Publications (44)101.68 Total impact
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Article: The Evidence of Occult Hypervolemia; Improvement of Cardiac Functions After Kidney Transplantation.
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ABSTRACT: The term cardiorenal syndrome (CRS) has been used to define interactions between acute or chronic dysfunction of the heart or kidney. When primary chronic kidney disease contribute to cardiac dysfunction, it is classified as type 4 CRS. Cardiac dilatation, valve regurgitations, and left ventricular dysfunction are observed in end-stage renal failure patients with uremic cardiomyopathy. Because of perioperative risks in these patients, they may not be considered a candidate for kidney transplantation. However, uremic cardiomyopathy can be corrected when volume control is achieved by appropriate dose and duration of ultrafiltration. By presenting two cases with occult hypervolemia in uremic cardiomyopathy whose cardiac functions improved early after kidney transplantation, attention is drawn to the importance of kidney transplantation on cardiac function in such patients primarily and the importance of strict volume control on cardiac function in dialysis patients waiting for kidney transplantation.Renal Failure 04/2013; · 0.82 Impact Factor -
Article: The associations between serum paraoxonase 1 activity and carotid atherosclerosis in renal transplant patients.
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ABSTRACT: Backgrounds and aims: Paraoxonase 1 (PON1) is a novel marker that has been shown to exert protective functions on atherosclerosis by preventing oxidative modification of serum lipoproteins. In this study, we investigated the effects of PON1 on CA-IMT in renal transplant patients. Methods: A total of 98 adult renal transplant recipients was enrolled in the study. CA-IMT was determined by B-mode Doppler ultrasonography. PON-1 activity was assessed by the rate of enzymatic hydrolysis of paraoxon to p-nitrophenol. Results: Mean age was 39.4 ± 9.6 years and 10% of the patients were diabetic. Time after transplant was 76 ± 59 months. Mean PON1 level was 62.1 ± 43.3 U/l. PON1 levels were negatively correlated with CA-IMT and positively with HDL cholesterol. Mean CA-IMT was 0.62 ± 0.10 mm (0.40 - 0.98). CA-IMT was positively correlated with age, male gender and negatively with proteinuria and PON1 levels. In linear regression analysis, PON1 levels were associated with CA-IMT. Conclusion: Reduced PON1 activity is significantly associated with increased carotid atherosclerosis in renal transplant patients.Clinical nephrology 04/2013; · 1.17 Impact Factor -
Article: Effect of Fluid Management Guided by Bioimpedance Spectroscopy on Cardiovascular Parameters in Hemodialysis Patients: A Randomized Controlled Trial.
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ABSTRACT: BACKGROUND: Fluid overload is the main determinant of hypertension and left ventricular hypertrophy in hemodialysis patients. However, assessment of fluid overload can be difficult in clinical practice. We investigated whether objective measurement of fluid overload with bioimpedance spectroscopy is helpful in optimizing fluid status. STUDY DESIGN: Prospective, randomized, and controlled study. SETTING & PARTICIPANTS: 156 hemodialysis patients from 2 centers were randomly assigned to 2 groups. INTERVENTION: Dry weight was assessed by routine clinical practice and fluid overload was assessed by bioimpedance spectroscopy in both groups. In the intervention group (n = 78), fluid overload information was provided to treating physicians and used to adjust fluid removal during dialysis. In the control group (n = 78), fluid overload information was not provided to treating physicians and fluid removal during dialysis was adjusted according to usual clinical practice. OUTCOMES: The primary outcome was regression of left ventricular mass index during a 1-year follow-up. Improvement in blood pressure and left atrial volume were the main secondary outcomes. Changes in arterial stiffness parameters were additional outcomes. MEASUREMENTS: Fluid overload was assessed twice monthly in the intervention group and every 3 months in the control group before the mid- or end-week hemodialysis session. Echocardiography, 48-hour ambulatory blood pressure measurement, and pulse wave analysis were performed at baseline and 12 months. RESULTS: Baseline fluid overload parameters in the intervention and control groups were 1.45 ± 1.11 (SD) and 1.44 ± 1.12 L, respectively (P = 0.7). Time-averaged fluid overload values significantly decreased in the intervention group (mean difference, -0.5 ± 0.8 L), but not in the control group (mean difference, 0.1 ± 1.2 L), and the mean difference between groups was -0.5 L (95% CI, -0.8 to -0.2; P = 0.001). Left ventricular mass index regressed from 131 ± 36 to 116 ± 29 g/m2 (P < 0.001) in the intervention group, but not in the control group (121 ± 35 to 120 ± 30 g/m2; P = 0.9); mean difference between groups was -10.2 g/m2 (95% CI, -19.2 to -1.17 g/m2; P = 0.04). In addition, values for left atrial volume index, blood pressure, and arterial stiffness parameters decreased in the intervention group, but not in the control group. LIMITATIONS: Ambulatory blood pressure data were not available for all patients. CONCLUSIONS: Assessment of fluid overload with bioimpedance spectroscopy provides better management of fluid status, leading to regression of left ventricular mass index, decrease in blood pressure, and improvement in arterial stiffness.American Journal of Kidney Diseases 02/2013; · 5.43 Impact Factor -
Article: Mortality and cardiovascular events in online haemodiafiltration (OL-HDF) compared with high-flux dialysis: results from the Turkish OL-HDF Study.
