Cenk Demirci
Ege University
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Featured researches published by Cenk Demirci.
Nephrology Dialysis Transplantation | 2013
Ercan Ok; Gulay Asci; Huseyin Toz; Ebru Sevinc Ok; Fatih Kircelli; Mumtaz Yilmaz; Ender Hur; Meltem Sezis Demirci; Cenk Demirci; Soner Duman; Ali Basci; Siddig Momin Adam; Ismet Onder Isik; Murat Zengin; Gultekin Suleymanlar; Mehmet Emin Yilmaz; Mehmet Ozkahya
BACKGROUND Online haemodiafiltration (OL-HDF) is considered to confer clinical benefits over haemodialysis (HD) in terms of solute removal in patients undergoing maintenance HD. The aim of this study was to compare postdilution OL-HDF and high-flux HD in terms of morbidity and mortality. METHODS In this prospective, randomized, controlled trial, we enrolled 782 patients undergoing thrice-weekly HD and randomly assigned them in a 1:1 ratio to either postdilution OL-HDF or high-flux HD. The mean age of patients was 56.5 ± 13.9 years, time on HD 57.9 ± 44.6 months with a diabetes incidence of 34.7%. The follow-up period was 2 years, with the mean follow-up of 22.7 ± 10.9 months. The primary outcome was a composite of death from any cause and nonfatal cardiovascular events. The major secondary outcomes were cardiovascular and overall mortality, intradialytic complications, hospitalization rate, changes in several laboratory parameters and medications used. RESULTS The filtration volume in OL-HDF was 17.2 ± 1.3 L. Primary outcome was not different between the groups (event-free survival of 77.6% in OL-HDF versus 74.8% in the high-flux group, P = 0.28), as well as cardiovascular and overall survival, hospitalization rate and number of hypotensive episodes. In a post hoc analysis, the subgroup of OL-HDF patients treated with a median substitution volume >17.4 L per session (high-efficiency OL-HDF, n = 195) had better cardiovascular (P = 0.002) and overall survival (P = 0.03) compared with the high-flux HD group. In adjusted Cox-regression analysis, treatment with high-efficiency OL-HDF was associated with a 46% risk reduction for overall mortality {RR = 0.54 [95% confidence interval (95% CI) 0.31-0.93], P = 0.02} and a 71% risk reduction for cardiovascular mortality [RR = 0.29 (95% CI 0.12-0.65), P = 0.003] compared with high-flux HD. CONCLUSIONS The composite of all-cause mortality and nonfatal cardiovascular event rate was not different in the OL-HDF and in the high-flux HD groups. In a post hoc analysis, OL-HDF treatment with substitution volumes over 17.4 L was associated with better cardiovascular and overall survival.
Nephrology Dialysis Transplantation | 2011
Meltem Sezis Demirci; Cenk Demirci; Oner Ozdogan; Fatih Kircelli; Fehmi Akcicek; Ali Basci; Ercan Ok; Mehmet Ozkahya
BACKGROUND Chronic fluid overload (FO) is frequently present in peritoneal dialysis (PD) patients and is associated with hypertension and left ventricular hypertrophy and dysfunction, which are important predictors of death in dialysis patients. In the present study, we investigated the relationship between nutrition, inflammation, atherosclerosis and body fluid volumes measured by multi-frequency bioimpedance analysis (m-BIA) in PD patients. In addition, we analysed the relationship of extracellular volume values by m-BIA to echocardiographic parameters in order to define its usefulness as a measure of FO. METHODS Ninety-five prevalent PD patients (mean age 50 ± 13 years, 10 of them diabetic) were enrolled. Extracellular water (ECW), total body water (TBW), dry lean mass (DLM) and phase angle (PA) were measured by m-BIA. Volume status was determined by measuring left atrium diameter (LAD) and left ventricular end-diastolic diameter (LVEDD). Measurement of carotid artery intima-media thickness (CA-IMT) was used to assess the presence of subclinical atherosclerosis. Serum albumin was used as a nutritional marker, and serum C-reactive protein (CRP) was used as an inflammatory marker. RESULTS Mean ECW/height was 10.0 ± 1.0 L/m for whole group and 9.3 ± 0.6 L/m in patients with normal clinical hydration parameters. In correlation analysis, markers of nutrition, inflammation and atherosclerosis correlated well with m-BIA parameters. When we used echographically measured LAD (> 40 mm) or LVEDD (> 55 mm) as a confirmatory parameter, a cut-off value of 10.48 L/m ECW/height (78% specificity, with a sensitivity of 77% for LAD and 72% specificity, with a sensitivity of 70% for LVEDD) was found in ROC analysis for the diagnosis of FO. Patients with FO were older and had higher systolic blood pressure, cardiothoracic index, serum CRP level and mean CA-IMT than patients without FO. Patients with inflammation had higher CA-IMT values. In multivariate analysis, only two factors-low urine output and ECW/height-were independently associated with the presence of inflammation. CONCLUSIONS FO defined by m-BIA is significantly correlated with markers of malnutrition, inflammation and atherosclerosis in PD patients. The indices obtained from m-BIA, especially ECW/height, correlated well with volume overload as assessed by echocardiography and might be a measure worth testing in a properly designed clinical study.
