Plasma adiponectin concentration in patients after successful kidney transplantation--a single-center, observational study.

BACKGROUND AND AIM: Adiponectin is an anti-inflammatory protein secreted almost exclusively by adipocytes which improves insulin sensitivity and presents antiatherogenic properties. Plasma adiponectin concentration is almost 3 times higher in hemodialysis patients and markedly decreased after successful kidney transplantation. However, until now, there are no studies analyzing plasma adiponectin concentration in kidney transplant patients (KTx) during the long-term period after transplantation. Therefore, the aim of present study was to examine plasma adiponectin concentration in KTx patients during the wide range of time after transplantation. MATERIAL AND METHOD: Single center, cross-sectional study including 228 KTx adult recipients (143 M and 85 F) with estimated glomerular filtration rate (eGFR) > or = 15 ml/min, 80 hemodialysis patients (34 M and 46 F) and 52 healthy subjects (33 M and 19 F). Plasma adiponectin concentration was estimated together with HOMA-IR (homeostasis model assessment insulin resistance index) and plasma lipid profile. RESULTS: In KTx patients plasma adiponectin concentration 14.0 (13.1-15.0) microg/ml was significantly (p < 0.001), lower than in hemodialysis ones 29.0 (24.7-33.3) microg/ml, however, significantly (p < 0.001) higher than in healthy subjects 10.1 (8.8-11.5) microg/ml. Among KTx patients the highest plasma adiponectin concentration was observed in the subgroup of patients surviving with the functioning graft more than 8 years after transplantation. In KTx patients, significant, negative correlations were found between plasma adiponectin concentration and BMI (p = 0.017), HOMA-IR (p = 0.02) and estimated GFR (p < 0.009), respectively. Multiple regression analysis performed in the group of KTx patients, with plasma adiponectin concentration as the dependent variable and BMI, age, gender, estimated GFR as independent variables showed that in this model (R2 = 0.09) plasma adiponectin concentration significantly depends on BMI (p = 0.035), gender (p = 0.004) and eGFR (p = 0.023). CONCLUSIONS: Patients with long-term renal graft survival are characterized by a higher plasma adiponectin concentration. Kidney graft function (assessed as estimated GFR) is an important factor influencing plasma adiponectin concentration.

Cardiovascular Risk Factors and Markers of Atherosclerosis in Stable Kidney Transplant Recipients.

BACKGROUND: There is limited evidence regarding the risk factors influencing vascular injury in kidney transplant recipients, except for accelerated vasculopathy and endothelial dysfunction in the pre-transplantation period of end-stage renal failure. Therefore, we performed a cross-sectional study to evaluate the role of traditional and novel or potential nontraditional risk factors in vascular and endothelial dysfunction in a cohort of stable kidney transplant recipients. METHODS: One hundred forty-two kidney transplant recipients at 8.4 ± 1.8 years after transplantation were enrolled into the study. Different markers of vascular injury, such as carotid intima-media thickness (IMT), pulse wave velocity (PWV), and peripheral arterial tonometry (PAT), were assessed. Inflammatory markers, oxidative stress and endothelial function surrogate markers, adhesion molecules, and parathormone and osteoprotegerin levels were measured. RESULTS: Among traditional risk factors, only age, pre-transplantation diabetes, left ventricular hypertrophy (LVH) and cardiovascular disease (CVD) were related to increased IMT and PWV, whereas PAT values were significantly decreased only in diabetics and patients with CVD and were similar in patients with and without LVH. In multivariate regression analysis, IMT was explained by age, previous CVD episodes, and higher high-sensitivity C-reactive protein levels, and PWV by age and pre-transplantation diabetes. The regression analysis failed to find any significant explanatory variables for PAT. CONCLUSIONS: 1. In stable kidney transplant recipients, age, pre-transplantation diabetes, previous cardiovascular episode, and systemic microinflammation were predictors of vascular injury. 2. PAT is poorly associated with traditional CV risk factors and does not correspond with levels of biochemical markers of endothelial dysfunction in those patients.

Association between gene polymorphisms of the components of the renin-angiotensin-aldosteron system, graft function, and the prevalence of hypertension, anemia, and erythrocytosis after kidney transplantation.

INTRODUCTION: Genetic predisposition, including polymorphisms of the renin-angiotensin system (RAS) genes, are among the potential factors that may affect the occurrence of hypertension, anemia, or erythrocytosis as well as transplanted kidney function. However, the association of the RAS genes polymorphism and the kidney transplant outcomes is controversial. The aim of this study was to analyze the association between polymorphic variants of the angiotensin-converting enzyme (insertion/deletion [I/D]), angiotensinogen (M235T), and angiotensin II receptor type 1 (A1166C) genes, and the early and long-term kidney graft outcomes, as well as the prevalence of hypertension, anemia and erythrocytosis after kidney transplantation. PATIENTS AND METHODS: We included 331 consecutive kidney transplant patients performed between 1998 and 2003. Of the total, 87.9% of patients completed a 5-year follow-up. Subjects were genotyped for the I/D, M235T, and A1166C polymorphisms. RESULTS: None of the examined polymorphism affected early or long-term graft function or was associated with hypertension before or after kidney transplantation. There was no significant difference in genotype distribution between patients with and without posttransplant erythrocytosis. However, posttransplant anemia (PTA) seemed to be significantly more common among kidney recipients with TT and MT than MM angiotensinogen genotypes (35.7% vs 20.7%; P=.03). The T allele was associated with the risk of development of PTA (odds ratio, 2.12; 95% confidence interval, 1.12-3.99; P=.02). CONCLUSION: Our results do not support the hypothesis that polymorphism of the genes coding RAS components may by an independent risk factor for the development of interstitial fibrosis/tubular atrophy, posttransplant hypertension, or PTE. Further studies are necessary to investigate the association between angiotensinogen M235T genotypes and PTA.