Background: Inflammatory mediators secreted by leukocytes are implicated in atherogenesis. Chlamydia (C.) pneumoniae infection has been suggested as a trigger of this process. We investigated relationships between C. Pneumoniae serology, inflammatory mediators and symptomatic cardiovascular disease in old age.
Methods: In a cross-sectional study at baseline with a prospective 4 year follow-up, intraplatelet cyclic 3'-5'adenosine monophosphate (cAMP) and cyclic 3'-5'guanosine monophosphate (cGMP), plasma neutrophil gelatinase associated lipocalin (NGAL), plasma soluble tumor necrosis factor receptor-1 (TNFR-1) plasma neopterin and plasma endothelin-1 (ET-1) were analysed together with IgG and IgA antibodies for C. Pneumoniae in an elderly reference population (n=140, median age 71 years, 71 females). Twenty-one subjects had clinical manifestations of cardiovascular disease at baseline and another 21 were diagnosed with cardiovascular disease during follow-up.
Results: In age adjusted logistic regression, subjects with cardiovascular disease showed higher plasma levels of neopterin (p=0.02), NGAL (p=0.04), and ET-1 (p<0.01). If subjects with cardiovascular disease at baseline were excluded from the analysis, higher plasma neopterin (p=0.01) and lower serum HDL cholesterol (p=0.03) predicted cardiovascular disease during follow-up. The presence of IgG or IgA against C. pneumoniae was not associated with cardiovascular disease. Neither were there any associations between inflammatory or endothelial parameters and C. pneumoniae serology.
Conclusions: The inflammatory mediators neopterin and NGAL and endothelial derived vasoconstrictive ET-1 were increased in elderly subjects with symptomatic cardiovascular disease. Increased plasma neopterin predicted cardiovascular disease during follow-up. No relationships were found between C. Pneumoniae serology and cardiovascular disease.