Hypoxia Stress Test Reveals Exaggerated Cardiovascular Effects in Hypertensive Rats After Exposure to the Air Pollutant Acrolein

Exposure to air pollution increases the risk of cardiovascular morbidity and mortality, especially in susceptible populations. Despite increased risk, adverse responses are often delayed and require additional stress tests to reveal latent effects of exposure. The goal of this study was to use an episode of “transient hypoxia” as an extrinsic stressor to uncover latent susceptibility to environmental pollutants in a rodent model of hypertension. We hypothesized that exposure to acrolein, an unsaturated aldehyde and mucosal irritant found in cigarette smoke, diesel exhaust, and power plant emissions, would increase cardiopulmonary sensitivity to hypoxia, particularly in hypertensive rats. Spontaneously hypertensive and Wistar Kyoto (normotensive) rats, implanted with radiotelemeters, were exposed once for 3h to 3 ppm acrolein gas or filtered air in whole-body plethysmograph chambers and challenged with a 10% oxygen atmosphere (10min) 24h later. Acrolein exposure increased heart rate, blood pressure, breathing frequency, and minute volume in hypertensive rats and also increased the heart rate variability parameter LF, suggesting a potential role for increased sympathetic tone. Normotensive rats only had increased blood pressure during acrolein exposure. The hypoxia stress test after acrolein exposure revealed increased diastolic blood pressure only in hypertensive rats and increased minute volume and expiratory time only in normotensive rats. These results suggest that hypertension confers exaggerated sensitivity to air pollution and that the hypoxia stress test is a novel tool to reveal the potential latent effects of air pollution exposure

Population approaches to improve diet, physical activity, and smoking habits: a scientific statement from the American Heart Association.

BackgroundPoor lifestyle behaviors, including suboptimal diet, physical inactivity, and tobacco use, are leading causes of preventable diseases globally. Although even modest population shifts in risk substantially alter health outcomes, the optimal population-level approaches to improve lifestyle are not well established.Methods and resultsFor this American Heart Association scientific statement, the writing group systematically reviewed and graded the current scientific evidence for effective population approaches to improve dietary habits, increase physical activity, and reduce tobacco use. Strategies were considered in 6 broad domains: (1) Media and educational campaigns; (2) labeling and consumer information; (3) taxation, subsidies, and other economic incentives; (4) school and workplace approaches; (5) local environmental changes; and (6) direct restrictions and mandates. The writing group also reviewed the potential contributions of healthcare systems and surveillance systems to behavior change efforts. Several specific population interventions that achieved a Class I or IIa recommendation with grade A or B evidence were identified, providing a set of specific evidence-based strategies that deserve close attention and prioritization for wider implementation. Effective interventions included specific approaches in all 6 domains evaluated for improving diet, increasing activity, and reducing tobacco use. The writing group also identified several specific interventions in each of these domains for which current evidence was less robust, as well as other inconsistencies and evidence gaps, informing the need for further rigorous and interdisciplinary approaches to evaluate population programs and policies.ConclusionsThis systematic review identified and graded the evidence for a range of population-based strategies to promote lifestyle change. The findings provide a framework for policy makers, advocacy groups, researchers, clinicians, communities, and other stakeholders to understand and implement the most effective approaches. New strategic initiatives and partnerships are needed to translate this evidence into action