Recommendation Statement
Date: June 2008
Summary of Recommendations
Screening
Men
- The U.S.
Preventive Services Task Force (USPSTF)
strongly recommends screening men aged 35 and older for lipid disorders.
Grade: A recommendation.
- The USPSTF recommends screening men aged 20 to 35
for lipid disorders if they are at increased risk for coronary heart disease.
Grade: B recommendation.
Screening
Women at Increased Risk
- The USPSTF strongly recommends screening women aged 45 and
older for lipid disorders if they are at increased risk for coronary heart
disease.
Grade: A recommendation.
- The USPSTF recommends screening women aged 20 to 45 for
lipid disorders if they are at increased risk for coronary heart disease.
Grade: B recommendation.
Screening
Young Men and All Women Not at Increased Risk
- The USPSTF makes no recommendation for or against routine
screening for lipid disorders in men aged 20 to 35, or in women aged 20 and
older who are not at increased risk for coronary heart disease.
Grade: C recommendation.
|
Go to the Clinical Considerations section for a discussion of "increased
risk."
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Contents
Rationale
Clinical Considerations
Discussion
Update of Previous USPSTF Recommendation
Recommendations of Others
References
Members of the USPSTF
Rationale
Importance
There
is good evidence that high
levels of total cholesterol and low density lipoprotein-cholesterol (LDL-C) and
low levels of high density lipoprotein-cholesterol (HDL-C) are important risk
factors for coronary heart disease. The risk for coronary heart disease is
highest in those with a combination of risk factors. The 10-year risk for
coronary heart disease is lowest in young men and in women who do not have
other risk factors, even in the presence of abnormal lipids.
Detection
The
USPSTF found good evidence that lipid measurement can identify asymptomatic men
and women who are eligible for preventive therapy.
Benefits
of Detection and Early Treatment
There
is good evidence that lipid-lowering drug therapy substantially decreases the
incidence of coronary heart disease in persons with abnormal lipids. The
absolute benefits of lipid-lowering treatment depend on a person's underlying
risk for coronary heart disease. Men over the age of 35 and women over the age of 45 who are
at increased risk will realize a substantial benefit from treatment; younger
adults with multiple risk factors for coronary disease, including dyslipidemia,
will realize a moderate
benefit from treatment; and younger men and women without risk factors for
coronary heart disease will realize a small benefit from treatment, as seen in
the risk reduction in 10-year CHD event rate.
Harms
of Detection and Early Treatment
There
is good evidence that the harms from screening and treatment are small and
include possible labeling and the adverse effects associated with
lipid-lowering therapy (e.g., rhabdomyolysis).
USPSTF
Assessment
The
USPSTF concludes that the benefits of screening for and treating lipid
disorders in all men aged 35 and older and women aged 45 and older at increased
risk for coronary heart disease substantially outweigh the potential harms.
The
USPSTF concludes that the benefits of screening for and treating lipid
disorders in young adults at increased risk for coronary heart disease
moderately outweigh the potential harms.
The USPSTF
concludes that the net benefits of screening for lipid disorders in young
adults not at increased risk for coronary heart disease are not sufficient to
make a general recommendation.
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Clinical Considerations
- Lipid disorders,
also called dyslipidemias, are abnormalities of lipoprotein metabolism and
include elevations of total cholesterol, LDL-C, or triglycerides (TG), or
deficiencies of HDL-C. These disorders can be acquired or familial (e.g., familial
hypercholesterolemia). This recommendation applies to adults aged 20 and older
who have not previously been diagnosed with dyslipidemia.
- Increased risk,
for the purposes of this recommendation, is defined by the presence of any one
of the risk factors listed below. The greatest risk for CHD is conferred by a
combination of multiple listed factors. While the USPSTF did not use a specific
numerical risk to bound this recommendation, the framework used by the USPSTF
in making these recommendations relies on a 10-year risk of cardiovascular
events:1
- Diabetes.
