What are the diagnoses and classification of Hyperlipidemia (high cholesterol)?

From the Guidelines

Hyperlipidemia (high cholesterol) is diagnosed and classified based on lipid profiles, including LDL cholesterol, HDL cholesterol, and triglycerides. The most commonly used measure of cholesterol is total cholesterol, but more sensitive measures include the total:HDL cholesterol ratio and non-HDL cholesterol levels 1.

Classification of Hyperlipidemia

• LDL cholesterol: High levels indicate surplus lipids in the blood, increasing the risk of cardiovascular complications 1.
• HDL cholesterol: Transports lipids back to the liver for recycling and disposal; high levels are an indicator of a healthy cardiovascular system 1.
• Triglycerides: Excess levels in plasma are positively and independently associated with cardiovascular disease 1.
• VLDL cholesterol: Positively correlates with triglycerides and is independently associated with cardiovascular risk, even in individuals with normal LDL cholesterol levels 1.

Diagnosis and Risk Assessment

• The Framingham risk assessment algorithm is used to identify patients with multiple risk factors who would benefit from more intensive therapy 1.
• LDL-C is considered the primary target of therapy, and non-HDL-C is a secondary treatment goal in patients with hypertriglyceridemia 1.
• The European Society of Cardiology (ESC) guidelines recommend measuring Lp(a) in patients at high risk of cardiovascular disease and targeting levels below 50 mg/dL 1.

Treatment Goals

• LDL-C goals: < 1.8 mmol/L (70 mg/dL) for patients at very high CV risk, and < 2.6 mmol/L (100 mg/dL) for patients at high CV risk 1.
• Statin therapy: Recommended as the usual first-line treatment to reach LDL-C goals, and should be used up to the highest recommended dose or highest tolerable dose to reach the goal 1.

Special Considerations

• Familial Hypercholesterolaemia (FH): A genetic disorder characterized by high LDL-C levels, and requires early diagnosis and treatment to prevent premature coronary artery disease and death 1.
• Lp(a) levels: Mainly determined by genetic traits, and high levels are associated with increased risk of cardiovascular disease 1.

From the Research

Diagnoses of Hyperlipidemia

• The primary lipid panel for hyperlipidemia diagnosis includes total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, and calculated non-HDL cholesterol 2
• LDL cholesterol is the primary target of lipid-lowering therapies, while non-HDL cholesterol or apolipoprotein B should be used as secondary therapeutic targets in patients with mild-to-moderate hypertriglyceridemia 2
• Lipoprotein (a) is included in LDL cholesterol and should be measured at least once in all patients at cardiovascular risk 2

Classification of Hyperlipidemia

• A practical classification of primary hyperlipidemias includes three main frames: pure or essential hypercholesterolemia, mixed or combined hyperlipidemias, and major hyperglyceridemia 3
• Type III hyperlipoproteinemia is a highly atherogenic dyslipoproteinemia characterized by hypercholesterolemia and hypertriglyceridemia due to markedly increased numbers of cholesterol-enriched chylomicron and very-low-density lipoprotein (VLDL) remnant lipoprotein particles 4
• The classification of hyperlipidemia can be based on lipoprotein analyses by electrophoresis and ultracentrifugation, as well as simpler methods such as the observation of plasma and measurements of cholesterol and triglycerides 5

Diagnostic Criteria

• The diagnosis of hyperlipidemia can be based on the measurement of total cholesterol, triglycerides, HDL cholesterol, and LDL cholesterol 2
• The apoB algorithm can be used to diagnose type III hyperlipoproteinemia, which involves measuring apolipoprotein B, total cholesterol, and triglycerides 4
• The National Cholesterol Education Panel's Adult Treatment Program-3 (ATP-III) guidelines provide a framework for the classification and treatment of hyperlipidemia, although new guidelines are expected to be released in the near future 6

Key Lipid Parameters

• Total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, and non-HDL cholesterol are key lipid parameters used in the diagnosis and classification of hyperlipidemia 2, 5
• Apolipoprotein B is an important parameter in the diagnosis of type III hyperlipoproteinemia and can be used as a secondary therapeutic target in patients with mild-to-moderate hypertriglyceridemia 2, 4