LOW-DENSITY-LIPOPROTEIN SUBFRACTION PROFILES IN CHRONIC-RENAL-FAILURE

Background. Small low-density lipoprotein (LDL) particle size, a newly recognized risk factor for cardiovascular disease in the general popu lation, is frequently associated with hypertriglyceridaemia, the predo minant plasma lipid abnormality present in uraemia. Methods. Plasma li pids and LDL subfraction profiles were examined in 33 non-dialysed pat ients with chronic renal failure (predial), 40 patients on continuous ambulatory peritoneal dialysis (CAPD), 42 haemodialysis patients (HD), 47 renal transplant recipients (RTR), and 44 controls. LDL subfractio ns separated by gel electrophoresis were scored by densitometric analy sis (higher scores indicate profiles comprising smaller particles). Re sults. All groups with renal failure had significantly elevated (mean +/- SD) LDL scores (predial 1.36 +/- 0.6, CAPD 1.71 +/- 0.9, HD 1.68 /- 0.9, RTR 1.92 +/- 0.8 vs control 0.87 +/- 0.4, all P < 0.001), this being the only lipid abnormality detected in the predialysis patients . In CAPD and HD patients, LDL scores were associated with serum trigl yceride (r = 0.81, P < 0.001 and r = 0.70, P < 0.001 respectively), ch olesterol (r = 0.55, P < 0.001 and r = 0.49, P < 0.01) and HDL-cholest erol (r = -0.43, P < 0.01 and r = -0.51, P < 0.01), whilst no such rel ationship was seen in the predialysis and RTR groups, suggesting that other factors were important. Conclusions. The presence of small LDL p articles appears to be an early and unexplained feature of the uraemic dyslipidaemia. This abnormality persists after renal transplantation and may represent an important atherogenic risk factor.