Person: KOÇ, MEHMET
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KOÇ
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MEHMET
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Publication Metadata only Statin use is associated with lower inflammation and erythropoietin responsiveness index in hemodialysis patients(WILEY, 2011) KOÇ, MEHMET; Koc, Mehmet; Dogan, Cengiz; Arinsoy, Turgay; Tonbul, Zeki; Ayli, Deniz; Cirit, Mustafa; Sever, Mehmet Sukru; Yilmaz, Mehmet Emin; Unsal, Abdulkadir; Suleymanlar, Gultekin; Ok, Ercan; Basci, Ali; Yildiz, AlaatinPatients with end-stage renal disease are prone to inflammation and inflammation is related to erythropoietin-stimulating agent hyporesponsiveness and mortality in this population. Statins have been demonstrated to reduce cardiovascular mortality in selected populations of end-stage renal disease patients. These drugs have pleiotrophic effects such as anti-inflammation. In this retrospective analysis, we determined whether the use of statins improves inflammation and inflammation-related anemia in a cohort of hemodialysis patients. Data were analyzed from Fresenius Medical Care Dialysis Clinics in Turkey between 2005 and 2007. Seventy prevalent hemodialysis patients who were on statins at the start of the study and have been on statins during follow-up (statin users) and 1293 patients who were not on statin at the start of the study and had never been prescribed any lipid-modifying drugs during follow-up (statin nonusers) were included in the study. High-sensitive C-reactive protein levels were significantly decreased in statin users (1.50 +/- 1.49 vs. 1.33 +/- 1.11 mg/L, P=0.05) compared with nonusers (1.93 +/- 3.22 vs. 2.05 +/- 2.77 mg/L). Hemoglobin levels and the rate of erythropoietin-stimulating agent users were similar. However, the prescribed erythropoietin-stimulating agent dose (31.6 +/- 27.5 vs. 47.3 +/- 45.2 U/kg/week, P < 0.05) and the erythropoietin response index (2.90 +/- 2.73 vs. 4.51 +/- 4.48 U/kg/week/Hb, P=0.001) were lower in statin users compared with statin nonusers. On stepwise multiple regression analysis, gender, high-sensitive C-reactive protein, duration of hemodialysis, serum ferritin, and statin use were independent determinants of the erythropoietin responsiveness index. Our results suggest that statin treatment leads to lower inflammation and improves hematopoiesis in hemodialysis patients.Publication Open Access Circulating endothelial cells are associated with future vascular events in hemodialysis patients(ELSEVIER SCIENCE INC, 2005-03) KOÇ, MEHMET; Koc, M; Richards, HB; Bihorac, A; Ross, EA; Schold, JD; Segal, MSBackground. Endothelial dysfunction and injury are thought to have a key role in the pathogenesis of cardiovascular disease. We hypothesized that the presence of circulating endothelial cells, as a reflection of ongoing endothelial injury, might provide a novel means for predicting cardiovascular events in hemodialysis subjects who are known to be at marked increased risk for cardiovascular disease. Methods. Circulating endothelial cell number was determined in 29 hemodialysis patients who were then followed for vascular events for 470 172 days. In a second cohort of 44 hemodialysis patients, circulating endothelial cell number was correlated with markers of inflammation, namely high sensitivity C-reactive protein (hs-CRP), interleukin (IL)-6, IL-10, and monocyte chemoattractant protein-1 (MCP-1), and endothelial dysfunction, soluble vascular cellular adhesion molecule-1 (VCAM-1). Results. Seven of the 19 subjects with elevated circulating endothelial cells (defined as > 19 cells per mL) had cardiovascular (N = 5) or vascular (N = 5) events during follow-up, whereas no events occurred in subjects with a low number of circulating endothelial cells (less than or equal to19 CECs per mL) (P = 0.04 by Fisher Exact Test). In the second cohort, the number of circulating endothelial cells was