The endothelial cell layer is responsible for molecular traffic between the blood and surrounding tissue, and endothelial integrity plays a pivotal role in many aspects of vascular function. Cardiovascular disease (CVD) is the main cause of death in patients with chronic kidney disease (CKD) and its incidence and severity increase in direct proportion with kidney function decline. Non-traditional risk factors for CVDs, including endothelial dysfunction (ED), are highly prevalent in this population and play an important role in cardiovascular (CV) events. ED is the first step in the development of atherosclerosis and its severity has prognostic value for CV events. Several risk markers have been associated with ED. Reduced bioavailability of nitric oxide plays a central role, linking kidney disease to ED, atherosclerosis, and CV events. Inflammation, loss of residual renal function, and insulin resistance are closely related to ED in CKD. ED may be followed by structural damage and remodelling that can precipitate both bleeding and thrombotic events. The endothelium plays a main role in vascular tone and metabolic pathways. ED is the first, yet potentially reversible step in the development of atherosclerosis and its severity has prognostic value for CV events. Therefore, evaluation of ED may have major clinical diagnostic and therapeutic implications. In patients with CKD, many risk factors are strongly interrelated and play a major role in the initiation and progression of vascular complications that lead to the high mortality rate due to CVD.

Objectives: Aim of the present study was to investigate serum concentration of leptin and its association with values of body mass index (BMI), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) in hemodialysis (HD) patients. Methods: This cross-sectional study included 60 HD patients (34 male, 26 female) and 30 age- and sex-matched (4 males, 26 females) apparently healthy subjects. Serum leptin concentration was determined by an enzyme-linked immunosorbent assay (ELISA). Serum CRP concentration was measured by means of particle-enhanced immunonephelometry. ESR value was determined by Western Green method. BMI was calculated as weight (kg) divided by height squared (m2). Results: Results have shown that median serum leptin concentration (30.65 ng/mL; 12.48-86.40 ng/mL) was statistically significantly higher in HD patients compared to median serum leptin concentration (15.75 ng/mL; 9.15-30.65 ng/mL) in the control group of healthy subjects (p<0.05). Likewise, median serum CRP concentration (5.5 mg/L; 1.93-8.9 mg/L) and median ESR value (57.5 mm/h; 40.5-77.0 mm/h) were significantly higher in HD patients compared to median serum CRP concentration (0.8 mg/L; 0.38-1.43 mg/L) (p<0.001) and median ESR value (10.0 mm/h; 6.5-14.0 mm/h) (p<0.001) determined in the control group. Statistically significant positive correlation was found between BMI values and serum leptin concentration in HD patients (rho=0.434; p<0.001). Positive, although not significant, correlation was observed between serum CRP and leptin levels in HD patients (rho=0.171; p>0.05). Negative correlation between ESR values and serum leptin concentrations in HD patients was determined but it was not statistically significant (rho= -0.029; p>0.05). Conclusions: Increased serum concentration of leptin as pro-inflammatory cytokine as well as elevated serum values of CRP and ESR indicate presence of systemic micro inflammation in HD patients. Results of the present study point to possible use of serum leptin concentration as an indicator of nutritional status in HD patients based on observed significant positive correlation between serum leptin concentrations and BMI values. However, absence of significant association between serum leptin and CRP levels as well as between serum leptin concentrations and ESR values in HD patients requires further investigation and clarification.

Exercise training may increase production of free radicals and reactive oxygen species in different ways. The training type and intensity may influence free radicals production, which leads to differences in oxidative stress status between athletes, but the results of the previous studies are incosistent. The aim of our study was to estimate oxidative stress status in elite athletes engaged in different sport disciplines. The study included 39 male highly skilled professional competitors with international experience (2 Olympic players): 12 wrestlers, 14 soccer players and 13 basketball players in whom we determined the levels of advanced oxidation protein products (AOPP) and malondialdehyde (MDA), as markers of oxidative stress and the total antioxidative capacity (ImAnOX) using commercially available assay kits. The mean AOPP concentration was not significantly different between soccer players, wrestler and basketball players (60.0 ± 23.0 vs. 68.5 ± 30.8 and 80.72 ± 29.1 μmol/L respectively). Mean ImAnOX concentration was not different between soccer players (344.8 ± 35.6 μmol/L), wrestlers (342.5 ± 36.2 μmol/L) and basketball players (347.95 ± 31.3 μmol/L). Mean MDA concentration was significantly higher in basketball players (1912.1 ± 667.7 ng/mL) compared to soccer players (1060.1 ± 391.0 ng/mL, p=0.003). In spite of this fact, oxidative stress markers levels were increased compared to referral values provided by the manufacturer. Type of sports (soccer, wrestler or basketball) have no impact on the levels of oxidative stress markers. Elite sports engagement is a potent stimulus of oxidative stress that leads to the large recruitment of antioxidative defense. Oxidative stress status monitoring followed by appropriate use of antioxidants is recommended as a part of training regime.

