HDL acceptor capacities for cholesterol efflux from macrophages and lipid transfer are both acutely reduced after myocardial infarction

Abstract

Background: The transport of lipids from the artery wall is one of the most essential anti-atherogenic functions of high-density lipoprotein (HDL). Recent reports of changes in the HDL composition, during myocardial infarction (MI), suggest that this function may be altered.

Methods: Forty-one consecutive patients with ST-segment elevation MI enrolled at the Brasilia Heart Study were selected. The following HDL-related measures were determined upon admission (D1) and on the fifth day (D5) after MI: C-reactive protein, CETP and PLTP activity, HDL composition, efflux of cholesterol from J774 macrophages to HDL, and transfer of unesterified and esterified cholesterol, triglycerides and phospholipids from a donor nanoemulsion to HDL.

Results: From D1 to D5, the activity of CETP decreased by 25%, but PLTP activity remained unchanged. Esterified cholesterol (-23%) and phospholipid (-9.5%) contents of HDL decreased. Transfer of triglycerides (-36.5%) and esterified cholesterol (-14.7%) to HDL from nanoemulsions was reduced, but other lipids transfers were unchanged. Cholesterol efflux to HDL was also diminished by 8.5% (p=0.04) on D5 compared to D1. It was more pronounced in patients above the 75th percentile of C-reactive protein.

Conclusions: After an MI, a simultaneous decrease in lipid transfer to HDL and in the capacity of HDL to efflux cholesterol from cells occurs. Thus, HDL with inferior atheroprotective properties may be generated in the acute post-MI period.

Keywords: High density lipoprotein; Lipid transfer; Myocardial infarction.