Chapter 12 in Health: The Basics - Cardiovascular Disease, Diabetes, and Cancer.

12
Cardiovascular Disease,
Diabetes, and Cancer
REDUCING YOUR RISK
What’s the difference between good and bad cholesterol?
Does cardiovascular disease run in families?
What can I do to reduce my risk for diabetes?
If I’m already a smoker, will quitting now
reduce my risk of lung cancer?
Is a tanning booth safer than the sun?
OBJECTIVES
■ Discuss the incidence, prevalence, and outcomes of cardiovascular
disease in the United States, including its impact on society.
■ Review major types of cardiovascular disease, controllable and
uncontrollable risk factors, methods of prevention, and current
strategies for diagnosis and treatment.
■ Understand prediabetes, diabetes, and metabolic syndrome; their risk
factors; and what you can do to reduce your risks of developing them.
■ Explain what cancer is, and describe the different types of cancer,
including the risks they pose to people at different ages and stages
of life.
■ Discuss cancer’s risk factors, and outline strategies and
ISBN: 0-558-34154-3
recommendations for prevention, screening, and treatment.
Health: The Basics, Eighth Edition, by Rebecca J. Donatelle. Published by Benjamin Cummings. Copyright © 2009 by Pearson Education, Inc.

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In this chapter we consider three major health 100
issues: cardiovascular disease, diabetes, and can-
90
cer. What do they have in common? Although
these may seem to be different diseases, all of
80
Males
them pose serious health threats both in the
70
Females
United States and globally. All of them are re-
60
sponsible for significant rates of disability and death. Further-
50
more, often they develop over time as chronic health condi-
40
tions, and many cases are related to lifestyle factors such
30
as obesity, being sedentary, selected dietary factors, stress,
ercent of population
P
smoking, or excessive alcohol consumption. The most impor-
20
tant point they have in common is this: making healthy
10
lifestyle choices now can significantly reduce your risk of
0
developing any of them in the future. Among people who
20–39
40–59
60–79
80+
Ages
have a genetic predisposition to these diseases, lifestyle
choices can delay their development and contribute to in-
FIGURE 12.1 Prevalence of Cardiovascular Diseases in Adults
creased numbers of healthy years.
Aged 20 and Older by Age and Sex
Source: American Heart Association, Heart Disease and Stroke Statistics—
Cardiovascular Disease:
2007 Update (Dallas: American Heart Association, 2007). Reproduced by
permission. © 2007 American Heart Association.
An Epidemiological
telling us what to do to avoid risks. Nevertheless, growing
rates of obesity, hypertension, and diabetes contribute to the
Overview
high incidence of CVD. Put into perspective, CVD claims
more lives each year than the next four leading causes of
In 2007, nearly 80 million Americans—one out of every
death combined (cancer, chronic lower respiratory diseases,
three adults—had some type of cardiovascular disease
accidents, and diabetes), accounting for nearly 37 percent
(CVD), the broad term used to describe diseases of the
of all deaths in the United States.1 Although we’ve made
heart and blood vessels. Although numbers continue to
advances in diagnosis and in pharmaceutical and surgical
increase, it’s important to note that CVD has been the
treatments, CVD continues to pose a serious threat to
leading killer of U.S. adults in every year since 1900, with
the health of all Americans, no matter their age, socio-
the exception of 1918, when a pandemic flu killed more
economic status, or gender (Figure 12.1). Consider the
people. We spend billions on research searching for preven-
following facts:2
tion strategies, treatments and cures, and we have the most
■
sophisticated media warnings and educational programs
Over 147,000 Americans killed by CVD each year are
under age 65.
■ The probability at birth of eventually dying of CVD is
47 percent; of dying from cancer, 22 percent; from acci-
dents, 3 percent; from diabetes, 2 percent; and from HIV,
0.7 percent.
■ Among women, 1 in 30 deaths is from breast cancer; 1 in
2.6 is from CVD.
■ If all forms of major CVD were eliminated, life expectancy
would rise by almost 7 years; if all forms of cancer were
eliminated, the gain would be 3 years.
The best defense against CVD is to prevent it from devel-
oping in the first place. How can you cut your risk? First,
you need to take careful stock of just what your own risks
are. From there, you need to take steps to reduce the risks
that you can by changing certain behaviors. Controlling
high blood pressure and reducing intake of saturated fats
Cardiovascular disease can affect even the youngest and most fit
people. Daryl Kile, a 33-year-old professional baseball player, died
suddenly from atherosclerosis. It was discovered after his death that
two of the main arteries in his heart were 80 to 90 percent blocked.
cardiovascular disease (CVD) Disease of the heart and
His heart was also enlarged, weighing 20 percent more than normal.
blood vessels.
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CHAPTER 12
Cardiovascular Disease, Diabetes, and Cancer
347
Health: The Basics, Eighth Edition, by Rebecca J. Donatelle. Published by Benjamin Cummings. Copyright © 2009 by Pearson Education, Inc.

