Today, a key concept in medicine and public health is “prevention is better than cure.” As a result, the focus is shifting from waiting to treat disease toward identifying risk factors and detecting disease as early as possible.

One group of diseases that consistently ranks among the top three causes of death worldwide and in Thailand is related to atherosclerotic cardiovascular disease (ASCVD), including:

1. Coronary artery disease
2. Ischemic stroke (paresis–paralysis)
3. Peripheral arterial disease

 

Well-known risk factors include high blood pressure, diabetes, smoking, obesity, physical inactivity (sedentary lifestyle), and one of the most important underlying factors: abnormal blood lipids, especially LDL cholesterol.

 

“LDL: The lower, the better”

There is now strong medical evidence from multiple meta-analyses showing that for every 1 mmol/L reduction in LDL (approximately 40 mg/dL):

• The risk of coronary artery disease is reduced by about 23%
• The overall risk of atherosclerotic cardiovascular disease is reduced by about 21%

 

Moreover, lowering LDL from a young age and maintaining it long term provides greater benefits than starting treatment later in life or after disease has already developed. This concept is known as:

“The earlier, the longer, the better”

However, it is not feasible to prescribe lipid-lowering medication to everyone due to limitations in resources and cost. Current guidelines therefore emphasize risk-based treatment. Groups that clearly benefit from lipid-lowering therapy include:

• Patients with established coronary artery or cerebrovascular disease
• Patients with diabetes
• Individuals with LDL ≥ 190 mg/dL
• Or total cholesterol ≥ 310 mg/dL

What about those who do not meet these criteria but are still “not normal”? In real-world practice, many people have not developed disease and do not have very high LDL levels, yet their values are not optimal. In such cases, physicians may use additional risk assessment tools such as carotid ultrasound, coronary artery calcium (CAC) scoring, and one particularly important marker: Lipoprotein(a).

 

Lipoprotein(a), pronounced “lipo-protein A” or “lipo-protein A-little,” is commonly abbreviated as Lp(a).

Lp(a) is a type of LDL with an additional structural protein called apolipoprotein(a), which gives it more “harmful” properties than typical LDL. Key characteristics of Lp(a) include:

• Lp(a) levels are largely genetically determined
• Levels are elevated from childhood (around age 5) and remain stable throughout life
• Diet control, exercise, and commonly used lipid-lowering drugs such as statins and ezetimibe do not effectively reduce Lp(a)

 

Currently, medications that directly lower Lp(a) are under clinical research, but data on efficacy and safety are still required for at least another 5–10 years.

 

How high Lp(a) increases cardiovascular risk?

• Lp(a) ≥ 30 mg/dL: Associated with an increased risk of ischemic stroke and a slight increase in ASCVD risk; often considered borderline or elevated
• Lp(a) ≥ 50 mg/dL: Clearly recognized by international guidelines (ESC/EAS, ACC/AHA) as a risk-enhancing factor, significantly increasing the risk of coronary artery disease, myocardial infarction, and associated with aortic valve stenosis

 

If Lp(a) cannot be lowered, why test it?

The answer is because LDL can still be lowered.

Although Lp(a) itself cannot be reduced, knowing that Lp(a) is elevated helps physicians assess risk more accurately, initiate lipid-lowering therapy earlier, or set lower LDL targets than usual. In medical practice, Lp(a) is referred to as a:

Risk-enhancing factor—an additional marker confirming that “this patient should receive more aggressive preventive treatment.”

 

How is Lp(a) tested?

Testing for Lp(a) is simple:

• Only a single blood draw is required
• Fasting is not necessary
• It can be performed together with routine lipid testing

Many international guidelines now recommend measuring Lp(a) at least once in a lifetime

Especially in individuals who:

• Have a family history of heart disease
• Develop cardiovascular disease at a young age
• Or have multiple risk factors despite only mildly elevated LDL levels

 

In summary

• Lp(a) is a genetically determined, high-risk lipid particle
• It cannot be reduced by diet, exercise, or standard lipid-lowering medications
• A level ≥ 50 mg/dL is an important warning sign
• Although Lp(a) cannot be lowered, it supports stricter LDL control
• Knowing the risk means gaining an opportunity to prevent disease before it occurs