Residual daily urine volume association with inflammation and nutrition status in maintenance hemodialysis patients

Background. This study determines the clinical significance of residual renal function (RRF), defined as residual daily urine volume (RDUV), in maintenance hemodialysis (MHD) patients. Methods. This multi-center study enrolled 704 MHD patients. Geographic, hematological, biochemical, and dialysis-related data were obtained. Values for nutritional and inflammatory markers were analyzed together with RDUV. Results. In total, 670 of 704 patients (95.2) with HD duration greater than 1 year had abnormal RDUV (<500 ml). Patients with higher RRF were younger, had shorter HD duration, higher prevalence of hypertension and levels of serum albumin, high density lipoprotein (HDL), and lower mid-week inter-dialysis body weight increase (MIBWI), cardio-thoracic ratio, levels of intact parathyroid hormone, high sensitivity C-reactive protein (Hs CRP), and KTV (Daugirdes) values than those with low RRF. Stepwise multiple regression analysis demonstrated that RRF was positively correlated with serum albumin, HDL levels, and presence of hypertension, and negatively correlated with age, HD duration, and MIBWI in MHD patients. Moreover, after adjusting factors that were significantly related to serum albumin or Hs CRP, RRF was still positively correlated with serum albumin (0.000137 ± 0.000585, p0.0197) and negatively correlated with log Hs CRP (-0.000184 ± 0.000952, p 0.0533). A one-liter increase in RDUV was associated with a 1.4 gL increase in serum albumin level in MHD patients. Conclusion. This clinical study first demonstrated that RRF affects nutritional and inflammatory status in MHD patients. Because malnutrition and inflammation can cause high mortality in MHD patients, preserving RRF is important for these patients.