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PURPOSE: Coronary artery calcification (CAC) is an independent predictor of cardiovascular (CV) events in renal transplant recipients (RTR). Carotid-femoral pulse wave velocity (PWV), a non-invasive measure of large artery stiffness, also predicts CV events in RTR. The study investigated the relationship between CAC and PWV in RTR and assessed the performance of PWV measurement in predicting CAC. PATIENTS/METHODS: The study was performed as cross-sectional analysis in 104 RTR. CAC was determined as total calcium score (CS) and calcium mass (CM). Carotid-femoral PWV was also measured. Sensitivity, specificity and receiver operating characteristic (ROC) curve were used to assess the performance of PWV as diagnostic test for presence of CAC. RESULTS: CAC was found in 69% of participants. PWV was higher in RTR with CAC than in RTR without CAC (10.2±2.2 vs. 8.6±15; p<0.001). In univariate analysis CS was significantly correlated with age, duration of hypertension, waist circumference, PWV, hemoglobin concentration, and serum glucose. In multiple linear regression analysis CS was independently associated with age only, but not with PWV. Sensitivity and specificity of PWV>7.6m/s as cut-off for detecting CAC>0 was 0.889 and 0.406, respectively. Sensitivity and specificity of PWV>10.2m/s as cut-off for detecting severe CAC (CS>400) was 0.319 and 0.969, respectively. CONCLUSIONS: The study confirmed high prevalence of coronary artery calcification in renal transplant recipients. The study does not support the hypothesis that aortic stiffness is independently associated with coronary artery calcification in RTR. PWV measurement may be useful in excluding severe CAC in RTR.

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BACKGROUND: An aim of this study was to assess the feasibility of DWI in the early period after kidney transplantation. We also aimed to compare ADC and eADC values in the cortex and medulla of the kidney, to estimate image noise and variability of measurements, and to verify possible relation between selected labolatory results and diffusion parameters in the transplanted kidney. MATERIAL/METHODS: Examinations were performed using a 1.5 T MR unit. DWI (SE/EPI) was performed in the axial plane using b-values of 600 and 1000. ADC and eADC measurements were performed in four regions of interest within the renal cortex and in three regions within the medulla. Relative variability of results and signal-to-noise ratio (SNR) were calculated. RESULTS: The analysis included 15 patients (mean age 52 years). The mean variability of ADC was significantly lower than that of eADC (6.8% vs. 10.8%, respectively; p<0.0001). The mean variability of measurements performed in the cortex was significantly lower than that in the medulla (6.2% vs. 11.5%, respectively; p<0.005). The mean SNR was higher in the measurements using b600 than b1000, it was higher in ADC maps than in the eADC maps, and it was higher in the cortex than in the medulla. ADC and eADC measured at b1000 in the cortex were higher in the group of the patients with eGFR ≤30 ml/min./1.73 m(2) as compared to patients with eGFR >30 ml/min./1.73 m(2) (p<0.05). CONCLUSIONS: Diffusion-weighted imaging of transplanted kidneys is technically challenging, especially in patients in the early period after transplantation. From a technical point of view, the best quality parameters offer quality ADC measurement in the renal cortex using b1000. ADC and eADC values in the renal cortex measured at b1000 present a relationship with eGFR.

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INTRODUCTION: Post-transplant diabetes mellitus (PTDM), pre-diabetes-impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) are frequent complications after organ transplantation. The aim of this study was to assess the frequency of PTDM, IFG and IGT in a group of renal transplant recipients, to compare the frequency of glucose metabolism disorders in subjects treated with tacrolimus and with cyclosporine, and to establish the influence of different risk factors on the development of glucose metabolism disorders. MATERIAL AND METHODS: We examined 206 non-diabetic kidney allograft recipients (age 46.4 ± 12.3 years, time since transplantation 45.5 ± ± 33.6 months, BMI 26.3 ± 4.5 kg/m2). Glucose metabolism disorders were diagnosed using an oral glucose tolerance test. Logistic regression was used to assess the influence of each risk factor (age, BMI, waist circumference, physical activity, the presence of cardiovascular disease, positive family history of diabetes, cholesterol and triglycerides concentration) on the development of glucose metabolism disorders. RESULTS: In 103 patients (50%), we diagnosed glucose metabolism disorders. 19% of patients had PTDM, 14% IFG, and 17% IGT. We did not find any differences in the frequency of glucose metabolism disorders between patients treated with tacrolimus and with cyclosporine. Multivariate analysis identified BMI and a family history of diabetes as independent risk factors of glucose metabolism disorders. CONCLUSIONS: We found a high prevalence of glucose metabolism disorders in the examined group. This suggests that kidney transplant recipients should be screened for these disturbances. Patients with higher BMI and with first-degree relatives with diabetes had an increased risk of glucose metabolism disorders after kidney transplantation.

