The association between ambient particulate matter exposure and anemia in HIV/AIDS patients.

Background: Anemia is common among HIV/AIDS patients, impacting prognosis. Particulate matter (PM) exposure is an understudied, potentially modifiable risk factor in this group.

Methods: We gathered 36,266 hemoglobin (Hb) measurements from 6,808 HIV/AIDS patients from the HIV/AIDS Comprehensive Response Information Management System from January 1, 2004, to December 31, 2021. We evaluated the relationship between Hb levels and short-term PM exposure using linear mixed-effects models. We used logistic regression to estimate the association of long-term PM exposure with baseline anemia prevalence and time-varying Cox models to estimate association of long-term PM exposure with follow-up incidence of anemia. Mediation analysis explored the role of chronic kidney disease (CKD) in the association between PM exposure and anemia.

Results: For every 5 µg/m³ increase in 28-day average PM1, Hb levels decreased 0.43 g/L. For a 10 µg/m³ increase in PM2.5, Hb decreased 0.55 g/L; for the same increase in PM10, Hb decreased 0.35 g/L. A 5 µg/m³ increase in 1-year average PM1 corresponded to 7% higher prevalence of anemia at baseline, a 10 µg/m³ increase in PM2.5 to 8% higher prevalence, and 10 µg/m³ increase in PM10 to 6% higher prevalence. These rises in average PM concentrations during follow-up were associated with increased incident anemia by 54% (PM1), 72% (PM2.5), and 51% (PM10). CKD partially mediated the positive associations between PM exposure and the incidence of anemia.

Conclusion: PM exposure was associated with lower Hb levels and higher incidence of anemia in HIV/AIDS patients and CKD with mediating estimated effects in PM-induced anemia.