Managing metabolic complications of peritoneal dialysis

Aims: The purposes of this paper are: to report our experience employing a comprehensive, multifaceted treatment program to improve the metabolic disturbances of dyslipidemia, hyperglycemia and weight gain observed in our peritoneal dialysis patients, and by post-hoc analysis to demonstrate how the routine clinical lipid profile can be manipulated arithmetically to estimate levels of atherogenic low-density lipids and thereby achieve a more sophisticated clinical analysis of dyslipidemia and its response to therapy. Methods: Data are reported for 56 patients who were stable on peritoneal dialysis for at least 6 months and who had metabolic data available prior to beginning peritoneal dialysis. Metabolic complications of peritoneal dialysis were treated by a comprehensive strategy involving diet, glycemic control and lipid-lowering medications with an emphasis on weight control and exercise. From the measured lipid profile (total cholesterol (TC), high-density lipoprotein (HDL) and triglyceride (TG)), levels of atherogenic low-density lipids (low-density lipoprotein (LDL), non-HDL, very-low-density lipoprotein (VLDL) and intermediate-low-density lipoprotein (IDL) were calculated. Results: Before initiation of peritoneal dialysis therapy, the most common lipid abnormalities were low levels of HDL (59%) and elevated levels of triglyceride (41%) with infrequent elevations of total cholesterol (9%) and low-density lipoprotein (23%). After initiation of peritoneal dialysis therapy, all lipid levels, except HDL, increased significantly, and hyper-lipidemia, hyperglycemia and obesity, singly or in combination, occurred in 84% of patients. With treatment, elevated lipid levels decreased significantly with reversal of the adverse cardiovascular risk profile of lipids that developed during peritoneal dialysis therapy, and HDL levels increased significantly. On peritoneal dialysis therapy, all diabetic patients required insulin, and glycemic control was achieved in most patients (79%). Excessive weight gain (10 - 24% body weight) occurred in 20% of peritoneal dialysis patients. Diabetic patients had a higher incidence of being overweight and obese. Post-hoc analysis revealed that levels of VLDL and IDL frequently were elevated both before (57 - 61%) and during (68 - 84%) peritoneal dialysis and that target levels of these atherogenic low-density lipoproteins infrequently (22 - 26%) were achieved. Conclusions: The metabolic complications of peritoneal dialysis are responsive to a comprehensive treatment strategy. Controlling weight gain on peritoneal dialysis therapy may be a difficult challenge for some patients, particularly those who are diabetic. Patients with renal failure and on dialysis, especially peritoneal dialysis, frequently have elevated levels of the atherogenic lipoproteins fragments VLDL and IDL. Future clinical trials should focus on the efficacy and safety of aggressive therapy to achieve target levels of these atherogenic lipids.