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ABSTRACT: 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.ResultsThe 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 12/2012; · 3.40 Impact Factor -
Article: Epicardial adipose tissue volume and cardiovascular disease in hemodialysis patients.
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ABSTRACT: OBJECTIVE: Epicardial adipose tissue (EAT) is proposed as a cardiovascular risk marker in non-uremic subjects. However, little is known about its role in patients with higher cardiovascular risk profile such as chronic kidney disease. The aim of this study was to investigate the relationship between EAT and several cardiovascular surrogate markers (coronary artery calcification (CAC), arterial stiffness and atherosclerosis) in patients on maintenance hemodialysis. METHODS: A total of 191 prevalent hemodialysis patients were enrolled in this cross-sectional study. EAT and CAC scores (CACs) were determined by multi-slice computerized tomography, arterial stiffness by carotid-femoral pulse wave velocity (PWV), and carotid artery intima-media thickness (CA-IMT) by B-mode doppler ultrasonography. RESULTS: Mean age was 59 ± 13 years and time on hemodialysis 75 ± 44 months. Twenty percent of the patients had diabetes. Mean EAT volume was 62.6 ± 26.8 cm(3)/m(2). Mean CA-IMT and PWV values increased across the EAT tertiles. EAT was correlated with age, female gender, body mass index, albumin and lipid parameters. Additionally, CA-IMT and PWV values were positively correlated with EAT. EAT volume was significantly higher in patients with CACs >10 compared to the patients with CACs ≤10. Despite the univariate associations between EAT and cardiovascular surrogate markers, only age, body mass index and total cholesterol levels were associated with EAT in adjusted models. CONCLUSIONS: In prevalent hemodialysis patients, EAT is correlated with atherosclerosis, arterial stiffness and the presence of CAC. However, this correlation is not independent of other risk factors.Atherosclerosis 11/2012; · 3.79 Impact Factor -
Article: Pre-transplant HbA1c level as an early marker for new-onset diabetes after renal transplantation.
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ABSTRACT: BACKGROUND: New-onset diabetes after transplantation (NODAT) is a common complication in renal transplant (RT) patients. The clinical significance of pre-transplant HbA1c level remains unclear in RT patients. Thus, we investigated the predictive role of pre-transplant HbA1c levels for the NODAT diagnosed in 1 year after renal transplantation. METHODS: Two hundred and four RT patients older than 18 years were analyzed. NODAT diagnosis during the 1-year follow-up after RT was based on the 2003 modified criteria of the ADA. HbA1c level was measured at pre-transplantation period and every 3 months after RT. RESULTS: Mean age was 39.3 ± 10.7 (20-73) years and 36 % were female. Mean pre-transplant HbA1c level was 4.9 ± 0.5 % (4.0-6.4 %). Pre-transplant HbA1c level was positively correlated with age, pre-transplant body mass index (BMI) and cholesterol level. Fifty-four patients (25.9 %) developed NODAT and 33.8 % had impaired fasting blood glucose levels. Patients with NODAT were significantly older and had higher pre-transplant BMI and HbA1c than those without. Use of Tacrolimus was also higher in patients with NODAT. In stepwise logistic regression analysis, pre-transplant HbA1c level was an independent predictor for the development on NODAT (OR = 4.63, 95 % CI: 2.09-10.2, p < 0.001) together with age, Tacrolimus-based regimen and pre-transplant fasting blood glucose level. CONCLUSIONS: Assessment of pre-transplant HbA1c levels may be a valuable tool for early diagnosis of NODAT in RT recipients.International Urology and Nephrology 10/2012; · 1.47 Impact Factor -
Article: Neither oxidized nor anti-oxidized low-density lipoprotein level is associated with atherosclerosis or mortality in hemodialysis patients.
