Systemic Inflammation (C-Reactive Protein) in Older Chinese Adults Is Associated with Long-Term Exposure to Ambient Air Pollution

Abstract

There is an established association between air pollution and cardiovascular disease (CVD), which is likely to be mediated by systemic inflammation. The present study evaluated links between long-term exposure to ambient air pollution and high-sensitivity C reactive protein (hs-CRP) in an older Chinese adult cohort (n = 7915) enrolled in the World Health Organization (WHO) study on global aging and adult health (SAGE) China Wave 1 in 2008–2010. Multilevel linear and logistic regression models were used to assess the associations of particulate matter (PM) and nitrogen dioxide (NO2) on log-transformed hs-CRP levels and odds ratios of CVD risk derived from CRP levels adjusted for confounders. A satellite-based spatial statistical model was applied to estimate the average community exposure to outdoor air pollutants (PM with an aerodynamic diameter of 10 μm or less (PM10), 2.5 μm or less (PM2.5), and 1 μm or less (PM1) and NO2) for each participant of the study. hs-CRP levels were drawn from dried blood spots of each participant. Each 10 μg/m3 increment in PM10, PM2.5, PM1, and NO2 was associated with 12.8% (95% confidence interval; (CI): 9.1, 16.6), 15.7% (95% CI: 10.9, 20.8), 10.2% (95% CI: 7.3, 13.2), and 11.8% (95% CI: 7.9, 15.8) higher serum levels of hs-CRP, respectively. Our findings suggest that air pollution may be an important factor in increasing systemic inflammation in older Chinese adults.

Posttraumatic Stress Disorder Mediates the Association between Traumatic World Trade Center Dust Cloud Exposure and Ongoing Systemic Inflammation in Community Members

“…In our study cohort, persistent symptoms of PTSD and depression have emerged as two highly prevalent and comorbid post-traumatic stress responses to the WTC disaster exposures. The existing literature on air pollution studies indicates that air pollution can lead to systemic inflammation and elevated CRP [ 61 , 62 , 63 , 64 , 65 , 66 ], and systemic inflammation has emerged in the literature as one of the plausible biological mechanisms in the pathogenesis of depression and PTSD [ 95 , 96 ]. Note that we have previously reported that most of the subjects with symptoms of PTSD experience chronic or persistent symptoms [ 37 ].…”

“…The biological mechanisms contributing to this wide range of adverse health effects have been hypothesized to involve systemic inflammation resulting from oxidative stress [ 51 , 59 , 60 ]. Indeed, measures of the inflammatory markers in the blood, including C-reactive protein (CRP) [ 61 , 62 , 63 , 64 , 65 , 66 ], white blood cell (WBC) counts [ 67 ], and Interleukin 6 (IL-6) [ 68 ], were shown to be elevated in populations with high particulate air pollution exposure. Importantly, most of the community members who were caught in the WTC dust cloud on 9/11 also had a traumatic life-threatening experience, thus, we and others have reported that elevated levels of CRP were associated with symptoms of PTSD and depression among the members of the WTC EHC [ 34 , 69 , 70 , 71 ].…”

Long-Term Effects of Ambient Particulate and Gaseous Pollutants on Serum High-Sensitivity C-Reactive Protein Levels: A Cross-Sectional Study Using KoGES-HEXA Data

“…Elderly individuals are generally considered more susceptible to the adverse health impacts of ambient air pollution [ 46 ]. Aging entails a substantial burden regarding the onset and exacerbation of chronic disorders, perturbations in immune system function, and changes in activity status [ 47 , 48 ]. These findings are consistent with the associations between pollutants and CRP reported by several observational studies of susceptible older individuals, including factors such as diabetes, obesity, hypertension, coronary heart disease, and chronic obstructive pulmonary disease [ 49 , 50 , 51 , 52 ].…”

“…The results remained stable or demonstrated slightly attenuated effect estimates. Short-term air pollution exposure may potentially affect the long-term associations between inflammatory markers and outdoor air pollution exposure; however, participants with potential acute infections (hs-CRP levels > 10 mg/L) were excluded before analysis, which may have reduced the potential confounding effect of short-term exposure to air pollutants on the chronic health effects of air pollutants [ 48 ]. Previous epidemiological studies of long-term exposure to air pollutants on hs-CRP levels also included participants with hs-CRP levels less than 10 mg/L and demonstrated stable estimates which were not affected by adjusting for short-term exposure to air pollution [ 38 , 66 ].…”

Associations between Short-Term Air Pollution Exposure and the Peripheral Leukocyte Distribution in the Adult Male Population in Beijing, China

“…Exposure to air pollution, especially particulate matter (PM), induces systemic inflammatory responses [ 14 , 15 , 16 , 17 , 18 ] that lead to the release and redistribution of peripheral white blood cells (WBCs) [ 19 ], which may be a critical factor in the effect of air pollution on human health. Nevertheless, earlier studies on the association between air pollution and peripheral WBC count were inconsistent, which might have been due to study population differences or relatively small samples and the lack of the assessment in consideration of the potential effects of confounding factors.…”