- Previous
personal history of CHD or non-coronary atherosclerosis (e.g., abdominal aortic
aneurysm, peripheral artery disease, carotid artery stenosis).
- A family
history of cardiovascular disease before age 50 in male relatives or age 60 in
female relatives.
- Tobacco use.
- Hypertension.
- Obesity
(BMI >30).
- The
preferred screening tests for dyslipidemia are total cholesterol and HDL-C on
non-fasting or fasting samples. There is currently insufficient evidence of the
benefit of including TG as a part of the initial tests used to screen routinely for dyslipidemia. Abnormal screening test results should be confirmed by a
repeated sample on a separate occasion, and the average of both results should
be used for risk assessment.
- Measuring
total cholesterol alone is acceptable for screening if available laboratory
services cannot provide reliable measurements of HDL-C; measuring both total cholesterol
and HDL-C is more sensitive and specific for assessing coronary heart disease
risk than measuring total cholesterol alone. In conjunction with HDL-C, the
addition of either LDL-C or total cholesterol would provide comparable
information, but measuring LDL-C requires a fasting sample and is more
expensive. Direct LDL-C testing, which does not require a fasting sample
measurement, is now available; however, calculated LDL (total cholesterol minus
HDL minus TG/5) is the validated measurement used in trials for risk assessment
and treatment decisions. In patients with dyslipidemia identified by screening,
complete lipoprotein analysis is useful.
- The
optimal interval for screening is uncertain. On the basis of other guidelines
and expert opinion, reasonable options include every 5 years, shorter intervals
for people who have lipid levels close to those warranting therapy, and longer
intervals for those not at increased risk who have had repeatedly normal lipid
levels.
- An age
to stop screening has not been established. Screening may be appropriate in
older people who have never been screened; repeated screening is less important
in older people because lipid levels are less likely to increase after age 65. However,
because older adults have an increased baseline risk for coronary heart
disease, they stand to gain greater absolute benefit from the treatment of
dyslipidemia, compared with younger adults.
- Treatment
decisions should take into account a person's overall risk of heart disease
rather than lipid levels alone. Overall risk assessment should include the
presence and severity of the following risk factors: age, gender, diabetes,
elevated blood pressure, family history (in younger adults), and smoking. Risk
calculators that incorporate specific information on multiple risk factors
provide a more accurate estimation of cardiovascular risk than tools that
simply count numbers of risk factors.1
- Drug
therapy is usually more effective than diet alone in improving lipid profiles,
but choice of treatment should consider overall risk, costs of treatment, and
patient preferences. Guidelines for treating lipid disorders are available from
the National Cholesterol Education Program of the National Institutes of Health
(http://www.nhlbi.nih.gov/about/ncep/).
- Although
lifestyle modifications (diet and physical activity) are appropriate initial
therapies for most patients, a minority achieves substantial reductions in
lipid levels from changes in diet alone; drugs are frequently needed to achieve
therapeutic goals, especially for those at increased risk for coronary heart
disease. Lipid-lowering treatments should be accompanied by interventions
addressing all modifiable risk factors for heart disease, including smoking
cessation, treatment of blood pressure, diabetes, and obesity, as well as
promotion of a healthy diet and regular physical activity. Long-term adherence
to therapies should be emphasized.
