Resumen de Inflamación en la enfermedad renal crónica avanzada: características clínicas asociadas y valor pronóstico
Francisco Caravaca Magariños, Emilio Sánchez Casado
Introduction. Inflammation has been identified as an epidemiologically important risk factor for cardiovascular mortality in the general population, and it strongly predicts allcause and cardiovascular mortality rates among the dialysis patient population. However, the role of inflammation as a determinant of mortality in patients with advanced chronic disease who have not yet initiated dialysis is less clear. Aims. To know the prevalence of an abnormal elevation of CRP, the clinical characteristics related with this elevation of CRP, as well as its prognostic value in chronic renal failure patients in the predialysis setting. Patients and methods. The study group consisted of 187 unselected patients (83 females, mean age 63 ± 16 years), with advanced chronic renal failure. Diabetic nephropathy was the the most common etiology of renal failure (24%). Thirty-three percent of patients had cardiovascular disease, and 16% had antecedent of congestive heart failure. Inflammation of uncertain origin (INF) was defined as an increment of high-sensitive CRP > 5 mg/L in patients with no evidence of inflammatory or infectious disease. The best clinical characteristics related with INF were analyzed by logistic regression. The following variables were included: demographics, body mass index (BMI), comorbidity, blood pressure, renal function, treatment with statins, aspirin, ACE-inhibitors, EPO, and the main hematological and biochemical parameters. The best determinants of new cardiovascular events and all-cause mortality in the study group were analyzed by Cox regression. Results. Mean CRP levels was 10.21 ± 17.44 mg/l, and the prevalence of INF was 37%. The best clinical characteristics related with INF were: a previous history of congestive heart failure (odds ratio: 5.20), a previous history of cardiovascular diseases (OR: 3.16), BMI (OR: 1.09), serum albumin (OR: 0.42), and the diagnosis of diabetes mellitus (OR: 0.41). The sensibility and specificity of this model were 48% and 86%, respectively. The mean follow-up time per patient was 653 days. The best determinants of new cardiovascular events were: BMI (OR:1.11), a previous history of inflammatory or infectious disease (OR:5.99), and a previous history of cardiovascular disease (OR16.22). The best determinants of all-cause mortality were: the age (OR:1.03), BMI (OR:1.07), and a previous history of cardiovascular disease (OR:2.71). A CRP value > 5 mg/L did not enter in any predictive equation over new cardiovascular events, or all-cause mortality. Conclusion. INF is highly prevalent among patients with advanced chronic renal disease. INF relates mainly with cardiovascular comorbidity. However, a single determination of CRP was not able to predict new cardiovascular events, or all-cause mortality.