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on blood pressure drugs
Behind the scenes at your doctor’s office debate continues about
which drug should be the first line of treatment for high blood pressure.
Diuretics (also known as water pills) have been around for decades, but
the makers of newer, more specialized — and more costly — drugs
have been wooing physicians and their patients. The question isn’t
whether these drugs work effectively to lower blood pressure; they do.
But evidence indicating which is best at reducing heart disease and other
cardiovascular events has been missing — until now.
The ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent
Heart Attack Trial) study was designed to compare a diuretic to three
other commonly prescribed classes of antihypertensive drugs — calcium
channel blockers (CCBs), alpha-adrenergic blockers, and angiotensin-converting
enzyme (ACE) inhibitors. The study involved 42,000 patients over the
age of 55 with hypertension and one other risk factor for heart disease,
such as previous heart attack or stroke. Each of the patients was randomly
assigned to receive one of the study drugs for four to eight years. Researchers
monitored the patients’ blood pressures and recorded evidence of
heart disease and cardiovascular events.
Part of the study was halted early when evidence showed patients taking
the alpha-adrenergic blocker had higher rates of cardiovascular disease
and heart failure than patients taking the diuretic.
The primary results of the comparison of the ACE inhibitor lisinopril
and the CCB amlodipine to the diuretic chlorthalidone were striking.
The occurrence of death from heart disease was the same across each of
the groups, and the rate of nonfatal heart attack was also similar. However,
a slightly higher percentage of patients taking the diuretic chlorthalidone
achieved better blood pressure control. Chlorthalidone was also better
at preventing heart failure than amlodipine, the CCB. Patients taking
the ACE inhibitor lisinopril had a higher risk of stroke, angina, and
heart failure. In particular, black participants who took lisinopril
had a 40% higher risk of stroke than black participants who took the
The findings of the ALLHAT study indicate that when it comes to drugs
for high blood pressure, newer and more costly does not mean better.
In fact, diuretics should be the first line of treatment for many people
with high blood pressure. Not only are they better at controlling high
blood pressure while preventing major cardiovascular events, diuretics
also cost less than the other drugs. A one-year supply of Chlorthalidone
costs about $96, while the CCB amlodipine would set you back $480. Lisinopril
costs $384 a year for the brand name drug (either Zestril or Prinovil),
and $240 for the generic.
What should you do with these study results? If you’re just starting
drug treatment for high blood pressure, you might want to try a diuretic
first. If you, like most people, need a combination of drugs to keep
your blood pressure in check, one should probably be a diuretic. If you’re
already taking a different kind of medicine and it is working well for
you, there’s no need to switch. However, if you want to cut down
your drug bills, you might want to talk to your doctor about a diuretic.
(Journal of the American Medical Association, December 18,
February 2003 Update
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Every winter, about 1,200 Americans die from a heart attack or some
other cardiac event during or after a big snowstorm, and shoveling is
often the precipitating event.
Why is shoveling so hazardous?
- Shoveling uses your shoulders and arms, and upper body exercise tends
to put strain on the heart because those muscles aren’t well
- Working in an upright position adds to the arduousness because blood
pools in the legs and feet, so to maintain blood pressure, your heart
must work harder.
- Much of snow shoveling is isometric exercise: your muscles are working,
but there's little actual movement until you finally heave a shovelful
up on the bank. During isometric exercise of any type, your heart rate
goes up, and your blood vessels constrict, presumably to send more
blood to the straining muscles. As a result, your blood pressure goes
- Without knowing it, shovelers sometimes perform a version of the Valsalva maneuver,
bearing down as they would during a bowel movement while holding their
breath. Waiting to exhale while straining like that can lead to abrupt
changes in your heartbeat and blood pressure.
- First thing in the morning, the time when many people dig out from
a storm, stress hormone levels tend to be higher, platelets in the
blood “stickier,” and heart attacks more likely.
- Shoveling involves exposure to the cold, another cardiac stressor.