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Discussion
Burden
of Disease
Cardiovascular disease, including coronary heart disease,
accounts for nearly half of all deaths in the United States. Over the past 50
years, there has been a long-term downward trend in
cardiovascular mortality associated with improved risk factor management and
access to early detection and new treatments. The 2002 age-adjusted death rate
for heart disease was 59% lower than the rate in 1950.2
The
lifetime risk of having a coronary heart disease event, calculated at age 40,
is estimated to be 49% for men and 32% for women in the United States; nearly one third of coronary heart disease events are attributable to total
cholesterol levels above 200 mg/dL. Consistent, good-quality evidence from
long-term prospective studies has shown that high levels of total cholesterol and
LDL-C and low levels of HDL-C are important risk factors for coronary heart
disease. The risk for coronary heart disease events and mortality increases
with increasing levels of total cholesterol and LDL-C and declining levels of
HDL-C, in a continuous and graded fashion, with no clear threshold. Coronary
heart disease mortality is associated with several
risk factors, including dyslipidemia, high blood pressure, tobacco use,
diabetes, a family history of premature coronary heart disease, older age, male
gender, and diet; other risk factors for coronary heart disease include
socioeconomic status, obesity, and physical inactivity. Consideration of
lipid levels along with other risk factors allows for an accurate estimation of
coronary heart disease risk.3
Scope of
Review
The USPSTF
reviewed the literature on the accuracy of screening tests, the efficacy of
treatment, and the harms of screening and treatment for dyslipidemia.
Accuracy
of Screening Tests
Serum lipid screening is an accurate measure of serum
lipids. Good-quality evidence shows that total cholesterol, LDL-C, and HDL-C
are independent predictors of coronary heart disease risk, and ratios of total
cholesterol to HDL-C (total cholesterol/HDL-C) or LDL-C to HDL-C (LDL-C/HDL-C)
classify risk better than total cholesterol alone. Although the triglyceride
level is a strong univariate predictor of coronary events, its association with
coronary heart disease events is reduced substantially by adjustment for other
risk factors. At least two serum lipid measurements are necessary to ensure
that true values are within 10% of the mean of the measurements.4
Effectiveness
of Treatment
The USPSTF examined the evidence for the efficacy of
various treatments for dyslipidemia, including diet, exercise, and
lipid-lowering drug therapy. Lipid screening does not clearly improve the
effectiveness of routine diet interventions.
The only
trials examining diet and its association with coronary heart disease outcomes
have used modified diet in conjunction with interventions for other risk
factors, modified diet in patients with heart disease, or modified diet using
atypical institutional diets. Reduction in dietary saturated fat and weight
loss have been shown to lower total cholesterol and LDL-C as much as 10% to 20%
in some individuals, but the average effect of diet interventions in
outpatients is relatively modest (2% to 6% reduction in total cholesterol). A
meta-analysis of 95 studies found that subjects assigned to exercise had
post-intervention cholesterol levels that were 7 to 13 mg/dL lower than
controls; interventions associated with weight loss have resulted in greater
reductions in lipid levels.5
A
meta-analysis of 4 fair- to good-quality primary prevention trials conducted
mainly among middle-aged men of European descent (Lipid Research Clinical Trial
[LRC], using a bile-acid binding resin; Helsinki Heart Study [HHS], using a
fibric acid derivative; and the West of Scotland Coronary Prevention Study
[WOSCOPS] and the Air Force/Texas Coronary Atherosclerosis Prevention Study
[AFCAPS-TexCAPS], both using HMG Co-A reductase inhibitors) found that
cholesterol-lowering drug treatment for 5 to 7 years decreased the risk of
coronary heart disease events (defined as the sum of nonfatal myocardial
infarctions and deaths from coronary heart disease) by approximately 30% in people
with high total cholesterol or average cholesterol and low HDL-C.6 According to this meta-analysis, drug therapy reduced the relative risk of
coronary heart disease death by 26%, with a 95% CI from 2% to 43%, but had
little overall effect on total mortality for the 5 to 7 years over which these
trials were conducted (OR, 0.91; 95% CI, 0.78, 1.07). Longer-term follow-up
recently available from WOSCOPS demonstrated enduring significant decreases in
both cardiovascular mortality and all cause mortality over the trial period and
the 10 years following.7
Subsequent
to this meta-analysis, 5 fair- to good-quality trials addressed the efficacy of
HMG CoA reductase inhibitors in patients at increased risk for coronary heart
disease (e.g., those who had a history of coronary heart disease, diabetes,
hypertension, and other coronary heart disease risk factors).8-12
Four of these trials showed a 15% to 37% reduction in coronary heart disease
events in those treated for 3.2 to 5.5 years with statins, compared with those
in the placebo group. One trial, ALLHAT (Antihypertensive and Lipid-Lowering
Treatment to Prevent Heart Attack—Lipid-lowering Arm), a fair-quality,
open-label randomized trial comparing a group treated with statins with a group
receiving usual care, found no statistically significant reduction in coronary
heart disease events; however, nearly 30% of the usual-care group had received
statins by the 6th year of the trial, thereby confounding results.7
Primary
prevention trials examining the efficacy of lipid-lowering agents in
asymptomatic women have yielded conflicting results, with some studies showing
no benefit and others showing some coronary heart disease event benefit.13 In the secondary prevention studies, women with diabetes, coronary heart disease,
or coronary heart disease-equivalent conditions had statistically significant
reductions in coronary heart disease mortality, coronary heart disease events,
nonfatal myocardial infarctions, and revascularization; the magnitude of
benefit was similar to those for men. The risk for total mortality was not
lower in women treated with lipid-lowering drugs, regardless of whether or not
they had prior coronary heart disease.
