Apolipoprotein B

Apolipoprotein B

This test is used to assess risk for cardiovascular disease, guide decisions on lipid-lowering therapy, and diagnose certain lipid disorders.

See also 2 related tests 4 related guides Test Guide List

Apolipoprotein B

Test Summary

 

Apolipoprotein B

Test codes: 91726, 5224

 

Clinical use

  • Assess risk for atherosclerotic cardiovascular disease (CVD)
  • Guide decisions on lipid-lowering therapy
  • Diagnose certain lipid disorders such as familial dysbetalipoproteinemia and familial combined hyperlipidemia (FCHL)

Clinical background

Low-density lipoprotein cholesterol (LDL-C) level has been the primary marker for CVD risk and target for lipid-lowering therapy. However, LDL-C level alone may provide an incomplete assessment of risk and treatment adequacy because CVD risk is more closely related to the number of atherogenic particles in plasma than their cholesterol content.1–3 Therefore, relying on LDL-C alone can lead to misclassification of risk and undertreatment.4

Apolipoprotein B (apoB) level predicts CVD risk and treatment efficacy more accurately than LDL-C and non–high-density lipoprotein cholesterol (HDL-C) levels.2,4,5 ApoB is the main structural protein found on all atherogenic particles, including low-, very low- and intermediate-density lipoprotein, chylomicron remnants, and lipoprotein(a). Because each of these particles contains 1 apoB molecule, apoB level represents the total burden of atherogenic particles.3

ApoB level is most clinically meaningful when apoB and LDL-C levels are discordant.1,4 Data from >95,000 people in the Copenhagen General Population Study showed that discordantly higher apoB was dose-dependently associated with CVD risk.6 Discordance is seen in individuals with elevated triglycerides and metabolic disorders, who tend to have an abundance of small, cholesterol-poor low-density lipoprotein particles, resulting in lower LDL-C relative to apoB.2,4 Discordance is also seen in patients receiving lipid-lowering therapy, which reduces LDL-C relatively more than apoB.4

In addition to CVD risk assessment, apoB is used to diagnose certain lipid disorders, including familial dysbetalipoproteinemia and FCHL.7 Familial dysbetalipoproteinemia is characterized by elevated non–HDL-C but normal apoB levels, resulting in high total cholesterol/apoB and non–HDL-C/apoB ratios.8 FCHL, a complex, multigenic disorder that causes premature CVD, is characterized by elevated apoB and triglyceride levels with a family history of premature CVD.5

ApoB measurement is included in clinical guidance from several professional societies (Table 1).

Table 1. Summary of Guideline Recommendations for ApoB Testing

Professional society

Guideline recommendations

American Heart Association and American College of Cardiology9,10
  • Elevated apoB (≥130 mg/dL) is a risk-enhancing factor for CVD that may be useful when triglyceride level is ≥200 mg/dL.
  • Among other risk-enhancing factors, apoB can help guide decisions on interventions for individuals with borderline to intermediate risk (10-year CVD risk ≥5% and <20%).

American Association of Clinical Endocrinologists and American College of Endocrinology11
  • ApoB testing for CVD risk assessment should be considered based on individual patient circumstances.
  • ApoB testing is useful for assessing the success of lipid-lowering therapy.

National Lipid Association4,7
  • ApoB testing is reasonable for patients receiving lipid-lowering therapy and may be reasonable for initial evaluation of CVD risk.
  • ApoB testing can be used to help diagnose familial dysbetalipoproteinemia and FCHL.
European Society of Cardiology and European Atherosclerosis Society5
  • ApoB testing can be used for CVD risk assessment, especially for certain patients.a ApoB can be used as an alternative to LDL-C for screening, diagnosis, and management and may be preferred over non–HDL-C for certain patients.a
ApoB, apolipoprotein B; CVD, cardiovascular disease; FCHL, familial combined hyperlipidemia; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol.
a Patients with high triglyceride levels, diabetes, obesity, or very low LDL-C levels.

