Cholesterol, Total and Fractions


Core Lab Study

alpha1-Lipoprotein cholesterol, high-density lipoprotein cholesterol (HDLC); and beta-lipoprotein cholesterol, low-density lipoprotein cholesterol (LDLC), very-low-density lipoprotein (VLDL); lipid fractionation; lipoprotein phenotyping.

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

A small group of studies in this manual have been identified as Core Lab Studies. The designation is meant to assist the reader in sorting the basic “always need to know” laboratory studies from the hundreds of other valuable studies found in the manual—a way to begin putting it all together.

Normal, abnormal, or various combinations of core lab study results can indicate that all is well, reveal a problem that requires further investigation with additional testing, signal a positive response to treatment, or suggest that the health status is as expected for the associated situation and time frame.

Cholesterol is the study most commonly used to screen and assess risk for atherosclerotic cardiovascular disease. 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. 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 (Acceptable 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
LDLC (Acceptable 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 100 mg/dL2.59 mmol/L
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

Critical Findings and Potential Interventions

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