Major Lipoproteins
| Lipoprotein | Primary Function | Major Apolipoprotein | Principal Lipid |
|---|---|---|---|
| Chylomicron | Transport dietary triglycerides | ApoB-48 | Triglycerides |
| VLDL | Transport hepatic triglycerides | ApoB-100 | Triglycerides |
| IDL | Transitional remnant particle | ApoB-100, ApoE | Triglycerides and cholesterol |
| LDL | Deliver cholesterol to tissues | ApoB-100 | Cholesterol |
| HDL | Reverse cholesterol transport | ApoA-I | Cholesterol |
Major Apolipoproteins
| Apolipoprotein | Primary Function |
|---|---|
| ApoA-I | Initiates reverse cholesterol transport and activates LCAT |
| ApoB-48 | Structural protein of chylomicrons |
| ApoB-100 | Structural protein of all hepatic atherogenic lipoproteins; binds the LDL receptor |
| ApoC-II | Activates lipoprotein lipase |
| ApoC-III | Inhibits triglyceride clearance |
| ApoE | Mediates hepatic uptake of remnant particles |
Principal Lipid-Lowering Medications
| Drug Class | Primary Target | Main Effect |
|---|---|---|
| Statins | HMG-CoA reductase | Increase LDL receptor activity |
| Ezetimibe | NPC1L1 | Reduce intestinal cholesterol absorption |
| PCSK9 inhibitors | PCSK9 | Preserve LDL receptors |
| Inclisiran | PCSK9 mRNA | Reduce hepatic PCSK9 production |
| Bempedoic acid | ATP-citrate lyase | Increase LDL receptor expression |
| ANGPTL3 inhibitors | ANGPTL3 | Enhance triglyceride-rich lipoprotein clearance |
Biomarkers Commonly Used in Preventive Cardiology
| Biomarker | Clinical Significance |
|---|---|
| ApoB | Number of atherogenic particles |
| LDL-C | Cholesterol carried within LDL |
| Non-HDL-C | Cholesterol in all ApoB-containing particles |
| Lipoprotein(a) | Genetically determined cardiovascular risk |
| Triglycerides | Marker of triglyceride-rich lipoproteins and metabolic health |
| hs-CRP | Systemic inflammation |
| Coronary Artery Calcium Score | Burden of calcified coronary atherosclerosis |
Fundamental Principles
- Cholesterol is essential for life.
- Lipoproteins transport cholesterol.
- ApoB reflects atherogenic particle number.
- Lifetime ApoB exposure drives atherosclerotic risk.
- The LDL receptor is the principal mechanism of particle clearance.
- Lifestyle modification remains the cornerstone of prevention.
- Pharmacologic therapy complements, but does not replace, healthy living.
- Earlier intervention provides greater lifetime benefit.