title: Blood urea impairs brachial artery flow mediated dilation.
abstract: OBJECTIVE
  Urea, the main product of protein catabolism, is a biochemical marker of renal function. Though it is known that serum urea impairs vascular health, the relationship between its concentration and vascular reactivity in vivo has not been explored. Our study was undertaken to investigate possible association between serum urea and endothelial function in subjects without chronic kidney disease (CKD).
  
  
  METHODS
  Eighty free-living subjects with serum creatinine ≤1 mg/dL and without CKD were enrolled for the present study. Serum analyses and evaluation of endothelial function were performed in all subjects. Endothelial function was measured using the flow-mediated dilation (FMD) technique. Simple and multiple regression analyses were used to test the association between FMD and considered variables.
  
  
  RESULTS
  In correlation analyses FMD was found directly associated with HDL cholesterol (r=0.21; P=0.05) and eGFR (r=0.25; P=0.02) and inversely associated with age (r=-0.26; P=0.02), serum urea (r=-0.37; P<0.01), serum creatinine (r=-0.31; P<0.01) and brachial artery baseline diameter (r=-0.41; P<0.01). In multiple regression analysis only baseline artery diameter and serum urea predicted FMD; age, gender and cardiovascular risk factors did not relate with FMD.
  
  
  CONCLUSIONS
  Our study demonstrates the association between serum urea and FMD, suggesting that the accumulation of waste products of protein metabolism may impair vascular health in subjects without CKD.
authors: Department of Clinical and Experimental Medicine, "Magna Græcia" University, Catanzaro, Italy.
authors: C
authors: C
authors: Tripolino
authors: C
authors: C
authors: Irace
authors: C
authors: C
authors: Carallo
authors: M S
authors: MS
authors: De Franceschi
authors: E
authors: E
authors: Della Valle
authors: A
authors: A
authors: Gnasso
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers; D001916:Brachial Artery / Q000503:physiopathology*; D008076:Cholesterol, HDL / Q000097:blood*; D003404:Creatinine / Q000097:blood*; D003430:Cross-Sectional Studies; D004730:Endothelium, Vascular / Q000503:physiopathology; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012307:Risk Factors; D014508:Urea / Q000097:blood*; D014664:Vasodilation / Q000502:physiology*
chemical_list: D015415:Biomarkers; D008076:Cholesterol, HDL; D014508:Urea; D003404:Creatinine