- People who are out of shape often shovel, making the sudden intense
exercise even harder on the heart.
- Most people don’t warm up before they shovel or cool down afterward.
If you have a heart condition, you shouldn’t shovel under any
circumstances. People older than 50 should also try to avoid it. Contact
your local council on aging to see if they provide a list of teens in
your neighborhood who you can hire to do the job for you. Or buy a snow
blower. If you must shovel, take it easy. Rest often. Dress warmly and
stay well hydrated. Wherever possible, push the snow rather than lift
it. Clear only the snow that blocks your path into the house, the rest
will melt on its own. And of course, listen to your body. Head home if
you experience potential signs of heart trouble, including chest pain,
palpitations, undue shortness of breath, fatigue, lightheadedness, or
nausea. Also stop if your fingers or toes get numb or hurt — you
could have frostbite.
January 2003 Update
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High blood pressure may be the most common chronic condition plaguing
adults. Physicians need to know the best method for screening patients
to identify and treat those patients with hypertension.
According to previous studies, ambulatory monitoring of blood pressure
is the most accurate method. The patient wears a portable device programmed
to automatically measure and record blood pressure at frequent intervals.
But the device is expensive.
So what is the best alternative? A study published in the August 3,
2002, issue of the British Medical Journal attempts to answer
this question. In addition to ambulatory monitoring, blood pressure may
be measured by a nurse or doctor, or by the patient. Measurements by
a doctor are known to be elevated in some patients because of “white
coat hypertension.” In these cases, the anxiety of having one’s
blood pressure measured by a doctor causes elevated levels.
One of the purposes of the BMJ study was to determine whether
white coat hypertension is seen only in research settings or whether
it also turns up in primary care practices. In addition, the study aimed
to compare the results of different methods for screening blood pressure.
The study involved 200 participants being considered for high blood pressure
treatment or who had poorly controlled high blood pressure. Participants
had their blood pressure measured multiple times on separate occasions
by a doctor, by a nurse, through ambulatory monitoring, and by themselves
at home. In general, blood pressure measurements by a doctor were much
higher and less accurate compared with the other methods.
The same researchers authored another study in the same issue of the British
Medical Journal. They used a questionnaire to determine which
method of blood pressure monitoring is most preferred or acceptable
to patients. The findings showed patients preferred taking their own
blood pressure at home to all the other options. Ambulatory monitoring
was less acceptable because it causes discomfort and disturbances to
daily life and sleep.
The results of these two studies suggest the most accurate blood pressure
readings result from self-screening. If it is not possible, measurement
by the patient or a nurse in the clinic will also provide acceptable
readings. By screening patients with these methods, patients with white
coat hypertension will not be diagnosed with and treated for high blood
November 2002 Update
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Aspirin and heart disease
Should you take aspirin to prevent a heart attack? According to a new
study, aspirin helps lower cardiovascular risk, but whether or not you
should take it depends on a bevy of factors.
The study, published in the May 9, 2002, issue of the New England
Journal of Medicine, analyzes the major trials on the subject.
Four out of five of the randomized trials show a reduction in cardiovascular
events (especially heart attacks) with aspirin use. (In randomized
trials, researchers randomly assign patients to one of the treatments
being tested.) But the studies' statistics vary wildly. For example,
risk reduction ranged from 4%44%, depending on the study. All
but one trial showed that aspirin use increased the risk of bleeding,
most commonly in the stomach.
Two large observational studies also showed that aspirin use decreased
coronary events in both people with and without heart disease. (In observational
studies, researchers simply monitor subjects' behaviors and health, they
do not test a specific treatment on them.) Subjects' ages had an impact
in both studies, with aspirin's benefit on the heart kicking in when
subjects hit 50 years old in one, 60 years old in the other. Other trials
have found that aspirin has the greatest effect on patients with high
risk for heart disease.
So what should you do? That depends a lot on your heart disease risk.
