Abstract
BACKGROUND: Despite advancements in antiretroviral therapy, people living with HIV/AIDS (PLWHA) still experience elevated mortality risks compared to the general population. While ambient air pollution is increasingly recognized as a risk factor for mortality, cohort studies on the long-term effects of ambient nitrogen dioxide (NO(2)) exposure on PLWHA remain scarce. METHODS: This retrospective cohort study included all individuals diagnosed with HIV/AIDS in Hubei Province from 2008 to 2020. Cox proportional hazard models were employed to assess the association between long-term exposure to NO(2) and cause-specific mortality among PLWHA. Restricted cubic spline models characterized the concentration-response curves for NO(2) exposure and cause-specific mortality. We estimated the number of avoidable deaths and gained life expectancy if reached the World Health Organization's Air Quality Guidelines level (WHO AQG level) of NO(2). RESULTS: Long-term exposure to NO(2) was significantly associated with increased risks of non-accidental, AIDS-related deaths, and non-AIDS-related deaths among PLWHA. Each 1 µg/m(3) increase in annual NO(2) concentration was linked to an excess risk of 1.44% [95% confidence interval (CI): 1.05, 1.82] for non-accidental deaths, and 2.72% (95% CI: 2.11, 3.34) for AIDS-related deaths, and 0.59% (95% CI: 0.10, 1.09) for non-AIDS-related deaths. Individuals aged over 65 years and those with lower initial CD4 + cell counts exhibited higher susceptibility to NO(2) exposure. If the WHO AQG level had been achieved, approximately 970 non-accidental deaths, 646 AIDS-related deaths, and 149 non-AIDS-related deaths could have been avoidable, respectively. The extended life expectancy of PLWHA aged between 20 and 24 years old was up to 4.19 years in 2020. CONCLUSIONS: Long-term NO(2) exposure is associated with increased mortality risks among PLWHA. Implementing stringent air quality standards and targeted interventions for high-risk populations could mitigate the adverse health effects of NO(2) pollution, and extend the lives of PLWHA.