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BACKGROUND: Pulse wave velocity (PWV) is a marker of arterial stiffness. Data from general population and end-stage renal disease patients suggest that PWV increases with age by about 0.1 m/s for each year of life and that PWV increase is steeper after the fifth decade. Recent follow-up studies showed decrease of arterial stiffness during the first year after kidney transplantation (KTx). This study aimed to investigate PWV change in kidney transplant recipients (KTR) during long-term follow-up. MATERIAL/METHODS: Carotid-femoral PWV was measured at baseline (PWV1) and then after at least 24 months (range 24-34, mean ±SD 28±3) of follow-up (PWV2) in 61 KTR aged 46±12 years. Baseline PWV measurements were performed at 36±27 months (range 4-121) after KTx. Clinical and laboratory data were also analyzed. GFR was calculated with MDRD formula (eGFR). ∆PWV was calculated as (PWV2-PWV1)/PWV1. RESULTS: Significant increase in PWV (9.1±1.7 vs. 9.8±2.0; p<0.002) and pulse pressure (PP) (50±11 vs. 53±14; p<0.05) was found during follow-up, but systolic, diastolic and mean arterial pressure did not change. eGFR did not change during follow-up (55±16 vs. 56±16 ml/min/1.73 m2). PWV increase was observed in patients aged ≥50 years (9.8±1.8 vs. 10.8±1.9; p<0.01), while not in younger patients (8.5±1.5 vs. 8.9±1.5; p=0.14). Significant positive correlation was found between ∆PWV and duration of the follow-up period. CONCLUSIONS: The study revealed progressive arterial stiffening in kidney transplant recipients during long-term follow-up. Further studies are necessary to explain the pathophysiology of this phenomenon.

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BACKGROUND: Pulse wave velocity (PWV) is a marker of arterial stiffness. It was shown that PWV is related to increased cardiovascular risk in renal transplant recipients (RTR). Renal transplantation leads to decrease of arterial stiffness when compared with dialysis patients. Despite many studies, causes of increased arterial stiffness in RTR are not well defined. This study sought to investigate the association between cardiovascular risk factors, graft function, cardiovascular and immunosuppressive therapy, and carotid-femoral PWV in renal transplant recipients. MATERIAL/METHODS: Carotid-femoral PWV were measured with Complior device in 207 (73 female and 134 male) RTR aged 45+/-12 years, and in 21 healthy volunteers as controls. RESULTS: Pulse wave velocity was higher in RTR compared with controls: 9.2+/-2.1 m/s vs 8.3+/-1.5m/s (P<.05). In RTR group, significant correlations were found between PWV and age (r=0,55; P<.001), male sex (r=0.17; P<.02), body weight (r=0.23; P<.01), systolic (SBP) (r=0.36; P<.001), and diastolic blood pressure (DBP) (r=0.19; P<.01), pulse pressure (pulse pressure) (r=0.34; P<.001), mean arterial pressure (MAP) (r=0.28; P<.001), number of antihypertensive medication (r=0.17; P<.02), fasting glucose (r=0.24; P<.01), presence of diabetes (r=0.24; P<.01), eGFR (r=-0.19; P<.01), therapy with cyclosporine (r=0.29; P<.001), and therapy with tacrolimus (r=-0.22; P<.01). In stepwise multiple regression analysis, age, male sex, MAP, cyclosporine, and fasting glucose concentration were independently associated with increased PWV. CONCLUSIONS: Arterial stiffness is increased in RTR. Type of immunosuppressive regimen, high blood pressure, and glucose metabolism disturbances should be considered as potential targets to reduce increased arterial stiffness in RTR.

