Small dense LDL particles
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High-quality testing run in a CLIA-certified and CAP-accredited lab in Santa Clara, California.
About sdLDL
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About sdLDL
Overview and History
sdLDL is a biochemical subfraction of low-density lipoprotein (LDL) defined by particle size and density rather than by a distinct protein. Analytic methods such as nuclear magnetic resonance, gradient gel electrophoresis, and ultracentrifugation have been used to separate and quantify these smaller, denser LDL particles.
Historically identified during lipid research into atherogenic patterns, sdLDL drew attention because its physical properties—reduced size and increased density—affect how it interacts with arterial tissue and circulating enzymes. Biologically, LDL transports cholesterol and lipids; the small dense form shows different susceptibility to modification and different kinetics in the bloodstream compared with larger, buoyant LDL particles.
Interpreting Highs and Lows
Higher proportions of sdLDL are commonly associated with patterns of lipid metabolism that include elevated triglycerides, insulin resistance, or a higher number of LDL particles; in isolation this association indicates altered lipid quality and particle distribution rather than a specific disease. Lower sdLDL proportions generally reflect a lipid profile with larger, more buoyant LDL particles and often align with lower triglyceride levels or differing metabolic states. Interpretation of high or low sdLDL should be integrated with total LDL, LDL particle number (LDL‑P or ApoB), triglycerides, HDL, inflammatory markers, and clinical context provided by the full panel.
Featured Test
sdLDL is included in the Foundation Zoomer to refine assessment of lipid quality and particle distribution. It helps providers detect metabolic patterns—such as shifts toward smaller LDL particles—that may not appear from routine cholesterol measures alone, supporting more precise, system-level interpretation with the panel’s other metabolic and inflammatory markers.
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We’re the leading provider of specialty wellness lab testing because we develop our testing with rigorous, ongoing research by top clinical experts, doctors, and scientists.
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The gold standard of accuracy in the lab industry
Our tests run on a proprietary 3Dense microchip technology platform that boasts unrivaled specificity and sensitivity. While most other labs carry only CLIA certification, we're CAP-accredited by the College of American Pathologists.
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Mary Beth Augustine
DCN, RDN, FAND- Lead Clinical Educator
Suzanne Barker
MS, RDN, LD, CTTS, CGP- Clinical Educator
Suzette Garcia
MSc- MHNE- Clinical Educator
Brooke Mader Ganev
MS, CNS, LDN, FDN- Clinical Educator
Adair Anderson
MS, RDN, LDN- Clinical Educator
Lillie Luu Nguyen
DCN, CNS, LDN- Clinical Educator
Jason Barker
ND- Clinical Educator
Emaline Brown
ND- Clinical Educator
Dana Filatova
DCN, CNS, LDN- Clinical Educator
Jessy Dhanjal
ND- Clinical Educator
Nour Amri
MS, LDN, CNS, CKNS- Clinical Educator
