Metabolic acidosis in kidney transplant recipients.

Introduction Metabolic acidosis (MA) may accelerate the progression of chronic kidney disease (CKD) and is an important risk factor for increased mortality in CKD patients. The clinical value of MA in kidney transplant (KTx) recipients has not been extensively studied so far. Objectives The aim of this clinical single­­center case­­control study was to assess the prevalence of MA in KTx recipients in comparison with CKD patients and to identify pathogenic factors for MA in KTx recipients. Patients and methods Venous blood concentrations of bicarbonate (HCO3-) and blood hemoglobin concentrations were measured in 500 KTx recipients and 500 CKD patients matched for sex, age, and estimated glomerular filtration rate (eGFR). None of these patients received alkali treatment before the study. MA was diagnosed in KTx recipients with HCO3- levels lower than 22 mmol/l. Results The prevalence of MA was lower in KTx recipients than in CKD patients (12.0% vs 19.6%; P = 0.001). In both groups, the prevalence increased with progression of CKD stages (P <0.001 for trend) and was higher in patients with anemia. In a multivariable analysis, hemoglobin concentrations correlated independently with eGFR and HCO3- in KTx recipients (ß = 0.314, P <0.001 and ß = 0.274, P <0.001, respectively). Similar correlations were observed in CKD patients (ß = 0.273, P <0.001 and ß = 0.123, P = 0.006, respectively). Conclusions Our study revealed that the prevalence of MA is lower in KTx recipients than in CKD patients. Moreover, in KTx recipients, blood bicarbonate concentrations are related to kidney function and blood hemoglobin concentrations.

Serum Anti-Müllerian Hormone Concentration in Young Women with Chronic Kidney Disease on Hemodialysis, and After Successful Kidney Transplantation.

BACKGROUND/AIMS: In women with chronic kidney disease (CKD) fertility abnormalities occur frequently. Anti-Müllerian hormone (AMH) inhibits excessive recruitment of primordial follicles. The aim of the study was to evaluate the serum AMH concentration in women on hemodialysis and after kidney transplantation (KTx). METHODS: 46 hemodialysed women and 14 with CKD about to undergo kidney transplantation were enrolled into the study. The control group consisted of 40 healthy women. In all subjects serum concentration of AMH was determined (in chronic hemodialysis women and in control group once, and in women after KTx immediately before surgery, and 3 times after the transplantation). RESULTS: Serum AMH concentration in hemodialysed women and in the control group did not differ significantly, while in hemodialysed women with regular menstrual cycles it was significantly lower than in the control group: 2.20 (1.08-3.55ng/ml) and 3.30 (1.80-6.10ng/ml) respectively, (p=0.02). In the KTx group, a significant decrease in serum AMH concentration was found from 3.30ng/ml (2.20-6.50ng/ml) at baseline to 1.90ng/ml (1.30-2.40ng/ml) at 6 months after KTx (p=0.007). CONCLUSIONS: 1. Significantly lower serum AMH concentration was found in the regularly menstruating CKD women on hemodialysis in comparison with the healthy controls. 2. Serum AMH decreased significantly after successful KTx.

The association of long-functioning hemodialysis vascular access with prevalence of left ventricular hypertrophy in kidney transplant recipients.

Left ventricular hypertrophy (LVH) is frequently observed in chronic dialysis patients and is also highly prevalent in kidney transplant recipients. This study evaluates the impact of long-functioning hemodialysis vascular access on LVH in single center cohort of kidney transplant recipients. 162 patients at 8.7 ± 1.8 years after kidney transplantation were enrolled. Echocardiography, carotid ultrasound, and assessment of pulse wave velocity were performed. LVH was defined based on left ventricular mass (LVM) indexed for body surface area (BSA) and height(2.7). There were 67 patients with and 95 without patent vascular access. Both study groups were comparable with respect to gender, age, duration of dialysis therapy, and time after transplantation, kidney graft function, and cardiovascular comorbidities. Patients with patent vascular access were characterized by significantly elevated LVM and significantly greater percentage of LVH, based on LVMI/BSA (66.7 versus 48.4%, P = 0.02). OR for LVH in patients with patent vascular access was 2.39 (1.19-4.76), P = 0.01. Regression analyses confirmed an independent contribution of patent vascular access to higher LVM and increased prevalence of LVH. We concluded that long-lasting patent hemodialysis vascular access after kidney transplantation is associated with the increased prevalence of LVH in kidney transplant recipients.

Genotypes of renin-angiotensin system and plasma adiponectin concentration in kidney transplant patients.

BACKGROUND: Low plasma adiponectin concentration was recently recognized as a novel risk factor for new-onset diabetes after transplantation. Pharmacological modulation of the renin-angiotensin system activity and genetic predisposition were shown to have an influence on plasma adiponectin level. Therefore the aim of this study is to analyze the association between angiotensin-converting enzyme (ACE) I/D, angiotensin II type 1 receptor (AT1R) A1166C and angiotensinogen (AGT) M235T genotypes and plasma adiponectin concentration as well as insulin resistance in a cohort of kidney transplant patients. MATERIAL/METHODS: AGT M235T, ACE I/D and AT1R A1166C genotyping and plasma adiponectin and insulin concentrations assessment were performed in 372 patients with functioning kidney allograft (eGFR >20 ml/min/1.73 m2) from 2 transplant centres. RESULTS: Females with II ACE I/D genotype had a significantly higher plasma adiponectin concentration than the ID+DD subgroup, which could partially be explained by a lower BMI in the II subgroup. Males with TT genotype of the AGT M235T gene polymorphism (and higher BMI) had higher plasma concentration of insulin and HOMAIR values than those in the MT+MM subgroup. A multiple regression analysis revealed that only female sex (b=0.239), BMI (b=­0.208) and ACE II genotype (b=0.129) were significantly associated with plasma adiponectin concentration variability. A similar analysis for HOMA-IR showed that its variability was associated with BMI (b=0.333), eGFR (b=­0.115) and plasma adiponectin concentration (b=­0.064) irrespective of any of the analyzed genotypes. CONCLUSIONS: Plasma adiponectin concentration, but not insulin resistance, seems to be modulated only by ACE I/D polymorphism in kidney transplant patients. Polymorphisms of the other renin-angiotensin system components do not influence plasma adiponectin concentration or insulin resistance in these patients.

