Blood sugar control impacts stroke risk

NEW YORK (Reuters Health) – Impaired glucose tolerance, a
precursor to full-blown diabetes, is associated with an
increased risk of stroke in non-diabetic patients who have
already experienced a minor or mini-stroke, Dutch researchers
report.

Symptoms of a mini-stroke, known medically as a transient
ischemic attack (TIA), are exactly the same as those of a
full-fledged stroke, but resolve within 24 hours. While TIAs in
themselves cause no long-term problems, they substantially
increase the likelihood of having a full-fledged stroke soon
afterwards.

Impaired glucose tolerance has been linked to stroke in
patients with coronary artery disease. However, it was unclear
if this metabolic derangement increased the risk in patients
with a prior TIA or minor stroke.

Dr. Sarah E. Vermeer, from the Erasmus Medical Center in
Rotterdam, and colleagues assessed the impact of glucose
tolerance on stroke risk in 3,127 patients with a prior TIA or
minor stroke.

During an average of 2.6 follow-up, 272 patients developed
a stroke and 200 patients experienced heart attack or cardiac
death.

An 80 percent increased stroke risk was seen in patients
with impaired glucose tolerance. Patients with excessively low
glucose levels also had a 50 percent greater risk than did
those with normal glucose levels.

The biggest risk of stroke — a nearly threefold increased
risk compared with normal glucose levels — was in patients
with overt diabetes.

By contrast, the glucose levels seemed to have no bearing
on the risk of heart attack or heart-related death, the report
indicates.

“Intensive glucose control in both type 1 and type 2
diabetic patients seems to reduce stroke and other
macrovascular events,” the authors state. “New secondary
prevention trials should be initiated to investigate whether
intensive glucose control reduces stroke incidence in these
patients.”

SOURCE: Stroke June 2006.