Objective To evaluate the effects of peritoneal rest on peritoneal transport and morphology in a rat model of peritoneal dialysis. Design Twenty-four rats (Sprague-Dawley, male, 250 300 g) were divided into three groups: group 1 (control, n = 6) without dialysis, group 2 (n = 9) sacrificed immediately after 3 weeks of dialysis, and group 3 (n = 9) sacrificed after 4 weeks of peritoneal rest after 3 weeks of dialysis. Both dialysis groups were dialyzed twice daily with an intraperitoneal instillation volume of 25 mL of 3.86% dextrose solution for 3 weeks. Peritonitis was induced by supplementing the dialysis fluid with lipopolysaccharide (5 μg/mL) on days 8, 10, and 12 in both dialysis groups. Peritoneal equilibration tests were performed on each animal at baseline. The equilibration tests were repeated at the 4th and the 8th week of dialysis. Morphometric analyses of the peritoneal membrane were carried out in tissue specimens obtained at the time of sacrifice. Results The DIDo ratio for glucose at two hours in groups 2 and 3 at the beginning of week 4 was significantly lower than at baseline, indicating an increase in peritoneal permeability to glucose after 3 weeks of dialysis. DIDo in group 3 at the beginning of week 8, after 4 weeks of peritoneal rest, was significantly higher than at week 4. The drain volume in groups 2 and 3 at week 4 was significantly lower than at baseline; however, the drain volume in group 3 at week 8 was significantly higher than at week 4. The thickness of the parietal peritoneal membrane in group 3 was significantly greater than in group 1 and less than in group 2 (group 1, 11.4 ± 7.6 μm; group 2, 37.5 ± 18.4 μm; group 3,21.4 ± 12.1 μm). Conclusions Peritoneal rest improves ultrafiltration in rats by decreasing the hyperpermeability of glucose and also reduces the degree of peritoneal thickening. These data suggest that dialysis -induced changes in peritoneal transport and morphology are reversible under the conditions of peritoneal rest in this experimental model.

Health-related quality of life (HRQOL) is an important clinical outcome for dialysis patients. However, relative superiority in HRQOL between automated peritoneal dialysis (APD) and continuous ambulatory peritoneal dialysis (CAPD) are not clearly known. We compared HRQOL over time between APD and CAPD patients and evaluated factors associated with HRQOL.All 260 incident patients initiating APD or CAPD at multiple centers throughout Korea were prospectively enrolled in this study between October 2010 and February 2013. HRQOL, depressive symptoms, and renal treatment satisfaction were assessed 1 and 12 months after the start of dialysis by the Kidney Disease Quality of Life Short Form 36 (KDQOL-36), the Beck Depression Inventory (BDI), and the Renal Treatment Satisfaction Questionnaire (RTSQ), respectively.Of 196 patients who completed all questionnaires and did not change the peritoneal dialysis (PD) modality during the 1-year follow-up period, 160 were matched. APD patients showed better baseline HRQOL than CAPD patients for the symptoms, patient satisfaction, pain, and social function domains. There were no differences in HRQOL between the 2 groups at 12 months, and CAPD patients had significantly greater improvements in symptoms (P = 0.02), the mental composite summary (P = 0.03), and health status domains (P = 0.03) than APD patients. There were similar improvements in depressive symptoms (P = 0.01) and patient satisfaction with treatment (P = 0.01) in CAPD and APD patients. Interestingly, depressive symptoms, not PD modality, was the most influential and consistent factor for HRQOL. Despite the spontaneous improvement of depressive symptoms, considerable PD patients still had depressive symptoms at the 1-year appointment.APD has no advantage over CAPD for HRQOL. Considering the substantial negative effect of depressive symptoms on HRQOL, it is important to evaluate PD patients for depression and to treat those with depression to improve their HRQOL.