Natural changes in peritoneal equilibration test results in continuous ambulatory peritoneal dialysis patients: A retrospective, seven year cohort survey

We conducted a retrospective, 7 year cohort survey to examine the natural c hanges in peritoneal equilibration test (PET) results in patients with long -term uneventful continuous ambulatory peritoneal dialysis (CAPD). Thirty-t wo (17 males, 15 females) patients on CAPD with two or more standard PETs p erformed more than 6 months apart, in the absence of peritoneal insult, wer e included. Changes and pattern of PET results were evaluated by the dialys ate to plasma ratio of creatinine (D:P-cre), the fourth h dialysate to inst illed glucose ratio (D-4:Do) and ultrafiltration volume (UF, ml). The subgr oups included high (H), high-average (HA), low-average (LA), or low (L) tra nsporters with the dividing ratios (D:P-cre) of >0.81, >0.65 to 0.81, >0.5 to 0.65, and <0.5, respectively. The median D:P-cre significantly decreased (p = 0.04), but neither the D-4:Do nor the final median UF significantly d ecreased. The change in D:P-cre was strongly and inversely correlated with the initial D:P-cre value (r = -0.68; p < 0.05). A similar relationship was found between the change in the final D-4:Do and the initial D-4:Do (r = - 0.752; p < 0.01) and between the change in the final UF and the initial UF (r = -0.875; p < 0.01). No correlation was found between the change in D:P- cre and the age of the patient, the time interval between PETs, monthly dia lysate glucose exposure, or underlying diabetes/non-diabetes. The final per itoneal transport pattern was altered with 5 (15.6%) patients remaining in the extreme subgroups (H or L) and, by contrast, 84.4% (27/32) of the patie nts now in the averaged (HA or LA) groups (p < 0.01, chi(2) test). We demon strated a natural "centralization" migration of PET results after long-term uneventful CAPD, which may help to explain why patients with extreme PET c haracteristics, that is, H or L, continued to do well on CAPD.