Objective: To investigate whether the specific lipoprotein (LP) abnormalities of peritoneal dialysis (PD) are associated with functional variables of this mode of dialysis.
Design: A survey of the LP profile in relation to peritoneal dialysis capacity (PDC) variables. The LP profile was compared to that of a group of age- and sex-matched controls.
Setting: The Peritoneal Dialysis Unit at Sahlgrenska University Hospital in Gothenburg, Sweden.
Patients: Twenty-two nondiabetic PD patients (5 women, 17 men) who had been on PD for at least 6 months.
Main outcome measures: The LP profile included plasma lipids, apolipoproteins (Apo), and individual ApoA- and ApoB-containing LP. The PDC measurement determined peritoneal glucose uptake, protein losses, effective peritoneal surface area, and total weekly creatinine clearance.
Results: The patients had been on PD for 6 to 48 months (mean 15.3 months) and had a total weekly creatinine clearance of 69.7+/-13.3 L/1.73 m2 body surface area, an average peritoneal glucose uptake corresponding to 446+/-162 kcal/24 hour, and a protein loss of 8.1+/-2.5 g/24 hr. The patients had significantly higher total cholesterol (7.1 mmol/L),VLDL-cholesterol (1.0 mmol/L), LDL-cholesterol (4.7 mmol/L), and triglyceride levels (2.5 mmol/L); whereas the HDL-cholesterol level (1.2 mmol/L) was significantly lower than in controls. The PD patients had increased levels of ApoB-containing LPs, both of the cholesterol-rich LP-B and of the triglyceride-rich LP-B complex, reflected in higher plasma concentrations of ApoB, ApoC-III, and ApoE. Furthermore, they had significantly lower levels of LP-A-I:A-II, as well as of ApoA-I and ApoA-II. The LP-A-I:A-II and ApoA-II levels correlated inversely with the duration of PD treatment (r = 0.54, p < 0.01 and r = 0.52, p < 0.05, respectively). The ApoA-II level was inversely correlated with the peritoneal surface area (r = 0.53, p < 0.05). There were no other correlations between LP variables and PDC variables, nor did any of the LP variables correlate with peritoneal glucose uptake or protein losses.
Conclusion: The proatherogenic lipoprotein profile of patients on PD is characterized by increased concentrations of cholesterol-rich and triglyceride-rich ApoB-containing LPs. While the duration of treatment appears to have some influence on the development of this type of dyslipidemia, the pathophysiological links to the dialysis mode must be further explored.