There
is limited evidence about primary prevention of coronary heart disease using
drugs in older populations; however, several secondary prevention trials that
included individuals aged 65 and older showed a reduction in coronary heart
disease events in the group receiving statins compared with the group receiving
placebo.5,14 In the
Heart Protection Study, for example, HMG Co-A reductase inhibitors reduced
major vascular events compared with placebo (28.7% vs. 23.6%) in subjects 70
years and older; and, in subjects aged 75 to 80 at study entry, the reduction
in coronary heart disease was even greater compared with placebo (32.3% vs.
23.1%). In one meta-analysis of the 6 secondary prevention trials reporting
results for subjects 65 and older, statins reduced all-cause mortality by 15%
compared with placebo (RR, 0.85; 95% CI, 0.73-0.99; ARR, 1.8%; n=4941).11
Potential
Harms of Screening and Treatment
Screening
for and identifying lipid disorders in adults do not appear to have important
psychological sequelae or produce important changes in indices of mental
health. The research to date has not been sufficient, however, to rule out
important changes in small subsets of patients or to detect subtle changes in
anxiety.
There
is good quality evidence on the harms of drug therapy. Statins can cause muscle
damage (ranging from mild elevations in creatine phosphokinase [CPK]
levels to muscle weakness related to rhabdomyolysis); the incidence of fatal
rhabdomyolysis associated with statins is estimated at 0.15 per million
prescriptions. Observational studies suggest that older age, hypothyroidism,
surgery or trauma, heavy exercise, excessive alcohol intake, and renal or liver
impairment can increase the risk of myopathy with statins. Combinations of
statins with some fibrates may increase the risk of rhabdomyolysis. Increased
liver transaminases (prevalence 2% to 5%) is a common side effect of statins
and is more prevalent in those with underlying liver disease. In addition,
neuropathy, pancreatitis, and memory loss may be rare complications of statin
use.2
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Update of Previous USPSTF Recommendation
This
recommendation updates the prior recommendation released in 2001. The major
change in the current recommendation is that adult women at any age should be
screened only if other risk factors for cardiovascular disease are present; the
2001 version recommended screening for younger higher risk women (20-45 years)
and all women over 45 years of age.
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Recommendations
of Others
A fasting lipoprotein profile (total cholesterol, LDL-C, HDL-C, and TG)
in all adults over the age of 20 once every 5 years is recommended by the National
Cholesterol Education Program's Adult Treatment Panel III (ATP III), sponsored
by the National Institutes of Health, and endorsed by the American Heart
Association.15 The American Academy of Family Physicians strongly recommends periodic cholesterol measurement
in men aged 35 to 65 and in women aged 45 to 65.16 The American College of Obstetricians and Gynecologists recommends screening
women every 5 years beginning at age 45; screening is recommended for women
aged 19-44 based on risk factors.17
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References
1. Wilson PW, D'Agostino RB, Levy D, Belanger AM, Silbershatz H, Kannel
WB. Prediction of coronary heart disease using risk factor
categories. Circulation 1998;97:1837-1847.
