Kaan Ceken

Publications (2)4.71 Total impact

• Article: Advanced oxidative protein products are independently associated with endothelial function in peritoneal dialysis patients.

  Huseyin Kocak, Saadet Gumuslu, Emel Sahin, Kaan Ceken, Yesim A Gocmen, Gulsen Yakupoglu, F Fevzi Ersoy, Murat Tuncer
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  ABSTRACT: Oxidative stress (OS) and asymmetric dimethylarginine (ADMA) are accepted as non-classical cardiovascular risk factors in end-stage renal disease patients. To clarify the role of these factors in the atherosclerotic process, we investigated if OS and ADMA are associated with endothelial function (EF) in peritoneal dialysis (PD) patients. Fifty-two non-diabetic PD patients without known atherosclerotic disease as well as 30 age- and sex-matched healthy individuals were included. We measured serum thiobarbituric acid-reactive substances (TBARS), malondialdehyde (MDA), advanced glycation end-product (AGE), pentosidine, advanced oxidation protein products (AOPP), ADMA and EF as described by Celermejer et al. in all subjects. TBARS, MDA, AOPP, AGE, pentosidine and ADMA levels were significantly higher in PD patients than in controls (P < 0.001). Flow-mediated dilatation (FMD)% and nitrate mediated dilatation (NMD)% in PD patients were lower than in the control group (7.7 +/- 4.0% vs 11.70 +/- 5.50%, P < 0.01 and 17.6 +/- 8.3% vs 26.4 +/- 4.6%, P < 0.01). Additionally, it was found that AOPP are independently correlated with FMD% and NMD% in PD patients (beta = -463, P < 0.01 and beta = -420, P < 0.05). This study shows that PD patients without known atherosclerotic disease can also be characterized by endothelial dysfunction and AOPP levels independently predict endothelial function level in PD patients.
  Nephrology 12/2008; 14(3):273-80. · 1.31 Impact Factor
• Article: Effect of renal transplantation on endothelial function in haemodialysis patients.

  Huseyin Kocak, Kaan Ceken, Asuman Yavuz, Selcuk Yucel, Alihan Gurkan, Okan Erdogan, Fevzi Ersoy, Gulsen Yakupoglu, Alper Demirbas, Murat Tuncer
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  ABSTRACT: Haemodialysis patients (HD) have been characterized by a high incidence and prevalence of atherosclerotic cardiovascular disease. Based on the traditional cardiovascular risk factors in this population, we cannot explain this high incidence and prevalence. One of the mechanisms contributing to cardiovascular risk in HD patients may be to uraemic toxins. Cardiovascular risk factors and uraemic toxins themselves may cause endothelial dysfunction, which may play a pivotal role in the development and progression of atherosclerosis in this population. We hypothesized that elimination of uraemic toxins in response to renal transplantation (RTx) can improve endothelial function as assessed by flow-mediated dilatation of brachial artery in haemodialysis (HD) patients. Endothelial function measured by flow-mediated dilatation of the brachial artery (FMD) and glyceryltrinitrate-induced dilatation of the brachial artery (NMD) were assessed twice, during haemodialysis treatment and after RTx in 30 chronic haemodialysis patients. All patients were characterized by absence of known atherosclerotic disease and traditional cardiovascular risk factors. We also studied age- and gender-matched 20 normotensive healthy controls. FMD values significantly improved after RTx (6.69+/-3.1% vs 10.50+/-3.0%, P<0.001) in HD patients. FMD of patients both during haemodialysis and after RTx was lower than in healthy controls (6.69+/-3.1%, 10.50+/-3.0% vs 14.02+/-2.3%, P<0.001 and P<0.01, respectively). There was no change in NMD values after RTx in HD patients (16.27+/-1.9% vs 16.30+/-1.8%, P>0.05). Also, NMD values in all patients were similar to healthy control values. There is an improvement of endothelial function as assessed by FMD of the brachial artery after RTx in HD patients. This may be attributed to the elimination of uraemic toxins by successful RTx.
  Nephrology Dialysis Transplantation 02/2006; 21(1):203-7. · 3.40 Impact Factor