CHAP TER 7 Methods of Tertiary Prevention 209 been associated with decreased cardiovascular risk. LDL, the for example, TC tends to be normal, but there is an adverse bad cholesterol, is likewise not just cholesterol bi pattern of lipoproteins-high triglycerides and low HDL. ticle that contains it. Elevated LDL levels have been associ- This pattern originally was discerned in the Framingham ated with increased cardiovascular risk. A high level of Heart Study and is sometimes referred to as syndrome X In chegenesis(development of fatty arterial plaques ). Much of as the presence of a non-HDL cholesterol level 200 mg/dL damage may be caused by oxidative modification of the or greater on two successive measurements, Many clini LDL, making it more atherogenic. 2 VLDL, another "bad cians find this index useful because it uses the total contribu cholesterol, " is actually a precursor of LDL. The particle is tion of cholesterol fractions currently considered harmful predominantly triglyceride. Some specialists pay attention to the ratio of the tc level to he previous formulas clarify why total cholesterol alone the HDL level, as discussed later is not the best measure for cardiovascular risk, cholesterol is cholesterol, but the risk for heart disease comes from how is packaged in different VLDL, LDL, and HDL particles HIGH-DENSITY LIPOPROTEIN LEVEL Additional measures of potential interest in risk stratifica- In general, the higher the HDL level is, the better. The tion are related to lipids not routinely included in the lipid minimum recommended HDl level is 50 mg/dL in women panel. These include HDL subfractions, the size and density and 40 mg/dL in men. An HDL level less than 40 mg/dL is of LDl particles, and lipoprotein(a), or Lp(a) lipoprotein. of special concern if the LDL level or the triglyceride level is high(see later). An HDL level greater than 60 mg/dL is L. Assessment considered a negative risk factor, or a protective factor, reducing an individuals risk of cardiovascular disease A variety of index measures have been proposed to assess the need for intervention and to monitor the success of preven- tive measures. The most frequently used guidelines are those LOW-DENSITY LIPOPROTEIN LEVEI of the Third National Cholesterol Education Program In an adult without known atherosclerotic disease or major NCEP),as modified based on more recent research. This risk factors for cardiovascular disease, an LDL level of less discussion and Table 17-1 indicate the levels of blood lipids than 130 mg/dL is considered acceptable, and another lipid suggested by the widely accepted NCEP recommendations profile is recommended within 5 years. If the LDL is border for deciding on treatment and follow-up. New NCEP recom- line elevated(130-159 mg/dL), and the patient has no more mendations are expected in 2012 than one cardiovascular risk factor, the lipid profile should be repeated within I year. If two or more risk factors are resent, however, dietary and lifestyle changes should be TOTAL CHOLESTEROL LEVE recommended. If the LDL level is 160 mg/dL or greater, Some screening programs measure only the total cholesterol dietary and lifestyle changes should be recommended, and (TC)level. In adults without known atherosclerotic disease, lipid-lowering therapy should be considered. A LDL greater a TC level less than 200 mg/dl does not require the need for than 190 mg/dL usually calls for pharmacotherapy action, although the level should be checked every 5 years. A In the presence of demonstrated atherosclerotic disease level between 200 and 239 mg/dL is considered borderline or multiple major risk factors, the criteria have been tight high, and a fasting lipid profile is recommended, with action ened. LDL was the primary focus of the revisions to the determined on the basis of the findings. If TC level is 240 NCEP-Ill recommendations. For high-risk patients,an in addition, lipid-lowering drugs should be considered lts mg/dL or greater, d enosiS based on a fasting lipid prof LDL level of 100 mg/dL or more should lead to the institu- eded, and dietary and lifestyle changes should be initia ion of dietary and lifestyle changes and to treatment with lipid-lowering medications. The NCEP-lIl recommenda The TC level may be misleading and is a poor summary tions state that the Ldl target should be less than 70 mg/dL measure of the complicated lipoprotein-particle distribu- in very-high-risk patients, such as patients with CAD or tions that more accurately define risk In insulin resistance, CAD equivalents, such as peripheral vascular disease, carotid Table 17-l Evaluation of Blood Lipid Levels in Persons without and with Coronary Risk Factors or Coronary Artery Disease(CAD) Lipid Fraction Optimal mg/dL Acceptable mg/dL Borderline mg/dL Abnormal mg/dL For Persons with No CAd and No more than One Risk Factor* Total cholesterol 200 200-239 100-129 130-159 40-59 Triglycerides For Persons with Major CHD Risk Factors or Existing CHD LDL isk factors are cigarette smoking, diabetes, hypertension, and family history of early CAD CHD, Coronary heart disease; HDL, high-density lipoprotein; LDL, low-density lipoprotein; mg/dL, milligrams per deciliter