Background: Cardiovascular (CV) disease is the leading cause of morbidity and mortality in chronic hemodialysis (HD) patients. Inflammation is a potent risk factor for CV disease in the general population. Recent evidence suggests infection, particularly with agents such as Chlamydia pneumoniae (C.pneumoniae) and Helicobacter pylori (H.pylori), as a source of sustained inflammation. Our study tested the hypothesis that C-reactive protein (CRP) and positive serology for antibodies to C.pneumoniae and H.pylori can be associated with the occurrence of new CV events in chronic HD patients.
Methods: We evaluated 76 chronic HD patients (33 women and 43 men, aged 60.5+/-17.3 years) by measuring baseline CRP levels as well as the titres of antibodies (IgG and IgA) to C.pneumoniae and(IgG) to H.pylori. In addition, risk factors such as hypertension, smoking, diabetes, cholesterol levels and albumin were assessed at baseline. The incidence of new CV events (myocardial infarction and ischemic stroke) was recorded during a 36-month follow-up period. The effect of prognostic factors was evaluated by logistic regression analysis.
Results: The incidence of CV events was significantly higher in patients seropositive for C.pneumoniae antibodies than in those seronegative (16.1 vs. 4.3 events/100 patient-years, p=0.017, risk ratio 3.76), whereas it did not differ for H.pylori (12.2 vs. 11.7 events/100 patient-years,p=0.91, risk ratio 1.04). Logistic regression analysis showed C.pneumoniae seropositivity (odds ratio 10.11, p=0.04) and CRP levels (odds ratio 1.78, p=0.03) to be independent predictors of the occurrence of CV events.
Conclusions: CRP levels and C.pneumoniae antibodies, but not H.pylori antibodies, were predictors of CV morbidity in the chronic HD patients studied.