Short-term effect of simvastatin treatment on inflammatory parameters in peritoneal dialysis patients.

OBJECTIVE: Increased serum pro-inflammatory cytokine levels are associated with an increased mortality rate in end-stage renal disease (ESRD) patients. Statins decrease cardiovascular mortality and serum C-reactive protein (CRP) levels in hemodialysis patients. As the anti-inflammatory effect of statins has not previously been studied in peritoneal dialysis (PD) patients with a non-inflammatory status, we wanted to investigate the anti-inflammatory effect of simvastatin in these patients. MATERIAL AND METHODS: Forty-eight PD patients were randomly allocated to either simvastatin treatment (n=25) or placebo (n=23). Patients in the active-treatment group received simvastatin 20 mg/day for 1 month. At baseline and after 1 month of treatment, blood samples were drawn and high-sensitivity CRP, interleukin-6, tumor necrosis factor (TNF)-alpha and plasma lipid profiles were determined. These parameters were compared between the groups at baseline and at the end of the study period. RESULTS: Twenty-five subjects in the treatment group and 20 in the placebo group completed the study. Three patients in the placebo group were excluded from the study due to the occurrence of bacterial peritonitis during the study period. Clinical characteristics and baseline parameters were similar in both groups. Serum total and low-density lipoprotein cholesterol levels, and triglyceride and serum TNF-alpha levels decreased significantly compared to baseline in the treatment group; there were no corresponding differences in the placebo group. CONCLUSIONS: Simvastatin decreased the serum TNF-alpha level in PD patients with a non-inflammatory status. A decrease in the TNF-alpha level could be one of the possible mechanisms of the anti-atherogeneic effect of simvastatin. We suggest that different treatment strategies aimed at decreasing serum cytokine levels could be evaluated to decrease cardiovascular morbidity and mortality in the dialysis population.

The effect of serum albumin level on iron-induced oxidative stress in chronic renal failure patients.

BACKGROUND: Intravenous iron (IVIR) administration is widely used to treat anemia in chronic renal failure (CRF) patients and causes oxidative stress. Despite the fact that proteins are extremely susceptible to oxidative stress, there have been no studies investigating the relationship between the severity of iron-induced acute oxidative stress and serum albumin. Therefore, we wanted to investigate the relation between the severity of iron-induced acute oxidative stress and serum albumin level in CRF patients. METHODS: A total of 68 patients (22 on hemodialysis, 24 on continuous ambulatory peritoneal dialysis and 22 predialytic CRF) with absolute iron deficiency were included to the study. Patients with acute inflammatory status, serum ferritin level > or = 100 ng/mL, transferrin saturation > or = 20%, hemoglobin level > or = 12 g/dL or serum C-reactive protein (CRP) level > or = 10 mg/dL were excluded. Serum direct 8-isoprostoglandin F2 alpha (IsoPG-F2 alpha) level was used as an oxidative stress marker. After baseline sampling, 100 mg ferric sucrose was infused within 30 minutes. Blood samples were drawn to assess changes in oxidative stress marker at the end of the IVIR infusion and at 240 minutes. Patients with serum albumin level <4 g/dL were defined as hypoalbuminemic and > or = 4 g/dL as normoalbuminemic. RESULTS: There were 34 hypoalbuminemic and 34 normoalbuminemic patients. Serum IsoPG-F2 alpha level increased in all patients after the administration of IVIR. The severity of iron-induced acute oxidative stress was more prominent in patients with a low serum albumin level. Serum albumin level, presence of diabetes mellitus (DM) and hemoglobin level were found as significant predictors of time-dependent changes in serum IsoPG-F2 alpha level. When the analyses were repeated in nondiabetic patients, serum albumin level was similarly found to be a significant predictor of time-dependent changes in serum IsoPG-F2 alpha level. CONCLUSION: This study demonstrated a negative interaction between iron-induced acute oxidative stress and serum albumin level in CRF patients. Because CRF patients with low serum albumin level are at greater risk for iron-induced acute oxidative stress, new strategies are necessary in this population.

Psychological symptoms are greater in caregivers of patients on hemodialysis than those of peritoneal dialysis.

BACKGROUND: The purpose of this study was to evaluate and compare psychosocial characteristics in caregiving relatives (caregivers) of hemodialysis (HD) and peritoneal dialysis (PD) patients. METHODS: Thirty-three caregivers (17 women, 16 men) of HD patients, 27 caregivers (11 women, 16 men) of PD patients, and a control group of 49 subjects who do not care for family members with chronic illness (23 women, 26 men) are included in this study. The brief symptom inventory (BSI), social disability schedule (SDS), and brief disability questionnaire (BDQ) were used for the psychosocial evaluation. RESULTS: The mean age, men-to-women ratios, duration of education, and distribution of marital status did not differ significantly among the three groups. In addition, dialysis duration and distribution of caregiver type were not different between the HD and PD groups. Although the mean global severity index scores of the three groups were similar, somatization and depression scores from BSI subitems were greater in the HD group than the scores of the PD and control groups. Although the mean SDS and BDQ scores were higher in the HD group, the differences did not achieve statistical significance. BSI subitems such as somatization, obsession-compulsion, interpersonal sensitivity, depression, and anxiety were positively correlated among themselves. Hostility and somatization were negatively correlated with age and education, respectively. Nevertheless, somatization was positively correlated with age. Social disability was negatively correlated with duration of education. CONCLUSION: Somatization and depression are greater in the caregivers of center HD patients compared to PD and control groups. According to the findings of this study, we suggest that caregiving family members of dialysis patients especially on HD also should be evaluated for psychosocial problems and supported as needed. Further studies are needed to explore whether psychosocial parameters of caregivers predict outcomes for caregivers and patients.