2. National Center for Health Statistics, US, 2004 with Chartbook on Trends in
the Health of Americans. Hyattsville, Maryland, 2004.
3. Helfand M, Carson S. Screening for lipid disorders in adults: Selective update
of 2001 U.S. Preventive Services Task Force review. Prepared for the Agency
for Healthcare Research and Quality; by the Oregon Evidence-based Practice Center at the Oregon Health and Science University, Portland, Oregon, under Contract
Number 290-02-0024. April 2008. Evidence Synthesis No. 49. AHRQ Publication
No. 08-05114-EF-1. Available at
http://www.ahrq.gov/downloads/pub/prevent/pdfser/lipides.pdf.
4. Pignone MP, Philllips CJ, Lannon CM et al. Screening for Lipid Disorders. Rockville, Maryland: Agency for Healthcare Research and Quality; April 2001. AHRQ
Publication No. 01-S004.
5. Tran ZV, Weltman A. Differential effects of exercise on serum lipid and
lipoprotein levels seen with changes in body weight: A meta-analysis JAMA 1985;254:919-924.
6. Pignone M, Philllips C, Mulrow C. Use of lipid lowering drugs for primary
prevention of coronary heart disease: meta-analysis of randomized trials. BMJ
2000;321:983-986.
7. Ford I, Murray H, Packard CJ et al. Long-term follow-up of the West of Scotland
Coronary Prevention Study Group. New Engl J Med 2007;357(15):1477-1486.
8. Heart Protection Study Collaborative Group. MRC/BHF Heart Protection Study of
cholesterol lowering with simvastatin in 20,536 high-risk individuals: a
randomised placebo-controlled trial. Lancet 2002;360:7-22.
9. Sever PA, Dahlof B, Poulter NR et al. Prevention of coronary and stroke events
with atorvastatin in hypertensive patients who have average or
lower-than-average cholesterol concentrations, in the Anglo-Scandinavian
Cardiac Outcomes Trial—Lipid Lowering Arm (ASCOT-LLA,): a multicentre
randomised controlled trial. Lancet 2003;361:1149-1158.
10. ALLHAT Investigators. Major outcomes in moderately hypercholesterolemic,
hypertensive patients randomised to pravastatin versus usual care. JAMA 2002;288:2998-3007.
11. Sheperd J, Blauw GJ, Murphy MB, et al, Pravastatin in elderly individuals at
risk of vascular disease (PROSPER): a randomised controlled trial. Lancet
2002;360:1623-1630.
12. Colhoun HM, Betteridge DJ, Durrington PN, et al. Primary prevention of
cardiovascular disease with atorvastatin in type 2 diabetes in the
Collaborative Atorvastatin Diabetes Study (CARDS): Multicenntre randomised
placebo-controlled trial. Lancet 2004;364:685-696.
13. Grady D, Chaput L, Kristof M. Systematic Review of Lipid Lowering Treatment to
Reduce Risk of Coronary Heart Disease in Women. Rockville, Maryland: Agency for
Healthcare Research and Quality; 2003.
14. Wilt TJ, Bloomfield HE, MacDonald R et al. Effectiveness of statin therapy in
adults with coronary heart disease. Archives of Internal Medicine 2004;164:1427-1436.
15. Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol
in Adults. Executive summary of the third report of the National Cholesterol
Education Program Expert Panel on Detection, Evaluation, and Treatment of High
Blood Cholesterol in Adults (ATP III). JAMA 2001;285:2486-2497.
16. American Academy of Family Physicians.summary of policy recommendations for
periodic health examinations. Revision 5.4, August 2003. Available at:
http://www.aafp.org/PreBuilt/PHErev54.pdf. Accessed April 2, 2008.
