title: Factors influencing peritoneal transport parameters during the first year on peritoneal dialysis: peritonitis is the main factor.
abstract: BACKGROUND
  Studies on the evolution of peritoneal transport during the first year of peritoneal dialysis (PD) are scarce and their results are contradictory. The aim of the present study was to analyse the evolution of peritoneal transport and residual renal function during the first year on PD, and to determine the factors that may influence them.
  
  
  METHODS
  We studied 249 patients on continuous ambulatory PD with glucose exchange solutions (117 men, 132 women, mean age 51.9+/-16 years) 59 of whom had diabetes (25 type I). At baseline and after 1 year, we determined the mass transfer coefficients of urea (U-MTAC) and creatinine (Cr-MTAC), net ultrafiltration and residual renal function.
  
  
  RESULTS
  Residual renal function decreased significantly during the first year (from 3.9+/-2.8 to 2.4+/-2.2 ml/min, P<0.001). Both U-MTAC and Cr-MTAC decreased after 1 year [U-MTAC from 22.7+/-7.8 to 20.7+/-6.6 ml/min (P<0.001), Cr-MTAC from 10.5+/-5.3 to 10.1+/-4.6 ml/min (NS)]. The ultrafiltration capacity increased significantly (from 923+/-359 to 987 U 341 ml/4 h, P<0.001). The evolution of MTAC values was independent of age, sex, diabetes and amount of hypertonic glucose used. When patients were grouped according to their initial Cr-MTAC, we observed a tendency toward normalization of the parameters of peritoneal function. Patients with peritonitis (n = 88) showed a first year increase in Cr-MTAC, which was significantly higher than in patients without peritonitis (11.1+/-5 vs 9.5+/-4.2, P<0.01). Ultrafiltration decreased in patients with more than four accumulated days of peritonitis (from 1062+/-447 to 1024+/-340 ml/4 h, NS); it increased in patients without peritonitis.
  
  
  CONCLUSIONS
  The peritoneal transport parameters tended toward normalization during the first year on PD, mainly with a decrease of small solute transport and an increase of ultrafiltration capacity. This evolution is independent of age, gender, diabetes and higher exposure to glucose in PD solutions. Peritonitis was the only independent factor that affected peritoneal function during the first year on peritoneal dialysis.
authors.affiliation: Department of Nephrology, University Hospitals La Paz, Madrid. Spain. gpeso.hulp@salud.madrid.org
authors.forename: Gloria
authors.initials: G
authors.lastname: del Peso
authors.forename: María José
authors.initials: MJ
authors.lastname: Fernández-Reyes
authors.forename: Covadonga
authors.initials: C
authors.lastname: Hevia
authors.forename: María Auxiliadora
authors.initials: MA
authors.lastname: Bajo
authors.forename: María José
authors.initials: MJ
authors.lastname: Castro
authors.forename: Antonio
authors.initials: A
authors.lastname: Cirugeda
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Sánchez-Tomero
authors.forename: Rafael
authors.initials: R
authors.lastname: Selgas
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001692:Biological Transport; D002648:Child; D003404:Creatinine; D005260:Female; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D010531:Peritoneal Dialysis, Continuous Ambulatory; D010537:Peritoneum / Q000378:metabolism*; D010538:Peritonitis / Q000453:epidemiology / Q000503:physiopathology; D014462:Ultrafiltration; D014508:Urea
chemical_list: D014508:Urea; D003404:Creatinine