Cardiovascular disease (CVD), which encompasses coronary heart disease, cerebrovascular disease, and peripheral arterial disease, is the leading cause of morbidity and mortality in the United States, resulting in 1 of every 2.9 deaths in 2006.1-2 CVD is estimated to result in an average of one death in the United States every 37 seconds, nearly 2400 deaths every day.1 The initial presentation in up to one-third of patients is sudden death.3
Hyperlipidemia is a major risk factor for coronary heart disease (CHD) and is found in approximately 16% of adults in the United States. CHD is a narrowing of the small blood vessels that lead to the heart, usually a result of atherosclerosis.1,4-5 Low-density lipoprotein cholesterol (LDL-C) can provoke several components of the atherosclerotic inflammatory response, including promoting unstable lesions concentrated with lipid-laden macrophages.6 For every 1 mg/dL change in LDL-C, the relative risk for CHD is changed in proportion by about 1%, although this link is weaker in women and in the elderly.3-4,6 Elevated triglycerides (TG) can cause acute pancreatitis and may also predict CHD.5-7 TG appear to have indirect atherosclerotic effects related to procoagulant properties, adverse impact on endothelial function, and correlation with low HDL-C and small, dense LDL-C particle formation.6
In contrast, high-density lipoprotein cholesterol (HDL-C) is a strong inverse predictor for CHD.3,5 HDL-C is involved in reverse cholesterol transport, delivering cholesterol from the cell wall to the liver for disposal. HDL-C can prevent LDL-C oxidation and may also inhibit platelet aggregation and activation.6,8 For every 1 mg/dL increase in HDL-C, the risk of future CVD is reduced by 2% in men and 3% in women; death from myocardial infarction or coronary disease is reduced by 6%.7-8
A fasting lipoprotein profile is recommended once every 5 years in adults aged 20 years or older after a 9- to 12-hour fast.4-5 If testing is nonfasting, only the HDL-C and total cholesterol (TC) will be accurate, and follow-up lipoprotein profile is required if total cholesterol is ≥200 or HDL-C is <40 mg/dL.5 Most patients with diabetes should have a fasting lipid profile performed at least annually, although those with low-risk lipid values (LDL-C <100 mg/dL, HDL-C >50 mg/dL, and TG <150 mg/dL) may be repeated every 2 years.9 Acutely ill patients or those with a recent stroke or myocardial infarction may have significant drops in LDL-C within 24 to 48 hours of the event and suppressed levels for many weeks. Therefore, clinicians should use lipid levels obtained within 24 hours of admission to guide initial choice of therapy, recognizing that medication requirements may increase over time.
The Adult Treatment Panel III (ATP III) of the National Cholesterol Education Program defines a total cholesterol <200 mg/dL as desirable, 200 to 239 as borderline high, and ≥240 as high. LDL-C <100 mg/dL is optimal, 100 to 129 near/above optimal, 130 to 159 borderline high, 160 to 189 high, and ≥190 very high. HDL-C <40 mg/dL is low and ≥60 is high. TG <150 mg/dL is normal, 150 to 199 borderline high, 200 to 499 high, and ≥500 very high.4 The LDL-C can be measured directly or calculated using the Friedewald equation (LDL-C = TC − HDL-C − TG/5). This calculation is less ...