To calculate your risk go to this downloadable
scoring system on the National Institutes of Health Web site.
Then, if you answer yes to any of these questions, talk to your doctor
about starting aspirin therapy:
- Is your risk for heart disease 1.5% or higher per year?
- Is your risk between 0.7% and 1.4% per year? If so, and you answer
yes to one or more of the following questions, ask your doctor about
- Are you in poor physical shape?
- Do you have diabetes or high blood pressure and damage to your
- Do you strongly want to start aspirin therapy?
But if your risk is 0.6% or lower per year, you're probably not a good
candidate for aspirin therapy. You should also avoid the therapy if you're
allergic to aspirin, prone to bleeding, or suffer from platelet disorders
or ulcers. Your own preference is another important factor in making
Keep in mind that if you have high blood pressure, you'll need to take
extra care to control it in order to get the most benefits from aspirin.
Also, besides stomach bleeding, aspirin use may cause hemorrhagic stroke.
July 2002 Update
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New guidelines for stroke prevention
With more than 700,000 Americans having strokes each year, doctors and
patients need to focus on stroke prevention. In light of this, the American
Heart Association (AHA) has issued a statement that details how to identify
and modify risk factors. Here are the AHA's tips, along with other general
guidelines for lowering stroke risk:
Blood pressure. You should get your blood pressure checked
at least every two years because many people with high blood pressure
don't even know they have it (130139 mm Hg systolic pressure over
8589 diastolic pressure is considered high-normal, while anything
above 140 over 90 is considered high). If you have high blood pressure,
the following lifestyle changes can help lower it:
- Eat more fruits and vegetables. Potassium-rich foods like bananas
and oranges may be especially good.
- Pass on salt. Salt makes the body hold onto water, and the heart
has to work harder to pump the extra fluid.
- Lose weight. The heavier you are, the harder your heart has to work
to pump blood to all parts of your body.
- Exercise. Even if you don't need to lose weight, exercise can reduce
high blood pressure and may even prevent it.
- Limit your alcohol. Having more than two alcoholic drinks a day significantly
increases your risk of high blood pressure.
- Quit smoking. Smoking increases your risk of heart attack, as well
as many other diseases. And if you live with a smoker, make sure he
or she quenches his cravings outside. Exposure to secondhand smoke
can double your risk of stroke.
- Learn to relax. Various kinds of behavioral therapy, like biofeedback,
yoga, and tai chi may lower blood pressure.
These lifestyle changes can also help with other causes of stroke, like
atherosclerosis (hardening of the arteries) and high cholesterol. If
the changes don't lower your blood pressure, your doctor may prescribe
a medication such as a diuretic or beta blocker.
Other conditions. The AHA recommends that patients with
diabetes and children with sickle cell disease closely monitor their
blood pressure with screenings every six months.
Non-modifiable risk factors. Black, Hispanic, Chinese,
and Japanese people are at increased risk for stroke compared to whites.
Men and postmenopausal women are also at higher risks than others. If
one of your parents had a stroke, you are at greater risk as well, either
because of genetics or shared lifestyle traits.
While you can't do anything about non-modifiable risk factors it's helpful
to know if you fall into a high-risk group so you can carefully monitor
July 2002 Update
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Blood Pressure Medication May Affect Stroke
Your choice of high blood pressure medication may affect your risk of
stroke. Research published in the March 23, 2002, issue of The Lancet comparing
the effectiveness of two high blood pressure is the first with solid
evidence showing the importance of how we treat high blood pressure.
In the trial, called the LIFE study, researchers compared the number
of strokes, heart attacks, and deaths due to cardiovascular events in
over 9,000 patients taking either losartan or atenolol.
