Assessment of Electrolyte Free Water Clearance in Renal Transplant Recipients

Few studies have been done on free water excretion capacity in renal transplant recipients.
This study was designed to compare electrolyte free water clearance (E-CH2O) in renal transplant recipients with healthy control group.
A cross-sectional study was conducted to determine three-hour creatinine clearance (CCl), E-CH2O, and percent urine output in 3 hours after administering 20 mL/Kg oral water loading following 12-hour fasting, in 22 renal transplant recipients with good graft function (creatinine We recruited 25 recipients (73% patients in living and 27% in cadaveric donor transplantation) and 26 healthy control groups.3 patients refused to collect urine and finally 22 patients finished the protocol. The mean age of subjects was 37.68 ± 13.88 and 31.40 ± 8.20 years old in renal transplant recipients and control groups, respectively. In patient group male to female ratio was 9/13 and in control group was14/12. Although the 3h-CCl was similar (126.49 ± 53.52 vs. 109.99 ± 47.06 mL/min) in two groups (P > 0.05), the E-CH2O (1.83 ± 1.22 vs. 2.94 ± 2.02) and 3-hour urine output percent (55.93 ± 22.86 vs74.11 ± 30.38) in kidney recipients was significantly lower than healthy controls (P This study demonstrated that E-CH2O has been decreased in renal transplant patients in comparison with control group when there was not any difference between3h- CCl in two groups. This indicates that E-CH2O may be decreased earlier than 3h-CCl in transplant patients.