[Association between short-term exposure to ambient nitrogen dioxide and the risk of heart failure hospitalization]

Objective: To assess the association between short-term exposure level of nitrogen dioxide and the hospitalization risk of heart failure. Methods: Based on China-PEACE Retrospective Heart Failure Study, 117 364 hospitalized patients with heart failure were recruited from 92 hospitals in 62 cities throughout China between January 1, 2015 and December 31, 2015. The daily exposure level of nitrogen dioxide, temperature, and humidity in the same cities during the same period were also collected. We applied the generalized additive model and Bayesian hierarchical model to quantify the lagged effect and cumulative effect of short-term (0-3 days) exposure to ambient nitrogen dioxide on the hospitalization risk of heart failure. We further conducted stratified analyses by age, region, and season to identify any difference in the associations between short-term nitrogen dioxide exposure and heart failure among subgroups. Results: The mean age for participants in the analysis was (70.32±12.22) years. The median, minimum and maximum of daily nitrogen dioxide concentration in 62 cities from January 1, 2015 to December 31, 2015 was 26.4 μg/m³, 2.33 μg/m³ and 150.25 μg/m³, respectively. The exposure level of nitrogen dioxide at the same day was associated with the hospitalization risk of heart failure (OR=1.022, 95%CI: 1.012, 1.031). Significant effects were also observed in the moving average concentrations from lag 0-1 to lag 0-3 day (OR=1.020, 95%CI: 1.009, 1.030; OR=1.016, 95%CI: 1.004, 1.028; OR=1.013, 95%CI: 1.001, 1.026). Moreover, all of the associations between short-term exposure to nitrogen dioxide and the risk of heart failure hospitalization were statistically significant, with no significant difference in all subgroups stratified by age, region, and season. Conclusion: A higher level of short-term exposure to nitrogen dioxide could trigger more hospitalizations with heart failure.