According to the results, both losartan and atenolol decreased blood
pressure effectively, but patients who took losartan had a 25% lower
risk of stroke than patients taking atenolol. In an accompanying study,
researchers found similar results in patients with diabetes and high
Researchers believe the difference in effectiveness may be a result
of the mechanisms by which each drugs works. Losartan belongs to a newer
class of drugs, called angiotensin II receptor blockers (ARBs). ARBs
lower blood pressure by preventing the smooth muscles of the arteries
from contracting. Atenolol, on the other hand, is a beta-blocker and
works to lower blood pressure by blocking substances that would otherwise
speed up the heart and increase the pressure at which it pumps blood.
Results of the LIFE study also showed that losartan provided benefits
beyond lowering blood pressure and reducing cardiovascular events. Patients
on this drug had a 25% lower incidence of new-onset diabetes compared
to patients on atenolol. In addition, patients in the losartan group
were less likely to discontinue the drug due to side effects than were
patients in the atenolol group.
Based on these findings, losartan or another ARB may quickly become
a vital part of the first line of treatment for high blood pressure.
Up until now, treatment with a beta-blocker, such as atenolol, and a
diuretic has been regarded as the best intervention. The results of an
upcoming National Institutes of Health study (due out in December) comparing
a larger array of high blood pressure medications may shed even more
light on the subject.
June 2002 Update
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Most people feel a bit anxious during a doctor's visit. But for some
people, their anxiety causes temporary high blood pressure, detectable
during the time of the visit. Physicians have been debating whether or
not they should treat this phenomenon, referred to as "white-coat" hypertension.
Some believe the short-lived blood pressure elevation is harmless, while
others believe it should be treated like persistent high blood pressure.
In a recent study, researchers compared changes in the heart's function
and size among people with persistent, untreated high blood pressure, "white
coat" high blood pressure, and normal blood pressure. Participants
were carefully matched by age, sex, and weight, as well as in-clinic
and out-of- clinic blood pressures. Results of the study show participants
with "white coat" hypertension, when compared to participants
with normal blood pressure, had thicker walls in portions of their hearts,
increased heart mass, and alterations in the diastolic (relaxing) portion
of the heartbeat. Those people with persistent high blood pressure had
even greater changes in the heart. These findings suggest "white
coat" hypertension, while a temporary condition, may cause damage
to the heart. This study reinforces the argument for treating "white
If you experience this condition, you should consult your doctor about
treatment options. Simple lifestyle changes may be all you need or medication
might be necessary. In any case, the possible benefits will outweigh
January 2002 Update
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High-Normal Blood Pressure Bad for the Heart
People with high-normal blood pressure are more likely to suffer a heart
attack, stroke, or heart failure than those with lower blood pressure,
according to recent findings from the Framingham Heart Study.
The researchers followed the cardiovascular events of 6,859 participants
of the famed study, which has been monitoring subjects from the Boston
suburb for more than 50 years. A third of participants had normal blood
pressure (120129 over 80-84 mm HG), a quarter had high-normal (130139
over 8589 mm Hg), and the remainder had optimal blood pressure
(less than 120 over less than 80 mm HG). People with high blood pressure
were excluded from the study.
Of those in the optimal category, 81 had cardiac events, over a ten-year
time period, compared to 136 people in the normal blood pressure category
and 180 in high-normal category. In all, people with high-normal blood
pressure were two to three times more likely to suffer a heart attack,
stroke, or heart failure than those with lower blood pressure. This held
true in both men and women, and was consistent in both age groups (35
to 64 and 65 and over), even after researchers adjusted for other cardiovascular
risk factors such as smoking and obesity. Indeed, the study found risk
increases in a stepwise fashion as blood pressure increases.
Blood pressure reflects how hard your heart is working and what conditions
your arteries are in. Risk factors include heavy drinking, smoking, eating
a diet high in salt, obesity, and family history. Doctors generally get
alarmed only if systolic blood pressure is above 140 mm Hg or if diastolic
blood pressure is above 90 mm Hg. However, this study calls for further
research to be done to see if patients in the high-normal group benefit
from lowering their blood pressure.
