To further understand
lipoprotein (a) [Lp(a)] and
atherosclerosis, we measured serum Lp(a),
lipoprotein, and
apolipoprotein levels in 55 patients (males, 24-73 years old) on maintenance
hemodialysis, and compared them with those of 82 controls (males, 21-81 years old). The serum Lp(a) levels in patients on maintenance
hemodialysis were significantly higher than those of the normal controls, while serum total
cholesterol (TC),
high-density lipoprotein-cholesterol, (HDL-C), HDL2-C, HDL3-C,
apolipoprotein (apo) Al, apo All levels, and
lecithin-cholesterol acyltransferase (LCAT) activities were significantly (p < 0.05) reduced in the patient group. The frequency distribution of serum Lp(a) levels in the patients was different from that in the control group, and no prognostic tendency of serum Lp(a) levels was noted by the etiology of
renal failure as histologically determined by the renal biopsies. In the patient group, we also found that serum Lp(a) levels negatively correlated with serum
triglycerides (TG) and total
protein (TP) concentrations (p < 0.05), but no correlation was found between the duration of
hemodialysis therapy or patient age and the serum levels of TC, TG,
apo B and Lp(a) levels when tested for simple regression. Significant (p < 0.05) positive correlations were also found between TP and serum TG,
apo B, and LCAT activities. These opposing tendencies of Lp(a) and serum TG,
apo B, when measured against TP concentrations, indicate that serum TP levels may not affect serum
lipoprotein and Lp(a) levels in the same direction. These data suggest that
hemodialysis or
end-stage renal disease itself, rather than
hypoproteinemia, may hold the key to high serum Lp(a) levels in
hemodialysis patients.