Association of serum sialic acid and MMP-9 with lipids and inflammatory markers

Background Inflammation of the arterial wall has emerged to be an important contributor to the process of atherosclerosis, the major cause of coronary heart disease. Several factors are currently under investigation as inflam matory markers of atherosclerosis. Serum sialic acid and matrix metalloprot einase-9 may provide such markers. We studied their association with the li pid profile and with the inflammatory markers C-reactive protein and leukoc yte count in a clinically healthy population of men. Materials and methods Cardiovascular risk-related laboratory tests were car ried out in 65 consecutive male employees in connection with an occupationa l health survey in 1996. The subjects were divided into tertiles on the bas is of serum sialic acid or matrix metalloproteinase-9 concentration. Results In a stepwise polychotomous logistic regression model adjusting for coronary heart disease risk factors, serum sialic acid concentration was n ot associated with markers of inflammation but rather with the lipid risk f actors of atherosclerosis: inversely with HDL cholesterol (OR = 0.081, 95% CI 0.0068-0.97) and positively with total cholesterol (OR = 2.4, 95% CI 1-5 .6). Matrix metalloproteinase-9 levels had a significant positive correlati on with the leukocyte count (OR = 2.3, 95% CI 1.4-4). Conclusions Serum sialic acid does not appear to be an indicator of inflamm ation but is somehow connected with the level of total and HDL cholesterol. Serum matrix metalloproteinase-9 may provide a useful marker of inflammati on because it correlates with the leukocyte count and is not associated wit h the lipid profile.