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and cholesterol are two examples of things you can do to
The Heart: A Mighty Machine
lower your chances of heart attack. By maintaining your
weight, exercising, decreasing your intake of sodium, not
The heart is a muscular, four-chambered pump, roughly the
smoking, and changing your lifestyle to reduce stress, you
size of your fist. It is a highly efficient, extremely flexible
can lower your blood pressure. You can also monitor the
organ that manages to contract 100,000 times each day and
levels of fat and cholesterol in your blood and adjust your
pumps the equivalent of 2,000 gallons of blood to all areas
diet to prevent arteries from becoming blocked. Having
of the body. In a 70-year lifetime, an average human heart
combinations of risk factors seems to increase overall
beats 2.5 billion times. This number is significantly higher
risk by a factor greater than those of the combined risks.
for hearts that must work to keep people moving who are
Happily, the converse is also true: reducing several risk
out of shape and overweight.
factors can have a dramatic effect. Understanding how
Under normal circumstances, the human body contains
your cardiovascular system works will help you understand
approximately 6 quarts of blood. This blood transports
your risk and how to reduce it.
nutrients, oxygen, waste products, hormones, and enzymes
>
throughout the body. Blood also aids in regulating body
temperature, cellular water levels, and acidity levels of body
try it NOW!
components, and in aiding bodily defense against toxins and
harmful microorganisms. An adequate blood supply is
Find out your risk of developing CVD! Right now, you
essential to health and well-being.
can find out whether you are prone to CVD and take
The heart has four chambers that work together to circu-
steps to modify your risk. The American Heart
late blood constantly throughout the body (Figure 12.2).
Association’s Risk Assessment Tool is an easy online
The two upper chambers of the heart, called atria, are large
tool that can evaluate your risks and provide practical
collecting chambers that receive blood from the rest of the
guidance to help you address and reduce those risks.
body. The two lower chambers, known as ventricles, pump
Visit www.americanheart.org/presenter.jhtml?
the blood out again. Small valves regulate the steady, rhyth-
identifier=3003499, and click on “Learn Your Risk”
mic flow of blood between chambers and prevent inappro-
to begin using the tool now.
priate backwash. The tricuspid valve (located between the
right atrium and the right ventricle), the pulmonary valve
(between the right ventricle and the pulmonary artery), the
Understanding the
mitral valve (between the left atrium and left ventricle),
and the aortic valve (between the left ventricle and the
Cardiovascular System
aorta) permit blood to flow in only one direction.
The cardiovascular system is the network of organs and
Heart Function
vessels through which blood flows as it carries oxygen and
Heart activity depends on a complex interaction of biochemi-
nutrients to all parts of the body. It includes the heart,
cal, physical, and neurological signals. Here are the basic
arteries, arterioles (small arteries), and capillaries (minute
steps involved in heart function:
blood vessels). It also includes venules (small veins) and
veins, the blood vessels through which blood flows as it
1. Deoxygenated blood enters the right atrium after having
returns to the heart and lungs.
been circulated through the body.
2. From the right atrium, blood moves to the right ventricle
and is pumped through the pulmonary artery to the lungs,
where it receives oxygen.
cardiovascular system A complex system consisting of
3. Oxygenated blood from the lungs then returns to the left
the heart and blood vessels. It transports nutrients, oxygen,
atrium of the heart.
hormones, metabolic wastes, and enzymes throughout the
4. Blood from the left atrium moves into the left ventricle.
body and regulates temperature, the water levels of cells,
The left ventricle pumps blood through the aorta to all
and the acidity levels of body components.
body parts.
atria The two upper chambers of the heart, which receive
Various types of blood vessels are required for different
blood.
parts of this process. Arteries carry blood away from the
ventricles The two lower chambers of the heart, which
heart; all arteries carry oxygenated blood, except for
pump blood through the blood vessels.
pulmonary arteries, which carry deoxygenated blood to
arteries Vessels that carry blood away from the heart to
the lungs, where the blood picks up oxygen and gives off
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other regions of the body.
carbon dioxide. As the arteries branch off from the heart,
348 PART FIVE Preventing and Fighting Disease
Health: The Basics, Eighth Edition, by Rebecca J. Donatelle. Published by Benjamin Cummings. Copyright © 2009 by Pearson Education, Inc.

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Deoxygenated blood flows into
Blood picks up oxygen and discards
the right atrium from the superior
carbon dioxide in the lungs; it then
and inferior venae cavae.
goes through the pulmonary veins
into the left atrium.
Pulmonary artery
Superior vena cava
Aorta
Left lung
Right lung
Pulmonary vein
Left atrium
Oxygenated blood is forced from
the left atrium into the left ventricle;
Right atrium
from there it is pumped through
the aorta into the rest of the
Blood moves from the right atrium
body’s blood vessels.
into the right ventricle; from
there it is pumped through the
pulmonary artery into the lungs.
Left ventricle
Right ventricle
Inferior vena cava
FIGURE 12.2 Anatomy of the Heart
they divide into smaller blood vessels called arterioles, and
Types of Cardiovascular
then into even smaller blood vessels known as capillaries.
