High concentrations of small dense low-density lipoprotein as highly specific markers of familial combined hyperlipidaemia

As it is still unclear whether small dense low-density lipoproteins (sdLDL) are associated with familial combined hyperlipidaemia (FCHL), a set of inherited conditions with hypertriglyceridaemic hyper-apo B phenotypes and shared features of the metabolic syndrome, in which cholesterol is preferentially distributed into VLDL and sdLDL apoB-carrying lipoproteins. To this end, serum levels of sdLDL, expressed as percentage of total LDL cholesterol (LDL score), were assessed in 137 participants with FCHL and in 133 healthy control subjects. Binary logistic regression analysis revealed that age- and gender-adjusted LDL score values above the 90th and 95th percentiles control group values were significant predictors of FCHL, independently of the metabolic syndrome. Even after adjusting for individual metabolic syndrome components, values of the LDL score above the 90th and 95th percentiles of control group values remained significantly related to FCHL status. Among FCHL patients, values of the LDL score above the 95th percentile of control group values were significantly related to personal and/or family history of CVD events, independently of metabolic syndrome status, and this remained true even after adjusting for individual metabolic syndrome components. sdLDL are highly specific predictors of FCHL, independently of metabolic syndrome status.

Abstract

Keywords:
Apolipoprotein B – Cardiovascular risk – Cholesterol – Hyperlipidaemia – Hypertriglyceridaemia – LDL particle size – Metabolic syndrome