Exposure to Air Pollution during Pre-Hypertension and Subsequent Hypertension, Cardiovascular Disease, and Death: A Trajectory Analysis of the UK Biobank Cohort

Abstract

Background: The associations between air pollution exposure and morbidity and mortality of cardiovascular diseases (CVDs) have been widely reported; however, evidence on such associations across different dynamic disease trajectories remain unknown. Objective: We examined whether ambient air pollution during the prehypertension (pre-HTN) stage could aggravate the progression from hypertension (HTN) to CVD, and consequent death. Methods: A total of 168,010 adults with pre-HTN ( systolic blood pressure or diastolic blood pressure) from the UK Biobank were included in this analysis. We used a multistate model to explore the associations between five air pollutants ( , absorbance, , , and ) and the risk of six disease transitions (from pre-HTN to HTN, from pre-HTN to CVD, from pre-HTN to death, from HTN to CVD, from HTN to death, and from CVD to death). Mediation analyses were further conducted to explore the role of intermediate diseases in the dynamic progression of CVDs. Results: During a median follow-up of 12 y, 13,743 (8.18%) of participants with pre-HTN developed HTN, whereas 12,825 (7.63%) and 4,467 (2.66%) directly developed CVD or died, respectively. Air pollution was positively associated with the dynamic disease progression. For example, a per-interquartile range increase of was significantly associated with the hazard ratios (HRs) of 1.105 [95% confidence intervals (CI): 1.083, 1.127], 1.045 (95% CI: 1.022, 1.068), and 1.086 (95% CI: 1.047, 1.126) in the transition from pre-HTN to HTN, CVD, and death, respectively. Higher levels of air pollution were associated with increased transition probability of disease progression. Mediation analyses indicated that intermediate diseases subsequently significantly mediated air pollutant-associated risk to develop more serious disease. Conclusions: This study provides evidence that air pollution might play a role in the early stages of CVD progression. Controlling air pollution might be an effective measure to prevent CVD progression and reduce the disease burden of CVD. https://doi.org/10.1289/EHP10967

Effect of soy isoflavone supplementation on blood pressure: a meta-analysis of randomized controlled trials

“…Publication bias was assessed through visual inspection of funnel plots and statistical testing using Egger’s test [ 36 ]. To explore potential sources of heterogeneity, subgroup analyses were conducted based on factors such as soy isoflavone dosage, intervention duration, baseline BMI, gender, mean age, resting blood pressure status (normotension: <120 mmHg SBP and <80 mmHg DBP; prehypertension: 120-139 mmHg SBP and/or 80-89 mmHg DBP; hypertension: ≥140 mmHg SBP and/or ≥90 mmHg DBP) [ 37 – 39 ], participants’ health status, and types of soy isoflavone. Meta-regression was conducted to examine the relationship between the effect size and several moderators, such as the dosage and duration of intervention.…”

Applying a multistate survival model to explore the role of fine particles in promoting frailty in the Medicare cohort

“…In a multistate survival analysis of the UK Biobank cohort, the authors reported positive, and generally statistically significant, hazard ratios for the association between PM 2.5 exposure and the risk of cardiovascular disease and cardiovascular death among prehypertensive and hypertensive individuals. For the association between PM 2.5 exposure and mortality among prehypertensive individuals, Zhang and coauthors 34 report an estimated hazard ratio of 1.08 per 1.28 µg/m 3 or about 1.06 per 1 µg/m 3 . The present analysis estimates a hazard ratio 35 aged 40-70 years old, the current analysis designed a cohort of Medicare beneficiaries aged 65 years and older who had no prior history of chronic illness.…”

Invited Perspective: A Multivariate Disease Process Perspective for Environmental Epidemiology

“…In conclusion, the well-conceived study by Zhang et al. 2 makes an important contribution to the existing literature owing to its comprehensive consideration of dynamic disease processes to elucidate the role of air pollution as a risk factor for CVD. It adds considerable evidence that ambient fine particles affect CVD risk.…”

“…The work by Zhang et al. published in this issue of Environmental Health Perspectives 2 provides an interesting perspective and an important direction for the study of the life course influence of environmental pollutants. The authors hypothesized that exposure to ambient air pollution during the prehypertension (pre-HTN) stage could lead to blood vessel damage and thus induce HTN and cardiovascular disease (CVD).…”

“… 4 Zhang et al. 2 included baseline confounders but did not address the issue of time-varying confounding, although the latter is likely in this longitudinal setting and renders the mediation contrasts not identifiable. Furthermore, the authors did not clarify the impact of competing risk of death in the causal interpretation of the estimates for the association between air pollution and HTN and CVD, or in the mediation analysis of the association between air pollution and CVD potentially mediated by HTN.…”