Individuals suitable for testing

  • Individuals undergoing CVD risk assessment
  • Individuals being considered for or currently receiving lipid-lowering therapy
  • Individuals with certain suspected lipid disorders (eg, familial dysbetalipoproteinemia or FCHL)

Method

  • Immunoturbidimetry using an apoB antibody
  • Reportable range: 12 mg/dL–240 mg/dL

Interpretive information

ApoB level can be used to help assess risk for a cardiovascular event and as a target for lipid-lowering therapy (Table 2).7,10,11

Table 2. Interpretation of ApoB Test Resultsa

Test result

Interpretation

<70 mg/dL
  • Treatment target for patients with extreme CVD risk (eg, progressive CVD, or established CVD with diabetes)11

<80 mg/dL
  • Treatment target for patients with very high CVD risk (eg, established CVD, or diabetes plus ≥1 additional risk factor)11

<90 mg/dLb
  • Optimal CVD risk7
  • Treatment target for patients with moderate to high CVD risk, including those with diabetes11

90-129 mg/mL
  • Moderate CVD riskc

≥130 mg/dLb
  • Higher CVD risk7,10
  • Favors initiation or intensification of lipid-lowering therapy in patients with intermediate 10-year CVD risk (≥7.5% to <20%)10
  • May favor initiation of lipid-lowering therapy in patients with borderline 10-year CVD risk (5% to <7.5%)10
ApoB, apolipoprotein B; CVD, cardiovascular disease.
a Enhanced reporting includes color coding to display progressive risk values vs goal using "optimal," "moderate," and "high" risk categories. ApoB testing is also offered without enhanced reporting (Quest Diagnostics test code 5224).
b According to the National Health and Nutrition Examination Survey 2005-2016, an apoB level of 90 mg/dL corresponds approximately to the 50th population percentile and 130 mg/dL to the 90th population percentile.4
c Inferred from combined recommendations.7,10

When apoB quantitation is used to diagnose a suspected lipid disorder, test results should be considered in conjunction with other clinical and laboratory assessments.

In very rare cases, gammopathy, particularly monoclonal IgM type (eg, Waldenstrom macroglobulinemia), may cause unreliable test results.

References

  1. Sniderman AD, Thanassoulis G, Glavinovic T, et al. Apolipoprotein B particles and cardiovascular disease. JAMA Cardiol. 2019;4(12):1287-1295. doi:10.1001/jamacardio.2019.3780
  2. Oliveira-Gomes DD, Joshi PH, Peterson ED, et al. Apolipoprotein B: bridging the gap between evidence and clinical practice. Circulation. 2024;150(1):62-79. doi:10.1161/circulationaha.124.068885
  3. Glavinovic T, Thanassoulis G, de Graaf J, et al. Physiological bases for the superiority of apolipoprotein B over low-density lipoprotein cholesterol and non–high-density lipoprotein cholesterol as a marker of cardiovascular risk. J Am Heart Assoc. 2022;11(20):e025858. doi:10.1161/jaha.122.025858
  4. Soffer DE, Marston NA, Maki KC, et al. Role of apolipoprotein B in the clinical management of cardiovascular risk in adults: an expert clinical consensus from the National Lipid Association. J Clin Lipidol. 2024;18(5):e647-e663. doi:10.1016/j.jacl.2024.08.013
  5. Mach F, Baigent C, Catapano AL, et al. 2019 ESC/EAS guidelines for the management of dyslipidaemias: lipid modification to reduce cardiovascular risk. Russ J Cardiol. 2020;25(5):3826. doi:10.15829/1560-4071-2020-3826
  6. Johannesen CDL, Langsted A, Nordestgaard BG, et al. Excess apolipoprotein B and cardiovascular risk in women and men. J Am Coll Cardiol. 2024;83(23):2262-2273. doi:10.1016/j.jacc.2024.03.423
  7. Wilson PWF, Jacobson TA, Martin SS, et al. Lipid measurements in the management of cardiovascular diseases: practical recommendations a scientific statement from the National Lipid Association writing group. J Clin Lipidol. 2021;15(5):629-648. doi:10.1016/j.jacl.2021.09.046
  8. Heidemann BE, Koopal C, Baass A, et al. Establishing the relationship between familial dysbetalipoproteinemia and genetic variants in the APOE gene. Clin Genet. 2022;102(4):253-261. doi:10.1111/cge.14185
  9. Grundy SM, Stone NJ, Bailey AL, et al. 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA guideline on the management of blood cholesterol. Circulation. 2019;139(25):e1082-e1143. doi:10.1161/cir.0000000000000625
  10. Arnett DK, Blumenthal RS, Albert MA, et al. 2019 ACC/AHA guideline on the primary prevention of cardiovascular disease. Circulation. 2019;140(11):e596-e646. doi:10.1161/cir.0000000000000678
  11. Handelsman Y, Jellinger PS, Guerin CK, et al. Consensus statement by the American Association of Clinical Endocrinologists and American College of Endocrinology on the management of dyslipidemia and prevention of cardiovascular disease algorithm — 2020 executive summary. Endocr Pract. 2020;26(10):1196-1224. doi:10.4158/cs-2020-0490
     

Content reviewed 05/2025

top of page

This test is used to assess risk for cardiovascular disease, guide decisions on lipid-lowering therapy, and diagnose certain lipid disorders.

