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Diuretics lower blood pressure in
blacks with metabolic syndrome
shows that diuretics are as protective in people with high blood
pressure who suffer a cluster of conditions that increase the risk for
heart disease as newer, more expensive medications.
The findings run counter to current medical practices that favor
angiotensin-converting enzyme (ACE)-inhibitors, alpha-blockers, and
calcium channel blockers for treatment of high blood pressure in those
with the heart risk factor, metabolic syndrome, particularly among
The latest findings from the Anti-hypertensive and Lipid-Lowering
Treatment to Prevent Heart Attack Trial (ALLHAT), sponsored by the
National Heart, Lung, and Blood Institute (NHLBI), were published in
the Jan. 28 issue of Archives of Internal Medicine.
ALLHAT is the largest study to compare a diuretic (chlorthalidone) with
three newer classes of medications to treat high blood pressure: a
calcium-channel blocker (amlodipine besylate); an alpha-blocker
(doxazosin mesylate); and an ACE inhibitor (lisinopril). Each drug was
used to start treatment, and other medications could be added if
necessary to control blood pressure. The study originally reported in
2002 that diuretics were the most beneficial of the drug classes
studied for treating high blood pressure and for protecting against
adverse cardiovascular outcomes.
This latest analysis shows that even among adults with metabolic
syndrome, and for black and non-black participants, the less costly
diuretics consistently control blood pressure and are equally
beneficial in preventing heart attack and coronary heart disease death.
They are also more beneficial than newer medications in preventing one
or more other forms of cardiovascular disease, including heart failure
Another ALLHAT paper, reported in the February issue of Diabetes Care,
reached similar conclusions when patients with diabetes were excluded.
People with metabolic syndrome have three or more risk factors for
heart disease, including elevated blood pressure, low good cholesterol
levels, and diabetes or pre-diabetes.
When compared with those taking diuretics, black participants with
metabolic syndrome receiving ACE-inhibitors had poorer blood pressure
control and a 24 percent greater risk of overall cardiovascular
disease. This included a 19 percent greater risk of coronary heart
disease, a 37 percent greater risk of stroke, and a 49 percent greater
risk of heart failure. They also had a 70 percent greater risk of
“In black patients with high blood pressure and metabolic syndrome, the
evidence from ALLHAT overwhelmingly supports the choice of
thiazide-type diuretics,” said Jackson Wright Jr., M.D., Ph.D.,
professor of medicine, Case Western Reserve University, the study’s
What is metabolic syndrome?
Metabolic syndrome is characterized by a group of metabolic risk
factors in a person that include:
- Abdominal obesity (excessive fat tissue in and around the
- Atherogenic dyslipidemia (blood fat disorders— high
triglycerides, low HDL cholesterol and high LDL cholesterol—that foster
plaque buildups in artery walls)
- Insulin resistance or glucose intolerance
People with metabolic syndrome are at increased risk of coronary heart
disease and other diseases related to plaque buildups in artery walls
(e.g., stroke and peripheral vascular disease) and Type 2 diabetes. The
metabolic syndrome has become increasingly common in the United States.
More than 50 million Americans are believed to have it.
- Prothrombotic state (e.g., high fibrinogen or plasminogen
activator inhibitor–1 in the blood)
The dominant underlying risk factors for this syndrome appear to be
abdominal obesity and insulin resistance. Insulin resistance is a
generalized metabolic disorder in which the body can’t use insulin
efficiently. (Metabolic syndrome is also called the insulin resistance
Other conditions associated with the syndrome include physical
inactivity, aging, hormonal imbalance and genetic predisposition.
Some people are genetically predisposed to insulin resistance. Acquired
factors, such as excess body fat and physical inactivity, can elicit
insulin resistance and the metabolic syndrome in these people. Most
people with insulin resistance have abdominal obesity.
The primary goal of clinical management of the metabolic syndrome is to
reduce the risk for cardiovascular disease and Type 2 diabetes. Then,
the first-line therapy is to reduce the major risk factors for
cardiovascular disease: stop smoking and reduce LDL cholesterol, blood
pressure and glucose levels to the recommended levels.
For managing long- and short-term risk, lifestyle therapies are the
first-line interventions to reduce the metabolic risk factors. These
interventions include weight loss to achieve a desirable weight;
increased physical activity, with a goal of at least 30 minutes of
moderate-intensity activity on most days of the week ; and healthy
Friday, Feb. 22, 2008
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