What labs should be ordered for an adult patient with hyperlipidemia?

Laboratory Testing for Hyperlipidemia in Adults

For adults with hyperlipidemia, order a standard lipid panel including total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides—this can be done on either fasting or non-fasting samples, though fasting is preferred for accurate triglyceride measurement. 1, 2

Standard Lipid Panel Components

The essential tests for evaluating hyperlipidemia include:

• Total cholesterol measures all cholesterol in the blood and serves as an initial screening parameter 2
• HDL cholesterol ("good cholesterol") can be measured on non-fasting samples and is critical for risk stratification 3, 2
• LDL cholesterol ("bad cholesterol") is the primary treatment target and can be calculated using the Friedewald equation when triglycerides are <300 mg/dL, or measured directly on fasting samples 2, 4
• Triglycerides should be included as they help calculate LDL and identify patients needing non-HDL cholesterol as a secondary target 2, 4
• Non-HDL cholesterol (calculated as total cholesterol minus HDL) should be used as a secondary therapeutic target in patients with triglycerides between 175-880 mg/dL 4, 5

Measurement Considerations and Confirmation

• Total cholesterol and HDL can be reliably measured on non-fasting samples, making screening more convenient 3, 2
• Abnormal results must be confirmed with a repeat sample on a separate occasion, and the average of both measurements should be used for risk assessment and treatment decisions 3, 2, 6
• LDL cholesterol calculation requires triglycerides <300 mg/dL; above this level, direct LDL measurement is necessary 2

Additional Testing in Specific Situations

For patients with elevated screening results or those requiring more detailed evaluation:

• Lipoprotein(a) should be measured at least once in all patients at cardiovascular risk, particularly to explain poor response to statin therapy 4
• Fasting lipoprotein analysis including triglycerides may provide useful information for selecting optimal treatments in high-risk patients 3, 6
• Apolipoprotein B can serve as a secondary therapeutic target in patients with mild-to-moderate hypertriglyceridemia (175-880 mg/dL) 4

Advanced Lipid Testing: Not Routinely Recommended

• Advanced lipoprotein testing beyond the standard lipid profile is not recommended for routine cardiovascular risk assessment in asymptomatic adults 1, 6
• LDL particle size, density, and concentration are not recommended for routine screening 2
• These advanced tests may have research value but lack sufficient evidence for routine clinical use 7

Monitoring Frequency

• For adults under 40 not on lipid-lowering therapy, obtain lipid profiles at initial evaluation and every 5 years thereafter 1, 6
• Shorter intervals are appropriate for patients with lipid levels close to treatment thresholds 1, 6
• For patients over 75 years on statin therapy, continue monitoring to assess medication adherence and efficacy 1
• Routine lipid testing can be discontinued in adults over 75 years not on therapy with consistently normal levels and no cardiovascular disease 1

Critical Pitfalls to Avoid

• Never rely on a single lipid measurement for diagnosis or treatment decisions—always confirm abnormal results 2, 6
• Do not use total cholesterol alone for risk assessment, as it fails to distinguish between protective HDL and atherogenic LDL 2
• Failing to account for non-fasting state when interpreting triglyceride levels can lead to misclassification 2
• Remember that lipid results should be integrated into global cardiovascular risk assessment, not used in isolation for treatment decisions 6