Lipid Disorders, Screening

Terminology

• The term dyslipidemia refers to disturbances leading to excess or reduction in levels of plasma lipoproteins. This term is associated with disease states leading to development of atherosclerotic cardiovascular disease or pancreatitis

• Hyperlipidemia is defined as excess of lipoproteins leading to hypercholesterolemia, hypertriglyceridemia, or excess lipoprotein (a) in plasma

• Hypolipidemia is defined as low levels of lipoproteins that lead to reduced values of cholesterol or triglycerides in plasma

• The term total cholesterol reflects cholesterol carried by all circulating lipoproteins in fasting (LDL-C; VLDL-C; and its remnants, mainly intermediate-density lipoprotein; HDL-C; and lipoprotein [a]). In postprandial states, total cholesterol includes all the before-mentioned lipoproteins, in addition to chylomicrons and their remnants

• Hypercholesterolemia (total cholesterol 200 mg/dL or higher) usually results from excess accumulation of LDL-C (LDL-C level 130 mg/dL or higher)

• Hypercholesterolemia may rarely occur due to excess accumulation of HDL-C1

• Hypertriglyceridemia (triglyceride level 150 mg/dL or higher) is characterized by excess accumulation of triglyceride-rich lipoproteins (VLDL-C; intermediate-density lipoprotein; and/or chylomicrons and remnants)1

• Low HDL-C level (hypoalphalipoproteinemia, HDL-C below 40 mg/dL) may occur in an isolated manner but usually occurs with hypertriglyceridemia

• Mixed dyslipidemia is characterized by elevation in both total cholesterol and triglycerides

• Elevation in lipoprotein (a) (50 mg/dL or higher) may occur in an isolated manner or in association with other forms of dyslipidemia,2 and may also cause hypercholesterolemia

Epidemiology

• Between 2011 and 2016, 38% and 11.7% of the adult population in the United States had total cholesterol levels 200 mg/dL or higher and 240 mg/dL or higher, respectively (1)

• LDL-C level 130 mg/dL or higher in US adults was encountered 28.9% and HDL-C level below 40 mg/dL was found in 19.2% (1)

• Severe hypercholesterolemia (LDL-C level 190 mg/dL or higher) is present in approximately 6% of the US population (3)

• The familial hypercholesterolemia phenotype is encountered in approximately 1 in 313 people in the general population (4)

• The familial hypercholesterolemia phenotype characterized by severe elevations in LDL-C is encountered in 1 in 31, 1 in 25, and 1 in 14, in people with ischemic heart disease, premature ischemic heart disease, and severe hypercholesterolemia, respectively (4)

• High LDL-C was the fifth leading cause of mortality worldwide between 1990 and 2017, according to the Global Burden of Disease study (5)

• Triglyceride levels are elevated (150 mg/dL or higher) in 22.2% of US adults (1)

• Severe forms of hypertriglyceridemia (triglyceride level 1000 mg/dL or higher) are encountered in roughly 0.4% of the US population (6)

• Lipoprotein (a) level varies according to ethnicity, being higher in Black and South Asian populations than in White and Chinese groups (7)

• Around 20% of White people have lipoprotein (a) above 50 mg/dL