Cholesterol, Total and Fractions

General

Core Lab Study

Synonym/Acronym:
high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC), very-low-density lipoprotein (VLDL); lipid fractionation, lipoprotein phenotyping.

Rationale
To assess and monitor risk for coronary artery disease (CAD).

This Core Lab Study is most commonly used to screen and assess risk for atherosclerotic cardiovascular disease and CAD. Cholesterol is included in the lipid panel.

Patient Preparation
There are no medication restrictions unless by medical direction. Instruct the patient to fast 6 to 12 hr before specimen collection if lipoprotein fractionation or triglyceride measurements are ordered and recommend fasting if cholesterol levels alone are measured for screening. Instruct the patient to avoid excessive exercise for at least 12 hr before lipoprotein fractionation testing and to refrain from alcohol consumption for 24 hr before lipoprotein fractionation testing. Protocols may vary among facilities.

Normal Findings
Method: Spectrophotometry for total cholesterol, HDLC and LDLC; liquid chromatography tandem mass spectrometry for ceramides; nuclear magnetic resonance for HDL/LDL particle number and size; enzymatic for small, dense LDL (sdLDL) particles. Lipoprotein fractionation: Electrophoresis and 4°C test for specimen appearance. There is no quantitative interpretation of this test. The specimen appearance and electrophoretic pattern are visually interpreted.

Total Cholesterol
Age and Risk StratificationConventional UnitsSI Units (Conventional Units × 0.0259)
Children and adolescents (less than 20 yr)
DesirableLess than 170 mg/dLLess than 4.4 mmol/L
Borderline170–199 mg/dL4.4–5.2 mmol/L
HighGreater than 200 mg/dLGreater than 5.2 mmol/L
Adults and older adults
DesirableLess than 200 mg/dLLess than 5.2 mmol/L
Borderline200–239 mg/dL5.2–6.2 mmol/L
HighGreater than 240 mg/dLGreater than 6.2 mmol/L
HDLC (Desirable Guidelines by Age)Conventional UnitsSI Units (Conventional Units × 0.0259)
Birth6–56 mg/dL0.16–1.45 mmol/L
Age 2 yr–17 yrGreater than 45 mg/dLGreater than 1.17 mmol/L
18 yr–adults and older adults
MaleGreater than or equal to 40 mg/dLGreater than or equal to 1 mmol/L
FemaleGreater than or equal to 50 mg/dLGreater than or equal to 1.3 mmol/L
Direct LDLC (Desirable Guidelines by Age)Conventional UnitsSI Units (Conventional Units × 0.0259)
Age 2 yr–17 yrLess than 110 mg/dLLess than 2.8 mmol/L
Adults and older adultsLess than 129 mg/dL; Less than 100 mg/dL (with coronary heart disease (CHD)); Less than 70 mg/dL (with diabetes and 1+ atherosclerotic cardiovascular disease (ASCVD) risk factors); Less than 55 mg/dL (with diabetes and established ASCVD)Less than 3.3 mmol/L; Less than 2.59 mmol/L (with CHD); Less than 1.8 mmol/L (with diabetes and 1+ ASCVD risk factors); Less than 1.4 mmol/L (with diabetes and established ASCVD)
HDL particle numberGreater than 30.5 micromol/L
HDL particle sizeGreater than 8.9 nm
LDL particle numberLess than 1,000 nmol/L
LDL particle sizeGreater than 20.5 nm
sdLDL particlesLess than 50 mg/dL
Hyperlipoproteinemia: Fredrickson TypeSpecimen AppearanceElectrophoretic Pattern
Type IClear with creamy top layerHeavy chylomicron band
Type IIaClearHeavy beta band
Type IIbClear or faintly turbidHeavy beta and pre-beta bands
Type IIISlightly to moderately turbidHeavy beta band
Type IVSlightly to moderately turbidHeavy pre-beta band
Type VSlightly to moderately turbid with creamy top layerIntense chylomicron band and heavy beta and pre-beta bands
Ceramides: Cer16:0, Cer18:0, Cer24:1 are associated with cardiovascular disease and insulin resistance
Cer16:00.19–0.36 mcmol/L
Cer18:00.05–0.14 mcmol/L
Cer24:10.65–1.65 mcmol/L
Blood Pressure
NondiabeticLess than 120/80 mm Hg
Diagnosed diabetesLess than 130/80 mm Hg

Critical Findings and Potential Interventions
N/A

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