title: Low triiodothyronine alters flow-mediated vasodilatation in advanced nondiabetic kidney disease.
abstract: OBJECTIVE
  Subclinical or frank hypothyroidism is causally implicated in endothelial dysfunction. Since the plasma concentration of the active form of thyroid hormone, triiodothyronine (T₃), is reduced in chronic kidney disease (CKD), where endothelial function is frequently altered, low T₃ may be a factor implicated in this disturbance in CKD patients.
  
  
  METHODS
  We investigated the relationship between flow-mediated vasodilatation (FMD) and thyroid hormones in a series of 217 nondiabetic patients with stage 3-4 CKD.
  
  
  RESULTS
  The plasma concentration of free T₃ (fT₃) was closely associated with FMD (r = 0.38; p < 0.001). fT₃ was also inversely associated with hemoglobin (r = -0.41; p < 0.001), systolic pressure (r = -0.28; p < 0.001) and the plasma concentration of the endogenous inhibitor of NO synthase, asymmetric dimethylarginine (ADMA; r = -0.18; p = 0.007). However, adjustment for ADMA markedly attenuated the fT₃-FMD link, a phenomenon suggesting that raised plasma ADMA, possibly driven by low fT₃, at least in part mediates the adverse effects of low T₃ on endothelial function in CKD.
  
  
  CONCLUSIONS
  Low T₃ in patients with moderate-to-severe CKD is a marker of endothelial dysfunction. This study sets a solid rationale for designing specific intervention studies aimed at clarifying the nature (causal or not causal) of the endothelial function-T₃ link in CKD.
authors.affiliation: Department of Nephrology, Gülhane School of Medicine, Ankara, Turkey. mahmutiyilmaz@yahoo.com
authors.forename: Mahmut Ilker
authors.initials: MI
authors.lastname: Yilmaz
authors.forename: Alper
authors.initials: A
authors.lastname: Sonmez
authors.forename: Murat
authors.initials: M
authors.lastname: Karaman
authors.forename: Seyit Ahmet
authors.initials: SA
authors.lastname: Ay
authors.forename: Mutlu
authors.initials: M
authors.lastname: Saglam
authors.forename: Halil
authors.initials: H
authors.lastname: Yaman
authors.forename: Selim
authors.initials: S
authors.lastname: Kilic
authors.forename: Tayfun
authors.initials: T
authors.lastname: Eyileten
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: Carmine
authors.initials: C
authors.lastname: Zoccali
mesh_terms: D000328:Adult; D003920:Diabetes Mellitus / Q000175:diagnosis; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood; D007249:Inflammation; D007674:Kidney Diseases / Q000097:blood* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011312:Pressure; D012044:Regression Analysis; D012307:Risk Factors; D014284:Triiodothyronine / Q000097:blood*; D014664:Vasodilation
chemical_list: D014284:Triiodothyronine