Macrocytosis may be associated with mortality in chronic hemodialysis patients: a prospective study

We conducted a single-centre prospective cohort study of 150 stable, adult CHD patients followed for nine months. Macrocytosis was defined as a mean corpuscular volume (MCV) > 97 fl. We analyzed MCV as a continuous variable, in tertiles and using a cutoff point of 102 fl.The mean MCV was 99.1 ± 6.4 fl, (range 66-120 fl). MCV was normally distributed. 92 (61%) of patients had an MCV > 97 fl and 45 (30%) > 102 fl. Patients were not B12 or folate deficient in those with available data and three patients with an MCV > 102 fl had hypothyroidism. In a logistic regression analysis, an MCV > 102 fl was associated with a higher Charlson-Age Comorbidity Index (CACI) and higher ratios of darbepoetin alfa to hemoglobin (Hb), [(weekly darbepoetin alfa dose in micrograms per kg body weight / Hb in g/L)*1000]. There were 23 deaths at nine months in this study. Unadjusted MCV > 102 fl was associated with mortality (HR 3.24, 95% CI 1.42-7.39, P = 0.005). Adjusting for the CACI, an MCV > 102 fl was still associated with mortality (HR 2.47, 95% CI 1.07-5.71, P = 0.035).Macrocytosis may be associated with mortality in stable, chronic hemodialysis patients. Future studies will need to be conducted to confirm this finding.Anemia is a common consequence of end-stage renal disease (ESRD). Several causes have been identified including iron deficiency [1], reduced production of erythropoietin [2], shortened red cell survival [3] and folate deficiency [4]. Among these, endogenous erythropoietin deficiency is the predominant cause [2].Erythropoiesis stimulating agents (ESAs) have been effective in treating the anemia of ESRD [5,6]. However, despite their use, anemia may still occur and is associated with significant morbidity and mortality in dialysis patients [7,8]. Furthermore, higher ESA doses have also been associated with increased mortality in hemodialysis patients [9-11]. Whether the increase in mortality observed with ESAs is due to achieved hemoglobin, ESA resistance due to inflammati