Fractional turnover of apolipoprotein(a) and apolipoprotein B-100 within plasma lipoprotein(a) particles in statin-treated patients with elevated and normal Lp(a) concentration.

Abstract

CONTEXT\nLipoprotein(a) [Lp(a)] is a highly atherogenic lipoprotein characterized by apolipoprotein(a) [apo(a)] covalently bounded to apoB-100 (apoB). However, the metabolism of apo(a) and apoB within plasma Lp(a) particles in patients on statins remains unclear.\n\n\nMETHODS\nThe kinetics of Lp(a)-apo(a) and Lp(a)-apoB were determined in 20 patients with elevated Lp(a) (≥0.8\u202fg/L; n\u202f=\u202f10) and normal Lp(a) (≤0.3\u202fg/L; n\u202f=\u202f10) using stable isotope techniques and compartmental modeling. Plasma apo(a) concentration was measured using liquid chromatography-mass spectrometry. All patients were on statin therapy and were studied in the fasting state.\n\n\nRESULTS\nThe fractional catabolic rate (FCR) of Lp(a)-apo(a) was not significantly different from that of Lp(a)-apoB in statin-treated patients with elevated or normal Lp(a) (P\u202f>\u202f0.05 in both). Lp(a)-apo(a) FCR was significantly correlated with Lp(a)-apoB in patients with elevated and normal Lp(a) concentrations (r\u202f=\u202f0.970 and r\u202f=\u202f0.979, respectively; all P\u202f<\u202f0.001) with Lin s concordance test showing substantial agreement between the FCRs of Lp(a)-apo(a) and Lp(a)-apoB in patients with elevated and normal Lp(a) concentrations (rc\u202f=\u202f0.978 and rc\u202f=\u202f0.966, respectively).\n\n\nCONCLUSION\nOur data indicate that the apo(a) and apoB proteins within Lp(a) particles have similar FCR and are therefore tightly coupled as an Lp(a) holoparticle in statin-treated patients with elevated and normal Lp(a) concentrations.