independent of all markers of inflammation and endothelial dysfunction. Conclusion. In this hemodialysis population, an increase in circulating endothelial cells was found to predict the development of cardiovascular and vascular events, and to be independent of other known markers of inflammation or endothelial dysfunction. These studies suggest that circulating endothelial cells may be a novel way to assess endothelial health and cardiovascular risk. Further studies to investigate the utility of circulating endothelial cells in predicting cardiovascular risk are needed.Publication Metadata only Waist circumference is associated with carotid intima media thickness in peritoneal dialysis patients(SPRINGER, 2013) VELİOĞLU, ARZU; Asicioglu, Ebru; Kahveci, Arzu; Arikan, Hakki; Koc, Mehmet; Tuglular, Serhan; Ozener, Cetin IshakAtherosclerosis is responsible for the high mortality rate in end-stage renal disease patients. Defining risk factors for atherosclerosis may lead to reduction in cardiovascular disease through modification of these factors. Peritoneal dialysis (PD) patients are subjected to high glucose loads on a daily basis, which results in considerable weight gain and an increase in waist circumference (WC). WC as an indicator of abdominal obesity is a risk factor for atherosclerosis in the general population. Carotid artery intima media thickness (CIMT) measurement is a reliable method for the detection of early atherosclerosis. The aim of this study was to investigate the relationship between WC and CIMT and to define risk factors associated with CIMT in PD patients. Fifty-five PD patients and 40 healthy controls were included. Atherosclerosis was assessed using measurement of CIMT. Fasting blood was collected for analysis. Anthropometric parameters (age, weight, BMI, and WC) were measured. Peritoneal dialysis patients had higher WC (93.9 +/- A 1.7 vs. 87.3 +/- A 1.2 cm, p < 0.05) and CIMT (0.70 +/- A 0.02 vs. 0.57 +/- A 0.01 mm, p < 0.01) than the control group. On univariate analysis, age, WC, plaque formation, and D/P creatinine were positively correlated with CIMT, whereas residual renal function, albumin, ultrafiltration volume, and D/D0 glucose were negatively correlated. On multivariate analysis, only age, WC, and plaque formation showed correlation (p < 0.001). Carotid artery intima media thickness is associated with age, plaque formation, and WC in PD patients. WC measurement is a simple, inexpensive, reproducible, and reliable method of evaluating atherosclerosis risk in PD patients and should be assessed at every visit. Appropriate counsel should be provided to patients with greater WC who are deemed to be at risk for atherosclerosis.Publication Open Access Night-time blood pressure load is associated with higher left ventricular mass index in renal transplant recipients(NATURE PUBLISHING GROUP, 2003-04) KOÇ, MEHMET; Toprak, A; Koc, M; Tezcan, H; Ozener, IC; Oktay, A; Akoglu, EThe absence of nocturnal fall in blood pressure (BP) is named as nondipper status, which has been shown to be an additional risk factor for the development of left ventricular hypertrophy and cardiovascular events in several high-risk groups. The aim of this study was to determine the influences of the nondipper status and nocturnal blood pressure loads on left ventricular mass index (LVMI) in renal transplant recipients. A total of 35 nondiabetic renal transplant recipients were included into the study. A 24-h ambulatory blood pressure monitoring (ABPM) was performed for all recipients. The nondipper status was defined as either an increase in night-time mean arterial pressure (MAP) or a decrease of no more than 10% of daytime MAP. LVMI was measured by using two-dimensional guided M-mode echocardiography. The night-time systolic blood pressure (SBP) load was defined as the percentage of the time, during which SBP exceeded 125 mmHg during night time. The nondipping was common among renal