Abstract and Introduction
Abstract
Hypertriglyceridemia is a commonly encountered lipid abnormality frequently associated with other lipid and metabolic derangements. The National Cholesterol Education Program recommends obtaining a fasting lipid panel in adults over the age of 20. The discovery of hypertriglyceridemia should prompt an investigation for secondary causes such as high fat diet, excessive alcohol intake, certain medications, and medical conditions (eg, diabetes mellitus, hypothyroidism). In addition, patients should be evaluated for other components of the metabolic syndrome. These include abdominal obesity, insulin resistance, low high-density lipoprotein (HDL), high triglyceride, and hypertension. Hypertriglyceridemia is classified as primary hypertriglyceridemia when there are no secondary causes identified. Primary hypertriglyceridemia is the result of various genetic defects leading to disordered triglyceride metabolism. It is important to treat hypertriglyceridemia to prevent pancreatitis by reducing triglyceride levels to <500 mg/dL. Furthermore, lowering triglycerides while treating other dyslipidemias and components of the metabolic syndrome will reduce coronary events. However, it is controversial how much isolated hypertriglyceridemia correlates directly with coronary artery disease and further studies are needed to clarify whether treatment for this condition leads to meaningful clinical outcomes. Therapeutic lifestyle changes (TLC) are the first line of treatment for hypertriglyceridemia. These changes include a low saturated fat, carbohydrate-controlled diet, combined with alcohol reduction, smoking cessation, and regular aerobic exercise. High doses of omega-3 fatty acids from fish and fish oil supplements will lower triglyceride levels significantly. When patients do not reach their goals by TLC, drug therapy should be started. In cases of isolated hypertriglyceridemia, fibrates are initially considered. When elevated low-density lipoprotein levels accompany hypertriglyceridemia, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors are preferred. In patients with low HDL levels and hypertriglyceridemia, extended release niacin can be considered. A combination of the medicines may be necessary in recalcitrant cases.
Introduction
Hypertriglyceridemia is defined as an abnormal concentration of triglyceride in the blood. According to the National Cholesterol Education Program Adult Treatment Panel (NCEP ATP III) guidelines, a normal triglyceride level is <150 mg/dL ( Table 1 ). In the United States, the prevalence of hypertriglyceridemia defined as a triglyceride level >150 mg/dL is ~30%. Hypertriglyceridemia may be primary or secondary in nature. Primary hypertriglyceridemia is the result of various genetic defects leading to disordered triglyceride metabolism. Secondary causes are acquired causes, such as, high fat diet, obesity, diabetes, hypothyroidism, and certain medications.
Hypertriglyceridemia is a risk factor for pancreatitis and it accounts for 1 to 4% of cases of acute pancreatitis. Although a few patients can develop pancreatitis with triglyceride levels >500 mg/dL, the risk for pancreatitis does not become clinically significant until levels are >1000 mg/dL. More importantly however, hypertriglyceridemia is typically not an isolated abnormality. It is frequently associated with other lipid abnormalities and the metabolic syndrome (abdominal obesity, insulin resistance, low high-density lipoprotein (HDL), high triglyceride, and hypertension), which are linked to coronary artery disease.
Considering the current obesity epidemic, there will be a significant rise in the incidence of the metabolic syndrome. Thus, primary care physicians will encounter hypertriglyceridemia more frequently and should be familiar with the evaluation and management of this common disorder.