SUBFRACTIONS OF ATHEROGENIC APOB-LIPOPROTEIDES IN PATIENTS WITH SEVERE HYPERCHOLESTEROLEMIA

Abstract

Aim . To investigate on the relation of lipoproteide (a) (Lpa), subfractions of intermediate density lipoproteides (IDL) and low density lipoproteides (LDL) with the probability of familial hypercholestrolemia diagnosis (FHE). Material and methods . Totally, 114 patients included, with severe hypercholesterolemia (LDL-C >4,9 mM/L), with no known coronary heart disease and not taking hypolipidemic therapy. For the probability assessment of FHE, Dutch Lipid Clinics Network criteria were applied. Lipid profile parameters were measured by enzymatic method; Lpa — by immune enzyme method; lipoproteides subfractions — with the Lipoprint® system (Quantimetrix, USA). Results . All patients were selected to subgroups in accordance with the Dutch criteria: I group — with low FHE probability (3-5 points, n=86) and II — with definite and porobable FHE (≥6 points, n=28). Patients from II group had higher atherogenic apoB100-containing lipoproteides (a) levels — 25,5±27,8 and 42,8±41,5 mg/dL (р=0,014), small dense subfractions of LDL — sdLDL: 2,3±3,7 and 7,1±10,1 mg/dL (р<0,01) and IDL-C — 26,6±9,7 and 37,0±10,7 mg/dL (р<0,0001). Monofactorial analysis revealed positive correlation of FHE presence with Lpa (r=0,261, p=0,005), IDL-A (r=0,212, p=0,024), IDL-В (r=0,256, p=0,006), IDL-С (r=0,324, p<0,001), large subfractions of LDL-2 (r=0,218, p=0,020), sdLDL (r=0,362, p=0,0001) and negative correlation with the low density cholesterol (HDL-C) (r=-0,174, p=0,012); however, by the multifactorial analysis the negative correlation was noted only for Lpa (r=0,230, р=0,005) and IDL-С (r=0,411, p=0,009). Combination of the Lpa concentrations ≥30 mg/dL and sdLDL ≥2 mg/dL in relation to Lpa <30 mg/dL and sdLDL <2 mg/dL, as well as Lpa ≥30 mg/dL and IDL-С ≥30 mg/dL in relation with Lpa <30 mg/dL and IDL-С <30 mg/dL significantly increases the probability of FHE diagnostics (odds ratio =11,3 (95% confidence interval 2,9-43,7), р<0,001, and odds ratio =9,0 (95% confidence ratio 2,3-34,9), р=0,002), respectively. Conclusion . In the patients with definite and probable FHE diagnosis, there is significantly increased concentration of the most atherogenic apoB100-containing lipoproteides: Lpa, IDL-C and sdLDL, and the levels of sdLDL ≥2 mg/dL or IDL-C ≥30 mg/dL together with hyperlipoproteidemia (a) increase the chance of FHE verification.