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American
College of Physicians Issues Guidelines for Obesity Management
CME
By
Amy Norton
April 4, 2005
- The American College of Physicians (ACP) has issued guidelines for
the pharmacologic and surgical management of obesity and has published
these guidelines in the April 5 issue of the Annals of Internal
Medicine.
"Each year an estimated 300,000 U.S. adults die of obesity-related
causes, and the direct cost of obesity and physical inactivity has been
estimated at 9.4% of U.S. health care expenditures," write Vincenza
Snow, MD from the American College of Physicians, Philadelphia,
Pennsylvania, and colleagues. "In response to the increase in obesity,
treatments for obesity have become both more numerous and more commonly
used."
To complement the guidelines of the U.S. Preventative Services Task
Force, an expert panel from the ACP developed these guidelines based on
the evidence report and accompanying background articles from the
Southern California Evidence-Based Practice Center.
"The College recommends that all clinicians refer to the Task Force
recommendations as part of an overall strategy for managing overweight
and obesity, which should always include appropriate diet and exercise
for all patients who are overweight or obese," the authors write. "The
intent of this guideline is to provide recommendations based on a
review of the evidence on pharmacologic and surgical treatments of
obesity."
The guidelines are directed to all clinicians caring for patients with
obesity, defined as a body mass index (BMI) of 30 kg/m2 or more. The
panel warns that these guidelines are not intended for use by
commercial weight loss centers, for direct-to-consumer marketing by
manufacturers, or for patients with BMI lower than 30 kg/m2.
Although the prospect of pharmacologic treatment for obesity has
created considerable interest both in clinicians and patients, five
drugs were removed from the U.S. and international markets as of 1997
because of efficacy and safety concerns. These were fenfluramine,
dexfenfluramine, and phenylpropanolamine internationally, and
diethylpropion and phentermine in Europe. Other drugs released
subsequently are sibutramine and orlistat.
Studies of obesity drugs reviewed by the panel had limitations
including short duration, small sample size, and high dropout rate. Use
of a weight loss drug for six to 12 months typically resulted in weight
loss of about 11 lb or less. However, other research suggests that this
modest amount of weight loss can improve diabetes control, blood
pressure, and cholesterol levels. Except for orlistat, there are no
studies of long-term efficacy beyond 12 months, and questions of
long-term adverse effects and possible benefits in terms of decreasing
morbidity and mortality from obesity complications remain unanswered.
Bariatric surgery has also increased substantially. In California, for
example, the number of weight-loss surgeries performed increased nearly
sixfold, from 1,134 in 1996 to 6,304 in 2000.
Many studies of obesity surgery reviewed by the panel had limitations
such as lack of a comparison group. However, these studies suggested
that patients could lose 44 to 67 lb and maintain that weight for up to
10 years, with associated improvements in diabetes, blood pressure, and
cholesterol level.
The mortality rate from complications of bariatric surgery is 1.9 per
100 patients. There are no head-to-head studies comparing the various
procedures with one another, but outcomes of bariatric surgery are best
at centers performing a large volume of these procedures. Based on five
randomized controlled trials comparing weight loss between or among
surgical procedures, gastric bypass appeared to produce weight loss
superior to that produced by gastroplasty procedures. There was no
difference in net weight loss in the pooled results from all studies
combined.
The ACP recommends that physicians counsel all obese patients about
diet and exercise, and that both physicians and patients determine
goals for weight loss, blood pressure, and blood glucose. When diet and
exercise alone are insufficient for patients to reach these goals,
available obesity drugs should be considered, such as sibutramine,
orlistat, phentermine, diethylpropion, fluoxetine, and bupropion.
To determine which drug is best for an individual patient, the adverse
effect profile of each drug should be carefully considered. Physicians
should counsel their patients concerning potential adverse events and
the lack of long-term studies of the effectiveness and safety of
obesity drugs.
In obese patients with BMIs of at least 40 kg/m2 as well as
obesity-related conditions such as high blood pressure, diabetes, or
sleep apnea, bariatric surgery may be a viable option. Possible adverse
outcomes of obesity surgery may include surgical complications, gall
bladder disease, and impaired digestion.
Because surgeons and surgical centers with high levels of experience
performing these procedures typically have better outcomes in terms of
higher efficacy and lower complication rate, these providers are to be
sought after for patients contemplating surgery. Several studies
highlight the significant learning curve associated with these
procedures.
