C-reactive protein and anti-chlamydia pneumoniae antibodies as risk factors of cardiovascular death in incident patients on peritoneal dialysis

Abstract

Objective: Recently it has been pointed out that inflamation and infections caused by germs such as Chlamydia pneumoniae are independent cardiovascular risk factors for the general population, but information about these relationships in dialysis patients is scarce.This work was done to analyze the association of C-reactive protein (CRP) and IgG anti-Chlamydia pneumoniae antibodies (anti-Chlp-IgG) as independent cardiovascular risk factors in incident patients on continuous ambulatory peritoneal dialysis (CAPD). Design: Single-cohort, prospective observational study. Setting: Three CAPD centers from the Instituto Mexicano del Seguro Social, and one from the Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, Mexico. Patients: A cohort of 75 adult incident patients on CAPD, without clinical signs of congestive heart failure, coronary heart disease, or peripheral arterial insufficiency. No restrictions for age, gender, or cause of renal failure were applied. Primary outcome: Mortality. Methods: Demographic variables, body composition by electrical bioimpedance, serum glucose, urea, creatinine, lipids, homocysteine, nutritional markers (albumin, pre-albumin, and transferrin), CRP, and anti-Chlp-IgG were measured and registered at the time of the first admission. When a patient died, the cause of death was determined by review of the clinical chart. Results: Mean follow-up time was 10.25 patient-months. There were 14 cardiovascular deaths. CRP was positive (> 10 mg/L) in 64% of the patients, and anti-Chlp-IgG in 64%; 29% of the patients were positive for both markers. The relative risk for cardiovascular mortality was 6.23 for patients positive for either CRP or anti-Chlp-IgG, and increased to 9.52 when both markers were positive. Multivariate analysis revealed that CRP and anti-Chlp-IgG were stronger cardiovascular death predictors than age, diabetes, and nutritional status. Conclusion: These data suggest that inflammation and the presence of Chlamydia pneumoniae infections are important predictors of cardiovascular death in patients on CAPD.