17. Primary and preventive care: periodic assessments. ACOG Committee Opinion No.
292. American College of Obstetricians and Gynecologists. Obstet Gynecol
2003;102:1117-24.
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Members of the U.S. Preventive Services Task Force
Corresponding
Author: Ned Calonge, MD, MPH, Chair, U.S. Preventive Services Task Force, c/o
Program Director, USPSTF, Agency for Healthcare Research and Quality, 540 Gaither Road, Rockville, MD 20850, E-mail: uspstf@ahrq.gov.
Members
of the U.S. Preventive Services Task Force* are Ned Calonge, MD, MPH, Chair, USPSTF (Chief Medical
Officer and State Epidemiologist, Colorado Department of Public Health and
Environment, Denver, CO); Diana B. Petitti, MD, MPH , Vice-chair, USPSTF (Department
of Preventive Medicine, Keck School of Medicine, University of Southern
California, Sierra Madre, CA); Thomas G. DeWitt, MD (Carl Weihl Professor of Pediatrics
and Director of the Division of General and Community Pediatrics, Department of
Pediatrics, Children's Hospital Medical Center, Cincinnati, OH); Leon Gordis, MD, MPH, DrPH
(Professor, Epidemiology Department, Johns Hopkins Bloomberg School of Public
Health, Baltimore, MD); Kimberly D. Gregory, MD, MPH (Director, Women's Health
Services Research and Maternal-Fetal Medicine, Department of Obstetrics and
Gynecology, Cedars-Sinai Medical Center, Los Angeles, CA); Russell Harris, MD,
MPH (Professor of Medicine, Sheps Center for Health Services Research,
University of North Carolina School of Medicine, Chapel Hill, NC); Kenneth W. Kizer, MD, MPH
(President and CEO, National Quality Forum, Washington, DC); Michael L.
LeFevre, MD, MSPH (Professor, Department of Family and Community Medicine,
University of Missouri School of Medicine, Columbia, MO); Carol Loveland-Cherry, PhD, RN
(Executive Associate Dean, Office of Academic Affairs, University of Michigan
School of Nursing, Ann Arbor, MI); Lucy N. Marion, PhD, RN (Dean and Professor, School of
Nursing, Medical College of Georgia, Augusta, GA); Virginia A. Moyer, MD, MPH
(Professor, Department of Pediatrics, University of Texas Health Science
Center, Houston, TX); Judith K. Ockene, PhD (Professor of Medicine and Chief of
Division of Preventive and Behavioral Medicine, University of Massachusetts
Medical School, Worcester, MA); George F. Sawaya, MD (Associate Professor, Department of
Obstetrics, Gynecology, and Reproductive Sciences and Department of
Epidemiology and Biostatistics, University of California, San Francisco, CA); Albert L. Siu, MD, MSPH (Professor
and Chairman, Brookdale Department of Geriatrics and Adult Development, Mount
Sinai Medical Center, New York, NY); Steven M. Teutsch, MD, MPH (Executive
Director, Outcomes Research and Management, Merck & Company, Inc., West
Point, PA)**; and Barbara P. Yawn, MD, MSPH, MSc (Department of Research,
Olmsted Medical Center, Rochester, MN).
*Members of the Task Force at the time this recommendation was finalized. For a list of current Task Force members, go to http://www.ahrq.gov/clinic/uspstfab.htm.
**Steven Teutsch, MD, MPH, was recused from voting on this topic.
Disclaimer: Recommendations made by the USPSTF are independent of the U.S. government. They should not be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services.
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Copyright Information
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AHRQ Publication No. 08-05114-EF-2
Current as of June 2008
Internet Citation:
U.S. Preventive Services Task Force. Screening for Lipid Disorders in Adults: U.S. Preventive Services Task Force Recommendation Statement. AHRQ Publication No. 08-05114-EF-2, June 2008 Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/clinic/uspstf08/lipid/lipidrs.htm