Dysbetalipoproteinemia

Excerpt

Dysbetalipoproteinemia, also known as familial dysbetalipoproteinemia (FD), hyperlipoproteinemia type III (HLP3), or broad β disease, is a genetic lipid disorder characterized by increased accumulation of triglyceride-rich remnant lipoproteins. The accumulation of lipoproteins is due to impaired remnant clearance. Most patients with dysbetalipoproteinemia are homozygous for the apolipoprotein E2 (APOE) gene. Additionally, FD is associated with poor adherence of apolipoprotein E to the LDL receptors. Although FD is an autosomal recessive condition in most cases, 10% of cases are due to autosomal dominant mutations. This lipoprotein metabolic abnormality promotes fatty deposit accumulation on arterial walls, elevated serum triglycerides and total cholesterol, and the development of palmar xanthomas. Dysbetalipoproteinemia is associated with complications, including coronary artery disease and peripheral vascular disease. FD has a 10-fold increased risk for premature coronary artery disease compared to population-based controls.

Establishing the presence of the dysbetalipoproteinemia phenotype and the APOE genotype, which are the underlying etiologies of dysbetalipoproteinemia, is essential for diagnosis. The management of dysbetalipoproteinemia primarily consists of dietary lipid restriction and pharmacologic therapy with statins and fibrates. Clinicians should monitor patients during treatment using non–high-density lipoprotein cholesterol (non–HDL-C) testing to ensure that atherogenic lipoproteins are well controlled.