title: Effects of thrice weekly nocturnal hemodialysis on arterial stiffness.
abstract: OBJECTIVE
  In this study, we compared the changes in arterial stiffness in chronic hemodialysis patients treated with 8-h vs. 4-h thrice weekly in-center hemodialysis.
  
  
  METHODS
  Sixty prevalent chronic hemodialysis patients assigned to 8-h nocturnal in-center thrice weekly HD (NHD) and 60 control cases assigned to 4-h thrice weekly conventional HD (CHD) were followed for one year. Radial-carotid pulse wave velocity, augmentation index and echocardiography were performed at baseline and 12th month.
  
  
  RESULTS
  Mean age of the patients was 49±11 years, 30.8% were female, 27.5% had diabetes mellitus and mean dialysis vintage was 57±47 months. Baseline demographical, clinical and laboratory parameters were similar between groups. During a mean follow-up of 15.0±0.1 months, blood pressure remained similar in both groups while the number of mean daily anti-hypertensive substances decreased in the NHD group. In the NHD group, time-averaged serum phosphorus and calcium-phosphorus product were lower than the CHD group. Pulse wave velocity and augmentation index decreased in the NHD group (from 11.02±2.51 m/s to 9.61±2.39 m/s and from 28.8±10.3% to 26.2±12.1%; p=0.008 and p=0.04, respectively). While augmentation index increased in the CHD group (28.0±9.4 to 31.0±10.7%, p=0.02), pulse wave velocity did not change. Subendocardial viability ratio and ejection duration improved in the NHD group (from 135±28 to 143±25%, p=0.01 and from 294±34 ms to 281±34 ms, p=0.003, respectively), accompanied by regression of left ventricular mass index. In multiple stepwise linear regression analyses, NHD was associated with improvements in augmentation index, ejection duration and subendocardial viability ratio.
  
  
  CONCLUSIONS
  These data indicate that arterial stiffness is ameliorated by implementation of longer hemodialysis sessions.
authors.affiliation: Division of Nephrology, Ege University School of Medicine, Izmir, Turkey. meltem.sezis@ege.edu.tr
authors.forename: Meltem Sezis
authors.initials: MS
authors.lastname: Demirci
authors.forename: Gulperi
authors.initials: G
authors.lastname: Celik
authors.forename: Mehmet
authors.initials: M
authors.lastname: Ozkahya
authors.forename: Murat
authors.initials: M
authors.lastname: Tumuklu
authors.forename: Huseyin
authors.initials: H
authors.lastname: Toz
authors.forename: Gulay
authors.initials: G
authors.lastname: Asci
authors.forename: Soner
authors.initials: S
authors.lastname: Duman
authors.forename: Ali
authors.initials: A
authors.lastname: Basci
authors.forename: Fatih
authors.initials: F
authors.lastname: Kircelli
authors.forename: Oner
authors.initials: O
authors.lastname: Ozdogan
authors.forename: Cenk
authors.initials: C
authors.lastname: Demirci
authors.forename: Levent
authors.initials: L
authors.lastname: Can
authors.forename: Ismet Onder
authors.initials: IO
authors.lastname: Isik
authors.forename: Ercan
authors.initials: E
authors.lastname: Ok
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001794:Blood Pressure; D002339:Carotid Arteries / Q000503:physiopathology*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D002940:Circadian Rhythm; D004548:Elasticity; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D011673:Pulsatile Flow; D017534:Radial Artery / Q000503:physiopathology*; D006435:Renal Dialysis / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome; D014421:Turkey; D055815:Young Adult