Body mass index, fat free mass, uric acid, and renal function as blood pressure levels determinants in young adults.

AIM: We assessed some major determinants of blood pressure (BP) in young adulthood to plan a lifestyle changes policy METHODS: A cross sectional survey was held, involving 2373 high school people (age 18-21), measuring BP, body mass index (BMI), waist circumference (WCirc), fat free mass (FFM); alcohol and smoking habits were evaluated by a questionnaire. In a subset of this population (n = 60) uric acid (UA), estimated glomerular filtration rate (eGFR) were also evaluated. RESULTS: Smoking and not alcohol was correlated to systolic blood pressure (SBP) through quartiles (31.7%, 39.1%, 46.5%, 45.5%). Systolic BP was significantly correlated with FFM in the whole population (r = 0.51) as well as in SBP quartiles (r = 0.243, 0.138, 0.118, 0.204). FFM-SBP cluster analysis gave two centroids corresponding to sexes; females n = 998; coordinates (116.4 mmHg, 38.9 kg) and males n = 1068; coordinates (131.3 mmHg, 56.7 kg). In the n = 60 substudy a multiple linear regression model (multiple R = 0.741) with SBP as dependent variable and UA, FFM, BMI, eGFR as explicative ones, only UA (ß coefficent = 0.363, partial r = 0.240, P < 0.01) was the determinant of BP particularly in men. Moreover in the same group we found an inverse relationship between eGFR (albeit always in the normal range) and UA, as well as for women (r = -0.54, P < 0.01) and men (r = -0.43, P < 0.01) analyzed separately. CONCLUSIONS: A significant correlation exists between BP and FFM; UA has proven to be the most important SBP determinant. At variance with paediatric age UA was negatively correlated with renal function. Dietary intervention on UA and alcohol habits in young adults seems advisable to prevent hypertension.

A vitamin E-coated polysulfone membrane reduces serum levels of inflammatory markers and resistance to erythropoietin-stimulating agents in hemodialysis patients: results of a randomized cross-over multicenter trial.

BACKGROUND: Oxidative stress is prevalent in dialysis patients and has been implicated in the pathogenesis of cardiovascular disease and anemia. Vitamin E is a fat-soluble antioxidant that plays a central role in reducing lipid peroxidation and inhibiting the generation of reactive oxygen species. The aim of this cross-over randomized study was to compare the effects of a vitamin E-coated polysulfone (Vit E PS) membrane and a non-vitamin E-coated polysulfone (PS) membrane on inflammatory markers and resistance to erythropoietin-stimulating agents (ESAs). METHODS: After a 1-month run-in period of standard bicarbonate dialysis with a synthetic membrane, 62 patients of both genders, and older than 18 years, dialysis vintage 48 ± 27 months, BMI 22 ± 3 (from 13 different dialysis units) were randomized (A-B or B-A) in a cross-over design to Vit E PS (treatment A) and to PS (treatment B) both for 6 months. C-reactive protein (CRP) and interleukin-6 (IL-6) concentrations were determined by a sandwich enzyme immunoassay at baseline and every 2 months; red blood cell count, ESA dose and ESA resistance index (ERI) were assessed monthly. RESULTS: Hemoglobin (Hb) levels significantly increased in the Vit E PS group from 11.1 ± 0.6 g/dl at baseline to 11.5 ± 0.7 at 6 months (p < 0.001) and remained unchanged in the PS group. Although ESA dosage remained stable during the observation periods in both groups, ERI was significantly reduced in the Vit E PS group from 10.3 ± 2.2 IU-dl/kg/g Hb week at baseline to 9.2 ± 1.7 at 6 months (p < 0.001). No significant variation of ERI was observed in the PS group. A significant reduction in plasma CRP and IL-6 levels was observed in the Vit E PS group: CRP from 6.7 ± 4.8 to 4.8 ± 2.2 mg/l (p < 0.001) and IL-6 from 12.1 ± 1.4 to 7.5 ± 0.4 pg/ml (p < 0.05). In the PS group, CRP varied from 6.2 ± 4.0 to 6.4 ± 3.7, and IL-6 from 10.6 ± 2.1 to 9.6 ± 3.5 (p = n.s.). CONCLUSIONS: Treatment with Vit E PS membranes seems to lead to a reduction in ESA dosage in HD patients; in addition, a low chronic inflammatory response may contribute to a sparing effect on exogenous ESA requirements.