transplant recipients, of whom 60% were nondipper in our study. LVMI was significantly higher in the nondipper group vs the dipper group (133 +/- 35 g/m(2) VS 109 +/- 26 g/m(2), P= 0.04). A fall in MAP at night time was 14.5 +/- 4.3% in the dipper group, while it was 1.4 +/- 6.1% in the nondipper group (P< 0.001). On stepwise multiple regression analysis, night-time SBP load and haemoglobin were independent predictors of LVMI (R-2 = 0.53). In conclusion, nondipping is common after renal transplantation. Night-time SBP load and low haemoglobin are closely related to the increase in LVMI in renal transplant recipients. ABPM may be a more useful tool in optimizing treatment strategies to reduce cardiovascular events in renal transplant recipients.Publication Metadata only Demographic and clinical characteristics of primary glomerular diseases in Turkey(SPRINGER, 2014) KOÇ, MEHMET; Ozturk, Savas; Sumnu, Abdullah; Seyahi, Nurhan; Gullulu, Mustafa; Sipahioglu, Murat; Artan, Serra; Bicik, Zerrin; Kutlay, Sim; Keles, Mustafa; Oygar, Deren; Odabas, Ali Riza; Kayatas, Mansur; Dursun, Belda; Sayarlioglu, Hayriye; Trablus, Sinan; Taymez, Dilek Guven; Ozdemir, Ali Abbas; Sahin, Gulizar Manga; Altun, Bulent; Azak, Alper; Altintepe, Lutfullah; Suleymanlar, Gultekin; Koc, Mehmet; Selcuk, Yilmaz; Kazancioglu, Rumeyza; Erkoc, Reha; Gursu, Meltem; Kucuk, Mehmet; Akcaoglu, Selma Alagoz; Yildiz, Abdulmecid; Unal, Aydin; Akarsu, Ozger; Ates, Kenan; Cankaya, Erdem; Turkmen, AydinThe aim of our study was to delineate the demographic and clinical properties of primary glomerular diseases of adult population in our country in the light of global knowledge. All over the country, a total of 25 centers entered data between May 2009 and July 2012 to the database created by 'Glomerulonephritis Study Group' of Turkish Society of Nephrology. Demographic and clinical characteristics, specific diagnoses of glomerular diseases and biopsy findings recorded to the database were analyzed. Among the 1,274 patients, who had renal biopsy within the defined time period, 55 % were male and 45 % were female. The mean age was 40.8 +/- A 14.6 years. The most frequent indication for biopsy was nephrotic syndrome (57.8 %), followed by nephritic syndrome including rapidly progressive glomerulonephritis (16.6 %) and asymptomatic urinary abnormalities (10.8 %). The most frequent primary glomerular disease was membranous nephropathy (28.8 %), followed by focal segmental glomerulosclerosis (19.3 %) and IgA nephropathy (17.2 %). The presented study displayed important data about the epidemiology of primary glomerular diseases among adults in our country. The predominance of membranous nephropathy in contrast to other countries, in which the most frequent etiology is IgA nephropathy, seems to be due to differences in the indications for renal biopsy.Publication Open Access Inferior vena cava diameter determines left ventricular geometry in continuous ambulatory peritoneal dialysis patients: an echocardiographic study(OXFORD UNIV PRESS, 2003-10-01) KOÇ, MEHMET; Toprak, A; Koc, M; Tezcan, H; Ozener, IC; Akoglu, E; Oktay, ABackground. Changes in left ventricular (LV) geometry are frequent in patients with continuous ambulatory peritoneal dialysis (CAPD). Geometric adaptation of LV to various stimuli was reported to have adverse prognosis. This study aimed to identify independent risk factors, which contribute to the development of LV geometric remodelling in CAPD patients. Methods. The left ventricles of 69 CAPD patients were classified echocardiographically into four different geometric patterns on the basis of LV mass and relative wall thickness. With respect to volume factor, we measured inferior vena cava (IVC) diameter and its decrease on deep inspiration [collapsibility index (CI)] by echocardiography. We modelled a stepwise multiple regression analysis to determine the predictors of LV geometry. Results. All four geometric models of LV