The utility of procollagen type 1 N-terminal propeptide (P1NP) in the management of metabolic bone diseases remains a subject of debate since the reference ranges are not rigorously established and fail to account for many of the preanalytical variables. We aimed to establish reference intervals for P1NP level in healthy and osteoporotic postmenopausal females stratified by age, body mass index and menopausal duration. We also aimed to assess the relationship between P1NP and BMD. This cross-sectional study enrolled 183 postmenopausal females who were divided in osteoporosis group (N=93) and control group (N=90) with preserved bone mass based on BMD assessed by DXA. In the osteoporosis group median P1NP was significantly higher (51.7 ng / mL; 95%CI 43.2-53.7) compared to control group (38.9 ng/mL; 95%CI 34.2-43.9)(p<0.01). After controlling for age, BMI and years since menopause, there was significant inverse association between BMD and P1NP at the femoral neck (r=-0.18), total hip (r=-0.207) and lumbar spine (r=-0.236). There was no significant difference in P1NP concentration across quartiles of age in postmenopausal females. P1NP was significantly lower in obese postmenopausal females with preserved bone mass compared to normal weight and overweight females in control and in osteoporosis group. In conclusion, we showed that P1NP is inversely associated with BMD even after controlling for age, BMI and years since menopause. Although, P1NP is significantly higher in postmenopausal females with osteoporosis compared to postmenopausal females with preserved bone mass its low specificity does not warrant its utility is diagnosing osteoporosis.

Endothelial dysfunction is associated with diabetic micro- and macroangiopathy as well as with the decline in creatinine clearance. It has been suggested that endothelial dysfunction presents in patients (pts) on continuous ambulatory peritoneal dialysis (CAPD). The objective of this study was to examine the plasma biomarkers of endothelial dysfunction and their association with IMT of carotid arteries in diabetic and non-diabetic patients on CAPD. This study included 37 CAPD pts (25 with type II diabetes and 12 non-diabetic pts) mean age 59.2 years ± 2.48. Plasma von Willebrand factor (vWF) activity, serum albumin, glucose, total cholesterol, triglycerides and lipoprotein (a) levels, as well as serum level of homocysteine, parathyroid hormone (PTH) in plasma and microalbuminuria was determined. Ultrasound examination of carotid arteries was performed in all patients by measured bilateral intima-media thickness of carotid artery (CIMT). Mean IMT value was significantly higher in type 2 DM patients (0.86 ± 0.04 mm) compared to non-diabetic patients (0.52 ± 0.06 mm) on peritoneal dialysis (p<0.0001). There was also a significant difference in lipids /triglycerides and Lp (a)/, procoagulation (fibrinogen, von Wilebrand factor, factor VIII) and inflammatory markers (CRP) level between type 2 DM and non-diabetic CAPD patients. A stepwise multiple regression analysis revealed that log triglycerides and factor VIII were independent factors for the IMT. The results of this research impose that diabetic type 2 CAPD patients have developed systemic alteration of endothelial function and higher risk of cardiovascular complications compared to non-diabetic CAPD patients.

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS). It is characterized by loss of myelin, the fatty tissue that surrounds and protects nerve fibres allowing them to conduct electrical impulses. Recent data indicate that oxidative stress (OS) plays a major role in the pathogenesis of multiple sclerosis (MS). The aim of this study was to estimate level of serum total antioxidative capacity in patients with multiple sclerosis. Our cross-sectional study included 33 patients with MS and 24 age and sex matched control subjects. All our patients had a Poser criteria for definite diagnostic categories of multiple sclerosis. Serum total antioxidant capacity (TAC) was measured by quantitative colorimetric determination, using Total antioxidant Capacity-QuantiCromAntioxidant Assay Kit (BioAssay systems, USA; DTAC-100). Mean serum TAC in multiple sclerosis group of patients was 119.2 mM Trolox equivalents and was significantly lower (p<0.001) compared to the control group of subjects (167.1 mM Trolox equivalents). Our results showed that oxidative stress plays an important role in pathogenesis of multiple sclerosis. This finding, also, suggests the importance of antioxidants in diet and therapy of MS patients.