Capillaries have thin walls that permit the exchange of
Disease
oxygen, carbon dioxide, nutrients, and waste products with
body cells. Carbon dioxide and other waste products are
There are several types of cardiovascular disease (Figure 12.3):
transported to the lungs and kidneys through veins and
venules (small veins).
■ Atherosclerosis (fatty plaque buildup in the arteries)
For the heart to function properly, the four chambers
■ Coronary heart disease (CHD)
must beat in an organized manner. Your heartbeat is
■ Chest pain (angina pectoris)
governed by an electrical impulse that directs the heart
■ Irregular heartbeat (arrhythmia)
muscle to move when the impulse moves across it, which
■ Congestive heart failure (CHF)
results in a sequential contraction of the four chambers.
■ Congenital and rheumatic heart disease
This signal starts in a small bundle of highly specialized
■ Stroke (cerebrovascular accident)
cells, the sinoatrial node (SA node), located in the right
atrium. The SA node serves as a natural pacemaker for
the heart. People with a damaged SA node must often
arterioles Branches of the arteries.
have a mechanical pacemaker implanted to ensure the
capillaries Minute blood vessels that branch out from the
smooth passage of blood through the sequential phases
arterioles; their thin walls permit exchange of oxygen, carbon
of the heartbeat.
dioxide, nutrients, and waste products among body cells.
The average adult heart at rest beats 70 to 80 times per
veins Vessels that carry blood back to the heart from other
minute, although a well-conditioned heart may beat only
regions of the body.
50 to 60 times per minute to achieve the same results. When
overly stressed, a heart may beat more than 200 times per
venules Branches of the veins.
minute. A healthy heart functions more efficiently and is less
sinoatrial node (SA node) Cluster of electricity-generating
likely to suffer damage from overwork.
cells that acts as a natural pacemaker for the heart.
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CHAPTER 12
Cardiovascular Disease, Diabetes, and Cancer
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Health: The Basics, Eighth Edition, by Rebecca J. Donatelle. Published by Benjamin Cummings. Copyright © 2009 by Pearson Education, Inc.

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17%
52%
Stroke
Coronary
0.4%
heart disease
Rheumatic fever/
rheumatic heart
disease
0.5%
Congenital
cardiovascular
defects
4%
Diseases of
the arteries
(a)
7%
Congestive
heart failure
6%
High blood
pressure
13%
Other
FIGURE 12.3 Percentage Breakdown of Deaths from
Cardiovascular Disease in the United States
Source: From Heart Disease and Stroke Statistics—2007 Update. Reproduced
with permission. © 2007, American Heart Association, Inc.
(b)
Methods of preventing and treating these diseases range from
(a) Cross section of a normal coronary artery. (b) A coronary artery
changes in diet and lifestyle to medications and surgery.
narrowed by plaque.
Atherosclerosis
Inflammatory Risks New research has led many
experts to believe that atherosclerosis is an inflammatory
Arteriosclerosis, thickening and hardening of arteries,
disease, and inflamed vessels are more prone to plaque
is a condition that underlies many cardiovascular health
formation.4 What causes this inflammation in arterial walls?
problems and is believed to be the biggest contributor to
Although researchers aren’t sure, there is evidence that a
disease burden globally. Atherosclerosis is actually a type
pathogen may be at the root of it. The most likely culprits
of arteriosclerosis and is characterized by deposits of fatty
are Chlamydia pneumoniae (a sexually transmitted infection),
substances, cholesterol, cellular waste products, calcium,
Helicobacter pylori (which causes stomach ulcers), herpes
and fibrin (a clotting material in the blood) in the inner lining
simplex virus (a virus to which the majority of Americans
of an artery. Hyperlipidemia (an abnormally high blood lipid
have been exposed by age 5), and cytomegalovirus (another
level) is a key factor in this process, and the resulting
herpes virus transmitted through body fluids and infecting
buildup is referred to as plaque.
most Americans before age 40).
Often, atherosclerosis is called coronary artery disease
During an inflammatory reaction, C-reactive proteins
(CAD) because of the resultant damage done to coronary
(CRPs) tend to be present at high levels. Many scientists
arteries. According to current thinking, four factors are
believe the presence of these proteins may signal elevated
responsible for this damage: inflammation, elevated levels
risk for angina and heart attack. In the near future, CRP tests
of cholesterol and triglycerides in the blood, high blood
might be given as routinely as cholesterol screening tests for
pressure, and tobacco smoke.3
heart disease.
Researchers have recently discovered another substance
that may signal increased risk for CVD: homocysteine, an
amino acid normally present in the blood. When present
at high levels, homocysteine may be related to higher risk
arteriosclerosis A general term for thickening and hardening
of coronary heart disease, stroke, and peripheral vascular
of the arteries.
disease.5 It is hypothesized that homocysteine works in
atherosclerosis Condition characterized by deposits of
much the same way as CRP, inflaming the inner lining of
fatty substances, cholesterol, cellular waste products, calcium,
arteries and promoting fat deposits on the damaged walls
and fibrin in the inner lining of an artery.
and development of blood clots.
