P0867ANEMIA AND IRON DEFICIENCY IN NON-DIALYISIS CHRONIC KIDNEY DISEASE: A LINK WITH ADVERSE OUTOCOMES?

Abstract

Abstract Background and Aims Anemia is a major complication of Chronic Kidney Disease (CKD). There are few large observational studies analyzing the association between anemia and significant clinical outcomes in non-dialysis dependent CKD (ND-CKD) patients. Our aim was to evaluate the prevalence of anemia and iron deficiency and their association with mortality, cardiovascular events, need for renal replacement therapy and hospitalizations in an outpatient ND-CKD population. Method A patient-level, retrospective, cohort analysis of all adult ND-CKD patients evaluated in an outpatient nephrology clinic between January 2012 to December 2017 with at least one year follow up. Anemia (defined according to the WHO definition - Hemoglobin [Hb] < 13.0 g/dL in men and 12.0g/dL in women), absolute iron deficiency (ferritin < 100 ng/mL), other demographic and clinical data (CKD staging and etiology, comorbidities) were assessed at the first visit through individual consultation of electronic medical records. Results During the 6-year period, 3008 patients were identified (mean age 70.9±14.1 years; 54.5% male; 91.7% white) with a mean follow-up of 3.3±2.0 years. The most frequent cardiovascular comorbidities were arterial hypertension (81.9%), obesity (58%), diabetes mellitus (57.9%) and dyslipidemia (43.9%). The mean Hb was 11.8 ±1.9 g/dL. Anemia was present in 49.9 % of patients, with similar distribution between genders (50.4% in men vs 49.6% in women) and more frequent in white patients (92% vs 8% p= 0.019). Anemia prevalence increased across CKD stages - 12.9%, 25.9%, 57.2%, 72.7% and 86.4% for stages 1 to 5, respectively (p<0,001 for the trend). Anemia was associated with cardiovascular comorbidities, such as diabetes (52% vs 32%, p<0.001), hypertension (86.7% vs 77.7%, p<0.001), obesity (65.5% vs 60.8 %, p=0.012) and dyslipidemia (46% vs 41.2%, p=0.01). Among patients with ferritin levels available (1638), 41.7% had absolute iron deficiency. Anemia was associated with increased mortality (74% vs 26%, p <0,001) and hospitalization (61,8% vs 38.2%, p <0.001). In multivariate logistic regression analysis, anemia (OR 1,923; 95%IC 1,362-2.716; p<0,001) and absolute iron deficiency (OR 0.531 95% IC 0.348-0.809; p=0.003) emerged as independent predictors of death. Cardiovascular events were more prevalent in the group of patients with Hb levels 10-12 g/dL (4.1 vs2.3% 2p=0.006). Conclusion As expected, anemia prevalence increases across CKD stages and, as well as absolute iron deficiency, is independently associated with adverse clinical outcomes in ND-CKD patients, including death. Future studies should be developed to investigate if correction of these factors improves adverse outcomes.