December 2001 Update
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Salt Restriction More Potent
Physicians often give patients with hypertension a daunting
list of lifestyle changes to help lower their blood pressure: lose weight,
exercise more, eat less salt, drink less alcohol, eat more foods rich
in calcium, potassium, and magnesium. Of course, these changes do work people
who follow them can reduce their need for medications or even do without
blood pressure-lowering drugs. But which of these lifestyle changes gives
you the biggest bang for your buck?
University of Colorado researchers recently compared the impact of exercise
or moderate salt restriction in 35 healthy older women with high-normal
blood pressure or mild hypertension (systolic blood pressure 130159
mm Hg), none of whom were using drugs to lower their blood pressure.
Half the women exercised for three months starting at 30 minutes
a day three or four times a week and working up to 45 minutes a day every
day, if possible. The other half tried to reduce their daily salt intake
to less than 2.4 grams of sodium (the amount in a level teaspoon of table
salt) without otherwise changing their diets. All were asked to try to
avoid gaining or losing weight.
The clear winner, reported in the American Journal of Cardiology,
was sodium restriction. Among the women who ate less salt, average systolic
blood pressures fell 16 mm Hg, compared with a still-respectable 5 mm
Hg in the exercise group. By the study's end of the study, systolic blood
pressure was lower in 88% of the women who ate less salt and in 55% of
So if you're trying to lower your blood pressure, should you just forget
about exercise and work harder at eating less salt? No. Exercise has
other benefits besides lowering blood pressure it can help control
weight, improve the cholesterol profile, stave off diabetes, and keep
bones strong. The real message from this study is that everyone should
exercise, but that people who are trying to control blood pressure should
lower their sodium intake, too.
December 2001 Update
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High Blood Pressure Drug Performs No Better Than
An FDA advisory panel has decided to inform doctors about the results
of a government study that found Cardura (doxazosin), a popular
blood pressure medication sold by Pfizer, was less effective than a generic
diuretic (chlorthalidone) in reducing some forms of cardiovascular
disease. But the panel also concluded the agency didn't need to extend
this warning to patients.
Cardura, which has been on the market for 10 years, is an alpha-adrenergic
receptor blocker that relaxes smooth muscle throughout the peripheral
parts of the body, including the blood vessels. It's often used for the
management of hypertension, a condition involving persistently high arterial
blood pressure. Hypertension is a major risk factor for the development
of coronary heart disease, heart attacks and strokes.
Cardura's role in managing hypertension was investigated as part of the
National Institute of Health's Antihypertensive and Lipid Lowering Treatment
to Prevent Heart Attack Trial (ALLHAT), the first large-scale blood pressure
treatment study to compare several newer drug treatments with a cheaper
The first part of ALLHAT was stopped early because users of Cardura had
25% more cardiovascular events and were twice as likely to be hospitalized
for congestive heart failure as users of the diuretic. But the study
didn't find Cardura users were any more likely to die than those using
the diuretic. As a result, the NIH advised high blood pressure patients
who now take Cardura consult with their doctors about a possible alternative.
They also suggested the drug may not be the best choice for new patients.
The American College of Cardiology followed with a clinical alert that
advised physicians to stop prescribing Cardura and reassess its treatment
Last year, a group of patients filed a lawsuit with a U.S. District court
claiming Pfizer did little to inform doctors and patients about the results
of ALLHAT, but the petition was handed over to the FDA. The FDA advisory
panel concluded that while it appeared the diuretic was more effective
than Cardura in preventing congestive heart failure, there was not enough
data to prove Cardura was harmful. The FDA often follows the recommendations
of its advisory panels. Pfizer continues to maintain that Cardura is
July 2001 Update
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Statins Reduce C-reactive Protein
Half of all heart attack victims have normal cholesterol
levels. Consequently, doctors are looking for new methods to improve
heart disease prevention. One promising new approach involves testing
for high levels of the inflammation marker C-reactive protein to identify
people who might benefit from drug therapy.