Test Guide List

Apolipoprotein B

Test Summary

 

Apolipoprotein B

Test codes: 91726, 5224

 

Clinical use

  • Assess risk for atherosclerotic cardiovascular disease (CVD)
  • Guide decisions on lipid-lowering therapy
  • Diagnose certain lipid disorders such as familial dysbetalipoproteinemia and familial combined hyperlipidemia (FCHL)

Clinical background

Low-density lipoprotein cholesterol (LDL-C) level has been the primary marker for CVD risk and target for lipid-lowering therapy. However, LDL-C level alone may provide an incomplete assessment of risk and treatment adequacy because CVD risk is more closely related to the number of atherogenic particles in plasma than their cholesterol content.1–3 Therefore, relying on LDL-C alone can lead to misclassification of risk and undertreatment.4

Apolipoprotein B (apoB) level predicts CVD risk and treatment efficacy more accurately than LDL-C and non–high-density lipoprotein cholesterol (HDL-C) levels.2,4,5 ApoB is the main structural protein found on all atherogenic particles, including low-, very low- and intermediate-density lipoprotein, chylomicron remnants, and lipoprotein(a). Because each of these particles contains 1 apoB molecule, apoB level represents the total burden of atherogenic particles.3

ApoB level is most clinically meaningful when apoB and LDL-C levels are discordant.1,4 Data from >95,000 people in the Copenhagen General Population Study showed that discordantly higher apoB was dose-dependently associated with CVD risk.6 Discordance is seen in individuals with elevated triglycerides and metabolic disorders, who tend to have an abundance of small, cholesterol-poor low-density lipoprotein particles, resulting in lower LDL-C relative to apoB.2,4 Discordance is also seen in patients receiving lipid-lowering therapy, which reduces LDL-C relatively more than apoB.4

In addition to CVD risk assessment, apoB is used to diagnose certain lipid disorders, including familial dysbetalipoproteinemia and FCHL.7 Familial dysbetalipoproteinemia is characterized by elevated non–HDL-C but normal apoB levels, resulting in high total cholesterol/apoB and non–HDL-C/apoB ratios.8 FCHL, a complex, multigenic disorder that causes premature CVD, is characterized by elevated apoB and triglyceride levels with a family history of premature CVD.5

ApoB measurement is included in clinical guidance from several professional societies (Table 1).

Table 1. Summary of Guideline Recommendations for ApoB Testing

Professional society

Guideline recommendations

American Heart Association and American College of Cardiology9,10
  • Elevated apoB (≥130 mg/dL) is a risk-enhancing factor for CVD that may be useful when triglyceride level is ≥200 mg/dL.
  • Among other risk-enhancing factors, apoB can help guide decisions on interventions for individuals with borderline to intermediate risk (10-year CVD risk ≥5% and <20%).

American Association of Clinical Endocrinologists and American College of Endocrinology11
  • ApoB testing for CVD risk assessment should be considered based on individual patient circumstances.
  • ApoB testing is useful for assessing the success of lipid-lowering therapy.

National Lipid Association4,7
  • ApoB testing is reasonable for patients receiving lipid-lowering therapy and may be reasonable for initial evaluation of CVD risk.
  • ApoB testing can be used to help diagnose familial dysbetalipoproteinemia and FCHL.
European Society of Cardiology and European Atherosclerosis Society5
  • ApoB testing can be used for CVD risk assessment, especially for certain patients.a ApoB can be used as an alternative to LDL-C for screening, diagnosis, and management and may be preferred over non–HDL-C for certain patients.a
ApoB, apolipoprotein B; CVD, cardiovascular disease; FCHL, familial combined hyperlipidemia; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol.
a Patients with high triglyceride levels, diabetes, obesity, or very low LDL-C levels.

Individuals suitable for testing

  • Individuals undergoing CVD risk assessment
  • Individuals being considered for or currently receiving lipid-lowering therapy
  • Individuals with certain suspected lipid disorders (eg, familial dysbetalipoproteinemia or FCHL)

Method

  • Immunoturbidimetry using an apoB antibody
  • Reportable range: 12 mg/dL–240 mg/dL

Interpretive information

ApoB level can be used to help assess risk for a cardiovascular event and as a target for lipid-lowering therapy (Table 2).7,10,11

Table 2. Interpretation of ApoB Test Resultsa

Test result

Interpretation

<70 mg/dL
  • Treatment target for patients with extreme CVD risk (eg, progressive CVD, or established CVD with diabetes)11

<80 mg/dL
  • Treatment target for patients with very high CVD risk (eg, established CVD, or diabetes plus ≥1 additional risk factor)11

