Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (807 page)

   Cholestasis

   Abetalipoproteinemia

   Familial hyper-α-lipoproteinemia (Tangier disease)

   Deficiency of apo A-I and apo C-III

   Limitations

   HDL is increased due to moderate ethanol consumption, estrogens, and insulin.

   HDL is decreased due to starvation; stress and recent illness; smoking; obesity and lack of exercise; drugs such as steroids, thiazide diuretics, and beta blockers; hypertriglyceridemia (>1,700 mg/dL); and elevated serum immunoglobulin levels.

   Other factors that may also increase cholesterol include cigarette smoking, age, hypertension, family history of premature heart disease, preexisting heart disease, and DM.

   Low levels of HDL-C (with or without associated co-lipid abnormalities) are seen in Asians than in non-Asians. This is a distinct phenotype associated with increased risk for CHD.

Suggested Reading

National Institutes of Health, National Heart Lung and Blood Institute’s National Cholesterol Education Program.
http://www.nhlbi.nih.gov/about/ncep/
. Accessed November 18, 2010.

CHOLESTEROL, LOW-DENSITY LIPOPROTEIN (LDL)

   Definition

   LDL cholesterol, also known as LDL-C, is produced by the metabolism of VLDL cholesterol and consists of mostly cholesterol, protein, and phospholipids that carry cholesterol in the bloodstream from the liver to the peripheral tissues. LDL-C is termed the “bad cholesterol,” and LDL-C levels are associated with atherosclerosis and coronary heart disease.

   
Normal range:
see Table 16.20.

TABLE 16–20. Reference Intervals for LDL Cholesterol