Selenium status indices, laboratory data, and selected biochemical parameters in end-stage renal disease patients.

We investigated the relations between selenium status (SeS) parameters, indexes of nutrition, erythropoiesis, and uremic toxemia, serum electrolytes, and other biochemical markers in end-stage renal disease (ESRD) patients, as no multivariate statistical analysis concerning all of these parameters was performed so far. SeS was evaluated by plasma Se concentration (plSe) and glutathione peroxidase (plGSHPx) activity in 69 uremic patients treated with hemodialysis (HD) and 40 healthy controls. The hierarchical multivariate partial least squares model (PLS2) was employed to establish data structure and correlations between parameters investigated. plSe and plGSHPx activity were significantly lower in patients when compared with controls (p=0.000). plSe was positively associated with indexes of erythropoiesis and nutritional status, as well as serum electrolytes and parameters of uremic toxemia. plGSHPx was inversely dependent on the pair of parameters: intact parathyroid hormone (iPTH) and aluminum plasma concentration (Al). We conclude that (1) ESRD strongly decreases selenium status and (2) the PLS2 approach revealed the existence of significant interactions among plSe, plGSHPx, and selected biochemical parameters or groups of such parameters; some of these associations need further studies to be clarified.

Changes in common carotid artery intima-media thickness over 1 year in patients on peritoneal dialysis.

BACKGROUND: Accelerated atherosclerosis and vascular calcifications increase cardiovascular morbidity and mortality in patients on dialysis. Common carotid artery (CCA) intima-media thickness (IMT) is considered useful for imaging atherosclerosis non-invasively. Since chronic inflammation may accelerate atherosclerosis in end-stage renal disease patients, the aim of this 1 year study was to assess changes in CCA-IMT in stable peritoneal dialysis (PD) patients, and to search for possible associations between these changes and selected cytokines, acute phase proteins and other risk factors of atherosclerosis. METHODS: Of the original cohort of 61 stable patients on PD-28 female, 33 male; mean age 50.4+/-13.6 years; dialyse for a median of 17.5 months at inclusion (range 1-96 months)-47 patients survived the 1 year period on PD. CCA-IMT was assessed at baseline and after 12 months. Pro-inflammatory cytokines (IL-6, TNFalpha), acute phase proteins (CRP, fibrinogen), calcium-phosphate balance and lipid profile were assessed at baseline and after 6 and 12 months. Anthropometric parameters (age, weight, BMI, waist-to-hip ratio) were measured at baseline. RESULTS: The mean CCA-IMT at baseline, 0.66+/- 0.19 mm, increased by a mean of 0.098+/-0.17 to 0.76+/-0.21 mm (P<0.001) in 1 year. In 14 patients (29.8%) at least one plaque was found in the CCAs examined. At the end of follow-up: 28 patients (59.6%) had increases in CCA-IMT (from 0.63+/-0.2 to 0.83+/- 0.21 mm; P = 0.03), and 19 (40.4%) remained stable or even showed slight, but non-significant, decreases of CCA-IMT (from 0.72+/-0.17 to 0.66+/-0.17 mm, P = NS). The 'progressors' had significantly higher initial BMI (P<0.05), and mean concentrations of calcium (P = 0.005), IL-6 (P = 0.05), TNFalpha (P = 0.05), CRP (P = 0.005) and lower HDL-cholesterol than 'non-progressors'. In univariate analysis, DeltaCCA-IMT correlated positively with age (R = 0.32, P = 0.03), BMI (R = 0.29, P = 0.05) and mean concentrations of CRP (R = 0.37, P = 0.01), TNFalpha (0.52, P = 0.0002), but inversely with HDL-cholesterol (R = -0.37, P = 0.01). In multiple regression analysis, however, only age appeared to be independently associated with increase in CCA-IMT (beta = 0.37, P<0.01; R(2) for the model 0.14). CONCLUSIONS: Our results suggest a possible role of non-specific inflammation in the progression of atherosclerosis in patients treated with PD, in addition to age.

Trends and dynamics of changes in calcification score over the 1-year observation period in patients on peritoneal dialysis.

