MONDAY, July 25 (HealthDay News) -- A standard test used to
measure blood sugar levels in people with diabetes could also help
predict their risk of cardiovascular disease, a new study
suggests.
The test -- which measures levels of hemoglobin A1c (HbA1c) in
blood -- enables doctors to assess how well their diabetic
patients' blood sugar is controlled over several months. Diabetes
is a known risk factor for cardiovascular disease, but the degree
of risk may differ in individuals, the researchers explained.
"It is possible that identification of people with [type 2] diabetes who have a low estimated 10-year risk of cardiovascular disease may be useful in making treatment decisions," said lead researcher Nina P. Paynter, an associate epidemiologist at Brigham and Women's Hospital in Boston.
Usually, all diabetics are considered at high risk for
cardiovascular disease and they are often treated aggressively with
cholesterol-lowering drugs and blood pressure medications to help
reduce the risk.
But many of them might be at substantially lower risk and not
need such aggressive therapy, the authors said.
"Some people with diabetes have an estimated 10-year cardiovascular risk lower than 20 percent, especially in populations with a low overall risk of cardiovascular disease," Paynter said.
The report was published online July 25 in the
Archives of Internal Medicine.
For the study, Paynter's team collected data on 24,674 women and
11,280 men who took part in the Women's Health Study and the
Physician's Health Study II.
Both studies collected data on the participants' HbA1c levels.
The men were followed for a median of 11.8 years and the women for
10.2 years, the researchers noted.
Over that period, 125 of the 685 women with type 2 diabetes had
a heart attack or stroke as did 170 of the 563 diabetic men. Among
participants without diabetes, 1,382 men and 666 women had
cardiovascular events, the researchers reported.
By adding HbA1c test results to the patient data, which also
included levels of cholesterol and C-reactive protein, the
researchers said they were able to more accurately predict the risk
of cardiovascular disease in the diabetic patients.
They found that 71.9 percent of diabetic women had less than a
20 percent risk of cardiovascular disease over 10 years, while only
24.5 percent of the men had a similarly low risk.
This difference may be partly explained by the increased risk
for cardiovascular disease that accompanies age, and the delayed
risk in women, the researchers said.
Noting further research is needed to confirm the findings, they
noted the prediction improvement was better in low-risk groups.
Paynter also said the test might help people without diabetes
evaluate their cardiovascular risk.
Dr. Mark J. Pletcher, an associate professor of epidemiology at
the University of California, San Francisco, and author of an
accompanying journal editorial, doesn't think predicting individual
risk of cardiovascular disease will change current treatment of
diabetic patients.
"Even though the risk estimation may be more accurate, it still may be a better decision to put them on cholesterol-lowering drugs, because of long-term risk of heart disease," he said.
Pletcher said in his own clinical practice he will continue to
treat diabetics aggressively.
"Risk prediction for risk prediction's sake is not really that useful an exercise," Pletcher said. "It's only useful if it informs a clinical decision. And when you are not going to change a decision, as I don't think I will, then I don't think it's worth that much to refine risk estimation."
More information
For more information on diabetes, visit the
U.S. National Library of Medicine.