Metabolic
Syndrome
Metabolic
syndrome is a condition that includes the presence
of a cluster of risk factors specific for cardiovascular
disease. Metabolic syndrome significantly raises
the risk of developing diabetes, heart disease,
and/or stroke.
Most
people who have metabolic syndrome have insulin
resistance. The body makes insulin to move glucose
(sugar) into cells for use as energy. Obesity,
commonly found in persons with metabolic syndrome,
makes it more difficult for cells to respond to
insulin. If the body cannot make enough insulin
to override the resistance, the blood sugar level
increases and diabetes can result. Metabolic syndrome
may be a beginning of the development of type
2 diabetes.
The
cluster of conditions and risk factors related
to metabolic syndrome was first named in 1988.
Dr. Gerald Reaven proposed that insulin resistance
was central to the cause of type 2 diabetes, high
blood pressure, and cardiovascular artery disease.
Reaven called this cluster of abnormalities "Syndrome
X." Since that time, Syndrome X has come
to be known by various names, including metabolic
syndrome, dysmetabolic syndrome, and insulin resistance
syndrome. Syndrome X is now widely known as metabolic
syndrome.
The
American Heart Association (AHA) recognizes metabolic
syndrome as a problem of growing concern. For
those over age 60, the percentage is estimated
to be about 43 percent. Because the population
of the United States is aging and because metabolic
syndrome prevalence increases with age, the AHA
has estimated that metabolic syndrome soon will
become the primary risk factor for cardiovascular
disease, ahead of cigarette smoking. Increasing
rates of obesity are also thought to be related
to the increasing rates of metabolic syndrome.
The
cluster of metabolic factors involved as defined
by the National Cholesterol Education Program's
Adult Treatment Panel III (NCEP-ATP III) report,
sponsored by the National Heart, Lung, and Blood
Institute, includes:
- abdominal obesity,
in which the waist circumference measures more
than 35 inches for women and more than 40 inches
for men - an increased waist circumference is
the form of obesity most strongly associated
with metabolic syndrome.
- high blood pressure
of 130/85 mm Hg (millimeters of mercury) or
higher - normal blood pressure is defined as
120 mm Hg or lower for systolic pressure (the
top number), and 80 mm Hg or lower for diastolic
pressure (the bottom number). High blood pressure
is strongly associated with obesity and is often
found in persons with insulin resistance.
- insulin resistance
- a condition in which being overweight or obese
makes it hard for cells to respond to insulin.
The body releases more insulin to help glucose
enter the cells until blood sugar increases.
Insulin resistance can lead to diabetes.
- high triglyceride levels
of more than 150 mg/dl (milligrams per deciliter)
- triglycerides are a type of fat in the blood
- HDL cholesterol (the
"good" cholesterol) of less than 40
mg/dl for men and less than 50 mg/dl for women
- proinflammatory state
- a condition that involves elevated C-reactive
protein, a substance that is thought to be a
marker for inflammation in the body
- prothrombotic state
- a condition that involves elevated blood clotting
factors
Because
of the involvement of several interconnected factors
in metabolic syndrome, the direct cause is not
clearly understood. The rise in obesity, coupled
with a sedentary lifestyle, contribute to risk
factors for metabolic syndrome, such as high cholesterol,
insulin resistance, and high blood pressure. These
risk factors may lead to cardiovascular disease
and type 2 diabetes.
Because
metabolic syndrome and insulin resistance are
closely associated, many healthcare professionals
believe that insulin resistance may be a cause
of metabolic syndrome. However, a direct link
between the two conditions has not been established.
Others believe that hormone changes, caused by
chronic stress, lead to the development of abdominal
obesity, insulin resistance, and elevated blood
lipids (triglycerides and cholesterol).
Other
factors which are thought to contribute to the
development of metabolic syndrome include genetic
variations in a person's ability to break
down lipids (fats) in the blood, older age, and
abnormalities in the distribution of body fat.
A risk
factor is anything that may increase a person's
chance of developing a disease. It may be an activity,
such as smoking, diet, family history, or many
other things. Different diseases have different
risk factors.
Knowing
your risk factors to any disease can help to guide
you into the appropriate actions, including changing
behaviors and being clinically monitored for the
disease.