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plaque Buildup of deposits in the arteries.
Folic acid and other B vitamins (such as B6 and B12) help
break down homocysteine in the body; however, conclusive
350 PART FIVE Preventing and Fighting Disease
Health: The Basics, Eighth Edition, by Rebecca J. Donatelle. Published by Benjamin Cummings. Copyright © 2009 by Pearson Education, Inc.

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evidence that folic acid reduces risk is not available, and
this time. See the Skills for Behavior Change box on
authorities such as the American Heart Association do not
page 352 to learn what to do in case of a heart attack.
currently recommend taking folic acid supplements to
lower homocysteine levels and prevent CVD.6 Other
Angina Pectoris
possible causes of inflammation include elevated low-density
lipoproteins, free radicals caused by cigarette smoking, high
Atherosclerosis and other circulatory impairments often
blood pressure, and diabetes mellitus (see “Diabetes:
reduce the heart’s blood and oxygen supply, a condition
Disabling, Deadly, and on the Rise,” later in this chapter).
known as ischemia. People with ischemia often suffer
In an effort to combat the effects of inflammation, an
from varying degrees of angina pectoris, or chest pain.
explosive amount of research is being published to assess
In fact, an estimated 2.6 million men and 4.2 million
the potential role of anti-inflammatory drugs, such as aspirin,
women suffer mild to crushing forms of chest pain each
ibuprofen, statins, and a new generation of “super-aspirins”
day, many of whom take powerful medications to control
in CVD prevention.7
their symptoms.10 Symptoms may range from slight indi-
gestion, to pain upon slight exertion, to a feeling that the
Metabolic Syndrome A group of obesity-related
heart is being crushed. Generally, the more serious the
health risk factors, metabolic syndrome dramatically
oxygen deprivation, the more severe the pain. Although
increases the risk of heart disease and diabetes. Also known
angina pectoris is not a heart attack, it does indicate
as syndrome X or MetS, metabolic syndrome is believed to
underlying heart disease.
increase the risk for atherosclerotic cardiovascular disease by
Currently, there are several methods of treating angina.
as much as threefold. Affecting over 26 percent of adults or
In mild cases, rest is critical. The most common treatments
50 million people, this disease has gained increasing attention
for more severe cases involve drugs that affect either the
worldwide.8 Two of the main characteristics of metabolic
supply of blood to the heart muscle or the heart’s demand
syndrome are weight gain, particularly in the abdominal area,
for oxygen. Pain and discomfort are often relieved with
and insulin resistance, which means that cells don’t work
nitroglycerin, a drug used to relax (dilate) veins, thereby
properly in handling blood glucose levels. Scientists indicate
reducing the amount of blood returning to the heart and thus
that when three or more of the following are present, the
lessening its workload. Patients whose angina is caused by
diagnosis is metabolic syndrome:
spasms of the coronary arteries are often given drugs called
■
calcium channel blockers, drugs that prevent calcium atoms
Abdominal obesity (waist measurement of more than
from passing through coronary arteries and causing heart
40 inches in men or 35 in women)
■
contractions. They also appear to reduce blood pressure and
Elevated blood fat (triglycerides greater than 150)
■
slow heart rate. Beta blockers, the other major type of drugs
Low levels of “good” high density lipoprotein cholesterol
used to treat angina, control potential overactivity of the
(HDL): less than 40 in men and less than 50 in women
■
heart muscle.
Blood pressure greater than 130/85 mm Hg
■ Elevated fasting glucose greater than 100 mg/dL (a sign
of insulin resistance)
Arrhythmias
Coronary Heart Disease
Over 4 million Americans have experienced some type of
arrhythmia, an irregularity in heart rhythm; about 480,400
of arrhythmia episodes have resulted in death.11 A person
Of all the major cardiovascular diseases, coronary heart dis-
who complains of a racing heart in the absence of exercise
ease (CHD) is the greatest killer, accounting for nearly one in
or anxiety may be experiencing tachycardia, the medical
five deaths in the United States. Of the nearly 1 million peo-
term for abnormally fast heartbeat. On the other end of the
ple who suffer a heart attack each year, over 38 percent will
continuum is bradycardia, or abnormally slow heartbeat.
die from it.9 A myocardial infarction (MI), or heart attack,
involves an area of the heart that suffers permanent damage
because its normal blood supply has been blocked. This con-
dition is often brought on by a blood clot in a coronary artery
metabolic syndrome A group of three or more character-
or an atherosclerotic narrowing that blocks an artery. When
istics, including abdominal obesity and high blood pressure,
blood does not flow readily, there is a corresponding decrease
that can cause metabolic problems that raise CVD risk.
in oxygen flow. If the blockage is extremely minor, an other-
myocardial infarction (MI; heart attack) A blockage of
wise healthy heart will adapt over time by enlarging existing
normal blood supply to an area in the heart.
blood vessels and growing new ones to reroute blood through
other areas.
ischemia Reduced oxygen supply to a body part or organ.
