Huang SHS, et al. - In this secondary analysis of the frequent hemodialysis network (FHN) trial, researchers investigated the impact of more frequent hemodialysis on serum cystatin C (CysC) and Beta-2 microglobulin (β2-M) levels. This ancillary study comprised of 49% and 52% of the patients from the FHN Daily and Nocturnal Trials, respectively. They compared variations between predialysis levels at baseline (while on conventional thrice weekly dialysis) and those following 12-months of study (on more frequent dialysis), separately by trial (Nocturnal, Daily). Following hemodialysis dose intensification by either modality, no change was evident in predialysis serum CysC levels. At 12 months, all patients and those without residual renal function at baseline demonstrated a significant lowering of the serum β2-M levels in the frequent Daily Trial hemodialysis group. According to the findings, a better biomarker of dialysis dose is possibly β2-M as compared with CysC. A potential long-term advantage of more intensive dialysis, suggested in this study, is attenuation in the level of potentially toxic long-lived proteins of the size of β-2M.