The effects of ambient fine particulate matter exposure and physical activity on heart failure: A risk-benefit analysis of a prospective cohort study

Background: Evidence supporting the adverse effects of air pollution and the benefits of physical activity (PA) on heart failure (HF) has continued to grow. However, their joint effects remain largely unknown. Methods: Our investigation included a total of 321,672 participants free of HF at baseline from the UK Biobank. Participants were followed up till March 2021. Information on participants' PA levels and additional covariates was collected by questionnaire. The annual fine particulate matter (PM2.5) concentration was estimated using a Land Use Regression (LUR) model. Cox proportional hazards models were used to assess the associations of PA and PM2.5 exposure with incident HF, as well as their interaction on both additive and multiplicative scales. Results: During a median follow-up of 12.0 years, 8212 cases of HF were uncovered. Compared with participants with low PA, the hazard ratios (HRs) were 0.69 (95 % CI: 0.65, 0.73) and 0.61(95 % CI: 0.58, 0.65) for those with moderate and high PA, respectively. PM2.5 was associated with an elevated risk of incident HF with an HR of 1.11(95 % CI: 1.08, 1.14) per interquartile range (IQR) increment. The synergistic additive interaction between low PA and high PM2.5 exposure on HF was observed. Compared with participants with high PA and low PM2.5 exposure, those with low PA and high PM2.5 exposure had the highest risk of HF [HR (95 % CI): 1.90 (1.76, 2.06)]. Conclusions: Our findings indicate that PA might still be an appropriate strategy to prevent HF for those living in areas with relatively high air pollution. Individuals with low PA may pay more attention to air pollution.