C-reactive protein (CRP) is secreted from the liver in response to inflammation
in the body. Because atherosclerosis is partly an inflammatory process,
high levels of CRP have been shown to predict the risk of heart disease.
A new study has found that statins can reduce the risk of coronary events
in people who have high levels CRP. These drugs are already used to lower
LDL cholesterol, but the researchers found its anti-inflammatory effect
was independent of its cholesterol-lowering abilities.
The five-year randomized trial done at Brigham and Women's Hospital and
Harvard Medical School involved 5,742 participants. The researchers found
that Lovastatin decreased both CRP levels by an average of 14.8% and
the rates of coronary events. Other statins has also previously been
shown to reduce CRP levels.
This study suggests statins may be an effective preventive therapy for
people with high CRP levels even if they have low or normal LDL
cholesterol. Though everyone is encouraged to make healthy lifestyle
changes to reduce their heart disease risk, only those at high-risk are
candidates for these costly drugs. And measuring CRP levels in conjunction
with cholesterol testing should better identify these high-risk individuals.
July 2001 Update
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Does Aspirin Prevent Preeclampsia?
Preeclampsia, also known as toxemia, is a condition that
affects pregnant women and their unborn baby. It is characterized by
high blood pressure, water retention, and protein in the urine. The condition,
which usually occurs after the 5th month of pregnancy, can lead to seizures,
kidney and liver damage, slow fetal growth, and even fetal or maternal
death. Preeclampsia affects up to 8% of pregnancies, and is responsible
for 10-15% of maternal deaths. In the past decade, several studies have
looked at the effectiveness of aspirin in preventing preeclampsia.
Early studies showed promising results. But larger, more recent studies
failed to show any benefit.
In an effort to reconcile these conflicting results, British researchers
reviewed several studies involving over 30,000 women who were at increased
risk for preeclampsia. (Risk factors include preexisting high blood pressure,
diabetes, a first pregnancy, pregnancy as a teenager or over the age
of 40, and pregnancy involving multiple fetuses.) The women had been
randomized to receive an antiplatelet drug (usually low-dose aspirin),
a placebo, or no antiplatelet medication.
The researchers concluded that aspirin reduced the risk of preeclampsia
by 15%. Their review also showed that aspirin decreased the risk of premature
births by 8% and the risk of stillbirths or newborn deaths by 14%. Based
on these results acknowledged by the researchers as showing only
small to moderate benefits the researchers recommended the use
of aspirin. Several issues including the optimal dosage, the proper time
to start treatment, and which women are most likely to benefit, remain
Despite the results of this review, some leading experts are unconvinced
that aspirin is effective at preventing preeclampsia. However, even physicians
who doubt aspirin's efficacy agree that at doses of less than 80 milligrams
per day, aspirin is not harmful. If your physician prescribes aspirin
to prevent preeclampsia, it may or may not be effective but in
any case, it won't be harmful.
March 2001 Update
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Low-Sodium DASH Diet Lowers Blood Pressure
The effect of reducing dietary salt on controlling hypertension, or
high blood pressure, has been surprisingly controversial. But in a recent
study, a collaboration of scientists, including researchers from Harvard
Medical School and the National Heart, Lung, and Blood Institute of the
National Institutes of Health, suggest that reducing salt intake may
dramatically lower blood pressure in people with or without hypertension,
regardless of age, race, or gender.
The trial, known as the Low-Sodium DASH Diet study, tested the effects
on blood pressure of lower levels of sodium intake combined with the
Dietary Approaches to Stop Hypertension (DASH) diet, which is low in
fat and rich in fruits, vegetables, whole grains, and low-fat dairy products.
More than 400 subjects were assigned either a typical American diet or
the DASH diet for 12 weeks. The salt content of every participant's diet
was randomly changed every four weeks to one of three sodium levels:
high (3,300 mg), intermediate (2,400 mg), or low (1,500 mg).