Risk
factors most closely associated with metabolic
syndrome include:
- age - the incidence
of metabolic syndrome increases with age
- ethnicity - African
Americans and Mexican Americans are more prone
to metabolic syndrome. African-American women
are about 60 percent more likely than African-American
men to have the syndrome.
- body mass index (BMI)
greater than 25 - the BMI is calculated as a
measure of body fat compared to height and weight.
- personal or family
history of diabetes - there is a greater risk
for metabolic syndrome for those who have experienced
diabetes during pregnancy (gestational diabetes)
or who have a family member with type 2 diabetes.
- smoking
- history of heavy drinking
- stress
- post-menopausal status
- high-fat diet
- sedentary lifestyle
While
there are few symptoms experienced in metabolic
syndrome, there may be several signs. A symptom
is evidence of disease or physical disturbance
that a person experiences and can describe. By
contrast, a sign is objective evidence of disease
as observed and interpreted by a physician or
other clinician.
Factors
such as high blood pressure, elevated triglycerides,
and/or overweight or obesity may be signs of metabolic
syndrome. Persons with insulin resistance may
have acanthosis nigricans, which is darkened skin
areas on the back of the neck, in the armpits,
and under the breasts. In general, however, persons
do not directly experience symptoms of metabolic
syndrome.
The
indications of metabolic syndrome may resemble
other conditions. Consult your physician for a
diagnosis.
The
National Cholesterol Education Program's Adult
Treatment Panel III (NCEP-ATP III), the World
Health Organization (WHO), and the American Association
of Clinical Endocrinologists (AACE) have each
developed a set of criteria to be used as an aid
in diagnosing metabolic syndrome.
Included
among the criteria of these organizations are:
- abdominal obesity
- body mass index (BMI)
- elevated triglycerides
- low HDL cholesterol
- high blood pressure
(hypertension) or use of antihypertensive medication
(medication used to lower blood pressure)
- elevated fasting blood
glucose - a blood test used to check how much
glucose is in the blood after fasting for a
certain period of time
- prothrombotic state
- insulin resistance
as identified by type 2 diabetes, impaired fasting
glucose, or impaired glucose tolerance (impaired
glucose tolerance test measures the body's
response to sugar)
- other risk factors
Each
organization has its own guidelines for using
the above criteria to establish a diagnosis of
metabolic syndrome.
Specific
treatment will be determined by your physician
based on:
- your age, overall health,
and medical history
- extent of the disease
- your tolerance for
specific medications, procedures, or therapies
- your signs and symptoms
- expectations for the
course of the disease
- your opinion or preference
Because
metabolic syndrome increases the risk for the
development of more serious, chronic conditions
such as cardiovascular disease and type 2 diabetes,
treatment for metabolic syndrome is important.
Other conditions that may develop as a result
of metabolic syndrome include:
- polycystic ovarian
syndrome
- fatty liver
- cholesterol gallstones
- asthma
- sleep disturbances
- some forms of cancer
Types
of treatment that may be recommended for metabolic
syndrome include:
- lifestyle management
A program of weight loss and exercise provide
the foundation of treatment for metabolic syndrome.
Weight loss increases HDL cholesterol (the "good"
cholesterol) and decreases the harmful type
of LDL cholesterol and triglycerides. Weight
loss can also reduce the risk of type 2 diabetes.
Even a modest weight loss of five to ten percent
of total weight can positively affect blood
pressure and increase sensitivity to insulin,
as well as reduce central obesity. Together,
diet and exercise improve risk factors more
than diet alone.
Other lifestyle management factors include smoking
cessation and limiting alcohol consumption.
- diet
Changes in dietary habits are important in the
treatment of metabolic syndrome. According to
the American Heart Association, treatment of
insulin resistance is necessary to achieve the
greatest benefit for modifying metabolic risk
factors. In general, the best way to treat insulin
resistance is through weight loss and increased
physical activity.
There is a variety of methods used to lose weight
and increase physical activity. Incorporating
multiple methods, such as making diet changes
as well as adding exercise, may be beneficial.
These methods include, but are not limited to,
the following:
- Although diet plans
high in protein and fat and low in carbohydrates
are gaining in popularity, some of these
plans may pose serious health risks in the
long run because of the emphasis on saturated
fat. Successful weight loss that is maintained
over a long period of time depends more
on limiting energy consumed (calories) and
increasing energy expenditure (exercise
and daily activity) than the composition
of the diet.
