Cholesterol (CHOL)

CPT Code: 82465
Specimen:  

Serum or plasma

Volume: 1 mL
Minimum Volume: 0.5 mL
Container: Red-top tube, gel-barrier tube, green-top (heparin) tube, or lavender-top (EDTA) tube
Methodology: Spectrophotometry (SP)
Collection:

Separate serum or plasma from cells within 45 minutes of collection.  Complete clot formation should take place before centrifugation.

Reference Range:

100-199 mg/dL

Stability: 

Temperatures Period
Room Temperature 8 Hours
Refrigerated (2-8 ⁰C) 2 Days
Frozen (≤ -20 ⁰C) Longer Storage

Repeated freezing and thawing should be avoided.

 

Use: Cholesterol, a soft, fat-like substance, is necessary for proper body cell function. “Lipoproteins” serve as packages in transporting cholesterol in the blood.  Cholesterol levels are used to evaluate lipid status and metabolic disorders.
Clinical Significance: High Cholesterol that reflects high levels of HPLs may be caused by an inherited defect in lipoprotein metabolism, by disease of the endocrine system, by liver disease, or by renal disease. Increased serum cholesterol in hypothyroid persons shows an increased LDL and decreased HDL Pregnancy is accompanied by a moderate increase. Cholesterol is also increased in early hepatitis, obstructed bile ducts, primary biliary cirrhosis, nephrotic syndrome, and diabetic meningitis.

Increased in primary hypercholesterolemia, secondary hyperlipoproteinemias including nephrotic syndrome, hypothyroidism, primary biliary cirrhosis, and some cases of diabetes mellitusLevy points out that the weak inverse relationship with cancer, mostly colon carcinoma, is limited to cholesterol levels.

Low Cholesterol levels in the plasma may reflect an inherited deficiency of either LDL or HDL, or they may reflect impairment of liver function.  Low cholesterols are found in cases of hyperthyroidism, severe liver disease, pernicious anemia, and with increased estrogens.  Low levels have been found in cases of malnutrition, malabsorption, hyperthyroidism, myeloma, macroglobulinemia of Waldenström, polycythemia vera, myeloid metaplasia, myelofibrosis, chronic myelocytic leukemia, analphalipoproteinemia (Tangier disease), abetalipoproteinemia (Bassen-Kornzweig syndrome) (acanthocytosis), and in some individuals who subsequently present with carcinoma.

Causes for Rejection: Improper labeling
 

Interfering

Substances:

Potassium oxalate/Sodium Fluoride can decrease cholesterol results an average of 12%. Li Heparin can depress cholesterol results by an average of 4 mg/dL at a level of 200 mg/dL. Bilirubin (conjugated) of 8.1 mg/dL and bilirubin (unconjugated) of 9.4 mg/dL decrease the CHOL result by 15 mg/dL at CHOL concentration of 150 mg/dL.

Bilirubin (conjugated) of 12.8 mg/dL and bilirubin (unconjugated) of 14.7 mg/dL decreases the CHOL result by 25 mg/dL at CHOL concentration of 250 mg/dL.

Bilirubin (unconjugated) of 20 mg/dL decreases a CHOL result of 178 mg/dL by 15%.

Hemoglobin (hemolysate) of 1000 mg/dL (monomer) decreases a CHOL result of 177 mg/dL by 15%.

Lipemia (Intralipid) at 1000 mg/dL.  Magnitude of the interference could not be determined.