We evaluated serial measurements of serum lipid levels in 68 patients aged 12.6 +/- 4.7 years undergoing treatment with continuous ambulatory peritoneal dialysis/continuous cycling peritoneal dialysis (CAPD/CCPD). Fasting mean levels of triglycerides (TG) and cholesterol (C) were elevated above the 95th percentile of published normal values by 102% and 19%, respectively, at the start of dialysis. Except for a short-term decrease in TG levels at 6 and 9 months, no significant change in mean lipid levels was observed during a follow-up period of 2 years. At initiation of dialysis, elevated TG and C levels were present in 90% and 69% of the patients, respectively. The prevalence of hyperlipidemia (HL) varied between 63% and 88% (TG) and 61% and 93% (C), respectively, during the follow-up period. TG and C levels were not correlated with caloric intake (evaluated in 17 patients), serum albumin levels, treatment modality (CAPD or CCPD), a history of the nephrotic syndrome, or previous treatment with hemodialysis or transplantation. However, a significant inverse correlation was observed between age and serum lipids at the initiation of dialysis treatment and after 1 year (TG: r = -0.40; C: r = -0.44). Our data indicate a high prevalence of HL but no significant change of serum lipid levels during 2 years of treatment with CAPD/CCPD.