What does high apolipoprotein A (ApoA) indicate?

From the Guidelines

High apolipoprotein A levels are generally considered beneficial for cardiovascular health and do not require treatment to lower them. Apolipoprotein A is a protein component of high-density lipoprotein (HDL), often called "good cholesterol" 1. When Apo A levels are elevated, it typically indicates higher HDL levels, which help remove excess cholesterol from the bloodstream and transport it to the liver for processing and elimination. This process, known as reverse cholesterol transport, helps prevent cholesterol buildup in the arteries that can lead to atherosclerosis and cardiovascular disease. Some key points to consider about Apolipoprotein A include:

• Apo A1 is the major protein of HDL and provides a good estimate of HDL concentration 1
• Plasma apo A1 of <120 mg/dL for men and <140 mg/dL for women approximately correspond to what is considered as low for HDL-C 1 Instead of focusing on lowering high Apo A levels, maintaining a heart-healthy lifestyle with regular exercise, a balanced diet rich in fruits, vegetables, whole grains, and healthy fats, avoiding smoking, and limiting alcohol consumption will help maintain optimal apolipoprotein profiles. If you're concerned about your Apo A levels, discuss them with your healthcare provider in the context of your overall lipid profile and cardiovascular risk factors.

From the Research

Apolipoprotein A-I Levels and Cardiovascular Risk

• High levels of apolipoprotein A-I (ApoA1) are associated with a higher risk of cardiovascular and all-cause mortality, as shown in a study of 402,783 participants 2.
• The relationship between ApoA1 levels and mortality is U-shaped, with both very low and very high levels being associated with higher risk 2.
• A study of 8,888 participants found that high HDL-C levels, particularly when associated with large HDL particles, may confer risk at very high values, but this does not hold true for very high levels of ApoA1 3.

Comparison of Apolipoprotein A-I and HDL Cholesterol

• ApoA1 and HDL cholesterol are both antiatherogenic, but methodological and physiological factors suggest that ApoA1 may be a better marker of risk 4.
• The apoB/ApoA1 ratio, which reflects the cholesterol balance between atherogenic and antiatherogenic lipoproteins, is a better risk marker than LDL cholesterol, HDL cholesterol, and lipid ratios in predicting cardiovascular risk and response to lipid-lowering therapy 4.
• A study of 2,566 statin-treated patients found that increasing levels of the HDL-C:ApoA1 ratio were associated with less progression of coronary atherosclerosis, suggesting that interventions increasing the cholesterol content of HDL particles may be of cardiovascular benefit 5.

HDL Cholesterol and Apolipoprotein A-I

• HDL cholesterol and ApoA1 are not always equivalent in terms of cardiovascular risk, and differences between the two should be considered when evaluating risk and developing therapies 6.
• Low HDL-C levels are an important independent risk factor for cardiovascular disease, and developing suitable therapies to reduce this residual risk through HDL-C related mechanisms is necessary 6.