Left ventricular diastolic dysfunction and cardiovascular disease in different ambient air pollution conditions: A prospective cohort study

Although previous studies indicated that the left ventricular diastolic dysfunction (LVDD) is associated with cardiovascular disease (CVD), it remains unclear whether effects would be enhanced or accelerated by long-term air pollution exposure. During 4.65 years (107,726 person-years) of follow-up, 942 cases of CVD events incident were identified among 23,143 participants from the China Hypertension Survey (CHS). Grading diastolic dysfunction was based on Recommendations for the evaluation of left ventricular diastolic function by echocardiography (2009). The annual average PM2.5, PM10 and NO2 concentrations were obtained by the chemical data assimilation system. Cox proportional hazards models were employed to estimate hazard ratios (HRs) for CVD in relation to LVDD. At baseline, the participants' mean age was 56.7 years, 46.8% were male. Compared to normal group, the HR (95% CI) of LVDD was 1.27 (1.07-1.50) after adjusting for all covariates. When stratified by ambient air pollution, we found that in middle and worst third PM2.5 areas, increased CVD risk was associated with increasing LVDD grade, both P for trend <0.05; The HRs (95% CI) of the CVD incidence were 1.52 (0.68-3.44), 4.97 (1.76-14.03) and 4.07 (1.44-11.49) for severe LVDD in the best, middle and worst third PM2.5 areas, respectively. Similar results were also presented for PM10 and NO2. In conclusion, our study highlights a stronger detectable adverse association between LVDD with CVD in worse ambient air quality assessed by any of the three primary ambient air pollutants (PM2.5, PM10 and NO2). Our study calls for appropriate interventions to reduce air pollution, which may promote great benefits to public health potentially by providing protection against the adverse CVD events.