were identified in our group of 69 CAPD patients. Eccentric left ventricular hypertrophy (eLVH) was observed in 32 (46%), concentric LVH (cLVH) in 19 (28%), normal geometry (NG) in 10 (14%) and concentric remodelling (CR) in eight (12%) CAPD patients. Mean IVC index of the eLVH group (10.72 +/- 2.19 mm/m(2)) was significantly higher than corresponding indexes of NG (7.90 +/- 1.54 mm/m(2)), CR (8.51 +/- 1.28 mm/m(2)) and cLVH (8.04 +/- 2.00mm/m(2)) groups (P < 0.001 for each comparisons). The eLVH group also had significantly lower mean CI value (0.48 +/- 0.11) than CR (0.58 +/- 0.09) and cLVH (0.57 +/- 0.07) groups (ANOVA P=0.008). Stepwise multiple regression analysis revealed that IVC index, CI and haemoglobin were the independent predictors of LV geometric stratification (R-2 =0.36, P < 0.001). Conclusion. Hypervolaemia, identified by IVC index and CI, and anaemia contribute independently to LV geometry in CAPD patients. Echocardiography as a non-invasive tool is not only useful to determine LV geometry, but also to assess the volume status of CAPD patients.Publication Metadata only Determinants of hemoglobin variability in stable peritoneal dialysis patients(SPRINGER, 2014) VELİOĞLU, ARZU; Arikan, Hakki; Asicioglu, Ebru; Velioglu, Arzu; Nalcaci, Serdar; Birdal, Gurdal; Guler, Derya; Koc, Mehmet; Tuglular, Serhan; Ozener, CetinSignificant within-patient hemoglobin (Hb) level variability is well recognized in particularly hemodialysis patients. Several factors such as hospitalizations, intercurrent diseases and IV iron therapy are found to be related to Hb variability (Hb-var). In this observational study, we aimed to identify predictors and outcome of Hb-var in peritoneal dialysis (PD) patients without hospitalization, intercurrent disease and IV iron therapy during the study period. All patients were in the maintenance phase of short-acting erythropoiesis-stimulating agents (ESAs) therapy. The target range of Hb was 11-12 g/dL according to KDOQI Guidelines in 2007. The desired range of Hb was 11-12.5 g/dL. Patients' demographic and laboratory data were collected at baseline. Atherosclerotic disease was assessed using carotid intima-media thickness (CIMT). We assessed Hb variability with various methods using SD Hb(mean), SD Hb(range) and the velocity of Hb change. Hb deflect(positive), Hb deflect(negative), Hb values and ESA dosing were recorded monthly for 6 months. This study included 50 prevalent PD patients (mean age 46.9 +/- A 13.7 years, 25 women). The mean velocity of Hb change was negatively correlated with age and positively correlated with frequent ESA dose changes. Higher albumin and residual renal function (RRF) were also positively correlated with Hb deflect(positive). Patients with CIMT a parts per thousand yen0.7 cm had lower SD Hb range compared to CIMT < 0.7 cm. Cumulative survival was better in patients with Hb levels consistently a parts per thousand yen10 g/dL compared to patients who had Hb < 10 g/dL for at least 1 month. However, Hb-var was not associated with mortality. In PD patients without hospitalization, intercurrent disease(s) or IV iron therapy, young age, higher albumin or RRF and lower CIMT were associated with greater oscillations in response to ESA therapy. Careful and appropriate ESA dose changes considering these parameters could minimize Hb variability in these patients.Publication Open Access Earthquakes and crush syndrome casualties: Lessons learned from the Kashmir disaster(ELSEVIER SCIENCE INC, 2007-01) KOÇ, MEHMET; Vanholder, R.; van der Tol, A.; De Smet, M.; Hoste, E.; Koc, M.; Hussain, A.; Khan, S.; Sever, M. S.Major earthquakes may provoke a substantial number of crush casualties complicated by acute kidney injury (AKI). After the 1988 Armenian earthquake, the International Society of Nephrology (ISN) established the Renal Disaster Relief Task Force (RDRTF) to organize renal care in large disastersPublication Metadata only Fibroblast