When heart blockage is more severe, however, the body is
angina pectoris Chest pain occurring as a result of
unable to adapt on its own, and outside lifesaving support is
reduced oxygen flow to the heart.
critical. The hour following a heart attack is the most crucial
arrhythmia An irregularity in heartbeat.
period—over 40 percent of heart attack victims die within
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CHAPTER 12
Cardiovascular Disease, Diabetes, and Cancer
351
Health: The Basics, Eighth Edition, by Rebecca J. Donatelle. Published by Benjamin Cummings. Copyright © 2009 by Pearson Education, Inc.

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SKILLS FOR behavior change
WHAT TO DO IN THE EVENT OF A HEART ATTACK
We tend to think of heart attacks ■ Shortness of breath.This can occur BE A HEART SAVER
as being like those shown on TV,
with or without chest discomfort.
If you’re with someone who is showing
in which someone clutches their
■
Other signs. These may include break-
signs of a heart attack and the warning
chest in apparent pain and top-
ing out in a cold sweat, nausea, or
signs last for 2 minutes or longer, act
ples over, gasping for breath. Sometimes,
lightheadedness or dizziness.
immediately. Expect a denial. It’s normal
heart attacks really are this obvious.
For both men and women, the most
for a person with chest discomfort to deny
However, for many people, the symptoms
common heart attack symptom is chest
the possibility of anything as serious as a
start out very slowly, with only mild pain
pain or discomfort. However, women are
heart attack. Don’t take no for an answer,
or discomfort similar to heartburn or
more likely than men to experience some
however. Insist on taking prompt action.
indigestion. Knowing how to spot both
of the other common symptoms, particu-
Call the emergency rescue service, or get
the subtle and more overt symptoms and
larly shortness of breath, nausea/vomiting,
to the nearest hospital emergency room
acting promptly can mean the difference
and back or jaw pain. These symptoms
that offers 24-hour emergency cardiac care.
between life and death for you or your
often appear over several hours rather
Know the signs of cardiac arrest: loss of
loved ones.
than minutes.
responsiveness, no normal breathing, and
no pulse. If you are with someone who
KNOW THE WARNING SIGNS
THE BOTTOM LINE: DON’T DELAY
goes into cardiac arrest, call 911 and
OF A HEART ATTACK
When it comes to treating heart attacks,
immediately begin CPR (cardiopulmonary
■
Chest discomfort. Most heart attacks
time is of the essence: 40 percent of heart
resuscitation).
involve discomfort in the center of
attack victims die within the first hour of
You don’t have to wait until an emer-
the chest that lasts more than a few
experiencing symptoms. Fast action can
gency to take action—sign up for a course
minutes or that goes away and comes
save lives and minimize permanent heart
in CPR, and learn the safe and proper
back. It can feel like uncomfortable
damage, so call 911 right away. Ambu-
techniques of mouth-to-mouth breathing
pressure, squeezing, fullness, or pain,
lance emergency medical staff can begin
and chest compression. The American
and it can sometimes be mistaken for
treatment as soon as they arrive and con-
Heart Association website provides infor-
gaseous stomach or heartburn.
tinue it on the way to the hospital. Patients
mation on the availability of CPR courses
■
Discomfort in other areas of the upper
with chest pain who arrive by ambulance
throughout the nation.
body. Symptoms can include pain or dis-
usually get faster treatment, and they can
Source: From Heart Attack, Stroke and Cardiac
comfort in one or both arms, the back,
benefit from new medications and treat-
Arrest Warning Signs, www.americanheart.org/
neck, jaw, or stomach. Sometimes it can
ments that, if given quickly, can make all
presenter.jhtml?identifier=3053. Reprinted with
radiate; other times it can come and go.
the difference.
permission. www.americanheart.org © 2007,
American Heart Association, Inc.
When a heart goes into fibrillation, it beats in a sporadic,
can trigger an arrhythmia episode. However, severe cases
quivering pattern that results in extreme inefficiency in
may require drug therapy or external electrical stimulus to
moving blood through the cardiovascular system. If
prevent serious complications.
untreated, fibrillation may be fatal.
Not all arrhythmias are life-threatening. In many
Congestive Heart Failure
instances, excessive caffeine or nicotine consumption
When the heart muscle is damaged or overworked and lacks
the strength to keep blood circulating normally through the
body, its chambers are often taxed to the limit. Congestive
fibrillation A sporadic, quivering pattern of heartbeat that
heart failure (CHF) affects over 5 million Americans and
results in extreme inefficiency in moving blood through the
dramatically increases risk of premature death.12 The heart
cardiovascular system.
muscle may be injured by a number of health conditions,
congestive heart failure (CHF) An abnormal cardiovas-
including rheumatic fever, pneumonia, heart attack, or other
cular condition that reflects impaired cardiac pumping and
cardiovascular problems. In some cases, the damage is due
ISBN: 0-558-34154-3
blood flow; pooling blood leads to congestion in body
to radiation or chemotherapy treatments for cancer. These
tissues.
weakened muscles respond poorly, impairing blood flow out of
the heart through the arteries. The return flow of blood through
352 PART FIVE Preventing and Fighting Disease
Health: The Basics, Eighth Edition, by Rebecca J. Donatelle. Published by Benjamin Cummings. Copyright © 2009 by Pearson Education, Inc.

