Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (809 page)

   Chronic anemia

   Lecithin cholesterol acyltransferase deficiency

   Apo C-II deficiency

   Hyperlipidemia type I

   Limitations

   LDL-C values may be high because of a diet high in saturated fats and cholesterol, pregnancy, or use of steroids.

   LDL values should be measured only on fasting samples.

   LDL cholesterol may be decreased because of acute stress, recent illness, and estrogens.

   Other factors that may affect LDL-C values: cigarette smoking, hypertension (blood pressure >140/90 mm Hg or taking antihypertensive medication), family history of premature CHD (CHD in male first-degree relative <55 years; CHD in female first-degree relative <65 years), and age (men >45 years; women >55 years). See Table 16.21 for additional information.

   At this time, there are no specific recommendations on the routine measurement of LDL particle size and number.

TABLE 16–21. Adult Treatment Panel III LDL-C Goals and Cutoff Points for Therapy

¹
When LDL-lowering drug therapy is employed, it is advised that intensity of therapy be sufficient to achieve at least a 30–40% reduction in LDL-C levels.
²
Coronary heart disease (CHD) includes history of myocardial infarction, unstable angina, stable angina, coronary artery procedures (angioplasty or bypass surgery), or evidence of clinically significant myocardial ischemia.
³
CHD risk equivalents include clinical manifestations of noncoronary forms of atherosclerotic disease (peripheral arterial disease, abdominal aortic aneurysm, and carotid artery disease [transient ischemic attacks or stroke of carotid origin or >50% obstruction of a carotid artery]), diabetes, and 2+ risk factors with 10-y risk for hard CHD >20%.
⁴
Very high risk favors the optional LDL-C goal of <70 mg/dL, and in patients with high triglycerides, non–HDL-C <100 mg/dL.
⁵
Any person at high risk or moderately high risk who has lifestyle-related risk factors (e.g., obesity, physical inactivity, elevated triglyceride, low HDL-C, or metabolic syndrome) is a candidate for therapeutic lifestyle changes to modify these risk factors regardless of LDL-C level.
⁶
If baseline LDL-C is <100 mg/dL, institution of an LDL-lowering drug is a therapeutic option on the basis of available clinical trial results. If a high-risk person has high triglycerides or low HDL-C, combining a fibrate or nicotinic acid with an LDL-lowering drug can be considered.
⁷
Risk factors include cigarette smoking, hypertension (BP >140/90 mm Hg or on antihypertensive medication), low HDL-C (<40 mg/dL), family history of premature CHD (CHD in male first-degree relative <55 y of age; CHD in female first-degree relative <65 y of age), and age (men ≥45 y; women ≥55 y).
⁸
Electronic 10-y risk calculators are available at
www.nhlbi.nih.gov/guidelines/cholesterol
.
⁹
Optional LDL-C goal <100 mg/dL.
¹⁰
For moderately high-risk persons, when LDL-C level is 100–129 mg/dL, at baseline or on lifestyle therapy, initiation of an LDL-lowering drug to achieve an LDL-C level <100 mg/dL is a therapeutic option on the basis of available clinical trial results.
¹¹
Almost all people with zero or 1 risk factor have a 10-y risk <10%, and 10-y risk assessment in people with zero or 1 risk factor is thus not necessary.