ABSTRACT
Background: Oxidative stress increases oxidizability of apolipoprotein-B containing lipoproteins and decreases paraoxonase (PON) activity in hemodialysis (HD) patients and plays an important part in the development of atherosclerotic cardiovascular diseases. In HD patients, plasma ascorbic acid (AA) levels are decreased either due to the loss by hemodialysis membranes or due to malnutrition and contribute to the imbalance of antioxidant defense mechanisms. We hypothesized that long-term ascorbic acid (AA) supplementation recovers oxidizability of lipoproteins in HD patients by reinforcing PON activity. Methods: Twenty-nine adult patients were treated with 100mg and 500mg AA at the end of each HD session thrice a week for two consecutive 16 weeks-periods, respectively. Blood samples were obtained before the first HD session and prior to the first HD sessions following the 100mg AA-supplemented and the 500mg AA-supplemented periods. Results: PON activities were significantly increased after 100mg (p<0.05) and 500mg AA (p<0.001) supplementation periods compared to the basal level. Apo-B lipoprotein oxidizability (Δ-MDA) was significantly decreased after 500mg AA supplementation compared to both basal (p<0.05) and 100mg AA supplementation periods (p<0.05). Plasma AA concentrations were negatively correlated with Δ-MDA levels (R=−0.327; p<0.01). Conclusion: Our results suggest that long-term parenteral 500mg AA supplementation improves PON activity alleviating apo B-containing lipoproteins oxidizability in HD patients. (AU)
Antecedentes: El estrés oxidativo aumenta la susceptibilidad a la oxidación de las apolipoproteínas-B que contienen lipoproteínas y reduce la actividad de paraoxonasa (PON) en pacientes de hemodiálisis (HD) formando un papel importante en el desarrollo de enfermedades arterioescleróticas cardiovasculares. En pacientes de HD, los niveles de ácido ascórbico (AA) plasmático disminuyen debido a la pérdida por membranas de hemodiálisis o por desnutrición, y contribuye al desequilibrio de los mecanismos de defensa antioxidantes. Nuestra hipótesis es que a largo plazo la suplementación con AA recupera la susceptibilidad a la oxidación de las lipoproteínas en pacientes de HD al reforzar la actividad de PON. Métodos: Se trataron 29 pacientes adultos con 100 y 500mg de AA al final de cada sesión de HD/3 veces por semana/durante 2 períodos consecutivos de 16 semanas, respectivamente. Se obtuvieron muestras de sangre antes de la primera sesión de HD y previo a las primeras sesiones de HD luego de los 100mg suplementados con AA y los periodos suplementados con 500mg de AA. Resultados: Las actividades de PON aumentaron significativamente después de los periodos de suplementación de 100mg (p<0,05) y de 500mg de AA (p<0,001) comparados con el nivel base. La susceptibilidad a la oxidación de la lipoproteína apoB (Δ-MDA) disminuyó significativamente luego de la suplementación de 500mg de AA en comparación con períodos de valores base (p<0,05) y los de 100mg de AA (p<0,05). La correlación entre las concentraciones de plasma AA y los niveles de Δ-MDA resultó negativa (R=−0,327; p<0,01). Conclusión: Nuestros resultados sugieren que la suplementación parenteral a largo plazo de 500mg de AA mejora la actividad de PON mitigando la susceptibilidad a la oxidación de las lipoproteínas que contienen apoB en pacientes en HD. (AU)
Subject(s)
Humans , Male , Female , Young Adult , Adult , Middle Aged , Aged , Oxidative Stress , Ascorbic Acid , Dietary Supplements/adverse effects , Renal Dialysis , Apolipoproteins B , AryldialkylphosphataseABSTRACT
BACKGROUND: Oxidative stress increases oxidizability of apolipoprotein-B containing lipoproteins and decreases paraoxonase (PON) activity in hemodialysis (HD) patients and plays an important part in the development of atherosclerotic cardiovascular diseases. In HD patients, plasma ascorbic acid (AA) levels are decreased either due to the loss by hemodialysis membranes or due to malnutrition and contribute to the imbalance of antioxidant defense mechanisms. We hypothesized that long-term ascorbic acid (AA) supplementation recovers oxidizability of lipoproteins in HD patients by reinforcing PON activity. METHODS: Twenty-nine adult patients were treated with 100mg and 500mg AA at the end of each HD session thrice a week for two consecutive 16 weeks-periods, respectively. Blood samples were obtained before the first HD session and prior to the first HD sessions following the 100mg AA-supplemented and the 500mg AA-supplemented periods. RESULTS: PON activities were significantly increased after 100mg (p<0.05) and 500mg AA (p<0.001) supplementation periods compared to the basal level. Apo-B lipoprotein oxidizability (Δ-MDA) was significantly decreased after 500mg AA supplementation compared to both basal (p<0.05) and 100mg AA supplementation periods (p<0.05). Plasma AA concentrations were negatively correlated with Δ-MDA levels (R=-0.327; p<0.01). CONCLUSION: Our results suggest that long-term parenteral 500mg AA supplementation improves PON activity alleviating apo B-containing lipoproteins oxidizability in HD patients.
