From the Guidelines
Hyperlipidemia is classified into several types, including primary and secondary hyperlipidemias, with the main types being Type I, IIa, IIb, III, IV, and V, based on which lipids are elevated in the blood. The classification of hyperlipidemia is crucial as it guides treatment approaches 1. The main types of hyperlipidemia include:
- Type I: elevated chylomicrons due to lipoprotein lipase deficiency
- Type IIa: elevated LDL cholesterol, also known as familial hypercholesterolemia
- Type IIb: elevated LDL and VLDL, causing high cholesterol and triglycerides
- Type III: elevated IDL particles, or dysbetalipoproteinemia
- Type IV: elevated VLDL and triglycerides
- Type V: elevated chylomicrons and VLDL
These classifications are important because they guide treatment approaches, with primary hyperlipidemias being caused by genetic factors, and secondary hyperlipidemias resulting from other conditions like diabetes, hypothyroidism, kidney disease, or medications 1.
Treatment Approaches
Treatment typically involves lifestyle modifications for all types, including diet changes, exercise, and weight management. Medication therapy varies by type, with statins being first-line for elevated LDL, fibrates for high triglycerides, and combination therapy often needed for mixed disorders 1.
Importance of Classification
Understanding the specific type of hyperlipidemia is essential for targeting treatment appropriately and reducing cardiovascular risk, as different lipid abnormalities contribute to atherosclerosis through distinct mechanisms 1.
From the FDA Drug Label
Therapy with nicotinic acid, alone or in combination with a bile-acid binding resin, is indicated as an adjunct to diet for the reduction of elevated total and LDL cholesterol levels in patients with primary hypercholesterolemia (Types IIa and IIb)†, when the response to a diet restricted in saturated fat and cholesterol and other nonpharmacologic measures alone has been inadequate Nicotinic acid is also indicated as adjunctive therapy for the treatment of adult patients with very high serum triglyceride levels (Types IV and V hyperlipidemia)† who present a risk of pancreatitis and who do not respond adequately to a determined dietary effort to control them † Classification of Hyperlipoproteinemias LipoproteinsLipid Elevations TypeElevatedMajorMinor C = cholesterol, TG = triglycerides LDL = low-density lipoprotein VLDL = very low-density lipoprotein IDL = intermediate-density lipoprotein I (rare)ChylomicronsTG↑→ C IIaLDLC..... IIbLDL, VLDLCTG III (rare)IDLC/TG..... IVVLDLTG↑→ C V (rare)Chylomicrons, VLDTG↑→ C
The types of hyperlipidemia are:
- Type I: Elevated chylomicrons and plasma triglycerides
- Type IIa: Elevated LDL cholesterol
- Type IIb: Elevated LDL and VLDL cholesterol and triglycerides
- Type III: Elevated IDL cholesterol and triglycerides
- Type IV: Elevated VLDL triglycerides
- Type V: Elevated chylomicrons and VLDL triglycerides 2
From the Research
Types of Hyperlipidemia
The types of hyperlipidemia can be categorized into different patterns, including:
- Hypercholesterolaemia with normal triglyceride 3
- Moderate hypertriglyceridaemia with normal cholesterol 3
- Combined moderate hypercholesterolaemia and hypertriglyceridaemia 3
- Severe hypertriglyceridaemia with moderate hypercholesterolaemia 3
- Pure or essential hypercholesterolemia 4
- Mixed or combined hyperlipidemias 4
- Major hyperglyceridemia: either exogenous or endogenous 4
- Hypercholesterolaemia (due to raised levels of β-lipoprotein) 5
- Increased level of endogenous triglyceride, with or without hypercholesterolaemia 5
- Exogenous hypertriglyceridaemia 5
- Familial hypercholesterolaemia 6
- Familial combined hyperlipidaemia 6
- Common hypercholesterolaemia 6
- Familial hypertriglyceridaemia 6
- Remnant (type III) hyperlipidaemia 6
Classification of Hyperlipidemia
Hyperlipidemia can be classified into primary and secondary hyperlipidemia, with primary hyperlipidemia including several distinct diseases characterized by elevated serum levels of cholesterol and/or triglyceride with or without abnormally low levels of HDL cholesterol 6.
Genetic Basis of Hyperlipidemia
The genetic basis of hyperlipidemia is complex, with multiple genes involved, and the possibility of combination of different gene defects 4.
Diagnosis and Treatment of Hyperlipidemia
The diagnosis and treatment of hyperlipidemia depend on reliable and well-controlled laboratory support, and the evaluation of hyperlipidaemia in the patient's family is often appropriate 6. The treatment of primary hyperlipidaemic states can be classified into three groups for the purpose of therapy 5, and new lipid-lowering medications have been developed to target metabolic pathways 7.