BACKGROUND: Accelerated vascular calcification is an important cause of excess mortality in patients on dialysis therapy. The aim of the study was to evaluate the trends in coronary artery calcification (CAC) score (CaSc) during a 1-year period in a group of stable peritoneal dialysis (PD) patients and identify factors that may be associated with CaSc changes. METHODS: Sixty-one stable patients (28 women, 33 men) on PD therapy with a mean age of 50.4 +/- 13.6 years were included. Forty-seven patients survived the entire study period on PD therapy and were suitable for the final analysis. CaSc was assessed at baseline and after 12 months by using multislice spiral computed tomography. Proinflammatory cytokines (interleukin-6, tumor necrosis factor-alpha [TNF-alpha]), acute-phase proteins (C-reactive protein [CRP], fibrinogen), calcium-phosphate balance, and lipid profile were assessed at baseline and after 6 and 12 months. RESULTS: Median CaSc was 22.6 Agatston units (range, 0 to 5,502.8 Agatston units) at baseline and increased to 84 Agatston units (range, 0 to 5,001.3 Agatston units) at a 1-year follow-up (P < 0.05). In the entire group of patients, 3 subgroups were identified: patients with progression (n = 21; P = 0.02 for the difference between initial versus follow-up CaSc), patients with regression (n = 12; P = 0.05), and subjects without change in CaSc after 1 year (n = 14). Patients without progression showed no calcifications at baseline and follow-up and were younger, less overweight, and characterized by significantly lower mean TNF-alpha, leptin, and CRP levels during 1 year compared with both progressors and regressors. Mean serum phosphate and calcium x phosphate product (Ca x P) values were gradually increasing from regressors through the no-calcification group to progressors (P < 0.01 for phosphate levels, P < 0.02 for Ca x P product). Significant correlations were found between changes in CaScs and mean values for phosphate (R = 0.44; P < 0.0005) and Ca x P product (R = 0.38; P < 0.005). CONCLUSION: Chronic nonspecific inflammation does not directly attribute to progression in CaScs. Calcium-phosphate balance abnormalities appear to be the only important factors promoting CAC, although a permissive or promoting role of inflammation cannot be ruled out.

An association between coronary artery calcification score, lipid profile, and selected markers of chronic inflammation in ESRD patients treated with peritoneal dialysis.

BACKGROUND: Chronic uremia is considered a proinflammatory state associated with high cardiovascular morbidity and mortality. The aim of the present study is to evaluate the potential relationship between the prevalence of coronary artery calcification (CAC) and selected factors that may be involved in the process of atherogenesis (lipid profile, acute-phase reactants, growth factors, and cytokines). METHODS: The study group consisted of 43 patients (19 women, 24 men) with a mean age of 50.6 +/- 13.4 years treated with peritoneal dialysis (PD) for a median period of 15 months (range, 2 to 96 months). Only patients with sinus rhythm were included. CAC score (CaSc) was measured using multirow spiral computed tomography (MSCT). As parameters of lipid profile, total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides were assayed. C-reactive protein (CRP) and fibrinogen represented the level of acute-phase activation. Proinflammatory cytokines (interleukin-6 [IL-6] and tumor necrosis factor-alpha [TNF-alpha]), leptin, and basic fibroblast growth factor (bFGF) also were measured. RESULTS: Median CaSc equaled 17.9 Agatston units (range, 0 to 5,502 Agatston units). No calcification was detected in 20 subjects (46.5%; CaSc < 10 Agatston units). CaSc correlated with age (R = 0.57; P < 0.0001), body mass index (R = 0.42; P < 0.005), and serum leptin (R = 0.3; P < 0.05) and CRP levels (R = 0.38; P < 0.05). The correlation with PD therapy duration was borderline statistically significant (P = 0.063). Patients with the greatest values for CaSc (> 400 Agatston units) were characterized by significantly greater levels of IL-6, bFGF, and CRP compared with subjects with a CaSc less than 10 Agatston units (P < 0.05 for all). Patients with history of coronary artery disease (CAD) had significantly greater CaSc values (median, 778.6 versus 3.3 Agatston units; P < 0.001) compared with those without CAD. Serum triglyceride levels were significantly greater and HDL cholesterol levels were significantly lower in patients with CAD. The first group also was characterized by significantly greater serum TNF-alpha (P < 0.01) and CRP levels (P < 0.005). In multiple regression analysis, only age was independently associated with CaSc (beta = 0.45; P = 0.002). CONCLUSION: Our results may suggest an association between CAC and chronic inflammation activity in the mentioned group of patients. To our knowledge, this is the first study reporting the prevalence of CAC in PD patients using the MSCT method. The association between CaSc results and classic, as well as inflammatory, risk factors for CAD found in this study should be interpreted with caution because of its method limitations (cross-sectional design, heterogeneity of study population, and small number of studied patients).