Dyslipoproteinemia, also referred to as dyslipidemia, encompasses a range of disorders of lipoprotein lipid metabolism that include both abnormally high and low lipoprotein concentrations, as well as abnormalities in the composition of these lipoprotein particles. Dyslipoproteinemias are clinically important because of their role in the pathogenesis of cardiovascular disease (CVD), which includes coronary artery disease (CAD), cerebrovascular disease, peripheral vascular disease, and renal disease. Thus the term dyslipoproteinemia is broader than the term hyperlipidemia, which focuses solely on the concentrations of the lipoproteins.
There is considerable evidence that dyslipoproteinemia is a risk factor for CVD in adults aged 60 to 80 years, with an expanding body of literature demonstrating dyslipoproteinemia as a risk factor for people older than 80 years of age. The consensus guidelines for the management of dyslipidemia are continually being reevaluated. Over the past several years, National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP) consensus guidelines have made the target lipoprotein concentrations more stringent for individuals with CVD. These guidelines have in turn led to more stringent recommendations for patients with CVD equivalents such as diabetes mellitus and renal disease, and for individuals with multiple CVD risk factors who are at increased risk for CVD events. Epidemiologic and clinical trial data suggest that the optimal concentration for low-density lipoprotein cholesterol (LDL-C) maybe <100 mg/dL, or even as low as 70 mg/dL for some high-risk patients. Similarly, the optimal concentration for high-density lipoprotein cholesterol (HDL-C) maybe >60 mg/dL. As discussed below, triglyceride, cholesterol, and LDL-C levels tend to rise with increasing age, before falling late in the sixth decade. HDL-C decreases at puberty and then is relatively constant across the age-span until the age of 70 years when it may increase (Figure 110-1). As a result, a majority of older individuals could be classified as having undesirable lipoprotein lipid concentrations and are candidates for lifestyle intervention and potentially for pharmacological therapy if their concentrations exceed treatment cut points. The changes in the treatment guidelines are reflected in secular changes in prescribing patterns of drugs to treat hyperlipidemia, as the number of older adults on cholesterol-lowering medications has quadrupled over the past 15 years. In 2002, more than 30% of Medicare patients between the ages of 65 and 84 years were prescribed a statin for cholesterol reduction.
Time-series analyses of lipid concentrations in U.S. adults aged 20–75+ yr. Data are from the NHANES surveys of 1976–1980, 1988–1994, and 1999–2002 (http://www.cdc.gov/nchs/nhanes.htm). NHANES data are a representative sample of the civilian, noninstitutionalized population. Age groups are indicated on the abscissa, lipid concentrations in mg/dL on the ordinate. Each age group contains mean lipid concentrations obtained at three time points. Over 26 yr of follow-up, LDL cholesterol concentrations have dropped in men and women. There is more variability in the patterns of change for HDL (data not shown) and triglycerides; however overall over the last 26 yr, triglyceride concentrations have generally increased. Data represent values for all races combined. Concentrations are expressed as arithmetic means for LDL ...