Extrarenal factors influencing resistance index in stable kidney transplant recipients.

BACKGROUND: Increased intrarenal resistance index (RI) has been associated with decreased long-term allograft and patient survival in kidney transplant recipients. Taking into account the potential role of endothelial dysfunction, systemic inflammation, arteriosclerotic lesions, and left ventricle remodeling, we performed a cross-sectional study that aimed to evaluate extrarenal factors that may have influence on kidney graft RI in a large cohort of stable kidney transplant recipients. METHODS: One hundred seventy-four kidney transplant recipients were enrolled into the study. Mean time after transplantation was 8.4±1.8 years. Echocardiography, carotid ultrasound (intima-media thickness), pulse wave velocity, and Doppler examination of kidney graft were performed. The inflammatory markers, adhesion molecules, and plasma N-terminal prohormone of brain natriuretic peptide concentrations were also measured. Patients were divided into quartile subgroups based on RI value (Q1: RI≤0.68, Q2: RI=0.69-0.72, Q3: RI=0.73-0.76, and Q4: RI≥0.77). RESULTS: The analyzed subgroups were comparable with respect to demographics (except age) and anthropometric parameters as well as comorbidities. The values of age, serum phosphate, pulse wave velocity, left ventricular mass (LVM), and LVM index (LVMI) increased in subsequent RI quartile subgroups. The strongest correlation was found between RI and age, LVM, LVMI, and plasma parathormone concentration and was negative with estimated glomerular filtration rate. In backward stepwise multivariate regression analysis, the RI variability was explained by age, LVMI, and serum phosphate concentration. CONCLUSION: Arterial stiffness and left ventricular hypertrophy may significantly influence the intrarenal vascular resistance measured using Doppler sonography in stable kidney transplant recipients.

Effect of low-dose atorvastatin on plasma concentrations of adipokines in patients with metabolic syndrome.

OBJECTIVE: It has not been conclusively proven whether or not the beneficial effect of statins on the cardiovascular system is mediated through their influence on adipokine secretion. We designed a prospective open-label study to assess the influence of 6 months' atorvastatin therapy on plasma concentrations of some adipokines in patients with metabolic syndrome. SUBJECTS: 36 adult patients with metabolic syndrome and serum LDL cholesterol >3.5 mmol/l, previously untreated with statins, were included in the study. MEASUREMENTS: Plasma concentrations of adiponectin, leptin, resistin and insulin were measured before initiation and after 2, 4 and 6 months of atorvastatin therapy (10 mg), and 2 months after treatment cessation. RESULTS: Treatment with atorvastatin was followed by a 35.6% decline in LDL cholesterol. Plasma adiponectin concentration decreased by 20.7% after 2 months; however, after 4 and 6 months, this did not differ significantly from the initial values. There was a negative correlation between the initial plasma concentration of leptin and changes in HDL cholesterol (R = -0.358; p = 0.04). CONCLUSIONS: Firstly, the long-term effect of atorvastatin therapy in patients with metabolic syndrome is not mediated by changes in the secretion of adiponectin, leptin and resistin by adipose tissue. Secondly, plasma leptin concentration seems to be a predictor of HDL cholesterol changes during atorvastatin therapy.

Plasma adiponectin concentration and left ventricular hypertrophy in kidney transplant patients.

BACKGROUND: Low plasma adiponectin concentration is associated with more frequent occurrence of left ventricular hypertrophy (LVH) and more exaggerated intima-media thickness of common carotid artery (IMT). IMT is an early surrogate marker of atherosclerosis. This study aimed to assess the relationship between plasma adiponectin concentration and left ventricular mass index (LVMI) and IMT in kidney transplant patients (KTP). METHODS: In 88 adult KTP, plasma adiponectin concentration, LVMI, and IMT were estimated. LVH was defined as LVMI >110 or >125 g/m(2) for females and males, respectively. Data presented are means and 95% CI. RESULTS: Plasma adiponectin concentration was similar in KTP with (n = 42) or without LVH (n = 46) (13.5 [11.4-15.6] vs. 13.1 [11.6-14.6] µg/mL, respectively), as well as in KTP subgroups divided according to the IMT value tertiles (p = 0.42) (11.7 [10.0-13.3], 14.2 [11.7-16.6], and 14.0 [11.7-16.4] µg/mL in the lowest, middle, and highest tertiles, respectively). Plasma glucose concentrations were similar in KTPs with LVH or without LVH. No significant correlation was found between plasma adiponectin concentration and both LVMI (R = -0.02; p = 0.87) and IMT (R = 0.09; p = 0.38), respectively. CONCLUSION: Results of this cross-sectional study do not confirm the roles of low adiponectin and high glucose in the pathogenesis of LVH and atherosclerosis in KTP.