Chronic inflammation induced by organic dust and related metabolic cardiovascular disease risk factors

Abstract

Objective. Chronic inflammation is now considered a risk factor for cardiovascular diseases. Exposure to organic dust induces an inflammatory response. This study was done to verify whether inflammation caused by exposure to organic dust increases the metabolic risk factors for cardiovascular diseases. Methods. Thirty-six nonsmoking men who worked in a swine confinement building and 35 unexposed matched controls were studied. Each person was evaluated for inflammatory markers, including white blood cell counts, cell-bound (CD11b, CD18, CD31, CD62L) and circulating soluble adhesion molecule levels (sICAM-1, sPECAM-1, sL, sE, and sP selectins), serum CRP (C-reactive protein), fibrinogen, and interleukin-6 (IL-6). Cardiovascular risk factors [the serum lipid profile, apoprotein B (Apo B)] and insulin levels were also assessed. Results. The groups were similar with respect to age, physical characteristics, and blood cell counts. The expression of adhesion molecules (P-values <0.01) and serum levels of sL-selectin (P< 0.0001) were higher for the workers than for the controls, while neutrophils and interleukin-6 were slightly higher for the workers (P=0.05). No differences in CRP, fibrinogen, lipid profile, Apo B, or insulin levels were observed. Conclusions. Exposure to contaminated organic dust induces a chronic inflammation that is not associated with increased metabolic or acute-phase cardiovascular risk factors; this finding suggests that chronic inflammation per se may not be a cardiovascular risk factor in this group of pig farmers.