What is the significance of an elevated Apolipoprotein B (ApoB) level of 136?

From the Guidelines

An apolipoprotein B (ApoB) level of 136 mg/dL is considered elevated and a risk-enhancing factor for atherosclerotic cardiovascular disease (ASCVD), as it exceeds the threshold of ≥130 mg/dL, as indicated in the 2022 ACC expert consensus decision pathway 1.

Key Considerations

• The ApoB level of 136 mg/dL corresponds to an increased risk of ASCVD, similar to an LDL-C level of ≥160 mg/dL, as noted in the 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA guideline on the management of blood cholesterol 1.
• Lifestyle modifications, including a Mediterranean or DASH diet and regular physical activity, are essential for managing elevated ApoB levels.
• If lifestyle modifications are insufficient, medication therapy may be necessary, typically starting with a moderate-intensity statin, as recommended in the 2022 ACC expert consensus decision pathway 1.

Management Recommendations

• Lifestyle modifications should be initiated immediately, including a diet rich in fruits, vegetables, whole grains, and lean proteins, and regular physical activity of at least 150 minutes of moderate-intensity exercise weekly.
• If ApoB levels do not decrease sufficiently within 3-6 months, medication therapy with a moderate-intensity statin, such as atorvastatin 10-20 mg daily or rosuvastatin 5-10 mg daily, should be considered.
• Regular follow-up testing every 3-6 months is crucial to monitor response to treatment and adjust therapy as needed, with the goal of bringing ApoB levels below 90 mg/dL, or even below 70 mg/dL if established cardiovascular disease or diabetes is present.

From the Research

Apolipoprotein B Level 136

• Apolipoprotein B (apoB) is a protein that is a component of low-density lipoprotein (LDL) cholesterol, and it has been recognized as a more accurate measure of cardiovascular risk than LDL-C or non-high-density lipoprotein cholesterol (HDL-C) 2.
• The 2019 European Society of Cardiology/European Atherosclerosis Society Guidelines concluded that apoB was a better guide to the adequacy of lipid lowering than LDL-C or non-HDL-C, and that it can be measured more accurately than LDL-C or non-HDL-C 2.
• A study found that reducing LDL-C to a pre-determined goal may still leave an excess of atherogenic lipoproteins, as reflected in apoB levels, and that during statin therapy, to reach an apoB target of <90 mg/dl, it was necessary to reduce non-HDL-C to <100 mg/dl or to reduce LDL-C to <70 mg/dl (in high-triglyceride patients) or <80 mg/dl (in lower-triglyceride patients) 3.
• However, there is no direct information available in the provided studies about an apolipoprotein B level of 136, and its implications for cardiovascular risk or treatment goals.

Relationship Between Apolipoprotein B and LDL-C

• The relationship between apoB and LDL-C is complex, and statin therapy can alter this relationship, making it necessary to reassess the targets for LDL-C and non-HDL-C in patients on statin therapy 3.
• A study found that during statin therapy, the tight correlation seen for non-HDL-C with apoB (R(2) = 0.92) implies that non-HDL-C may be an acceptable surrogate for direct apoB measurement 3.
• The use of LDL-C as the primary metric to guide statin/ezetimibe/PCSK9 therapy has been questioned, and it has been suggested that apoB should be the primary metric to guide this therapy 2.

Clinical Implications

• The clinical implications of an apolipoprotein B level of 136 are not clear from the provided studies, and more research is needed to understand the relationship between apoB levels and cardiovascular risk in different patient populations.
• The use of apoB as a guide to the adequacy of lipid lowering therapy may help to identify patients who are at high risk of cardiovascular events and who may benefit from more aggressive lipid lowering therapy 2.