Experts Divided on Significance of a Few Blood Pressure Points
May 18, 2000 (New York) — Type 2 diabetes and high blood pressure go
together like ham and eggs, but are even more lethal to the heart.
Type 2 diabetes, also called non-insulin dependent diabetes or adult-onset
diabetes, is most often seen in persons who are overweight. The disease usually
appears in middle age, but recently there has been an increase in cases of type
2 diabetes among adolescents. The disease is usually diagnosed by an increased
level of sugar in the blood. Most patients with type 2 diabetes also have high
blood pressure, meaning a blood pressure reading that is higher than
140/90.
Those are the facts, but what isn’t known is what comes first: diabetes or
high blood pressure? And the $1 million question is if one can lower blood
pressure in a diabetic patient, will that improve survival?
Yes, says Lennart Hansson, MD, a professor of medicine at the University of
Upsala in Sweden. No, says Peter Slight, MD, of Oxford University in England.
The two sides squared off Thursday at a press conference sponsored by the
American Society of Hypertension.
Hansson says that a very small drop in diastolic blood pressure, the bottom
or second number, can decrease death from heart attacks or strokes by as much
as 50%. Diabetics often also have high blood pressure, and the two together are
especially hard on the heart. Hansson tells WebMD that diabetic patients who
lowered their diastolic pressure to less than 80 “can virtually eliminate
the increased risk” of heart attacks and strokes associated with diabetes.
That’s very significant because people with type 2 diabetes are 250 times more
likely to die of heart disease or stroke than nondiabetics, he says. “When
diastolic pressure is brought down to 80 or less, that risk drops to 0.2 times
the excess risk, or almost nothing,” he says.
“This is good news because if one aggressively treats high blood
pressure in diabetics, lives will be saved,” he says. He suspects the
advantage gained by lowering pressure in diabetics is even greater than in
people without diabetes. The message is so important, says Hansson, that he
believes it is more important to treat high blood pressure in diabetics than it
is to treat the levels of sugar in their blood.
The significance of lowering the blood pressure, Hansson says, also was
shown in other studies, including a study performed by Slight called the HOPE
study. The trial compared a blood pressure medicine called Altace to a placebo.
The study was stopped early when a significant survival advantage was found
with Altace. Altace improved survival by 25% and reduced heart attacks by more
than 20%. Impressive numbers says Slight, but he says only about a third of the
survival advantage can be attributed to the three-point drop in blood
pressure.
Slight believes that Altace, in addition to controlling high blood pressure,
stops the buildup of blockages in the arteries supplying blood to the heart,
thus decreasing heart attacks. He feels this is the true explanation of the
survival advantage and not the drop in blood pressure. Although Slight says he
doesn’t agree with Hansson’s interpretation of the importance of a three- or
four-point drop in blood pressure, he does agree that diabetic patients need
aggressive treatment. “By all means, treat to less than 120/90,” he
says.