Growth Factor-23 Levels Are Associated With Uric Acid But Not Carotid Intima Media Thickness in Renal Transplant Recipients(ELSEVIER SCIENCE INC, 2014) VELİOĞLU, ARZU; Asicioglu, E.; Kahveci, A.; Arikan, H.; Koc, M.; Tuglular, S.; Ozener, C.Introduction. Cardiovascular disease (CVD) is the leading cause of mortality in chronic kidney disease (CKD) patients. Fibroblast growth factor-23 (FGF-23) is associated with atherosclerosis and cardiovascular mortality in CKD patients and healthy subjects. However, data in renal transplant recipients (RTR) are scarce. We aimed to determine factors associated with FGF-23 and to explore its relationship to atherosclerosis. Methods. Forty-six patients and 44 controls were included. FGF-23 was measured from plasma. Carotid intima media thickness (CIMT) was evaluated ultrasonographically. Results. Patients had higher waist circumference (WC; 92.2 +/- 14.9 vs 85.3 +/- 11.0 cm; P < .05), glucose (99.8 +/- 17.2 vs 90.3 +/- 6.5 mg/dL; P < .01), creatinine (1.43 +/- 0.6 vs 0.86 +/- 0.1 mg/dL; P < .01), triglyceride (160.4 +/- 58.9 vs 135.6 +/- 59.8 mg/dL; P < .05), white blood cells (WBC; 7938.6 +/- 2105.2 vs 6715.7 +/- 1807.5 WBC/mm(3); P < .01), ferritin (217.0 +/- 255.8 vs 108.3 +/- 142.4 ng/mL; P < .05), uric acid (6.5 +/- 1.6 vs 4.7 +/- 1.3 mg/dL; P < .01), C-reactive protein (CRP; 8.2 +/- 18.2 vs 5.3 +/- 7.9 mg/L; P < .01), parathyroid hormone (PTH; 89.7 +/- 59.2 vs 44.1 +/- 16.7 pg/mL; P < .01), and alkaline phosphatase (ALP; 162.5 +/- 86.6 vs 74.2 +/- 21.9 U/L; P < .01). FGF-23 was higher in patients (11.7 +/- 7.2 vs 9.6 +/- 6.8 pg/mL; P < .05). CIMT was similar (0.58 +/- 0.09 vs 0.57 +/- 0.1 mm; P > .05). WC, creatinine, and uric acid were positively correlated with FGF-23, whereas albumin showed negative correlation. On multivariate analysis only creatinine and uric acid were determinants of FGF-23. Conclusion. FGF-23 levels are associated with uric acid in RTR. Larger studies are needed to confirm this finding.Publication Metadata only Left Ventricular Hypertrophy Patterns and Cardiovascular Outcome in Peritoneal Dialysis Patients(ORTADOGU AD PRES & PUBL CO, 2011) BEKİROĞLU, GÜLNAZ NURAL; Tezcan, Hakan; Toprak, Ahmet; Arikan, Izzet Hakki; Koc, Mehmet; Bekiroglu, Nural; Ozener, Ishak CetinObjective: Left ventricular hypertrophy (LVH) is highly predictive of cardiovascular (CV) events in dialysis patients. The impact of different left ventricular (LV) geometric patterns on cardiovascular outcome has not been well established. The aim of this prospective observational study was to define the patterns of LVH and find out their impact on future cardiovascular events in patients on continuous ambulatory peritoneal dialysis (CAPD). Material and Methods: Patients were followed up between 1999 and 2006 for cardiovascular events. Left ventricular mass and geometric patterns were determined by echocardiography. Kaplan-Meier method and Cox regression analysis were used to evaluate the impact of LV geometric patterns on CV event free survival. Results: Sixty-five CAPD patients were enrolled in the study and were followed for 76 +/- 15 months. There were a total of 16 (14 fatal, two non-fatal) CV events. Mean event-free survival time for patients without LVH was 79 +/- 3 months (95% CI of 73 to 86 months). The mean CV event-free survival for the patients with concentric LV hypertrophy and eccentric hypertrophy was 75 +/- 3 months (95% CI of 69 to 81 months), and 76 +/- 3 months (95% CI of 69 to 82 months) respectively. Patients with eccentric [hazard ratio (HR): 20.2] and concentric (HR:18.7) LV hypertrophy had shorter time to CV event when compared to the patients without LV hypertrophy (p= 0.042). Conclusion: Left ventricular hypertrophy is a marker of poor cardiovascular prognosis irrespective of its pattern. Both eccentric and concentric LV hypertrophy are associated with shorter CV event-free survival compared to normal geometry and concentric remodeling.