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ABSTRACT: It is anticipated that oxidized low-density lipoprotein (oxLDL) and anti-oxLDL are associated with atherosclerosis and mortality. However, data on this issue are controversial and limited. We aimed to investigate the effect of these two markers on the extent and progression of atherosclerosis and mortality in a group of hemodialysis patients. In this prospective observational study with a follow-up of 36 months, 124 hemodialysis patients were studied. Ninety-five patients underwent carotid intima media thickness (CA-IMT) measurement by B-Mode ultrasonography both at baseline and at the end of the study. oxLDL and anti-oxLDL were measured by enzyme-linked immunosorbent assay. The extent and progression of CA-IMT, along with overall and cardiovascular mortality, were assessed. The mean age at baseline was 54.0 ± 14.8 years, 57.3% male and 20% diabetic. The mean oxLDL and anti-oxLDL levels were 8.11 ± 3.16 mU/L and 1.30 ± 0.31, respectively. Baseline mean CA-IMT was 0.82 ± 0.20 mm. Fifteen patients died during a follow-up period of 28.5 ± 6.6 months, 11 from cardiovascular causes. Only oxLDL, not anti-oxLDL, was correlated with the extent of atherosclerosis at baseline. However, both had no role in the progression of atherosclerosis. Also, in unadjusted and adjusted models, both parameters were not associated with overall or cardiovascular mortality. Neither oxLDL nor anti-oxLDL level is associated with the progression of atherosclerosis or mortality in hemodialysis patients.Hemodialysis International 04/2012; 16(3):334-41. · 1.54 Impact Factor -
Article: Soluble TWEAK level: is it a marker for cardiovascular disease in long-term hemodialysis patients?
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ABSTRACT: Background: Reduced soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) levels follow declining renal function, are strongly associated with endothelial dysfunction and predict cardiovascular events in nondialyzed chronic kidney disease patients. In contrast, elevated levels of sTWEAK predict poor survival in hemodialysis (HD) patients. Recent evidence suggests a role for sTWEAK in the pathophysiology of vascular calcification. The aim of the study was to investigate plausible links between sTWEAK, atherosclerosis, arterial stiffness and vascular calcification in HD patients. Methods: Coronary artery calcification score (CACs) determined by multislice computed tomography, arterial stiffness by pulse wave velocity (PWV) and carotid artery intima-media thickness (CA-IMT) by carotid Doppler ultrasonography were assessed in 131 long-term prevalent HD patients. sTWEAK levels were measured by ELISA (Bender MedSystems, Vienna, Austria). Results: Mean serum sTWEAK level was 237.0 ± 147.5 pg/mL (range 78-937). sTWEAK level was inversely correlated with CA-IMT at a borderline significance (r=-0.168, p=0.05). Neither carotid-radial PWV nor carotid-femoral PWV values correlated with sTWEAK. sTWEAK level was higher in patients with severe vascular calcification (CACs =400) compared to patients with CACs <400 (264.5 ± 146.8 pg/mL vs. 205.04 ± 122.4 pg/mL, p=0.02).The association between sTWEAK and vascular calcification persisted after multivariate adjustment. Conclusions: There exists a weak inverse correlation between sTWEAK and carotid atherosclerosis and a positive correlation with coronary artery calcification in long-term HD patients. Our data give support for a role for sTWEAK in the pathogenesis of vascular injury in HD patients.Journal of nephrology 04/2012; · 1.65 Impact Factor -
Article: Relationship between glucose exposure via peritoneal dialysis solutions and coronary artery calcification in non-diabetic peritoneal dialysis patients.
