title: The relationship between hemoglobin levels and endothelial functions in diabetes mellitus.
abstract: OBJECTIVE
  Hemoglobin (Hb) is the main carrier and buffer of nitric oxide. Evidence has been produced that Hb concentration is inversely related with endothelial function in human diseases. Testing whether this association exists also in diabetic patients stage 1 to 2 chronic kidney disease (CKD) is important because anemia in these patients starts at an earlier stage than in other renal diseases. The relationship was investigated between Hb and flow-mediated dilation (FMD) levels of the patients with diabetic nephropathy in a cross-sectional design.
  
  
  METHODS
  Eighty-nine diabetics with mild to moderate proteinuria and normal to mildly reduced GFR who were normotensive, nondyslipidemic, and cardiovascular-events free were enrolled. None of the patients was taking metformin or renin-angiotensin system blockers.
  
  
  RESULTS
  FMD was inversely related with Hb levels. Furthermore, there was an inverse link between proteinuria and FMD. However, further analysis of this association showed that the FMD-proteinuria link was confined to patients with proteinuria exceeding 150 mg/d, while no such association existed in patients with proteinuria <150 mg/d. Adjustment of the Hb-FMD relationship for pertinent Framingham risk factors, proteinuria, homeostasis model assessment (HOMA) index, and GFR levels had a modest influence on this association, which remained significant.
  
  
  CONCLUSIONS
  Endothelial function is inversely associated with Hb levels in diabetic patients with stage 1 to 2 CKD, and proteinuria is an effect modifier of this association. Overall, the observations of this study generate the hypothesis that proteinuria exposes a situation wherein Hb may limit the endothelium-mediated vasoregulation in diabetes.
authors.affiliation: Department of Nephrology, Gülhane School of Medicine, 06018 Etlik, Ankara, Turkey.
authors.forename: Alper
authors.initials: A
authors.lastname: Sonmez
authors.forename: Mahmut Ilker
authors.initials: MI
authors.lastname: Yilmaz
authors.forename: Mutlu
authors.initials: M
authors.lastname: Saglam
authors.forename: Selim
authors.initials: S
authors.lastname: Kilic
authors.forename: Tayfun
authors.initials: T
authors.lastname: Eyileten
authors.forename: Gokhan
authors.initials: G
authors.lastname: Uckaya
authors.forename: Kayser
authors.initials: K
authors.lastname: Caglar
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Oguz
authors.forename: Abdulgaffar
authors.initials: A
authors.lastname: Vural
authors.forename: Mujdat
authors.initials: M
authors.lastname: Yenicesu
authors.forename: Mustafa
authors.initials: M
authors.lastname: Kutlu
authors.forename: Can
authors.initials: C
authors.lastname: Kinalp
authors.forename: Carmine
authors.initials: C
authors.lastname: Zoccali
mesh_terms: D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000097:blood* / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D006454:Hemoglobins