title: Macrocytosis may be associated with mortality in chronic hemodialysis patients: a prospective study.
abstract: BACKGROUND
  Macrocytosis occurs in chronic hemodialysis (CHD) patients; however, its significance is unknown. The purpose of this study was to establish the prevalence and distribution of macrocytosis, to identify its clinical associations and to determine if macrocytosis is associated with mortality in stable, chronic hemodialysis patients.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  Macrocytosis may be associated with mortality in stable, chronic hemodialysis patients. Future studies will need to be conducted to confirm this finding.
authors.affiliation: Division of Nephrology, Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada. ktennankore@gmail.com
authors.forename: Karthik K
authors.initials: KK
authors.lastname: Tennankore
authors.forename: Steven D
authors.initials: SD
authors.lastname: Soroka
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: West
authors.forename: Bryce A
authors.initials: BA
authors.lastname: Kiberd
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D000068256:Darbepoetin alfa; D004909:Erythrocyte Indices; D004913:Erythrocytes, Abnormal / Q000378:metabolism; D004921:Erythropoietin / Q000008:administration & dosage / Q000031:analogs & derivatives; D005260:Female; D005492:Folic Acid / Q000378:metabolism; D006397:Hematinics / Q000008:administration & dosage; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000401:mortality* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D006435:Renal Dialysis; D013972:Thyrotropin / Q000097:blood; D014805:Vitamin B 12 / Q000097:blood
chemical_list: D006397:Hematinics; D006454:Hemoglobins; D004921:Erythropoietin; D000068256:Darbepoetin alfa; D013972:Thyrotropin; D005492:Folic Acid; D014805:Vitamin B 12