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ABSTRACT: INTRODUCTION: Vascular calcification is frequent in dialysis patients and is associated with increased mortality. Impaired glucose metabolism is proposed as a contributing factor for vascular calcification. We investigated whether glucose exposure via dialysate may have a role in vascular calcification in non-diabetic peritoneal dialysis patients. METHOD: We measured coronary artery calcification by multi-slice computerized tomography in 50 prevalent non-diabetic peritoneal dialysis patients and assessed its relations with fasting blood glucose, homeostasis model assessment of insulin resistance (HOMA-IR), and glucose exposure from peritoneal dialysis fluid. RESULTS: Twenty-four patients (48%) had no coronary calcification. When patients were grouped according to the presence or absence of calcification, patients with calcification were mostly men and had higher burden of cardiovascular disease history, vitamin D dose intake, serum calcium, total glucose exposure from dialysis solution, and lower total weekly Kt/V (urea). In multivariate analysis, dialysate glucose exposure was an independent predictor of coronary artery calcification score, besides serum calcium and Kt/V (urea). CONCLUSION: These data suggest that high glucose exposure from dialysis solution, which is potentially correctable, is a risk factor for vascular calcification in non-diabetic PD patients.International Urology and Nephrology 02/2012; · 1.47 Impact Factor -
Article: Impact of mean arterial pressure on progression of arterial stiffness in peritoneal dialysis patients under strict volume control strategy.
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ABSTRACT: 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). 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. 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.Clinical nephrology 02/2012; 77(2):105-13. · 1.17 Impact Factor -
Article: Effects of thrice weekly nocturnal hemodialysis on arterial stiffness.
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ABSTRACT: 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. 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. 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. These data indicate that arterial stiffness is ameliorated by implementation of longer hemodialysis sessions.Atherosclerosis 11/2011; 220(2):477-85. · 3.79 Impact Factor -
Article: The impact of low serum sodium level on mortality depends on glycemic control.
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ABSTRACT: Low serum sodium levels have been associated with mortality both in patients with and without chronic kidney disease. In this study, we investigated this association in relation to glycemic control in hemodialysis (HD) patients. Between March and September 2005, 697 prevalent HD patients were enrolled in this prospective observational study and followed up for all-cause and cardiovascular mortality. The associations of serum sodium concentration with both overall and cardiovascular survival rates were studied. At baseline, mean predialysis serum sodium concentration was 138.4 ± 2.3 mEq/L (range: 130-145 mEq/L). Mild hyponatremia (< 135 mEq/L) was present in only 41 subjects (5.9%), and no patient had serum sodium level < 130 mEq/L. During 20.2 ± 6.2 months of follow-up, 119 patients (15.9%) died, 68 from CV causes. In adjusted Cox regression analysis, lowest sodium quartile was associated with 2.13-fold increased risk of overall mortality (95% confidence interval (CI) 1.14-3.98, P = 0.01, model chi-square 114.6, P < 0.001). As a continuous variable, each 1 mEq/L increase in predialysis sodium concentration was associated with a hazard ratio (HR) of 0.87 for overall mortality (95% CI 0.81-0.95, P = 0.002) and 0.86 for cardiovascular mortality (95% CI 0.78-0.96, P = 0.007). The predictivity of low serum sodium was prominent in diabetic subjects but not in nondiabetics. However, relationship between serum sodium and patient survival in diabetics was lost after adjustment for the HbA1c level: HR 0.91 (95% CI 0.78-1.05, P = 0.20). Low serum sodium concentration is associated with mortality only in those with diabetes. Furthermore, the impact of serum sodium on survival in these patients seems to be derived from poor glucose control.European Journal of Clinical Investigation 10/2011; 42(5):534-40. · 3.02 Impact Factor -
Article: Associations of triiodothyronine levels with carotid atherosclerosis and arterial stiffness in hemodialysis patients.
