Diuretics Effective for People
with Diabetes and High Blood Pressure
In people with diabetes, diuretics work as well as
ACE-inhibitors and calcium channel blockers in protecting
against heart attack and improving survival, and offer
more protection against congestive heart failure.
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, are published in
the June 27 issue of Archives of Internal Medicine.
ALLHAT is the largest study to compare these three
major classes of medications to treat high blood pressure.
The study originally reported in 2002 that diuretics
were more beneficial as initial treatment for high
blood pressure for protecting against adverse cardiovascular
outcomes. This latest analysis shows that even among
diabetics and those with mildly elevated fasting glucose—a
sign of pre-diabetes—the less costly diuretics
are at least as effective, may be more beneficial
for some people.
About 73 percent of adults with diabetes have high
blood pressure—which in diabetic patients is
defined as greater than or equal to 130/80 mm Hg—
or use prescription medications for their hypertension.
Both diabetes and high blood pressure are major risk
factors for coronary heart disease, and when both
are present, significantly increase the risk for developing
heart and kidney diseases. High blood pressure can
lead to congestive heart failure, a condition in which
the heart is weakened and cannot pump enough blood
throughout the body.
“Controlling high blood pressure is an urgent
concern especially for people with diabetes. Our findings
demonstrate the advantages of diuretics in diabetics
as well as in those with impaired and normal fasting
glucose levels,” said NHLBI director Dr. Elizabeth
G. Nabel. “As a physician, I have seen the consequences
of poorly controlled hypertension and diabetes. These
results show many people and their families can be
spared that devastation.”
The ALLHAT blood pressure study was a randomized, double-blind
trial involving 42,418 participants with high blood
pressure, ages 55 and older. Of those, 31,512 participants
were randomly assigned to a diuretic (chlorthalidone);
a calcium channel blocker (amlodipine); an angiotensin
converting enzyme (ACE) inhibitor (lisinopril). 13,101
had diabetes, 1,399 had elevated fasting glucose and
17,012 had normal glucose levels.
Compared with the ACE inhibitor and the calcium channel
blocker, the diuretic was:
- More protective against congestive heart failure
in patients both with and without diabetes (by
about 1/6 compared with the ACE-inhibitor, and
by about 1/3 compared with the calcium channel
blocker).
- More effective in lowering systolic blood pressure—the
measure of blood pressure when the heart beats—among
those with and without diabetes.
- At least equally protective against fatal coronary
heart disease or non-fatal heart attacks in people
with diabetes, those with elevated fasting glucose,
and non-diabetics.
- Equally protective against death from all causes,
end-stage kidney disease, or cancer in people
with diabetes, those with elevated fasting glucose,
and non-diabetics.
- In Black study participants, more protective
against stroke in people with and without diabetes
(compared with the ACE-inhibitor).
“This study shows the advantage of diuretics
for preventing congestive heart failure in most people
with high blood pressure-- regardless of diabetes
status. Because some patients may respond differently
to medications, they should discuss these results
and their treatment with their doctors before making
any changes”, advises Dr. Jeffrey Cutler, NHLBI
Senior Adviser.
There were more heart attacks among participants with
impaired fasting glucose taking the calcium channel
blocker compared with those taking the diuretic. This
finding was unexpected and inconsistent with other
results and may have occurred just by chance, according
to Cutler.
Previous studies have found that ACE inhibitors slow
progression of kidney damage in diabetic patients
with kidney disease, who generally have protein in
their urine. ALLHAT did not collect urine samples
to measure protein (albumin) levels so analyses as
to whether the ACE inhibitor was superior to the diuretic
in this respect is not possible. However, an ALLHAT
report in the April 25 Archives of Internal Medicine
found no difference among the treatments in progression
of kidney disease among diabetic patients with reduced
kidney function.
To arrange an interview about ALLHAT, please contact
the NHLBI Communications Office at (301) 496-4236
or email
(nhlbi_news@nhlbi.nih.gov).
NHLBI is part of the National Institutes of Health
(NIH), the Federal Government’s primary agency
for biomedical and behavioral research. NIH is a component
of the U.S. Department of Health and Human Services.
NHLBI press releases and other materials including
information about high blood pressure and heart disease
are available online at www.nhlbi.nih.gov.
Current guidelines on high blood pressure treatment
can be found at http://www.nhlbi.nih.gov/guidelines/hypertension/index.htm.
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