American Journal of Nephrology | 2013
Cenk Demirci; Mehmet Ozkahya; Meltem Sezis Demirci; Gulay Asci; Timur Köse; Taskin Colak; Soner Duman; Huseyin Toz; Pinar Ergin; Sıddık M. Adam; Ercan Ok
Background: This prospective cohort study compared the changes in body water composition and nutritional parameters measured with multifrequency bioimpedance analysis between 8-hour three times weekly nocturnal hemodialysis (NHD) and 4-hour conventional hemodialysis (CHD) patients. Patients and Methods: 55 patients on CHD and 57 patients on NHD were included in the study. Multifrequency bioimpedance analysis was performed at baseline and at the 12th month. The primary outcomes of the study were changes in extracellular water (ECW), fat mass, dry lean mass and phase angle. Secondary outcomes of the study included changes in blood pressure and biochemical parameters related to nutrition and inflammation. Results: ECW/height values decreased in the NHD group, while they increased in the CHD group. Fat mass, dry lean mass, and serum albumin increased and high sensitive CRP decreased in the NHD group but did not change in the CHD group. When changes in parameters from baseline to the 12th month between the groups were compared, NHD was associated with improvement in volume parameter including ECW/height (difference -0.44 l/m, p < 0.001). Change in blood pressure was not different between the groups, however requirement for antihypertensive medication decreased from 26.5 to 8.5% in the NHD group (p = 0.002). NHD was also associated with increases in fat mass (difference 1.8 kg, p < 0.001), dry lean mass (difference 0.6 kg, p = 0.006), serum albumin (difference 0.19 g/dl, p < 0.001) and cholesterol (difference 18.8 mg, p < 0.001). Phase angle values decreased in the CHD group but did not change in the NHD group (difference between the groups 0.37°, p = 0.04). Conclusion: This study revealed that longer HD facilitates volume control and improves nutritional status.
Atherosclerosis | 2012
Meltem Sezis Demirci; Gulperi Celik; Mehmet Ozkahya; Murat Tumuklu; Huseyin Toz; Gulay Asci; Soner Duman; Ali Basci; Fatih Kircelli; Oner Ozdogan; Cenk Demirci; Levent Can; Ismet Onder Isik; Ercan Ok
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.
