Am Fam Physician. 2009;80(11):1281-1282
See related U.S. Preventive Services Task Force Recommendation Statement on page 1273.
Case Study
E.B. is a 50-year-old black woman who comes to your office for weight-loss counseling. She reports that her brother recently had a heart attack at 58 years of age. She does not smoke and takes no medications other than a daily multivitamin. Her body mass index (BMI) is 32 kg per m2. E.B.'s chart shows results from a fasting lipid profile performed three years ago. At that time, E.B.'s total cholesterol level was 195 mg per dL (5.05 mmol per L); her low-density lipoprotein (LDL) cholesterol level was 115 mg per dL (2.98 mmol per L); and her high-density lipoprotein (HDL) cholesterol level was 53 mg per dL (1.37 mmol per L).
Case Study Questions
1. According to the U.S. Preventive Services Task Force (USPSTF), increased risk of coronary heart disease (CHD) is defined by the presence of which of the following risk factors?
A. Black race.
B. Hypertension.
C. Diabetes.
D. BMI greater than or equal to 30 kg per m2.
2. Which one of the following reasons to screen E.B. for lipid disorders is best supported by scientific evidence?
A. Lipid screening should be repeated every three years in adults.
B. Lipid screening should be performed in all women older than 45 years.
C. Lipid screening should be performed before beginning a weight-loss program.
D. Lipid screening should be performed in all women at increased risk of CHD.
E. Lipid screening should be performed in all women with a family history of cardiovascular disease before 60 years of age in male relatives.
3. Which one of the following methods for screening for lipid disorders is preferred by the USPSTF?
A. Measure fasting total cholesterol and LDL cholesterol levels; repeat if abnormal and average the results for CHD risk assessment.
B. Measure fasting or nonfasting total cholesterol and LDL cholesterol levels; repeat if abnormal and use the higher result for CHD risk assessment.
C. Measure fasting or nonfasting total cholesterol and HDL cholesterol levels; repeat if abnormal and average the results for CHD risk assessment.
D. Measure fasting total cholesterol, HDL cholesterol, and triglyceride levels; repeat if abnormal and average the results for CHD risk assessment.
E. Measure fasting total cholesterol, LDL cholesterol, HDL cholesterol, and triglyceride levels; repeat if abnormal and use the higher result for CHD risk assessment.
Answers
1. The correct answers are B, C, and D. Based on recommendations from the USPSTF, increased risk of CHD is defined as the presence of any one of the following risk factors: diabetes; a personal history of CHD or non-coronary atherosclerosis; a family history of cardiovascular disease before 50 years of age in male relatives or before 60 years of age in female relatives; tobacco use; hypertension; and obesity (BMI greater than or equal to 30 kg per m2).
2. The correct answer is D. Decisions to screen for lipid disorders should be based on the patient's age and sex, and the presence of CHD risk factors. Because E.B. has a BMI of greater than 30 kg per m2, she is at increased risk of CHD. Another risk factor for CHD is a family history of cardiovascular disease before 50 years of age in male relatives or 60 years of age in female relatives. Women older than 20 years who are at risk of CHD are likely to benefit from screening. The optimal interval for lipid screening is uncertain. The USPSTF also recommends that all men 35 years and older receive screening for lipid disorders. However, in men 20 to 35 years of age and women 20 years and older who are not at risk of CHD, the benefits and harms of screening are closely balanced. Consequently, the USPSTF makes no recommendation for or against routine lipid screening in these groups.
3. The correct answer is C. According to the USPSTF recommendation, the preferred screening tests for dyslipidemia are total cholesterol and HDL cholesterol levels from fasting or nonfasting samples. There is insufficient evidence of the benefit of including triglycerides. Abnormal screening test results should be confirmed by a repeat sample on a separate occasion, and the average of the two results should be used for risk assessment. Treatment decisions should take into account a person's overall risk of heart disease rather than lipid levels alone.