What lipoprotein labs are recommended for an adult patient with Hyperlipidemia (HLD)?

Recommended Lipoprotein Labs for Adults with Hyperlipidemia

For adults with hyperlipidemia, obtain a fasting lipid profile that includes total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides, with calculation of non-HDL cholesterol. 1

Standard Lipid Panel Components

The baseline lipid evaluation should include the following measurements 1:

• Total cholesterol (TC) - sum of all cholesterol-containing lipoproteins 2
• LDL cholesterol (LDL-C) - the primary atherogenic lipoprotein and main target of therapy 1, 2, 3
• HDL cholesterol (HDL-C) - the protective lipoprotein with inverse cardiovascular risk association 2
• Triglycerides (TG) - markers of triglyceride-rich lipoproteins contributing to residual cardiovascular risk 2
• Non-HDL cholesterol - calculated as total cholesterol minus HDL-C, superior to LDL-C for predicting cardiovascular events especially when triglycerides >200 mg/dL 1, 2, 3

Fasting Requirements and Technical Considerations

Obtain fasting samples (12 hours) for accurate triglyceride and calculated LDL-C measurements. 1 However, if initial nonfasting testing reveals triglycerides ≥400 mg/dL (≥4.5 mmol/L), repeat the lipid profile in the fasting state 1.

For LDL-C calculation, use the Friedewald formula when triglycerides are <400 mg/dL (<4.5 mmol/L) 1:

• In mmol/L: LDL-C = TC - HDL-C - TG/2.2
• In mg/dL: LDL-C = TC - HDL-C - TG/5

When LDL-C is <70 mg/dL (<1.8 mmol/L), direct LDL-C measurement is reasonable to improve accuracy over the Friedewald formula 1.

Screening Frequency

The frequency of lipid testing depends on risk factors and baseline values 1:

• Every 5 years for adults with low-risk lipid values (LDL <100 mg/dL, HDL >60 mg/dL, triglycerides <150 mg/dL) 1
• At least annually for adults with diabetes or established cardiovascular disease 1
• More frequently when 2 or more CHD risk factors are present (smoking, hypertension, HDL-C <40 mg/dL, family history of premature CHD, or age ≥45 years for men or ≥65 years for women) 1
• More frequently if LDL-C levels are borderline or high 1

Special Considerations: Lipoprotein(a)

Screening for Lp(a) is NOT routinely recommended for primary prevention unless 1:

1. Unexplained early cardiovascular events have occurred in first-degree relatives, OR
2. High Lp(a) is known to be present in first-degree relatives

When measured, Lp(a) should be obtained once as it remains relatively stable over time 2, 3.

Common Pitfalls to Avoid

• Do not rely on a single lipid measurement - abnormal results should be confirmed with a repeat measurement on a separate occasion, and the average of both results should guide treatment decisions 2, 4
• Do not order advanced lipoprotein testing (particle size, subfractions) beyond the standard fasting lipid profile for routine cardiovascular risk assessment in asymptomatic adults, as this provides no additional benefit 4
• Do not use HDL ratios as obsolete measures - while total cholesterol/HDL-C ratio can be used for risk estimation, focus treatment decisions on absolute LDL-C and non-HDL-C values 1, 5

Treatment Targets Based on Risk

Once labs are obtained, LDL-C goals vary by cardiovascular risk 1:

• 0-1 CHD risk factor: LDL-C <160 mg/dL 1
• 2+ CHD risk factors with 10-year risk <20%: LDL-C <130 mg/dL 1
• CHD or CHD risk equivalent (diabetes, peripheral arterial disease, 10-year risk >20%): LDL-C <100 mg/dL, or optionally <70 mg/dL 1
• Non-HDL-C goals are 30 mg/dL higher than LDL-C goals when triglycerides ≥200 mg/dL 1