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the veins begins to back up, causing congestion in body tissues.
Other strokes affect parts of the brain that regulate heart
This pooling of blood enlarges the heart, makes it less efficient,
and lung function and kill within minutes. According to the
and decreases the amount of blood that can be circulated. Fluid
American Heart Association’s latest statistics, every year
begins to accumulate in other body areas, such as the vessels in
nearly 6 million Americans suffer strokes, 157,000 of whom
the legs, ankles, or lungs, where it can leak into surrounding
die as a result. Strokes cause countless levels of disability and
tissues and cause swelling or difficulty in breathing.
suffering, and they account for 1 in 15 deaths, surpassed only
Today, CHF is the single most frequent cause of hospital-
by CHD and cancer.16 About one in ten major strokes is pre-
ization in the United States.13 If untreated, it can be fatal.
ceded days, weeks, or months earlier by transient ischemic
However, most cases respond well to treatment that includes
attacks (TIAs), brief interruptions of the blood supply to the
diuretics (“water pills”) to relieve fluid accumulation;
brain that cause only temporary impairment. Symptoms of
drugs, such as digitalis, that increase the pumping action
TIA include dizziness, particularly when first rising in the
of the heart; and drugs called vasodilators, which expand
morning, weakness, temporary paralysis or numbness in the
blood vessels and decrease resistance, allowing blood to
face or other regions, temporary memory loss, blurred vision,
flow more easily and making the heart’s work easier.
nausea, headache, slurred speech, or other unusual physiolog-
ical reactions. TIAs are often indications of an impending
Congenital and Rheumatic
major stroke.
Warning signs of stroke include the following:
Heart Disease
■ Sudden weakness or numbness of the face, arm, or leg on
Approximately 1 out of every 125 children is born with some
one side of the body
form of congenital heart disease (disease present at birth).14
■ Sudden dimness or loss of vision, particularly in only
These forms may be relatively minor, such as slight murmurs
one eye
(low-pitched sounds caused by turbulent blood flow through
■ Loss of speech, or trouble talking or understanding speech
the heart) due to valve irregularities that some children
■ Sudden, severe headaches with no known cause
outgrow. Other congenital problems involve serious com-
■ Unexplained dizziness, unsteadiness, or sudden falls,
plications in heart function that can be corrected only with
especially with any of the previously listed symptoms
surgery. Their underlying causes are unknown but may be
If you experience any of these symptoms, or if you are with
related to hereditary factors; to maternal diseases, such as
someone who does, seek medical help immediately. The ear-
rubella, that occur during fetal development; or to chemical
lier treatment starts, the more effective it will be.
intake (particularly alcohol) by the mother during pregnancy.
One of the greatest medical successes in recent years has
Because of advances in pediatric cardiology, the prognosis
been the decline in the fatality rates from strokes, a rate that
for children with congenital heart defects is better than ever.
has dropped by one-third in the United States since the 1980s
Rheumatic heart disease can cause similar heart prob-
and continues to fall. Improved diagnostic procedures, better
lems in children. It is attributed to rheumatic fever, an inflam-
surgical options, clot-busting drugs injected soon after a stroke
matory disease that may affect many connective tissues of the
has occurred, and acute care centers specializing in stroke
body, especially those of the heart, joints, brain, or skin, and
treatment and rehabilitation have all been factors. Increased
that is caused by an unresolved streptococcal infection of the
awareness of risk factors for stroke, especially high blood
throat (strep throat). In a small number of cases, this infection
pressure, knowledge of warning signals, and an emphasis on
can lead to an immune response in which antibodies attack
prevention also have contributed. It is estimated that more
the heart as well as the bacteria. Many of the 82,000 annual
than half of all strokes could be avoided if more people fol-
operations on heart valves in the United States are related to
lowed the recommended preventive standards.
rheumatic heart disease.15
Stroke
congenital heart disease Heart disease that is present
Like heart muscle, brain cells must have a continuous ade-
at birth.
quate supply of oxygen in order to survive. A stroke (also
rheumatic heart disease A heart disease caused by
called a cerebrovascular accident) occurs when the blood
untreated streptococcal infection of the throat.
supply to the brain is interrupted. Strokes may be caused by a
stroke A condition occurring when the brain is damaged by
clot that obstructs a blood vessel or an aneurysm (a weaken-
disrupted blood supply.
ing in a blood vessel that causes it to bulge and in severe
cases burst, or hemorrhage). When any of these events
aneurysm A weakened blood vessel that may bulge under
occurs, oxygen deprivation kills brain cells, which do not
pressure and, in severe cases, burst.
have the capacity to heal or regenerate. Some strokes are
transient ischemic attack (TIA) Brief interruption of
mild and cause only temporary dizziness or slight weakness
the blood supply to the brain that causes only temporary
or numbness. More serious interruptions in blood flow may
impairment; often an indicator of impending major stroke.
impair speech, memory, or motor control.