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ABSTRACT: End-stage renal disease is linked to alterations in thyroid hormone levels and/or metabolism, resulting in a high prevalence of subclinical hypothyroidism and low triiodothyronine (T3) levels. These alterations are involved in endothelial damage, cardiac abnormalities, and inflammation, but the exact mechanisms are unclear. In this study, we investigated the relationship between serum free-T3 (fT3) and carotid artery atherosclerosis, arterial stiffness, and vascular calcification in prevalent patients on conventional hemodialysis. 137 patients were included. Thyroid-hormone levels were determined by chemiluminescent immunoassay, carotid artery-intima media thickness (CA-IMT) by Doppler ultrasonography, carotid-femoral pulse wave velocity (c-f PWV), and augmentation index by Sphygmocor device, and coronary artery calcification (CAC) scores by multi-slice computerized tomography. Mean fT3 level was 3.70 ± 1.23 pmol/L. Across decreasing fT3 tertiles, c-f PWV and CA-IMT values were incrementally higher, whereas CACs were not different. In adjusted ordinal logistic regression analysis, fT3 level (odds ratio, 0.81; 95% confidence interval, 0.68 to 0.97), age, and interdialytic weight gain were significantly associated with CA-IMT. fT3 level was associated with c-f PWV in nondiabetics but not in diabetics. In nondiabetics (n = 113), c-f PWV was positively associated with age and systolic BP but negatively with fT3 levels (odds ratio = 0.57, 95% confidence interval 0.39 to 0.83). fT3 levels are inversely associated with carotid atherosclerosis but not with CAC in hemodialysis patients. Also, fT3 levels are inversely associated with surrogates of arterial stiffness in nondiabetics.Clinical Journal of the American Society of Nephrology 08/2011; 6(9):2240-6. · 5.23 Impact Factor -
Article: The association between thyroid hormones and arterial stiffness in peritoneal dialysis patients.
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ABSTRACT: The association between thyroid hormones and arterial stiffness is unclear. In this study, we investigated, for the first time in a large cohort of euthyroid peritoneal dialysis patients, the relationship between thyroid hormone levels and arterial stiffness. Fifty-seven patients were enrolled. Serum TSH, free T3 and free T4 levels were measured by chemiluminescence immunoassay method. Pulse wave analysis [augmentation index (AIx) and subendocardial viability ratio (SEVR)] were measured to assess arterial stiffness. Mean age was 49 ± 12.3 years, and 56.1% were female. Mean TSH, fT3 and fT4 levels were 1.97 ± 0.99 mIU/ml, 2.80 ± 0.42 pg/ml and 1.22 ± 0.16 ng/dl, respectively. Mean AIx and SEVR were 22.3 ± 11.3 and 136 ± 21%, respectively. AIx was negatively correlated with residual urine volume (r = -0.372, P: 0.03) and fT3 levels (r = -0.382, P: 0.005). SEVR was correlated only with TSH level (r = -0.394, P: 0.003). In linear regression analysis adjusted for age, gender, history of diabetes and cardiovascular disease and residual diuresis, fT3 level (t = -3.949, P < 0.001) remained associated with AIx. Only TSH level (t = -2.409, P: 0.02) was related to SEVR. Low serum fT3 level is associated with arterial stiffness, and high TSH level within the normal range is related to lower SEVR in euthyroid PD patients.International Urology and Nephrology 07/2011; 44(2):601-6. · 1.47 Impact Factor -
Article: Calcineurin inhibitor-based and free regimens have distinct gene expression patterns in subclinical graft fibrosis.
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ABSTRACT: Chronic nephrotoxic effects of calcineurin inhibitors may be responsible for late allograft dysfunction and reduced allograft half-life. Mammalian target of rapamycin inhibitors (mTOR-i's), a newer class of immunosuppressant, do not have the chronic nephrotoxic effects shown with calcineurin inhibitors (CNI). Whether these drug classes have distinct features at the molecular level is not clear. Difference in gene expression profiles of kidney graft protocol biopsies from patients treated with CNI or mTOR-i's were investigated. Biopsies from patients using CNI (n=4) and mTOR-i-based treatments (n=4) were analyzed. The control group consisted of 5 biopsies obtained at the time of implantation (zero hour). Microarray hybridization was performed using the Affymetrix® GeneChip U133 plus 2.0 Array. In the CNI and mTOR-i groups, 64 up-regulated and 119 down-regulated genes were found compared to control subjects. A total of 29 genes in the CNI group and 101 genes in the mTOR-i group were up-regulated compared to each other. Despite similar clinical courses and histopathological appearances, different treatment strategies cause different gene expression profiles in kidney transplantation.Annals of transplantation: quarterly of the Polish Transplantation Society 06/2011; 16(2):76-87. · 2.02 Impact Factor -
Article: Association of insulin resistance with arterial stiffness in nondiabetic peritoneal dialysis patients.
