This article is more than 5 years old. Information may no longer be current.
Air pollution exposure may be associated with CVD
Healthy adults who are exposed to high levels of air pollution had negative metabolic changes and elevated stress hormone levels, according to a study published in Circulation.
Huichu Li, MS, of the School of Public Health at Fudan University in Shanghai, and colleagues analyzed data from 55 participants (mean age, 20 years; 28 men) who lived in nonsmoking dormitories in Shanghai from November to December 2015. Participants did not have a history of CVD, respiratory diseases or allergic diseases.
Air purification
Real purification and sham purification treatments were alternated within 17 dormitories for 9 days with a 12-day washout period. A high-efficiency purifier was used for the real purification treatment, and the filter gauze was removed for the sham treatment. Doors and windows were closed during the study period, and participants predominately stayed in their dormitories other than for classes.
Researchers collected data from self-administered questionnaires, a health test and concentrations of particulate matter at or above 2.5 µm, which was the main exposure of interest. Four biomarkers of oxidative stress, six serum biomarkers of systemic inflammation and three hormones were also reviewed.
Personal exposure to particulate matter was higher during sham purification (53.1 µg/m3) vs. real purification (24.3 µg/m3). Higher levels of particulate matter were associated with increased levels of cortisol (7.79%; 95% CI, 4.75-10.91), cortisone (3.76%; 95% CI, 1.84-5.71), epinephrine (5.37%; 95% CI, 3.3-7.48) and norepinephrine (11.7%; 95% CI, 7.36-16.22).
Increased exposure to particulate matter affected serum levels of metabolites, which are involved in metabolizing amino acids, glucose, lipids and fatty acids.
Increase in BP, hormones
During sham purification, participants had a 2.61% increase in systolic BP (95% CI, 0.39-4.79) compared with real purification. As particulate matter levels increased by 10 µg/m3, systolic BP increased by 0.86% (95% CI, 0.1-1.62). Sham purification was also associated with a 28.03% increase in corticotropin-releasing hormone (95% CI, 1.82-61) and a 6.71% increase in adrenocorticotropic hormone (95% CI, 0.51-12.53) vs. real purification.
Between-treatment differences were also seen for insulin resistance in addition to biomarkers for oxidative stress and inflammation.
“These novel findings provide insights into the potential mechanisms of the adverse health effects that have been found to be associated with [particulate matter] exposure,” Li and colleagues wrote. “Future studies should examine whether these health benefits from short-term air purification could be maintained and translated into improved health in the long run.”
In a related editorial, Robert D. Brook, MD, professor of medicine at the University of Michigan in Ann Arbor, and Sanjay Rajagopalan, MD, division chief of cardiovascular medicine at UH Cleveland Medical Center and clinical professor of medicine at Case Western Reserve University School of Medicine in Cleveland, wrote: “How does the inhalation of pollutants activate central nervous system loci resulting in a stress response? One possible explanation is the triggering of afferent nerves originating from the airways and lungs that mediate reflex efferent pathways that modulate systemic effects.” – by Darlene Dobkowski
Disclosures: The authors and Rajagopalan report no relevant financial disclosures. Brook reports receiving research grant support from RB Inc.