Lipoprotein

What are Lipoproteins?

Lipoproteins are lipid–protein complexes that transport lipids (cholesterol and triglycerides) in blood.

They consist of:

• Core: Triglycerides & cholesterol esters

• Surface: Phospholipids, free cholesterol & apolipoproteins

Types of Lipoproteins & Clinical Significance

1️⃣ Chylomicrons

• Transport dietary triglycerides

• Formed in intestine

↑ Seen in:

• Familial chylomicronemia

• Severe hypertriglyceridemia

Risk:

• Acute pancreatitis

2️⃣ VLDL (Very Low-Density Lipoprotein)

• Carries endogenous triglycerides

↑ Seen in:

• Diabetes mellitus

• Obesity

• Metabolic syndrome

Contributes to:

• Atherogenic dyslipidemia

3️⃣ LDL (Low-Density Lipoprotein)

• “Bad cholesterol”

• Transports cholesterol to tissues

↑ LDL is strongly associated with:

• Coronary artery disease (CAD)

• Myocardial infarction

• Stroke

Mechanism:

• LDL deposits cholesterol in arterial walls → Atherosclerosis

4️⃣ HDL (High-Density Lipoprotein)

• “Good cholesterol”

• Removes cholesterol from tissues

• Reverse cholesterol transport

↓ HDL increases risk of:

• Cardiovascular disease

Higher HDL is protective.

5️⃣ Lipoprotein(a) [Lp(a)]

• LDL-like particle with additional apolipoprotein(a)

↑ Lp(a) associated with:

• Premature CAD

• Thrombosis

Genetically determined risk factor.