Serum lipoprotein (a) concentrations in patients undergoing continuous ambulatory peritoneal dialysis

Lipoprotein (a) is a subspecies of low-density lipoprotein whichpossesses as part of its protein moiety a mutant form of plasminogentermed apolipo-protein (a), and which may be closely relatedto the risk of ischaemic heart disease and cerebral infarction.We have investigated the serum concentrations of lipoprotein(a) and other lipoproteins in 24 male patients on CAPD and comparedthem to healthy men (n= 100) and to age-matched healthy controls(n=38). The most striking finding was a substantial elevationof serum lipoprotein (a) in CAPD patients in whom it was 46.9(2.2–168) mg/dl (median and range) compared to 9.0 (<0.6–87.4)mg/dl in healthy control group and 6.7 (< 0.6–84.2)mg/dl in age-matched controls (both P<0.001). Patients, whencompared to healthy men, also had significantly increased serumtriglycerides (median and range, 1.94 (0.55–8.00) versus1.24 (0.36–4.40) mmol/1; P< 0.001), very-low-densitylipoprotein cholesterol (median and range, 0.98 (0.10–3.71)versus 0.46 (0.10–1.17) mmol/l; P<0.001), and lower-high-densitylipoprotein cholesterol (mean±1 sd, 1.26±0.29versus 1.35±0.31 mmol/l). Of these, however, only thedifference in very-low-density lipoprotein cholesterol remainedstatistically significant (P< 0.001) in comparison to age-matchedcontrols. The marked elevation of serum lipoprotein (a) in patientson CAPD may be due to increased hepatic synthesis as a consequenceof the substantial amounts of plasma proteins lost in the dialysate.Elevated serum lipoprotein (a) concentrations in CAPD patientsmay contribute to their risk of coronary artery disease.