Association between microRNA-21 concentration and lipid profile in patients with acute coronary syndrome without persistent ST-segment elevation

INTRODUCTION    MicroRNA (miRNAs) are noncoding RNAs involved in the regulation of gene expression. Certain miRNAs, especially miRNA-21 (miR-21), may be involved in lipid metabolism.
OBJECTIVES    The aim of the study was to evaluate the association between plasma free circulating miR-21 levels and lipid fractions: total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), non-HDL-C, and triglycerides (TG), as well as their atherogenic profile expressed as the ratio of individual lipid fractions (TC:LDL-C, TC:non-HDL-C, TG:HDL-C, and HDL-C:LDL-C) in patients with acute coronary syndromes without persistent ST -segment elevation (NSTE ACS).
PATIENTS AND METHODS    The study group consisted of 34 patients diagnosed with NSTE ACS on admission to the emergency department. Plasma miRNA levels were determined by real-time polymerase chain reaction and the ΔΔCt method. Serum lipid fractions were assessed after a minimum of 12-hour fasting during the first day of hospitalization.
RESULTS    MiR-21 levels showed a significant inverse correlation with TC (r = –0.5; P = 0.002), LDLC (r = –0.5; P = 0.001), and non-HDL-C (r = –0.6; P <0.001) levels. Moreover, they were inversely correlated with TC:HDL-Cratio (r = –0.6; P <0.001), LDL-C:HDL-Cratio (r = –0.6; P <0.001), TG:HDL-Cratio (r = –0.4; P = 0.037), and TC:non-HDLratio (r = 0.6; P <0.001). In a multivariate analysis, miR-21 levels (β = –0.41; P = 0.018) and the need for revascularization (β = 0.35; P = 0.027) were independent predictors of non-HDL-C levels.
CONCLUSIONS    Free circulating miR-21 levels inversely correlate with TC, LDL-C, and non-HDL-C and are an independent predictor of non-HDL-C levels in patients with NSTE ACS. Thus, the overexpression of miR-21 is associated with a less atherogenic lipid profile.