- Fasting may result
in rapid weight loss, but lean muscle mass
is lost as well as fat. All-liquid diets
must be medically supervised and may be
used for a short period of time in people
who are obese, but these diets are not the
long-term answer to weight loss.
- Fads, fasting,
and popular diets in which health effects
have not been determined by rigorous clinical
trials may not be healthy options for weight
loss. However, there are dietary recommendations
that, if followed, will lead to weight loss.
- To lose weight
and keep it off for a lifetime, begin thinking
about an individualized eating plan instead
of a "diet." A plan tailored to
personal likes and dislikes will have a
better chance of producing sustainable weight
loss. A balanced diet that is restricted
in calories - 1,200 to 1,400 calories for
women and 1,500 to 1,800 calories for men
- may work well. A registered dietician
(RD) can help to make an individualized
diet plan based on a person's particular
situation.
- Include a variety
of foods in the diet.
- All fats are not
bad. It is now known that polyunsaturated
and mono-unsaturated fats provide health
benefits such as helping to keep the heart
healthy. This means that nuts, seeds, and
some types of oils, such as olive, safflower,
and canola, have a place in a healthy eating
plan.
- Choose whole grains
such as brown rice and whole wheat bread
rather than white rice and white bread.
Whole grain foods are rich in nutrients
compared to more processed products. They
are higher in fiber and therefore absorbed
by the body more slowly and do not cause
a rapid spike in insulin, which can trigger
hunger and cravings. The Dietary Guidelines
2005 from the US Department of Agriculture
recommend that at least one half of the
grain intake of persons of all ages and
all calorie levels should be whole grains.
- According to the
Dietary Guidelines 2005, published by the
US Department of Health and Human Services
(HHS) and the US Department of Agriculture
(USDA), a person on a 2,000 calorie per
day diet should eat four and one-half cups
daily of fruits and vegetables. This amount
will vary depending on the calorie needs
of each person. Be sure to choose a variety
of fruits and vegetables, as different fruits
and vegetables contain varying amounts and
types of nutrients.
- When dining out
or ordering take-out food, ask for a take-home
box or avoid super-size selections when
you order. Many restaurant portions are
too large for one person, so consider sharing
an entrée or ordering an appetizer
instead of a main dish from the entrée
menu.
- Read food labels
carefully, paying particular attention to
the number of servings contained in the
product and the serving size. If the label
says a serving is 150 calories but the number
of servings per container is three and the
contents of the entire container are consumed,
the number of calories consumed is triple,
or 450 calories.
- exercise
Exercise benefits people who are overweight
or obese by helping to keep and add lean body
mass, or muscle tissue, while losing fat. It
also helps to increase the rate at which weight
is lost if a person is eating healthy food according
to a meal plan because muscle tissue has a higher
rate of metabolism, thus burning calories faster.
Walking is an excellent choice of exercise for
people who are obese. A walking program should
start slowly by walking 30 minutes a day a few
days a week and increase gradually to the goal
of walking for longer periods most days of the
week.
Exercise lowers blood pressure and can help
prevent type 2 diabetes. Exercise also helps
to improve emotional well-being, reduce appetite,
improve sleeping ability, improve flexibility,
and lower LDL cholesterol.
Consult your physician before starting any exercise
program.
- medication
Persons who have metabolic syndrome and who
are at risk may be candidates for medication
therapy, especially if other measures, such
as dieting and lifestyle changes, have failed
to produce acceptable results with weight loss,
decreased blood pressure, lowered cholesterol
levels, and/or decreased insulin resistance.
Medications may be prescribed to help lower
blood pressure, improve insulin metabolism,
lower LDL cholesterol and raise HDL cholesterol,
and/or increase weight loss.
- weight loss surgery
Weight-loss surgery (bariatric surgery) is the
only option today that effectively treats morbid
obesity in people for whom more conservative
measures such as diet, exercise, and medication
have failed.
Studies have shown that all aspects of metabolic
syndrome including blood pressure, cholesterol,
and increased body weight may be improved by
gastric bypass surgery for morbid obesity at
one year after the procedure.
There are a variety of approaches to bariatric
surgery, but all procedures are either malabsorptive,
restrictive, or a combination of the two. Malabsorptive
procedures change the way the digestive system
works. Restrictive procedures are those that
severely reduce the size of the stomach to hold
less food, but the digestive functions remain
intact.
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