SERUM ADVANCED GLYCOSYLATION END-PRODUCTS IN PATIENTS ON HEMODIALYSISAND CAPD

Objectives: Part I: To evaluate the long-term effects of daily glucose absorption from the peritoneal dialysis fluid on the formation of low -molecular-weight advanced glycosylation end-products (AGE-peptides) i n nondiabetic continuous ambulatory peritoneal dialysis (CAPD) patient s. Part II: To determine the acute effect of CAPD on serum AGE-peptide concentrations. Design: Part I: Noninterventional, parallel, cross-se ctional clinical trial. Part II: Crossover clinical trial. Setting: A university-based hospital, and clinics. Patients: Part I: Sixty nondia betic subjects recruited into three age-matched (+/- 5 years) groups, as follows: 20 healthy volunteers (controls); 20 hemodialysis patients ; and 20 CAPD patients. Part II: Eight patients with diabetes mellitus (type I or II) and chronic renal failure who were about to undergo CA PD. Intervention: Part I: None. Part II: Uninterrupted CAPD, as medica lly required. Measurements: Part I: To determine serum AGE-peptide con centrations blood samples were obtained randomly from controls and CAP D patients, and predialysis from hemodialysis patients. Hemoglobin A(1 c) was also measured in all subjects. Part II: To determine serum AGE- peptide concentrations, blood samples were collected within one month prior to initiation of CAPD (predialysis) and, again, one week after i nitiation of uninterrupted CAPD(postdialysis). Hemoglobin A(1c) was me asured predialysis. Results: Part I: Mean hemoglobin A(1c) values for all groups were within the normal range; however, the mean value for C APD patients was significantly higher than for both hemodialysis patie nts and healthy controls (controls, 5.21% +/- 0.6%; hemodialysis, 5.12 % +/- 0.5%; CAPD, 5.78% +/- 0.6%; p < 0.01). The dialysis patients had a significantly higher mean serum AGE-peptide concentration than the control subjects (controls, 7.02 +/- 3.4 units/mL; hemodialysis, 11.9 +/- 3.6 units/mL; CAPD, 11.1 +/- 4.5 units/mL; p < 0.01). There was no difference in the mean serum AGE-peptide concentration of patients in the hemodialysis and CAPD groups. Part II: The mean hemoglobin A(1c) value in the diabetic predialysis patients was 9.2% +/- 1.9%. There wa s no difference between the predialysis and postdialysis serum AGE-pep tide concentrations (predialysis, 16.9 +/- 9.6 units/mL; postdialysis, 16.0 +/- 2.9 units/mL; p = 0.78). Conclusions: Despite the increased glucose load and the higher hemoglobin A(1c) values, indicating poor g lycemic control, nondiabetic CAPD patients did not have higher serum A GE-peptide concentrations than the nondiabetic hemodialysis patients. In diabetic patients, CAPD did not further increase the serum concentr ations of AGE-peptides.