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ABSTRACT: Insulin resistance is a risk factor for cardiovascular morbidity and mortality in the general and end-stage renal disease populations. In this study, we investigated the association between insulin resistance and arterial stiffness in nondiabetic peritoneal dialysis (PD) patients. Fifty-three patients were enrolled. Patients were divided into 2 groups as homeostasis model assessment of insulin resistance (HOMA-IR) ≤ 2.97 (low) and >2.97 (high). Carotid-femoral pulse wave velocity (c-f PWV) analysis and intima-media thickness of the carotid artery were measured. Mean age was 46 ± 12 years and HOMA-IR was 2.97 ± 1.77 (0.77-8.88). Mean c-f PWV was 7.6 ± 1.7 m/s. HOMA-IR was positively correlated with age, body mass index, and c-f PWV and negatively with serum HDL cholesterol and parathormone. In linear regression analysis, age and mean arterial pressure were predictors for c-f PWV. When patients were divided into 2 groups according to median age as ≤ 49 and >50, mean arterial pressure, male gender, and age were predictors for c-f PWV in patients aged ≤ 49, whereas HOMA-IR was the only predictor for c-f PWV in patients aged >50 years. Insulin resistance is an independent risk factor for arterial stiffness in PD patients older than 50 years. IR is not associated with carotid intima-media thickness.International Urology and Nephrology 06/2011; 44(1):255-62. · 1.47 Impact Factor -
Article: Glycosylated hemoglobin levels are associated with cardiovascular events in nondiabetic peritoneal dialysis patients.
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ABSTRACT: High glycosylated hemoglobin (HbA1c) levels are recognized as a risk factor for cardiovascular disease in the diabetic dialysis population. However, it is not known whether this also applies to nondiabetic dialysis patients. We prospectively investigated the association between HbA1c levels and new cardiovascular events in nondiabetic patients treated with peritoneal dialysis. Eighty nondiabetic patients who had been on peritoneal dialysis treatment were prospectively followed for 5 years. HbA1c levels were measured at baseline and every 3 months. Fatal and nonfatal cardiovascular events were assessed during the follow-up. Mean age was 48.5 ± 15.2 years; 51% were male. Baseline HbA1c level was 5.46% ± 0.41% (range 4.6%-6.3%). Mean HbA1c was 5.44% ± 0.31% (range 4.8%-6.3%) during the study, and positively correlated with age and high-sensitivity C-reactive protein. Twenty fatal and nonfatal cardiovascular events were observed during a mean 41.8 ± 7.1 months of follow-up. Event-free survival was better in patients with HbA1c levels <5.45%, compared with that for those with HbA1c levels =5.45% (p=0.01). In crude Cox regression analysis, an increase in HbA1c level of 0.1% was associated with a 1.22-fold increase in new cardiovascular events (p=0.007). In Cox analyses, HbA1c level was found as a significant predictor of cardiovascular events. HbA1c levels predict fatal and nonfatal cardiovascular events in nondiabetic peritoneal dialysis patients.Journal of nephrology 05/2011; 25(1):107-12. · 1.65 Impact Factor -
Article: Ventricular arrhythmia in dialysis patients: a link with higher hemoglobin levels?
