected from Gansu Meteorological Administration and Lanzhou Environmental Protection Administration. Stratified analyses were performed by sex and two age-groups. Results: A total of 23555 IHD hospital admissions were recorded, of which 10477 admissions were for coronary artery disease (CAD), 13078 admissions were for acute coronary syndrome (ACS). Our results showed that there was a non-linear (J-shaped) relationship between temperature and IHD hospital admissions. The number of IHD hospital admissions were positively correlated with NO2, O3, humidity and pressure, indicating an increased risk of hospital admissions for IHD under NO2, O3, humidity and pressure exposure. Meanwhile, both extremely low (-12oC) and high (30oC) temperature reduced IHD hospital admissions, but the harmful effect increased with the lag time in Lanzhou, China, while the cold effect was more pronounced and long-lasting than the heat effect. Subgroup analysis demonstrated that the risk on CAD hospital admissions increased significantly in female and <65 years of age at -12oC. Conclusion: Our findings added to the growing evidence regarding the potential impact of meteorological factors, air pollutants on policymaking from the perspective of hospital management efficiency.