BOSTON — How COPD patients respond to particulate pollution based on personal characteristics and systemic responses is not well characterized. That’s why a new study sought to find out.
In a study published in Environmental Medicine, researchers from the VA Boston Healthcare System and Harvard Medicine School assessed whether diabetes, obesity, statins and nonsteroidal anti-inflammatory medications (NSAIDs) affect systemic inflammation or endothelial activation response to indoor black carbon (BC) and fine particulate matter ≤2.5 μm in diameter (PM2.5).1
To do that, the study team recruited 144 COPD patients without current smoking and without major in-home combustion sources at the VA Boston Healthcare System. Researchers measured PM2.5 and BC in each participant’s home seasonally for a week (up to four times; 482 observations). At the same time, they tested plasma biomarkers of systemic inflammation [C-reactive protein (CRP); interleukin-6 (IL-6)] and endothelial activation [soluble vascular adhesion molecule-1 (sVCAM-1)].
Results indicate that median (25%ile, 75%ile) indoor BC and PM2.5 were 0.6 (0.5,0.7) μg/m3 and 6.8 (4.8,10.4) μg/m3, respectively. “Although p-values for effect modification were not statistically significant, there were positive associations (%-increase/interquartile range; 95% CI) between CRP and BC greater among non-statin (18.8%; 3.6-36.3) than statin users (11.1%; 2.1-20.9),” according to the authors. “There were also positive associations greater among non-statin users between PM2.5 and CRP. For IL-6, associations with BC and PM2.5 were also greater among non-statin users.”
The study also found that associations between CRP and BC were greater (20.3%; 4.5-38.5) in diabetes patients than those without diabetes (10.3%; 0.92-20.6) with similar effects of PM2.5. No consistent associations that differed based on obesity were found, however, and effect modification was not observed for NSAID use, or with any factor considered with sVCAM-1.
“Associations between indoor BC and PM2.5 and CRP were greater in patients with diabetes and those not taking statins, and with IL-6 if not taking statins,” the researchers concluded. “These results suggest that these characteristics may modify the systemic response to indoor BC and PM2.5 in persons with COPD.”
- Busenkell E, Collins CM, Moy ML, Hart JE, Grady ST, Coull BA, Schwartz JD, Koutrakis P, Garshick E. Modification of associations between indoor particulate matter and systemic inflammation in individuals with COPD. Environ Res. 2022 Jan 29;209:112802. doi: 10.1016/j.envres.2022.112802. Epub ahead of print. PMID: 35101396.