The ACP operating budget funded the development of this guideline. One
of the authors reports potential financial conflicts of interest
(employment, stock ownership, and grants) from Merck.
Ann Intern Med. 2005;142:525-531 Learning Objectives for This
Educational Activity Upon completion of this activity, participants
will be able to:
* Identify medications that have been proven to promote weight loss in
obese patients.
* Describe advantages and disadvantages of bariatric surgery for obese
patients.
Clinical
Context
Nearly two of every three adults in the U.S. are either overweight or
obese, as defined by a BMI of more than 25 kg/m2 and 30 kg/m2,
respectively. Obesity-related diseases claim up to 300,000 lives in the
U.S. annually. However, weight loss of 5% to 10% of body weight has
been demonstrated to reduce the risk of developing such diseases.
Weight loss is one of the most difficult medical goals for patient and
physician alike. In the current publication, the ACP offers guidelines
for the management of obesity, with a focus on medical and surgical
treatment. Study Highlights
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The guideline is based on a report
from the Southern California Evidence-Based Practice Center and is
meant to accompany a recommendation from the U.S. Preventive Services
Task Force that calls on physicians to screen for obesity and treat it
appropriately.
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Although there is no direct
evidence to suggest that counseling on weight loss can improve
morbidity or mortality related to obesity, the guidelines recommend
that all patients with a BMI of more than 30 kg/m2 receive information
on diet and exercise.
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In patients for whom diet and
exercise fail to produce significant weight loss, medications may be
offered. Currently available agents with data from at least several
studies indicating efficacy in weight loss include sibutramine,
orlistat, phentermine, diethylpropion, fluoxetine, and bupropion. The
efficacy of sertraline, topiramate, and zonisamide in promoting weight
loss is not firmly established.
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The mean weight loss associated
with the above medications is summarized below:
- Sibutramine: 4.45 kg at 12 months
- Orlistat: 2.89 kg at 12 months
- Phentermine: 3.6 kg at 12 months
- Diethylpropion: 3.0 kg at 6 months
- Fluoxetine: 3.15 kg at 12 months
- Bupropion:
2.8 kg at 6 to 12 months
- The adverse effect profile should
be considered when selecting a particular weight-loss medication. Major
adverse effects are listed below:
- Sibutramine: modest increases in
blood pressure and pulse and nervousness
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Orlistat: diarrhea, flatulence, and bloating
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Phentermine: cardiovascular
abnormalities
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Diethylpropion: tachycardia and
insomnia
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Fluoxetine: agitation and
nervousness
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Bupropion: paresthesia and insomnia
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Patients should also receive
counseling that data from randomized, controlled trials of weight-loss
agents have only extended to 12 months. Therefore, the long-term
efficacy and safety of these medications largely are unknown.
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Bariatric surgery can be
considered for patients with a BMI of 40 kg/m2 or more who have failed
a program of diet and exercise (with or without adjunctive medical
treatment). Patients with obesity-related complications such as
diabetes or hypertension may also be considered for surgery.
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Patients should be made aware of
the risks of bariatric surgery prior to choosing this option. Possible
complications include reoperation, gall bladder disease, and
malabsorption.
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Bariatric surgery appears to
promote sustained weight loss at 10 years, but the study reporting this
result may have been limited due to selection bias.
-
Bariatric surgery appears to
reduce the incidence of hypertension, diabetes, and hyperlipidemia at 2
years, but only rates of diabetes are reduced at 8 years. Surgery does
not seem to promote recovery from these conditions.
-
Gastric bypass surgery appears to
produce more significant weight loss when compared with gastroplasty
procedures.
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Rates of early mortality
associated with bariatric surgery are generally less than 1%. However,
early mortality may occur in up to 5% of cases treated by inexperienced
surgeons. Patients should be referred to bariatric surgery centers with
a strong record of experience with these procedures.
Pearls
for Practice
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Weight-loss medications can
promote modest effects on patient weight, but adverse effects can be
significant. Long-term data on these agents are lacking. Currently
available agents that have solid evidence in promoting weight loss
include sibutramine, orlistat, phentermine, diethylpropion, fluoxetine,
and bupropion.
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Bariatric surgery can promote
long-term weight loss and reduce the risk of some obesity-related
disease, but early mortality rates can be as high as 5% in patients who
receive care from inexperienced surgeons.
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