<90 mg/dLb
  • Optimal CVD risk7
  • Treatment target for patients with moderate to high CVD risk, including those with diabetes11

90-129 mg/mL
  • Moderate CVD riskc

≥130 mg/dLb
  • Higher CVD risk7,10
  • Favors initiation or intensification of lipid-lowering therapy in patients with intermediate 10-year CVD risk (≥7.5% to <20%)10
  • May favor initiation of lipid-lowering therapy in patients with borderline 10-year CVD risk (5% to <7.5%)10
ApoB, apolipoprotein B; CVD, cardiovascular disease.
a Enhanced reporting includes color coding to display progressive risk values vs goal using "optimal," "moderate," and "high" risk categories. ApoB testing is also offered without enhanced reporting (Quest Diagnostics test code 5224).
b According to the National Health and Nutrition Examination Survey 2005-2016, an apoB level of 90 mg/dL corresponds approximately to the 50th population percentile and 130 mg/dL to the 90th population percentile.4
c Inferred from combined recommendations.7,10

When apoB quantitation is used to diagnose a suspected lipid disorder, test results should be considered in conjunction with other clinical and laboratory assessments.

In very rare cases, gammopathy, particularly monoclonal IgM type (eg, Waldenstrom macroglobulinemia), may cause unreliable test results.

References

  1. Sniderman AD, Thanassoulis G, Glavinovic T, et al. Apolipoprotein B particles and cardiovascular disease. JAMA Cardiol. 2019;4(12):1287-1295. doi:10.1001/jamacardio.2019.3780
  2. Oliveira-Gomes DD, Joshi PH, Peterson ED, et al. Apolipoprotein B: bridging the gap between evidence and clinical practice. Circulation. 2024;150(1):62-79. doi:10.1161/circulationaha.124.068885
  3. Glavinovic T, Thanassoulis G, de Graaf J, et al. Physiological bases for the superiority of apolipoprotein B over low-density lipoprotein cholesterol and non–high-density lipoprotein cholesterol as a marker of cardiovascular risk. J Am Heart Assoc. 2022;11(20):e025858. doi:10.1161/jaha.122.025858
  4. Soffer DE, Marston NA, Maki KC, et al. Role of apolipoprotein B in the clinical management of cardiovascular risk in adults: an expert clinical consensus from the National Lipid Association. J Clin Lipidol. 2024;18(5):e647-e663. doi:10.1016/j.jacl.2024.08.013
  5. Mach F, Baigent C, Catapano AL, et al. 2019 ESC/EAS guidelines for the management of dyslipidaemias: lipid modification to reduce cardiovascular risk. Russ J Cardiol. 2020;25(5):3826. doi:10.15829/1560-4071-2020-3826
  6. Johannesen CDL, Langsted A, Nordestgaard BG, et al. Excess apolipoprotein B and cardiovascular risk in women and men. J Am Coll Cardiol. 2024;83(23):2262-2273. doi:10.1016/j.jacc.2024.03.423
  7. Wilson PWF, Jacobson TA, Martin SS, et al. Lipid measurements in the management of cardiovascular diseases: practical recommendations a scientific statement from the National Lipid Association writing group. J Clin Lipidol. 2021;15(5):629-648. doi:10.1016/j.jacl.2021.09.046
  8. Heidemann BE, Koopal C, Baass A, et al. Establishing the relationship between familial dysbetalipoproteinemia and genetic variants in the APOE gene. Clin Genet. 2022;102(4):253-261. doi:10.1111/cge.14185
  9. Grundy SM, Stone NJ, Bailey AL, et al. 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA guideline on the management of blood cholesterol. Circulation. 2019;139(25):e1082-e1143. doi:10.1161/cir.0000000000000625
  10. Arnett DK, Blumenthal RS, Albert MA, et al. 2019 ACC/AHA guideline on the primary prevention of cardiovascular disease. Circulation. 2019;140(11):e596-e646. doi:10.1161/cir.0000000000000678
  11. Handelsman Y, Jellinger PS, Guerin CK, et al. Consensus statement by the American Association of Clinical Endocrinologists and American College of Endocrinology on the management of dyslipidemia and prevention of cardiovascular disease algorithm — 2020 executive summary. Endocr Pract. 2020;26(10):1196-1224. doi:10.4158/cs-2020-0490
     

Content reviewed 05/2025

top of page

Top of Page

Reference ranges are provided as general guidance only. To interpret test results use the reference range in the laboratory report.

The tests listed by specialty and category are a select group of tests offered. For a complete list of Quest Diagnostics tests, please adjust the filter options chosen, or refer to our Directory of Services.