We investigated lipid peroxidation, resistance of plasma and red blood cells to oxidation, and antioxidant defense system in erythrocytes and sera in patients with type 2 diabetes mellitus. One group included newly diagnosed 20 patients and the other included 20 patients treated with oral antidiabetic agents (OAD). Twenty healthy subjects served as controls. Serum and red blood cell malondialdehyde (MDA), glutathione (GSH), resistance to oxidation, and plasma thiol (total -SH) levels were measured. In addition, glycated hemoglobin, serum fructosamine, uric acid, total protein, total cholesterol, triglyceride and glucose levels were determined. Although newly diagnosed patients had higher serum and erythrocyte MDA levels than those of controls, the highest levels of MDA were determined in patients treated with OAD. MDA levels after exposing to oxidation increased in OAD group more than in newly diagnosed patients. Total -SH and erythrocyte GSH levels of the both diabetic groups were lower than controls. These results show that serum and erythrocyte lipid peroxidation was increased in diabetic patients. The sera of the patients showed a decreased resistance against oxidation. We therefore suggest that the effect of increased free radicals may be prevented by antioxidant systems in early stages of type 2 diabetes but in advanced stages this relationship is impaired owing to decreased antioxidant activity. Decreased red blood cell GSH and serum total -SH levels may be due to a compensation mechanism of the antioxidants.

Visfatin was recently defined as an adipocytokine; however, the pathophysiological role of visfatin is not completely understood. A few studies suggest that visfatin may be a new proinflammatory adipocytokine. The aim of the present study was to compare serum visfatin levels between hemodialysis and continuous ambulatory peritoneal dialysis (CAPD) patients and evaluate the relationship between visfatin levels to IL-6, TNF-alpha, and left ventricular hypertrophy. Serum visfatin, IL-6, and TNF-alpha levels were measured by using the ELISA method, and echocardiographic evaluations were performed in 31 hemodialysis patients, 30 CAPD patients, and 21 healthy volunteers. Serum visfatin levels were higher in the CAPD group (265.27 +/- 387.86 ng/mL) than hemodialysis (97.68 +/- 244.96 ng/mL,) and control (41.33 +/- 48.87 ng/mL) groups (p = 0.04, p = 0.01, respectively). No significant difference was observed between the hemodialysis and control groups. In univariate analysis, visfatin levels were positively correlated with IL-6 (r = 0.24, p = 0.03), TNF-alpha (r = 0.34, p = 0.002), and BMI (r = 0.26, p = 0.03) and negatively correlated with some left ventricular diastolic parameters [Em and Em/Am (r = -0.305, p = 0.01), (r = -0.251, p = 0.03), respectively]. No relationship was found between visfatin and left ventricular mass index. In the linear regression analysis, visfatin levels independently related with TNF-( (beta = 0.369, p = 0.001) and IL-6 (beta = 0.284, p = 0.015). This study has found significantly higher levels of serum visfatin in CAPD patients when compared to healthy individuals. Increased visfatin levels seem to associate with proinflammatory cytokines such as IL-6 or TNF-alpha. As for the effects of on left ventricular structure and functions, visfatin might have negative effects on left ventricular diastolic function parameters but have no effects on left ventricular mass index.

Recent reports show the adverse impact of pre-transplantation iron overload on the outcome of haematopoietic stem cell transplantation (HSCT). We studied the pre-transplantation serum iron (SI) parameters including prohepcidin levels - a regulatory peptide of systemic iron homeostasis - and their role in early post-transplantation toxicities in allogeneic HSCT recipients. One hundred consecutive patients [36 women and 64 men; median age 27·5 years (range 16-63 years)] who underwent allogeneic HSCT between September 2003 and October 2007 at Gazi University were included in the study. Pre-transplantation serum prohepcidin levels did not show correlation with SI parameters and interleukin-6 levels (P>0·05). Prohepcidin levels were inversely correlated with the National Cancer Institute grade of mucositis (P=0·060), neutropenic fever (P<0·001), and the number of days with febrile neutropenia (P=0·003). SI levels were correlated with the severity of hepatotoxicity (P=0·015) while pre-transplantation transferrin saturation levels were positively correlated with the severity of hepatotoxicity (P=0·055), pulmonary toxicity (P=0·032), and sinusoidal obstruction syndrome (P=0·049). Pre-transplantation serum ferritin levels were positively correlated with the development of sinusoidal obstruction syndrome (P=0·010) and inversely correlated with the day of neutrophil engraftment (P=0·012). Overall survival was 41·26% with a median follow-up time of 13 months (range 0·0-60 months). Pre-transplantation serum prohepcidin levels and iron overload were not associated with survival in Cox regression analysis. Our results suggest that pre-transplantation iron parameters and prohepcidin levels might predict some of the early post-transplantation toxicities, however, without an impact on overall survival.