Clinical Nephrology | 2012
Mettem Sezis Demirci; Ozkan Gungor; Fatih Kircelli; Juan Jesus Carrero; Erhan Tatar; Cenk Demirci; Meral Kayikcioglu; Gulay Asci; Huseyin Toz; Mehmet Ozkahya; Ercan Ok
INTRODUCTION Arterial stiffness is an important contributor to the increased cardiovascular burden of uremia. The aim of the study was to identify determinants of arterial stiffness progression in peritoneal dialysis (PD) patients with strict volume control. PATIENTS AND METHODS 89 prevalent PD patients were enrolled. Assessment of arterial stiffness was performed at baseline and after nine months on average (range 8 - 12 months) by carotid-femoral pulse wave velocity (cf-PWV). RESULTS Mean age was 51 ± 13 y; preceeding time on PD was 40 ± 34 months. 57% of the patients were men and 9% were diabetic. At baseline, mean cf- PWV was 8.7 ± 2.7 m/s and was significantly higher in patients with diabetes and on automated PD therapy. Cf-PWV was positively correlated with age, history of cardiovascular disease, mean arterial pressure (MAP), blood glucose, left atrium diameter and left ventricular mass index. Sixty patients underwent a second cf-PWV measurement. 36% had progression of arterial stiffness. Delta cf- PWV value was 2.08 ± 1.89 m/s for progressors and -1.25 ± 1.43 m/s; p < 0.01 for nonprogressors (p < 0.01). In logistic regression analysis, the change in MAP was the only predictor for progression of arterial stiffness. CONCLUSIONS MAP is the main determinant of arterial stiffness progression. Our results suggest that efficient blood pressure control may contribute to preserved or reduced arterial stiffness in PD patients.
Turkish Nephrology Dialysis Transplantation | 2017
Cenk Demirci; Meltem Sezis Demirci; Gulay Asci; Aygul Celtik; Pınar Seymen; Fatih Kircelli; Taskin Colak; Ercan Ok
OBJeCTIVe: Pregnancy in women of reproductive age on dialysis is rare and has a poor outcome. Several studies published in the 1990s revealed pregnancy rates of 0.3 to 0.5 per 100 patient-years, but not all pregnancies resulted in live births. More recent studies suggest that intensive haemodialysis increases fertility and successful pregnancies with live births. Our objectives were to evaluate whether nocturnal home haemodialysis (NHHD) three times a week supports successful pregnancies and live births in addition to the changes in clinical and biochemical parameters. mATerIAL and meThODS: Descriptive cohort study analysing pregnancies and their outcomes in 60 women of reproductive age (14-44 years) who started NHHD between August 2010 and January 2015. reSULTS: During a mean follow-up of 20±11 months on NHHD, four pregnancies were identified (4 per 100 patient-years). In these four patients, the mean age was 37.3±4.8 years and the mean NHHD Cenk DemirCi1 meltem Seziş DemirCi2 Gülay AşÇI2 Aygül ÇeLTik3 Pınar SeYmeN1 Fatih kIrÇeLLi1 Taşkın ÇOLAk1 Ercan Ok2 1 Fresenius Medical Care, Nefroloji-Hemodiyaliz Ünitesi, İzmir, Türkiye 2 Ege Üniversitesi Tıp Fakültesi, Nefroloji Bilim Dalı, İzmir, Türkiye 3 Trabzon Kanuni Eğitim ve Araştırma Hastanesi, Nefroloji Bölümü, Trabzon, Türkiye
Archives of Renal Diseases and Management | 2016
Meltem Sezis Demirci; Cenk Gokalp; Cenk Demirci; Emrah Gunay; Ayhan Donmez; Sait Sen; Mehmet Ozkahya
Introduction: Membranoproliferative glomerulonephritis has been reported to occur in association with non-Hodgkin is lymphoma but there is few information about glomerulonephritis response to the treatment of non-Hodgkin is lymphoma.
Ndt Plus | 2011
Cees G. M. Kallenberg; Ulrich Specks; John H. Stone; Ercan Ok; Gulay Asci; Ebru Sevinc Ok; Fatih Kircelli; Mumtaz Yilmaz; Ender Hur; Meltem Sezis Demirci; Oner Ozdogan; Cenk Demirci; Ozen Onen Sertoz; Soner Duman; Mehmet Ozkahya; Meral Kayikcioglu; Hayriye Elbi; Ali Basci; Huseyin Toz; Muriel P.C. Grooteman; René van den Dorpel; Michiel L. Bots; Lars Penne; Neelke van der Weerd; Albert H.A. Mazairac; Claire H. den Hoedt; Ingeborg van der Tweel; Renée Lévesque; Menso J. Nubé; Pieter ter Wee
Peritoneal Dialysis International | 2009
Meltem Sezis Demirci; Mehmet Ozkahya; Gulay Asci; Ebru Sevinc; Mumtaz Yilmaz; Cenk Demirci; Huseyin Toz; Ali Basci; Ercan Ok
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