Hemoglobin is inversely related to flow-mediated dilatation in chronic kidney disease.
The microcirculation is regulated by oxygen gradients and by endothelial release of nitric oxide, which can react with hemoglobin to form S-nitroso derivatives. Here we induced flow-mediated dilatation of the brachial artery in response to ischemia in 141 non-diabetic patients with stage 3-4 chronic kidney disease who had no history of smoking, cardiovascular events or use of erythropoietin-based agents. Patients with hemoglobin concentrations above the cohort median of 11.6 g/dl were found to have significant reductions in flow-mediated dilatation compared to those below the median. This inverse relationship remained significant after adjustment for potential confounders, including insulin sensitivity, glomerular filtration rate, proteinuria, body mass index, serum urate, etiology of underlying renal disease, treatment with anti-hypertensive drugs, and traditional Framingham risk factors. Given that hemoglobin can act as an important nitric oxide carrier and buffer, our studies suggest that the mechanism by which hemoglobin influences the endothelium-dependent microcirculation requires its nitrosylation; however, more direct studies need to be performed.
Yilmaz
Mahmut I
MI
Department of Nephrology, Gülhane School of Medicine, Etlik-Ankara, Turkey. Electronic address: mahmutiyilmaz@yahoo.com.
Sonmez
Alper
A
Department of Internal Medicine, Gülhane School of Medicine, Etlik-Ankara, Turkey.
Saglam
Mutlu
M
Department of Radiology, Gülhane School of Medicine, Etlik-Ankara, Turkey.
Gulec
Mahir
M
Department of Epidemiology, Gülhane School of Medicine, Etlik-Ankara, Turkey.
Kilic
Selim
S
Department of Epidemiology, Gülhane School of Medicine, Etlik-Ankara, Turkey.
Eyileten
Tayfun
T
Department of Nephrology, Gülhane School of Medicine, Etlik-Ankara, Turkey.
Caglar
Kayser
K
Department of Nephrology, Gülhane School of Medicine, Etlik-Ankara, Turkey.
Oguz
Yusuf
Y
Department of Nephrology, Gülhane School of Medicine, Etlik-Ankara, Turkey.
Vural
Abdulgaffar
A
Department of Nephrology, Gülhane School of Medicine, Etlik-Ankara, Turkey.
Yenicesu
Mujdat
M
Department of Nephrology, Gülhane School of Medicine, Etlik-Ankara, Turkey.
Zoccali
Carmine
C
Department of Nephrology, Hypertension and Renal Transplantation, CNR-IBIM Clinical Epidemiology of Renal Diseases and Hypertension, Ospedali Riuniti, Reggio Calabria, Italy.
D000328:Adult; D001783:Blood Flow Velocity; D001916:Brachial Artery / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000503:physiopathology; D005260:Female; D006439:Hemodynamics; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007511:Ischemia / Q000503:physiopathology; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000503:physiopathology*; D008297:Male; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D015999:Multivariate Analysis; D012307:Risk Factors
D006454:Hemoglobins