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Cardiovascular Disease, Diabetes, and Cancer
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Health: The Basics, Eighth Edition, by Rebecca J. Donatelle. Published by Benjamin Cummings. Copyright © 2009 by Pearson Education, Inc.

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Unfortunately, people who survive a stroke do not always
When people stop smoking, regardless of how long or
make a full recovery. Some 50 to 70 percent of stroke sur-
how much they’ve smoked, their risk of heart disease
vivors regain functional independence, but 15 to 30 percent
declines rapidly.20 By 3 years after they quit, the risk of
are permanently disabled and require assistance. Today
death from heart disease and stroke for people who had
stroke is a leading cause of serious long-term disability and
smoked a pack a day or less is almost the same as for
contributes a significant amount to Medicaid and Medicare
people who have never smoked. Although the exact reasons
expenses for older Americans, particularly women.
are unknown, new findings from the Lung Health Study
indicate that lung function improves more in women than
in men after sustained smoking cessation.21
Reducing Your Risk for
Cut Back on Saturated Fat and Cholesterol
Cardiovascular Disease
Cholesterol is a soft, fatty, waxy substance found in the
bloodstream and in your body cells. Although we hear only
Factors that increase the risk for cardiovascular
the bad things about it, in truth cholesterol plays an important
problems fall into two categories: those we can
role in the production of cell membranes and hormones and in
control and those we cannot. Fortunately, we
other body functions. However, when it gets too high, risks for
can take steps to minimize many risk factors.
CVD escalate. Nearly 36 percent of adults in the United States
aged 18 and above have been told they have high cholesterol,
Risks You Can Control
and vast numbers of others have never been tested yet proba-
bly have higher than normal levels. Less than half of people
Avoid Tobacco In spite of massive campaigns to
who should be on cholesterol-reducing medications are on
educate us about the dangers of smoking, and in spite of
them, and many who are on them are unable to reach their
increasing numbers of states and municipalities that have
LDL and HDL goals.22
enacted policies to go “smoke-free,” cigarette smoking
Just like the TV ads say, you get cholesterol from two
remains the leading cause of preventable death in the
primary sources—from your body (which involves genetic
United States, accounting for approximately one of every
predisposition) and from food. Unfortunately, much of your
five deaths.17 These statistics are particularly surprising
cholesterol level is predetermined: 75 percent of blood
given the fact that smoking rates have declined by 49 percent
cholesterol is produced by your liver and other cells, and
among people aged 18 and older since 1965.18 The risk for
the other 25 percent comes from the foods you eat. It’s the
cardiovascular disease is 70 percent greater for smokers than
25 percent that you can control that may be the tipping point
for nonsmokers. Smokers who have a heart attack are more
in determining your CVD risks.
likely to die suddenly (within one hour) than are nonsmokers.
Why all the fuss about fats and cholesterol? Diets high in
Evidence also indicates that chronic exposure to environmen-
saturated fat are known to raise cholesterol levels, send the
tal tobacco smoke (ETS, or secondhand smoke) increases the
body’s blood-clotting system into high gear, and make the
risk of heart disease by as much as 30 percent, with over
blood more viscous in just a few hours, increasing the risk of
35,000 nonsmokers dying from ETS exposure each year.19
heart attack or stroke. Switching to a low-fat diet lowers the
How does smoking damage the heart? There are two
risk of clotting; even a 10 percent decrease in total cholesterol
plausible explanations. One is that nicotine increases heart
levels may result in an estimated 30 percent reduction in the
rate, heart output, blood pressure, and oxygen use by heart
incidence of heart disease.23
muscles. Because the carbon monoxide in cigarette smoke
A fatty diet also increases the amount of cholesterol in the
displaces oxygen in heart tissue, the heart is forced to work
blood, contributing to atherosclerosis. In past years, cholesterol
harder to obtain sufficient oxygen. The other explanation is
levels between 200 and 240 milligrams per 100 milliliters of
that chemicals in smoke damage and inflame the lining of
blood (mg/dL) were considered normal. Recent research indi-
the coronary arteries, allowing cholesterol and plaque to
cates that levels between 180 and 200 mg/dL are more desir-
accumulate more easily. This additional buildup constricts
able and that a level of 150 mg/dL would be even better in
the vessels, increasing blood pressure and forcing the heart
reducing CVD risk. People with multiple risk factors for CVD
to work harder.
are advised to follow even more stringent guidelines.24
See Table 12.1 for recommended levels.
It isn’t just the total cholesterol level that you should be
concerned about. Cholesterol comes in two main varieties:
low-density lipoproteins (LDLs) Compounds that facilitate
low-density lipoprotein (LDL) and
the transport of cholesterol in the blood to the body’s cells
high-density lipoprotein (HDL).
What’s the
and cause the cholesterol to build up on artery walls.