The researchers found that with either diet, the lower the salt intake,
the lower the blood pressure. But at each sodium level, blood pressure
was consistently lower for those on the DASH diet. Moreover, the largest
reductions in blood pressure were found among those who followed the
DASH diet while consuming 1,500 mg of salt per day, well below the government's
recommended daily intake of 2,400 mg, or 1 1/4 teaspoons. This combination
worked best for all participants, but particularly for patients with
hypertension, whose systolic blood pressure was 11.5 millimeters of mercury
(mm Hg) lower than hypertensive participants on the control diet with
a high sodium level. The beneficial effect of a lower sodium diet was
also more pronounced in women than men and in blacks than people of other
Controlling blood pressure reduces the risk of developing complications
associated with hypertension, which include heart disease and stroke.
New dietary guidelines from the American Heart Association recommend
that everyone adopt an eating plan similar to the DASH diet and limit
their sodium intake to less than 2,400 mg per day. Other things you can
do to keep blood pressure in check include maintaining a healthy body
weight, cutting down on dietary fat, and staying active.
January 2001 Update
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Reduce High Blood Pressure, Reduce the Risk
High systolic blood pressures (when the top blood pressure number is
above normal) in elderly people increases the chances that they will
develop the diminished mental capacity known as dementia. Certainly this
makes sense. High blood pressure damages blood vessels. When the blood
supply to the brain is compromised, there may be damage to the brain
tissue. Sometimes this damage is very abrupt, such as in the loss of
function that may accompany a stroke. Other times, the damage is recognized
gradually, as a person slowly loses some mental capabilities. This is
the case with vascular dementia.
A major European study tested the theory that treating high blood pressure
might reduce the incidence of dementia in elderly people. One-hundred-six
centers in 19 countries enrolled 3,162 patients in this trial. Investigators
randomly assigned these patients to receive either medicine to help lower
blood pressure or a placebo and then followed the health of these individuals
for two years. The results were so compelling that the study was stopped
early. In this study, treatment of high systolic blood pressure reduced
the incidence of dementia by 50%. Put another way, treating 1,000 patients
with high blood pressure, over five years, could prevent 19 cases of
Researchers are just beginning to understand the physiology of dementia
and how we might slow or prevent this process. Controlling high blood
pressure is an important part of staying healthy for many reasons, for
mind as well as body. For more information on dementia, see page 362
in the Family Health Guide.
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High Blood Pressure Drugs and Diabetes
Past studies have suggested that two types of drugs used
to treat high blood pressure also promote the development of type 2 diabetes.
These results led doctors to think twice about prescribing thiazide diuretics
and beta blockers to their patients at high risk for diabetes. But a
new, extensive study shows thiazide diuretics do not appear to increase
the risk of diabetes, while beta blockers may contribute. The data also
suggest that perhaps the risk of developing type 2 diabetes is associated
with high blood pressure itself, and not the medications used to treat
Thiazide diuretics and beta blockers are the first line of treatment
for most people with high blood pressure. Both therapies reduce the risk
for strokes and heart attacks and have been shown to help people with
high blood pressure live longer. Thiazide diuretics such as hydrochlorothiazide
and chlorthalidone decrease blood pressure by reducing the volume of
fluid in the body. Beta blockers such as propanolol and atenolol decrease
blood pressure by blocking the nervous systems response to stress
and thereby relaxing the heart muscle. Earlier studies suggested that
both drug classes might affect glucose tolerance and lead to diabetes,
but a more recent study suggests something different.
To determine the relationship between the use of antihypertensive medications
and the risk of developing diabetes, researchers in the U.S. followed
12,550 nondiabetic adults. They evaluated 3,804 hypertensive and 8,746
nonhypertensive patients for signs of diabetes three and six years later.
Results showed that adults with high blood pressure (treated or untreated)
were 2.5 times more likely to develop diabetes than were adults without
hypertension. The scientists also analyzed the results by medication.
