|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
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,
- Equally protective against death from all causes,
end-stage kidney disease, or cancer in people with
diabetes, those with elevated fasting glucose, and
- 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
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(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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