Low-density lipoprotein, often referred
difference
high-density lipoproteins (HDLs) Compounds that
to as “bad” cholesterol, is believed to
between
ISBN: 0-558-34154-3
facilitate the transport of cholesterol in the blood to the
build up on artery walls. In contrast, high-
good and bad
liver for metabolism and elimination from the body.
cholesterol?
density lipoprotein, or “good” cholesterol,
appears to remove cholesterol from artery
354 PART FIVE Preventing and Fighting Disease
Health: The Basics, Eighth Edition, by Rebecca J. Donatelle. Published by Benjamin Cummings. Copyright © 2009 by Pearson Education, Inc.

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walls, thus serving as a protector. In theory, if LDL levels get
too high or HDL levels too low, cholesterol will accumulate
TABLE 12.1
Classification of LDL, Total, and
inside arteries and lead to cardiovascular problems. Scientists
HDL Cholesterol (mg/dl) and
now believe that there are other factors that may also increase
Recommended Levels for Adults
CVD risk, such as lipoprotein-associated phospholipase A2
(Lp-PLA2), an enzyme that circulates in the blood and
LDL Cholesterol
attaches to LDL. Lp-PLA2 plays an important role in plaque
100
Optimal
accumulation and increased risk for stroke and coronary
100–129
Near optimal/above optimal
events, particularly in men. Studies suggest that the higher
the Lp-PLA
130–159
Borderline high
2 level, the higher the risk of developing CVD.25
Triglycerides, another type of fat in the blood, also
160–189
High
appear to promote atherosclerosis. As people get older,
190
Very high
heavier, or both, their triglycerides and cholesterol levels
HDL Cholesterol
tend to rise. Although some CVD patients have elevated
triglyceride levels, a causal link between high triglyceride
40
Low
levels and CVD has yet to be established. It may be that
60
High
high triglyceride levels do not directly cause atherosclerosis
Total Cholesterol
but, rather, are among the abnormalities that speed its
200
Desirable
development.
200–239
Borderline high
Current guidelines suggest that you should reduce
consumption of saturated fat (which comes mostly from
240
High
animal products) to less than 7 percent of your total daily
Triglycerides
caloric intake and minimize your consumption of trans fat,
150
Normal
which is found in partially hydrogenated products such
150–199
Borderline high
as margarine, fast foods, and packaged foods. By cutting
200–499
High
your intake of saturated fats and trans fats, and consuming
fewer than 200 milligrams per day of cholesterol, you can
500
Very high
significantly reduce your risks. Although it is wise to cut
back on saturated fat, be aware that some fat is necessary
Source: National Heart, Lung, and Blood Institute, Third Report of
the Expert Panel on Detection, Evaluation, and Treatment of High Blood
to overall health. (For a complete discussion of this topic,
Cholesterol in Adults. (NIH Publication no. 05–3290), 2005,
see Chapter 9.)
www.nhlbi.nih.gov/health/public/heart/chol/wyntk.htm.
Monitor Your Cholesterol Levels To get an
accurate assessment of your total cholesterol and LDL
Modify Other Dietary Habits The National
and HDL levels, consider having a lipoprotein analysis
Heart, Lung, and Blood Institute (NHLBI) guidelines
done by a reputable health provider. In general, LDL is
recommend the following dietary changes to reduce
more closely associated with cardiovascular risk than is
CVD risk:
total cholesterol. However, most authorities agree that
■
looking only at LDL ignores the positive effects of HDL.
Consume 5 to 10 milligrams per day of soluble fiber
Perhaps the best method of evaluating risk is to examine
from sources such as psyllium seeds, oat bran, fruits,
the ratio of HDL to total cholesterol, or the percentage of
vegetables, and legumes (see Chapter 9). Even this small
HDL in total cholesterol.
dietary modification may result in a 5 percent drop in
The goal is to manage the ratio of HDL to total cholesterol
LDL levels.
■
by lowering LDL levels, raising HDL, or both. Of the more
Consume about 2 grams per day of plant sterols or sterol
than 100 million Americans who need to worry about their
derivatives from substances such as Benecol or Take
cholesterol levels, almost half, particularly those at the low-
Control margarine. These were the first widely available
to-moderate risk levels, should be able to reach their LDL
sources of sterols, but many other choices are available.
and HDL goals through lifestyle changes alone. People who
This amount of plant sterols has the potential to reduce
are at higher risk or those for whom lifestyle modifications
LDL by another 5 percent.
are not effective may need to take cholesterol-lowering drugs
while they continue modifying their lifestyle. Among the
most commonly prescribed drugs are statins, which are very
triglycerides The most common form of fat in the body;
effective in reducing LDL levels. Folic acid and niacin drugs
excess calories are converted into triglycerides and stored as
are often prescribed for people with low HDL and high
body fat.
triglyceride levels.
ISBN: 0-558-34154-3
CHAPTER 12
Cardiovascular Disease, Diabetes, and Cancer
355
Health: The Basics, Eighth Edition, by Rebecca J. Donatelle. Published by Benjamin Cummings. Copyright © 2009 by Pearson Education, Inc.

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