Effect of protein leaking BK-F PMMA-based hemodialysis on plasma pentosidine levels.

BACKGROUND: Advanced glycation end-products (AGEs) are now considered to contribute to the middle molecule toxicity of uremia and, because they are not cleared by conventional low-flux hemodialysis, alternative strategies are needed to improve their removal. METHODS: In a prospective cross-over trial involving 18 adult chronic hemodialysis subjects, we evaluated the intradialytic removal and the long-term effect on predialysis levels of Protein-bound (PBPe) and Free (FPe) pentosidine by high-pore, protein-leaking BK-F Polymethylmethacrylate-based hemodialysis (BK-F-HD), by comparing it to hemodialysis using low-flux dialyzers (LF-HD). RESULTS: A single BK-F-HD session removed more PBPe, but not FPe, than LF-HD. Long-term BK-F-HD was associated with a significant decrease in pre-dialysis PBPe, FPe, and albumin (17.7 +/- 20.8, 25.3 +/- 17.3 and 8.0 +/- 3.3%, p<0.01) and no change in body mass index and protein catabolic rate, compared to LF-HD. Multiple stepwise regression analysis identified C-reactive Protein (CRP) (standardized beta coefficient=-0.629), pre-dialysis levels in LF-HD (beta=0.452) and dialysis vintage (beta=0.428) as significant determinants of BK-F-induced changes in predialysis PBPe, and predialysis FPe and PBPe levels in LF-HD as significant determinants of BK-F-induced changes in predialysis FPe (beta=0.720 and 0.286, respectively). CONCLUSIONS: Our study shows that long-term standard diffusive hemodialysis with BK-F membrane reduces predialysis PBPe and FPe levels by comparison with LF-HD, largely due to a greater intradialytic clearance of PBPe. Serum albumin is also reduced without any associated changes in nutritional status markers. The study also suggests that the effect of BK-F-HD in lowering PBPe levels is modulated by the body burden of pentosidine and is blunted or even lost in the presence of elevated CRP levels.

Aldosterone to Renin ratio in a primary care setting: the Bussolengo study.

The aim of the study was to evaluate the prevalence of hypertension associated with an elevated aldosterone to renin activity ratio (ARR) in a sample of adults aged 35-74 yr, randomly selected from the population register of the Bussolengo Health District (northern Italy) and representative of the total population of the district. Subjects (n = 1462) were randomly selected from the population register and examined by their general practitioners. Complete data for 1348 individuals were available for final statistical analysis. Apart from verapamil or alpha-blockers, no hypotensive drugs were allowed during the 4 wk before assay. Direct active renin and aldosterone were measured in the plasma of hypertensive patients after 2 h in the upright posture. Of 412 identified hypertensive patients, 287 subjects agreed to give blood (70% response rate). An aldosterone to active renin ratio (AARR) of 32 pg/ml was taken as the cut-off value, equivalent to an ARR of 50 ng/dl/ng/ml.h. An elevated AARR was observed in 32.4% of the hypertensive patients, with increased prevalence in females and in people aged 55 yr or older. As an elevated AARR is frequent in the general hypertensive population, screening should not be limited to the patients referred to specialist units.