ABSTRACT
PURPOSE: There are many studies on degeneration of the ganglion cells using visual evoked potential (VEP) in Diabetes mellitus (DM). The present study intended to investigate whether the retinopathy findings would be helpful for detecting the degeneration to develop or not in retinal ganglion cells with the VEP test before being detectable in ophthalmoscopic examination on prediabetic patients. MATERIALS AND METHODS: The present study was conducted prospectively after obtaining approval from the Ethics Committee. In our study, the subjects were divided into three groups as impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and normal patients. They also underwent physical, ophthalmological and VEP examination. Three main components of VEP obtained from these groups were N75, P100, and N145 latency and N75-P100 amplitude. RESULTS: The study participants consisted of the IFG group (n: 30, female/male ratio: 21/9; mean age: 49.17 ± 10.52 years), the IGT group (n: 30, female/male ratio: 23/7; mean age: 47.00 ± 11.09 years), and the Control Group (n: 40, female/male ratio: 30/10; mean age: 48.03 ± 10.96 years). Difference in sex and age between the study groups (p > 0.05). P100 latency was found to increase significantly in comparison between the IGT and Control Group for both eyes (p right: 0.003, p left: 0.001) whereas it did not increase significantly in the comparison between the IFG and the Control Group (p right: 0.065, p left: 0.116). CONCLUSION: It was observed that VEP may be a parameter of predictive value that might be used in evaluating prediabetic cases in terms of retinopathies similar to DM.
Subject(s)
Evoked Potentials, Visual , Glucose Intolerance/physiopathology , Visual Pathways/physiopathology , Adult , Blood Glucose/metabolism , Fasting , Female , Glucose Intolerance/diagnosis , Humans , Male , Middle Aged , Prospective Studies , Visual AcuityABSTRACT
BACKGROUND: Increased oxidative stress (OS) and inflammation are associated with atherosclerotic coronary artery disease in haemodialysis (HD) patients. Ferritin may have other effects in addition to its role in storing intracellular iron. This study was performed to determine any relationships between markers of OS, nutrition and inflammation in HD patients with normal and high ferritin levels. METHODS: Our cohort comprised 34 maintenance dialysis patients on erythropoietin therapy and 22 healthy controls. HD patients were divided into two groups: 17 with normal (<800 ng/ml) and 17 with high (>800 ng/ml) ferritin levels, and we measured lipid profile, albumin, highly sensitive C-reactive protein (hsCRP), anti-oxidant enzymes [whole blood glutathione peroxidase (Gpx), serum superoxide dismutase (SOD), paraoxonase, arylestherase (AE) and total anti-oxidant status (TAOC)], anti-oxidants (vitamin C) and lipid peroxidation products [red blood cell malondialdehyde (RBC MDA)]. RESULTS: Compared with controls, the HD patients had higher serum urea, blood pressure, triglyceride, hsCRP, RBC MDA, SOD and TAOC values and lower albumin, low-density lipoprotein cholesterol, apolipoprotein AI, paraoxonase, AE and whole blood Gpx activities. Serum vitamin C, uric acid, apolipoprotein B, total- and high-density lipoprotein cholesterol, apolipoprotein B MDA, and lymphocyte levels in the HD patients with normal and high ferritin levels were similar. The OS markers of HD patients did not differ, whether or not they received intravenous iron supplementation or had transferrin saturations < 50% or > or = 50%. CONCLUSION: HD patients are in a higher oxidative state, which results in the reduction of total anti-oxidant capacity and also have an increased inflammation status. We could not find a relationship between ferritin level and OS markers in HD patients receiving erythropoietin.
