title: Relationship between Hemoglobin Levels Corrected by Interdialytic Weight Gain and Mortality in Japanese Hemodialysis Patients: Miyazaki Dialysis Cohort Study.
abstract: BACKGROUND
  Although hemoglobin (Hb) levels are affected by a change in the body fluid status, the relationship between Hb levels and mortality while taking interdialytic weight gain (IDWG) at blood sampling into account has not yet been examined in hemodialysis patients.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Data from the Miyazaki Dialysis cohort study, including 1375 prevalent hemodialysis patients (median age (interquartile range), 69 (60-77) years, 42.3% female).
  
  
  METHODS
  Patients were divided into 5 categories according to baseline Hb levels and two groups based on the median value of IDWG rates at blood sampling at pre-HD on the first dialysis session of the week.
  
  
  RESULTS
  All-cause and cardiovascular mortalities during a 3-year follow-up.
  
  
  METHODS
  Hazard ratios were estimated using a Cox model for the relationship between Hb categories and mortality, and adjusted for potential confounders such as age, sex, dialysis duration, erythropoiesis-stimulating agent dosage, Kt/V, comorbid conditions, anti-hypertensive drug use, serum albumin, serum C-reactive protein, serum ferritin, and serum intact parathyroid hormone. Patients with Hb levels of 9-9.9 g/dL were set as our reference category.
  
  
  RESULTS
  A total of 246 patients (18%) died of all-cause mortality, including 112 cardiovascular deaths. Lower Hb levels (<9.0g/dL) were associated with all-cause mortality (adjusted HRs 2.043 [95% CI, 1.347-3.009]), while Hb levels were not associated with cardiovascular mortality. When patients were divided into two groups using the median value of IDWG rates (high IDWG, ≥5.4% and low IDWG, <5.4%), the correlation between lower Hb levels and all-cause mortality disappeared in high IDWG patients, but was maintained in low IDWG patients (adjusted HRs 3.058 [95% CI,1.575-5.934]). On the other hand, higher Hb levels (≥12g/dL) were associated with cardiovascular mortality in high IDWG patients (adjusted HRs 2.724 [95% CI, 1.010-7.349]), but not in low IDWG patients.
  
  
  CONCLUSIONS
  In hemodialysis patients, target Hb levels may need to be selected in consideration of IDWG at blood sampling.
authors.affiliation: Division of Circulatory and Body Fluid Regulation, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.|Department of Hemovascular Medicine and Artificial Organs, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
authors.forename: Tatsunori
authors.identifier: http://orcid.org/0000-0003-0135-599X
authors.initials: T
authors.lastname: Toida
authors.affiliation: Department of Internal Medicine, Miyazaki Konan Hospital, Miyazaki, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Iwakiri
authors.affiliation: Dialysis Division, University of Miyazaki Hospital, Miyazaki, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Sato
authors.affiliation: First Department of Internal Medicine, University of Miyazaki Hospital, Miyazaki, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Komatsu
authors.affiliation: Division of Circulatory and Body Fluid Regulation, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kitamura
authors.affiliation: Department of Hemovascular Medicine and Artificial Organs, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
authors.forename: Shouichi
authors.initials: S
authors.lastname: Fujimoto
mesh_terms: D000368:Aged; D001835:Body Weight; D002318:Cardiovascular Diseases / Q000150:complications / Q000401:mortality; D005260:Female; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007564:Japan; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000150:complications / Q000401:mortality* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D006435:Renal Dialysis; D015430:Weight Gain
chemical_list: D006454:Hemoglobins