Peritoneal Transport Characteristics, Comorbid Diseases and Survival in CAPD Patients

Abstract

Objective To evaluate the influence of initial peritoneal transport rate, serum albumin concentration, and comorbid diseases on continuous ambulatory peritoneal dialysis (CAPD) patient survival. Design A prospective single-center study with a long-term follow-up. Patients A total of 213 consecutive CAPD patients, who underwent a peritoneal equilibration test (PET) at a mean of 7 days (range 3 – 30 days) after beginning CAPD, were included in this study. One hundred twenty patients were male, 116 patients had comorbid diseases, and mean age was 49.5 years (range 18 – 76 years). Methods A modified PET was performed using 4.25% glucose dialysis solution. Based on the dialysate-to-plasma creatinine concentration ratio at 4 hours’ dwell (D4/P4 Cr, 0.62 ± 0.14), patients were divided into high (H), high-average (HA), low-average (LA), or low (L) transporters. Results Of 213 patients, 16.9% were classified as H transporters, 30.5% as HA, 36.6% as LA, and 16.0% as L transporters. The H transporter group had a higher proportion of men, higher proportion of patients with comorbid diseases, lower initial serum albumin concentration, lower D4/D0 glucose, and lower drained volume. The initial D4/P4 Cr correlated with initial serum albumin ( r = –0.35, p < 0.001). The patients with comorbid diseases had lower initial serum albumin and higher initial D4/P4 Cr. On Kaplan–Meier analysis, 2-year patient survival of group H was significantly lower compared to the other groups combined (57.1% vs 79.5%, p = 0.009). On Cox proportional hazards analysis, age, comorbid diseases, initial serum albumin concentration, and initial D4/P4 Cr were found to be independent risk factors for mortality. However, in the patients without comorbid diseases, patient survival was not different between group H and the other transport groups combined ( p > 0.05), and only age was found to be an independent risk factor for mortality. Conclusion These data suggest that a high peritoneal transport rate at initial PET is associated with high mortality, and that this is in part due to an increased prevalence of comorbid disease in H transporters. These H transporters with comorbid diseases represent a subset of patients with an especially poor prognosis. In patients without comorbid diseases, high transport status or low serum albumin concentration was not an independent risk factor for mortality.

Peritoneal Membrane Structural and Functional Changes during Peritoneal Dialysis

“…In 1998, the CANUSA study (42) and the Stoke PD Study (43) found that a fast transport status was associated with worse patient and technique survival independent of age, comorbidity, and residual renal function (RRF). This observation was subsequently confirmed by others (44,45). More recently, Heaf and Van Biesen, using the PDC test, suggested that patients with a high peritoneal transport status (which they found to be associated with peritoneal or systemic inflammation and large pore fluxes) exhibit poor prognosis (46,47).…”

Mitigating peritoneal membrane characteristics in modern peritoneal dialysis therapy

“…multivariate analysis. 9,16 A few studies have not found an association; however, in some cases this is likely to be due to being under powered, 17,18 or an association was found on univariate analysis only [19][20][21] or to be associated with morbidity but not mortality. 22 Two large studies have failed to find an association; in both cases, there were potential reasons for this, including a largely prevalent patient population, 23 nonstandard methods of measuring membrane function, and a non-prospective study design.…”

“…Several studies have looked at this and their findings are summarized in Table 1. 3,[6][7][8][9][10] Before discussing these in detail, two things should be noted. First, in general, although statistically significant relationships are found, they explain relatively little of the variance in solute transport.…”

Membrane transport status does not predict peritonitis risk in patients on peritoneal dialysis

“…13 Higher protein loss in patients with higher MTS has been proposed to contribute to malnutrition or fluid overload, which may in turn predispose to peritonitis. [14][15][16] Although there is agreement that hypoalbuminaemia is an independent risk factor for peritonitis and technique failure, any relationship between MTS and peritonitis has not been properly examined. The largest study from Australia and New Zealand to date 8 did not account for peritonitis as a confounder, and other studies have reported contradictory results.…”