Interleukin-8 is a powerful prognostic predictor of all-cause and cardiovascular mortality in dialytic patients.

BACKGROUND: Cohort studies have demonstrated an association between C-reactive protein (CRP) and interleukin-6 (IL-6) and all-cause and cardiovascular mortality in end-stage renal disease (ESRD) patients. Interleukin-8 (IL-8) appears to be not only the plasma expression of the acute-phase response but also a direct pathogenetic mediator of the atherosclerotic process. METHODS: To evaluate the role of IL-8 in predicting outcome, 76 chronic dialytic patients were prospectively followed for 18 months. At baseline, blood samples were taken for analysis of high-sensitivity CRP, IL-6, IL-8 and other standard laboratory analyses. RESULTS: Median IL-8 was 5.2 mg/l, therefore near half of the patients had IL-8 values within the range of 'normal limits'. IL-6 and CRP were significantly correlated (r = 0.45, p < 0.001) and a positive correlation was also found between IL-6 and IL-8 (r = 0.39, p < 0.001). The correlation coefficient between IL-6 and CRP was 0.43 (p < 0.001) and 0.50 (p < 0.001) in patients without and with history and/or clinical signs of cardiovascular disease, respectively. After a follow-up of 1.5 years, 8 patients had died from cardiovascular causes and another 7 patients for other reasons; furthermore 9 major nonfatal cardiovascular events were recorded. Stepwise regression analysis showed IL-8 as the strongest independent predictor of all-cause and cardiovascular events (p = 0.0025) even after adjustment for age and dialytic age, followed by IL-6 and CRP (p < 0.01). CONCLUSION: Despite a small population and a relatively short follow-up period, this study firstly demonstrated that IL-8 is a powerful independent predictive factor for cardiovascular and overall mortality cause in ESRD patients.

Divert to ULTRA: differences in infused volumes and clearance in two on-line hemodiafiltration treatments.

BACKGROUND: Mixed diffusive-convective dialysis therapies offer greater removal capabilities than conventional dialysis. The aim of this study was to compare two different on-line, post-dilution hemodiafiltration (HDF) treatments with regard to achieved convective volume and middle-molecule dialysis efficiency: standard volume control (sOL-HDF) and automated control of the transmembrane pressure (TMP) (UC-HDF). METHODS: We enrolled 30 ESRD patients (55.9 ± 14.0 years, 20/10 M/F) in a randomized, prospective, cross-over study. The patients received a 3-month period of sOL-HDF followed by UC-HDF for a further 3 months, or vice versa, using the same dialysis machine. In sOL-HDF, fixed exchange volumes were set according to a filtration fraction greater than or equal to 25%. In UC-HDF therapy, the exchanged volume was driven by a biofeedback system controlling the TMP and its set point in a double loop. Patients maintained their treatment time, dialyzer, blood flow rate, and anticoagulant regimen unchanged throughout the study. RESULTS: Greater convective volumes were achieved in UC-HDF than in sOL-HDF (23.8 ± 3.9 vs.19.8 ± 4.8 L; p<0.001) with high pre-dialysis Ht value (sOL-HDF 34.0 ± 4.5% and UC-HDF 34.0 ± 4.4%; p = 0.91). The average clearance values of ß2m and P were higher in UC-HDF than in sOL-HDF (respectively 123 ± 24 vs. 111 ± 22 ml/min, p<0.002 and 158 ± 26 vs. 152 ± 25 ml/min, p<0.05). Moreover, the UC-HDF mode led to a significantly increased rate of call-free sessions from 88% to 97% (p<0.0001). CONCLUSIONS: This study showed that the biofeedback module, applied to the automatic control of TMP in on-line HDF, results in higher convective volumes and correspondingly higher ß2m and P clearances. By making the HDF treatment more automated and less complex to perform, it significantly reduced the staff workload.