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ABSTRACT: We investigated the frequencies and associated risk factors of cardiac arrhythmias and heart rate variability (HRV) in hemodialysis (HD) patients. One hundred fifty prevalent HD patients underwent 48-hour Holter monitoring. Holter monitoring was analyzed in 4 phases: early post-HD phase (12 hours), late post-HD phase (20 hours), pre-HD phase (12 hours), and HD phase (4 hours). Echocardiography was applied to measure the left ventricular mass index in a subgroup of patients (n: 52). Patients with ventricular premature contraction (VPC) were significantly older, had a longer HD duration, and higher hemoglobin (Hb) levels. Left ventricular mass index was significantly correlated with the frequency of VPC, during the HD and pre HD phases (r: 0.435, 0.312, respectively). In logistic regression analysis, patients with Hb level >11.9 g/dL (high tertile) had a 4.5-fold increased risk of VPC compared with those with Hb levels <10.8 g/dL (P: 0.04). In HRV analysis, age (P<0.001), and diabetes (P: 0.03) were found to be independent predictors of low standard deviation of all mean normal-to-normal RR intervals. Increased left ventricular mass index is associated with a high frequency of VPC in the pre-HD and HD periods. The occurrence of VPC is predicted by older age, longer dialysis duration, and higher Hb levels, while older age and diabetes are the determinants of HRV. The relation between higher Hb levels and the frequency of VPC might provide a clue for the explanation of the detrimental effect of higher Hb levels on HD patients.Hemodialysis International 04/2011; 15(2):250-5. · 1.54 Impact Factor -
Article: The link between bone and coronary calcifications in CKD-5 patients on haemodialysis.
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ABSTRACT: Vascular calcifications are frequent in Stage 5 chronic kidney disease (CKD-5) patients receiving haemodialysis. The current study was designed to evaluate the associations between bone turnover/volume and coronary artery calcifications (CAC). In 207 CKD-5 patients, bone biopsies, multislice computed tomography of the coronary arteries and blood drawings for relevant biochemical parameters were done. The large number of CKD-5 patients enrolled allowed separate evaluation of patients with CAC versus patients without CAC and adjustment for traditional and non-traditional risk factors for CAC. When all patients were analysed, associations were found between CAC and bone turnover, bone volume, age, gender and dialysis vintage. When only patients with CAC were included, there was a U-shaped relationship between CAC and bone turnover, whilst the association with bone volume was lost. In these patients, the relationship of CAC with age, gender and dialysis vintage remained. Beyond the non-modifiable risk factors of age, gender and dialysis vintage, these data show that bone abnormalities of renal osteodystrophy amenable to treatment should be considered in the management of patients with CAC.Nephrology Dialysis Transplantation 03/2011; 26(3):1010-5. · 3.40 Impact Factor -
Article: Nutritional state alters the association between free triiodothyronine levels and mortality in hemodialysis patients.
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ABSTRACT: Serum free triiodothyronine (fT3) level is suggested to be a risk factor for mortality in unselected dialysis patients. We investigated the prognostic value of serum fT3 levels and also low-T3 syndrome on overall survival in a large cohort of hemodialysis (HD) patients with normal thyroid-stimulating hormone levels. A total of 669 prevalent HD patients were enrolled in the study. Serum fT3 level was measured by enzyme immune assay in frozen sera samples at the time of enrollment. Overall mortality was assessed during 48 months of follow-up. Baseline fT3 was 1.47 ± 0.43 (0.01-2.98) pg/ml, and low-T3 syndrome was present in 71.7% of the cases. During a mean follow-up of 34 ± 16 months, 165 (24.7%) patients died. fT3 level was a strong predictor for mortality in crude and adjusted Cox models including albumin or high-sensitivity C-reactive protein (hs-CRP). Further adjustment for both albumin and hs-CRP made the impact of fT3 on mortality disappear. The presence of low-T3 syndrome was associated with mortality in only the unadjusted model. Low-T3 syndrome is a frequent finding among HD patients, but it does not predict outcome. However, serum fT3 level is a strong and inverse mortality predictor, in part explained by its underlying association with nutritional state and inflammation.American Journal of Nephrology 03/2011; 33(4):305-12. · 2.54 Impact Factor
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Institutions
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2004–2013
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Ege University
- • Department of Nephrology
- • Department of Cardiology
İzmir, Izmir, Turkey
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2010
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Tepecik Teaching and Research Hospital
İzmir, Izmir, Turkey
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