LDL Particle Size · low result

What does a low LDL Particle Size mean?

Q: Does LDL particle size matter if my ApoB is normal?

Less than people think — particle number (ApoB or LDL-P) carries most of the risk information. Small size mainly tells you insulin resistance is present, which is itself worth acting on.

Short answer

Small LDL particles (below about 20.5 nm — 'pattern B') are more atherogenic than large ones: they enter the artery wall more easily and oxidize faster. Small size is driven almost entirely by high triglycerides and insulin resistance; it is the lipid signature of metabolic syndrome and type 2 diabetes. Lowering triglycerides shifts particles larger within months.

Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026

What is the normal range for LDL Particle Size?

age 18+: 20.6 – 22.0 nm

Smaller LDL particles (<20.5 nm) are more atherogenic and often linked to insulin resistance.

Full reference table, citations and testing options: LDL Particle Size biomarker page.

What are the common causes of low LDL Particle Size?

Insulin resistance, prediabetes, type 2 diabetes, central obesity
High triglycerides, low HDL
Refined-carbohydrate diets, inactivity
Genetic pattern B phenotype
Hypothyroidism

What symptoms go with low LDL Particle Size?

None

What do clinicians usually check next?

Triglycerides, fasting insulin or A1c, ApoB (the particle count matters more than size for risk decisions)
Lifestyle changes aimed at triglycerides; retest in 3–6 months
Cardiovascular risk review with a clinician

How do you recheck LDL Particle Size?

Prices are cash-pay; every order adds one $6 lab processing fee. Physician authorization is included; no insurance or referral needed.

Test or panel	Type	Price	Fasting	Results
Advanced Cholesterol Particle Test (NMR)	Test · 9 biomarkers	$70.99	Yes	3–5 business days

Common questions

Does LDL particle size matter if my ApoB is normal?