Diuretics Most Effective Blood Pressure Medication
for People with Metabolic Syndrome
Evidence Strongly Supports Diuretics as Initial Therapy, Especially
in Black Patients
New research shows that in people with high blood pressure as
part of metabolic syndrome, a cluster of conditions that increases
the risk for heart disease, diuretics offer greater protection
against cardiovascular disease, including heart failure, and are
at least as effective for lowering blood pressure as newer, more
expensive medications. The findings run counter to current medical
practices that favor ACE-inhibitors, alpha-blockers, and calcium
channel blockers for treatment of high blood pressure in those
with metabolic syndrome. In addition, the results provide important
new evidence supporting the use of diuretics for initial blood
pressure-lowering therapy in black patients with metabolic syndrome.
The latest findings from the "Antihypertensive and Lipid-Lowering
Treatment to Prevent Heart Attack Trial" or ALLHAT, sponsored
by the National Heart, Lung, and Blood Institute (NHLBI) of the
National Institutes of Health, are published in the January 28
issue of Archives of Internal Medicine.
"These findings are particularly important for patients
with metabolic syndrome because many doctors currently prescribe
alpha-blockers, calcium channel blockers, and ACE-inhibitors due
to their more favorable short-term effects on blood sugar and blood
cholesterol levels. However, this new analysis shows that diuretics
are better at preventing cardiovascular disease and thus does not
support the selection of the newer drugs over diuretics for preventing
poor health outcomes related to hypertension or for lowering high
blood pressure," said Elizabeth G. Nabel, M.D., director,
NHLBI.
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 angiotensin-converting enzyme (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 men and women with
metabolic syndrome, and for both black and non-black (Caucasians,
Hispanics, Asians/Pacific Islanders and American/Alaskan Natives)
participants, the less costly diuretics consistently control blood
pressure, 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 and stroke. Another ALLHAT
paper, published online on November 13, and reported in the February
2008 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 (130/85 mmHg
or higher), low HDL (good cholesterol) levels (HDL less than 40
mg/dL in men or less than 50 mg/dL in women), and diabetes or pre-diabetes
(fasting blood glucose of 100 mg/dL or greater).
The ALLHAT study was a randomized, double-blind trial involving
42,418 participants, ages 55 and older with high blood pressure
(140/90 mm Hg or greater) and at least one other risk factor for
heart disease. Of those, 23,077 had metabolic syndrome with diabetes
or pre-diabetes (fasting blood glucose of 100 mg/dL or greater)
at the time of enrollment. Roughly 35 percent of the participants
were black.
In both black and non-black study participants with metabolic
syndrome, the diuretic-based treatment was more protective against
heart failure and also against overall cardiovascular disease (coronary
heart disease, stroke, heart failure, or peripheral arterial disease
combined) when compared with the ACE-inhibitor and alpha-blocker-based
treatments. Compared with the calcium channel blocker-based
treatment, the diuretic-based treatment was more protective against
heart failure.
"The ALLHAT study has been remarkably consistent in showing
that the lower-cost diuretic is superior to newer medications for
the prevention of cardiovascular disease. The data show that diuretics
can be effective as a single-drug treatment for high blood pressure
and be included in multi-drug treatment regimens in most patients,
including those with metabolic syndrome," said Paula Einhorn,
M.D., program director, NHLBI Division of Prevention and Population
Sciences.
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 kidney failure.
"In black patients with high blood pressure and metabolic
syndrome, the evidence from ALLHAT overwhelmingly supports the
choice of thiazide-type diuretics," said Jackson T. Wright,
Jr., M.D., Ph.D., professor of medicine, Case Western Reserve University
and the study's lead author.
"Medications to treat hypertension should always be combined
with lifestyle approaches to lowering blood pressure. Patients
should discuss these study results and their treatment with their
doctors before making any changes," Einhorn added.
To arrange an interview about ALLHAT, please contact the NHLBI
Communications Office at (301) 496-4236 or email nhlbi_news@nhlbi.nih.gov.
To reach author Jackson Wright, please contact Alicia Reale in
the media relations department at University Hospitals, or email
at alicia.reale@uhhospitals.org.
Part of the National Institutes of Health, the National Heart, Lung,
and Blood Institute (NHLBI) plans, conducts, and supports research
related to the causes, prevention, diagnosis, and treatment of heart,
blood vessel, lung, and blood diseases; and sleep disorders. The
Institute also administers national health education campaigns on
women and heart disease, healthy weight for children, and other topics.
NHLBI press releases and other materials are available online at www.nhlbi.nih.gov.
The National Institutes of Health (NIH) — The Nation's
Medical Research Agency — includes 27 Institutes and
Centers and is a component of the U.S. Department of Health and
Human Services. It is the primary federal agency for conducting
and supporting basic, clinical and translational medical research,
and it investigates the causes, treatments, and cures for both
common and rare diseases. For more information about NIH and
its programs, visit www.nih.gov.
Resources:
High blood pressure: http://www.nhlbi.nih.gov/health/dci/Diseases/Hbp/HBP_WhatIs.html
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