A 48-year-old woman seeks health care after her older sister (age 52 years) was diagnosed with CAD. The patient reports that her sister was told she has “high cholesterol.” The patient is not taking any medications and is a nonsmoker. Blood pressure is 155/90 mm Hg, but the rest of physical examination is unremarkable. The patient agrees to screening laboratories including a fasting lipid panel. Total cholesterol is 270 mg/dL, HDL cholesterol 34 mg/dL, LDL cholesterol 178 mg/dL, and triglycerides 292 mg/dL. Fasting plasma glucose, serum creatinine, and markers of liver function are unremarkable. The patient agrees to take atorvastatin 10 mg daily. Six weeks later, a repeat fasting lipid panel shows total cholesterol 209 mg/dL, HDL cholesterol 36 mg/dL, LDL cholesterol 124 mg/dL, and triglycerides 248 mg/dL.
1. Who should be screened for lipid disorders?
2. What is the patient's lipid abnormality?
3. How should the patient's dyslipidemia be managed?
4. What can be done to improve hypertriglyceridemia?
All adults 20 years or older should be screened at least every 5 years. Individuals with cardiovascular risk factors (eg, tobacco use, family history, hypertension, diabetes mellitus), established cardiovascular disease, and under treatment for dyslipidemia should be checked more frequently.
History and lipid panel suggest familial combined hyperlipidemia (FCHL).
Since triglycerides are <500 mg/dL, an HMG-CoA reductase inhibitor (“statin”) is the initial treatment of choice.
Diet restricted in saturated fat, regular aerobic exercise, and adding a fibric acid derivative, niacin, or pharmacological doses of omega-3 fatty acids (fish oil supplements) are all interventions that are likely to improve hypertriglyceridemia.
Screening for dyslipidemias should begin in all adults aged 20 years or older. Screening is usually performed with a standard lipid profile (total cholesterol, HDL cholesterol, and triglycerides) obtained after a 12-hour fast. LDL cholesterol is then calculated from the Friedewald equation, although LDL cholesterol cannot be calculated when triglyceride levels exceed 400 mg/dL. Assays to directly measure LDL cholesterol are now available.
If a fasting lipid panel cannot be obtained, total and HDL cholesterol should be measured. A fasting lipid panel is indicated if the total cholesterol exceeds 200 mg/dL or HDL cholesterol is less than 40 mg/dL. If lipid levels are unremarkable and the patient has no major risk factors for cardiovascular disease, subsequent screening can be performed at 5-year intervals. Patients with multiple cardiovascular risk factors (eg, hypertension, tobacco use, family history) should be screened more frequently. Patients hospitalized for an acute coronary syndrome or coronary revascularization should have a lipid panel obtained within 24 hours of admission if lipid levels are unknown.
The patient has a newly diagnosed Fredrickson Type IIb combined hyperlipidemia. The Fredrickson classification of hyperlipidemias and corresponding lipoprotein abnormalities is presented in Table 54-1. ...