title: Impact of hemoglobin levels on renal and non-renal clinical outcomes differs by chronic kidney disease stages: the Gonryo study.
abstract: BACKGROUND
  Anemia greatly affects the development of renal and cardiovascular outcomes in chronic kidney disease (CKD) patients. However, the impact based on CKD stage remains unclear.
  
  
  METHODS
  We prospectively followed 2,602 Japanese CKD patients under the care of nephrologists. CKD was defined according to cause, estimated glomerular filtration rate <60 mL/min, and/or proteinuria. Patient outcomes [primary end-points: cardiovascular events (CVEs), all-cause mortality, and end-stage kidney disease (ESKD) requiring renal replacement therapy] were assessed in association with basal hemoglobin (Hb) levels (<10, 10-12 and ≥12 g/dL), stratified by CKD stages.
  
  
  RESULTS
  During follow-up, 123 patients developed CVEs, 41 died, and 220 progressed to ESKD. For stages G3, G4 and G5, ESKD frequencies were 2.8, 64.4, and 544.8 person-years, while CVEs and death were 25.6, 45.6, and 76.3 person-years, respectively. The combined endpoint rate was significantly higher in patients with Hb <10 versus Hb 10-12 g/dL, but a higher risk for CVEs and death with Hb <10 g/dL was found only in G3 [hazard ratio (HR) 4.49, (95 % confidence interval (95 % CI) 2.06-9.80)]. In contrast, risk for ESKD with Hb <10 g/dL was found only in G4 [HR 3.08 (95 % CI 1.40-6.79)] and G5 [HR 1.43 (95 % CI 1.01-2.05)]. No increased risks with higher Hb levels were found.
  
  
  CONCLUSIONS
  The impact of renal anemia of Hb <10 g/dL on clinical outcomes differed by CKD stage, with a significantly high risk for CVEs and all-cause mortality in G3 and progression to ESKD in G4 and G5.
authors.affiliation: Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan. tae.yamamoto@med.tohoku.ac.jp.
authors.forename: Tae
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan.|Center for Advanced Integrated Renal Science, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Miyazaki
authors.affiliation: Center for Advanced Integrated Renal Science, Tohoku University Graduate School of Medicine, Sendai, Japan.|Division of Nephrology, Hypertension, Diabetology, Endocrinology, and Metabolism, Fukushima Medical University School of Medicine, Fukushima, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Nakayama
authors.affiliation: Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan.
authors.forename: Gen
authors.initials: G
authors.lastname: Yamada
authors.affiliation: Center for Advanced Integrated Renal Science, Tohoku University Graduate School of Medicine, Sendai, Japan.|Department of Clinical Research, The Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Matsushima
authors.affiliation: Kidney Center, Japan Community Health Care Organization Sendai Hospital, Sendai, Japan.
authors.forename: Mistuhiro
authors.initials: M
authors.lastname: Sato
authors.affiliation: Kidney Center, Japan Community Health Care Organization Sendai Hospital, Sendai, Japan.
authors.forename: Toshinobu
authors.initials: T
authors.lastname: Sato
authors.affiliation: Center for Advanced Integrated Renal Science, Tohoku University Graduate School of Medicine, Sendai, Japan.|Kidney Center, Japan Community Health Care Organization Sendai Hospital, Sendai, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Taguma
authors.affiliation: Center for Advanced Integrated Renal Science, Tohoku University Graduate School of Medicine, Sendai, Japan.|Clinical Pharmacology and Therapeutics, Tohoku University Graduate School of Pharmaceutical Sciences, Sendai, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sato
authors.affiliation: Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan.|Center for Advanced Integrated Renal Science, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Sadayoshi
authors.initials: S
authors.lastname: Ito
mesh_terms: D000328:Adult; D000368:Aged; D000740:Anemia / Q000209:etiology*; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000150:complications / Q000401:mortality; D012720:Severity of Illness Index
chemical_list: D006454:Hemoglobins
keywords: Anemia; Chronic kidney disease; End-stage kidney disease; Hemoglobin; Nephrology; Outcome