Back to Endocrinology Articles
ALLHAT is the largest study to compare three major classes of
medications to treat 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
- 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
"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.
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
Are you a doctor or a nurse?
Do you want to join the Doctors Lounge online medical community?
Participate in editorial activities (publish, peer review, edit) and
give a helping hand to the largest online community of patients.
Click on the link below to see the requirements:
Doctors Lounge Membership