Introduction: Familial combined hyperlipidemia (FCH) is characterized by several phenotypes, including an atherogenic lipoprotein profile, low grade inflammation, visceral obesity, insulin resistance, and hypertension. In this study, we investigated which of the clinical and biochemical characteristics of FCH patients contributes most to their increased risk of cardiovascular disease, by determining the association of a broad variety cardiovascular risk factors with the intima media thickness (IMT) of the common carotid artery (CCA) in 94 FCH patients and 216 non-affected relatives.
Methods: All subjects filled out a questionnaire about their smoking and drinking habits, medical history and medication use, and venous blood was drawn in the fasting state after discontinuation of lipid lowering medication (if used). IMT of the far wall and near wall of both CCAs was measured by high-resolution B-mode ultrasonography.
Results: The mean IMT in FCH patients (adjusted for age and gender) was 33 microm thicker when compared to their non-affected relatives (p=0.006). In multivariate analysis, the waist-to-hip ratio, the apoB concentration and the pulse pressure were significant and independent predictors of IMT in both FCH patients and their normolipidemic relatives. The most important independent predictor of IMT in FCH patients however, was the VLDL-c/TG ratio, explaining 32.8% of the variation in age- and gender-adjusted IMT, whereas this ratio was not an independent predictor of IMT at all in their unaffected relatives.
Conclusion: Abdominal obesity, a higher blood pressure and dyslipidemia characterised by both an increased number of atherogenic particles and the presence of highly atherogenic remnant lipoproteins play an important role in the development of cardiovascular disease in FCH-patients.