What additional blood work is recommended for someone with hypercholesterolemia?

Additional Blood Work for High Cholesterol

For someone with high cholesterol, measure a complete lipid panel (total cholesterol, LDL-C, HDL-C, triglycerides, and calculated non-HDL-C) and obtain a one-time lipoprotein(a) [Lp(a)] measurement to assess cardiovascular risk and guide treatment intensity. 1

Core Lipid Testing

Standard lipid panel components:

• LDL-cholesterol (LDL-C) should be the primary lipid measurement for screening, risk assessment, diagnosis, and treatment monitoring 1
• HDL-cholesterol (HDL-C) is an independent risk factor and should be measured as part of the risk assessment 1
• Non-HDL-cholesterol (calculated as total cholesterol minus HDL-C) is a strong independent risk marker, particularly valuable in patients with elevated triglycerides, diabetes, obesity, or very low LDL-C 1
• Triglycerides to identify hypertriglyceridemia and assess need for additional therapies 1

Fasting vs. non-fasting: Blood can be drawn in either fasting or non-fasting state for most patients, though fasting samples are preferred when triglycerides are elevated (>175 mg/dL or 2.0 mmol/L) 1, 2

Critical One-Time Measurement

Lipoprotein(a) [Lp(a)] should be measured at least once in every adult's lifetime to identify those at very high lifetime cardiovascular risk 1. This is particularly important because:

• Lp(a) levels are genetically determined and remain stable throughout life 1
• Very high Lp(a) levels (>180 mg/dL or >450 nmol/L) help further stratify risk in patients with family history of premature cardiovascular disease or those at borderline risk categories 1
• Elevated Lp(a) cannot be lowered with currently available oral medications, making early identification crucial for aggressive management of other modifiable risk factors 1, 2

Additional Testing for Specific Scenarios

Consider apolipoprotein B (apoB) measurement when: 1

• Triglycerides are ≥200 mg/dL (≥2.3 mmol/L) 1
• Patient has diabetes, obesity, or metabolic syndrome 1
• LDL-C is very low but cardiovascular risk appears elevated 1
• ApoB can serve as an alternative primary target to LDL-C and may be preferred over non-HDL-C in these conditions 1

Screen for familial hypercholesterolemia (FH) if: 1

• LDL-C >190 mg/dL (>5 mmol/L) in adults or >150 mg/dL (>4 mmol/L) in children 1
• Personal history of coronary heart disease before age 55 (men) or 60 (women) 1
• Family history of premature cardiovascular disease or tendon xanthomas 1
• When FH is suspected, perform reverse-cascade screening of first-, second-, and third-degree biological relatives 1

Risk Stratification Testing

For asymptomatic adults >40 years without established cardiovascular disease, diabetes, chronic kidney disease, or familial hypercholesterolemia: 1

• Calculate total cardiovascular risk using a validated risk estimation system (such as SCORE in Europe or pooled cohort equations in the US) 1
• This determines treatment intensity and LDL-C goals 1

Additional biomarkers with strongest evidence for risk enhancement include: 1

• High-sensitivity C-reactive protein (hs-CRP) 1
• Coronary artery calcium (CAC) scoring 1
• Ankle-brachial index 1

Secondary Causes Evaluation

In patients with moderate hypertriglyceridemia (175-499 mg/dL or 2.0-5.6 mmol/L), assess for: 1

• Diabetes mellitus 1
• Chronic liver or kidney disease/nephrotic syndrome 1
• Hypothyroidism 1
• Medications that increase triglycerides 1

Monitoring After Treatment Initiation

Follow-up lipid testing should assess: 1

• Treatment adherence and response to therapy 1
• Achievement of risk-based LDL-C goals: <70 mg/dL (<1.8 mmol/L) for very high-risk patients or <100 mg/dL (<2.6 mmol/L) for high-risk patients 1
• Need for treatment intensification if goals not achieved within 8 weeks 1

Common Pitfalls to Avoid

• Do not skip Lp(a) measurement – this is a one-time test that provides lifelong risk information and cannot be adequately assessed through standard lipid panels 1
• Do not rely solely on total cholesterol – LDL-C is the primary target for treatment decisions 1
• Do not overlook familial hypercholesterolemia – severe LDL-C elevation (>190 mg/dL) warrants family screening regardless of genetic testing availability 1
• Do not forget non-HDL-C – this calculated value provides additional risk information, especially when triglycerides are elevated 1