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BACKGROUND: Pulse wave velocity (PWV) is a marker of the arterial wall stiffness and independent cardiovascular risk factor in hemodialysis patients. Cyclosporine A (CyA) and tacrolimus (TAC) are known to differ in the influence on cardiovascular risk factors in renal transplant recipients. Recent studies suggest that CyA may decrease arterial compliance. The aim of the study was to assess the influence of CyA and TAC on the PWV and arterial wall stiffness in renal transplant recipients. METHODS: The study population consisted of two groups of cadaveric renal transplant recipients, 76 patients each, matched for age, sex, blood pressure, body mass index, and length of the post-transplant follow-up. PWV between carotid and femoral artery was measured using a Complior device. Fasting blood was sampled for serum creatinine, lipid profile, uric acid, glucose, and C-reactive protein. RESULTS: Aortic pulse wave velocity -- a marker of increased arterial stiffness -- was significantly higher in CyA group compared with TAC group (9.33 +/- 2.10 vs. 8.54 +/- 1.35, respectively; p < 0.01). Uric acid, total cholesterol, triglycerides, and LDL-cholesterol concentrations were significantly higher in CyA group. Significant correlations were found between PWV and age, systolic and diastolic blood pressure, and fasting glucose in the CyA group, but only between PWV and age in TAC group. CONCLUSION: CyA-based immunosuppressive therapy is associated with an unfavorable profile of cardiovascular risk factors and increased arterial stiffness in renal transplant recipients.

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In animals and humans, the highest level of selenium (Se) occurs in the kidney. This organ is also the major site of the synthesis of the selenoenzyme glutathione peroxidase (GSH-Px). Decreased Se levels and GSH-Px activities in blood are common symptoms in the advanced stage of chronic renal failure (CRF). Blood samples for Se levels and GSH-Px activities measurements from patients were collected just before transplantation and 3, 7, 14, 30, and 90 d posttransplant. The Se levels in whole blood and plasma of patients before transplantation (79.5 and 64.5 ng/mL, respectively) were lower by 23% and 21%, respectively, as compared with controls (p < 0.0001), and 7 d after operation, it further decreased in both components (p < 0.01). Fourteen days after surgery, the levels reached the initial values and increased slowly in the later period. Red blood cell GSHPx activity in patients in the entire period of the study did not differ from the control group. Plasma GSH-Px of patients before the surgery was extremely low (76 U/L) as compared with controls (243 U/L; p < 0.0001) but increased rapidly to 115 U/L after 3 d, to 164 U/L after 14 d, and to 208 U/L after 3 mo posttransplant. In CRF patients, after kidney transplantation, plasma GSH-Px activity increased rapidly, approaching, after 3 mo, the values that were close to the normal levels. A negative correlation between creatinine level and plasma GSH-Px activity is observed in patients after kidney transplantation. Monitoring of plasma GSH-Px activity may be a useful additional marker of the transplanted kidney function.

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BACKGROUND: The kidney accumulates the highest level of selenium (Se) in the organism and is the major source of plasma glutathione peroxidase (GSH-Px). Se, as an integral part of the active site of GSH-Px, plays an important role in protecting cell membranes from oxidative damage. Decreased blood Se levels and GSH-Px activity are common in chronic renal failure (CRF) patients. Our study was an effort to evaluate the effect of erythropoietin (EPO) therapy and Se supplementation for CRF patients undergoing regular hemodialysis (HD) on blood Se, red cell glutathione (GSH), and blood lipid peroxidation product levels, and on blood activity levels of GSH-Px and blood superoxide dismutase (SOD). MATERIAL/METHODS: Our subjects were divided into three groups: I - CRF patients on regular HD and EPO, II - HD patients receiving EPO and Se, and III - healthy controls. Se levels, SOD and GSH-Px activities were measured spectrofluorometrically, the GSH level by Beutler's colorimetric method, and lipid peroxidation products using TBARS. RESULTS: EPO therapy with Se supplementation significantly increased whole blood and plasma Se in HD patients, and raised red cell GSH-Px activity, but plasma GSH-Px activity, plasma superoxide dismutase, and plasma and red cell TBARS did not respond to Se supplementation. EPO alone showed no effect on these parameters. CONCLUSIONS: Treatment with EPO and supplementation with Se significantly increased the element concentration in whole blood and plasma, and GSH-Px activity in red cells. Plasma GSH-Px activity did not respond to Se.

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