Not medically reviewed
Lipids
LDL cholesterol (LDL-C)
Not medically reviewed · Content last updated · 1 min read ·
This is the date the draft was written, not a medical review date.
LDL cholesterol is the main atherogenic lipoprotein fraction and the primary target of lipid-lowering therapy. It is measured directly or estimated (Friedewald or Martin-Hopkins equations).
Reference interval
| Conventional (mg/dL) | SI (mmol/L) | |
|---|---|---|
| Adults | < 100 (upper limit) mg/dL | < 2.6 (upper limit) mmol/L |
Specimen: Serum or plasma · Conventional × 0.0259 = SI
Causes of high values
Familial hypercholesterolaemia, polygenic hypercholesterolaemia, hypothyroidism, nephrotic syndrome, cholestasis, high saturated and trans fat intake, and some drugs.
Causes of low values
Hyperthyroidism, malnutrition, malabsorption, chronic liver disease, inherited hypobetalipoproteinaemia, and lipid-lowering treatment.
Pre-analytical and method notes
Conventional categories: optimal below 100 mg/dL (2.6 mmol/L), near-optimal 100-129, borderline 130-159, high 160-189, very high 190 and above; targets are risk-based and much lower for very-high-risk patients (for example below 70 mg/dL, 1.8 mmol/L, or lower in some ESC categories). The Friedewald equation is unreliable when triglycerides exceed about 400 mg/dL (4.5 mmol/L). Fasting is not required for most uses.
References
- 2018 AHA/ACC Guideline on the Management of Blood Cholesterol. American Heart Association / American College of Cardiology (2018) — Tier 2 (guidelines / primary literature)
- 2019 ESC/EAS Guidelines for the management of dyslipidaemias: lipid modification to reduce cardiovascular risk. European Society of Cardiology / European Atherosclerosis Society (2019) — Tier 2 (guidelines / primary literature)
- Rifai N, Horvath AR, Wittwer CT. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Elsevier, 6th edition (2018) — Tier 3 (textbook)
References are listed only where the article cites them. See the sources page for the full policy. How sources are chosen and credited