This cross-sectional study was undertaken to examine the relationship between plasma lipoprotein(a) [Lp(a)l level and peritoneal dialysis (PD) albumin clearance while controlling for the influence of the apolipoprotein(a) [apo(a)l phenotype. Plasma Lp(a) level, PD albumin clearance, and apo(a) phenotype thigh vs. low molecular weight, HMW vs. LMW) were determined in 54 PD patients. Apo(a) phenotypes were 24 LMW and 30 HMW. The plasma Lp(a) level was high (> 65 nmol/l) in 17 of 24 patients with LMW phenotype versus 2 of 30 with HMW phenotype (chi (2), p < 0.01). Spearman correlation coefficients of Lp(a) with PD, urine, and total albumin clearances were -0.05 (p = 0.74), -0.04 (p = 0.80), and -0.09 (p = 0.51), respectively. The apo(a) isoform size was the only significant predictor of Lp(a) in multivariate analysis. In this study, there was no association between PD albumin clearance and Lp(a) level. The association between apo(a) phenotype and Lp(a) level is in keeping with studies in the general population. There is a strong genetic influence on Lp(a) level in PD patients. Copyright (C) 2001 S. Karger AG, Basel.