Purpose: Residual renal function (RRF) contributes to dialysis adequacy, quality of life and survival of hemodialysis patients. There is an ongoing debate whether better preservation of residual renal function is the result of chronic fluid volume overload. Our prospective investigation analyzed the effects of different dialytic therapies on RRF and left ventricular hypertrophy, which may be considered--at least in part--a surrogate marker of chronic fluid overload.
Methods: Two cohorts of end-stage renal disease patients initiating renal replacement therapy (high efficiency post-dilution on-line hemodiafiltration (HDF) in 58 patients, conventional hemodialysis (HD) in 60 patients) were prospectively followed up. RRF was determined at baseline, 12 and 24 months, left ventricular mass index (LVMI) at baseline and after 24 months.
Results: Demographic and renal characteristics, medication or exposure to nephrotoxins were comparable among the two cohorts of patients. RRF declined in all patients throughout the 2-year study period. In HDF patients, the decline was less pronounced (28 %) than in conventional HD patients (68 %). More patients undergoing HD received cardio- and renoprotective antihypertensive drugs. CRP levels were significantly higher in conventional HD. Hypotensive episodes were fewer in HDF. LVMI decreased in 90 % of HDF compared to only 25 %of HD patients.
Conclusions: Our data clearly indicate that better preservation of RRF by high efficiency hemodiafiltration is not associated with left ventricular hypertrophy.