The risk of developing diabetes was 28% greater for patients taking beta
blockers than for patients taking no medication, regardless of hypertension. Patients
taking other drugs to treat their hypertension were not at an increased
The researchers pointed out that their study was limited by the lack
of information regarding the dosage and duration of treatment with antihypertensive
drugs. In addition to this, their results may have been affected by the
perceived risk of diabetes and its influence on what drugs doctors prescribe.
But the study was an improvement on past studies that were smaller and
influenced by confounding factors.
In light of the results, doctors can now easily identify a group of patients
at high risk for developing diabetes those that take beta blockers and
perhaps help them develop a prevention program. In addition, physicians
should be reassured about prescribing thiazide diuretics. The study investigators
noted that despite the apparent increase in risk for diabetes associated
with beta blockers, these drugs do have proven benefits for people with
heart disease, and that a careful weighing of the potential risks against
known benefits is important.
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Renal Artery Stenosis-Related
High Blood Pressure: Angioplasty vs. Medication
For many people with difficult to control high blood pressure,
the problem really begins with (or is made worse by) narrowing of the
arteries that supply the kidneys (renal stenosis). One way to manage
the resulting elevations in blood pressure is with antihypertensive medications.
Another way is balloon angioplasty the same procedure used to
clear narrowed or blocked coronary arteries, but applied to the renal
arteries. A study conducted in the Netherlands compared the effects of
balloon angioplasty with that of medical therapy (medication) on high
blood pressure caused by renal stenosis.
Patients in this study had similar blood pressure levels and took similar
doses of high blood pressure drugs at the beginning of the trial. Researchers
then randomly assigned these volunteers to two groups. One group continued
the two-drug regimen they had been taking, but could take a higher dose
of a drug or add a drug, as needed; the other group continued to take
a two-drug regimen and were also assigned to undergo balloon angioplasty.
The blood pressure of study participants was measured at three months
and at 12 months. At three months, there was no significant difference
in blood pressure between the two groups of patients. Also at three months,
nearly half of the patients in the drug-therapy group had received balloon
angioplasty either because drug therapy failed to adequately reduce blood
pressure or because they showed signs of worsening kidney function. Nevertheless,
the patients who only received drug therapy did not have higher blood
pressure than those who underwent balloon angioplasty did.
Researchers concluded that, compared with antihypertensive drugs, balloon
angioplasty does not always result in better blood pressure control for
patients with renal stenosis. In patients whose high blood pressure cannot
be controlled even when they take three or more medications or those
for whom the renal-artery blockages worsen, balloon angioplasty serves
only to lower blood pressure to the level that can be achieved by drug
therapy in other patients. In only a very few cases did balloon angioplasty
October 2000 Update
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Ramipril for Diabetics with Heart
The incidence of heart disease in the general population
has been dropping. This is good news of course, but for individuals with
diabetes, the statistics are not so promising. In fact, men with type
2 diabetes have experienced only a modest decline in heart disease rates,
while women with diabetes have actually experienced an increase.
Heart disease accounts for 70% of deaths in people with diabetes. So,
the outcome of a recent study, which demonstrated that the angiotensin-converting
enzyme (ACE) inhibitor, ramipril, significantly lowered the incidence
of heart disease, stroke, and death in people with diabetes who had a
history of heart disease and hypertension, should be welcome news.
The Heart Outcomes Prevention Evaluation (HOPE) study included people
with and without diabetes. More than one-third of the participants had
diabetes. Of the participants with diabetes, the average age was a little
over 65 years old, and one-third were women. All had a history of heart
disease and half had a history of high blood pressure as well. All study
volunteers were randomly assigned to either ramipril or a placebo. While
ramipril did not lower the blood pressure of participants much as
it was originally intended to do it did lower their risk for heart
attack by 22%, their risk for heart disease by 37%, and their risk for
stroke by 33%. Other studies conducted to evaluate the effects of ACE
inhibitors on blood pressure in people with diabetes have had similar
October 2000 Update
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