Diabetes Knowledge Has Little Effect on Improving Outcomes
DURHAM, N.C. -- A new study by Duke Clinical Research
Institute researchers finds little relationship between
what a diabetic patient knows about the disease and control of
its associated cardiovascular risk factors or how well the
patient ultimately fares.
The researchers said their analysis indicates that for
diabetics, improved disease knowledge alone does not translate
into improved blood sugar control, cholesterol levels, weight
management or mortality rates. While education may be
important, the researchers said that there are likely other
health care delivery issues that must be addressed to reduce
the risks of diabetic patients dying of heart disease, the main
cause of death for diabetic patients.
The results of the Duke analysis were published in the June
edition of the American Journal of Cardiology. The study was
supported by the American Diabetes Association and the Four
Schools Physician-Scientist Training Program, Philadelphia.
"We have long assumed that if we educate patients and make
them an active partner in the treatment of their disease, we
should be able to dramatically improve their ability to take
care of their disease," said Carlos Sanchez, M.D., first author
of the paper. Sanchez performed the analysis while a medical
student at Duke; he currently is a medical resident at the
University of Oregon Health Sciences Center, Portland.
"However, in our study, we found no relationship between
patients' knowledge of their disease and improvements in the
indicators for cardiovascular risk factors.
"We spend so many resources on patient education with the
assumption that it will make a difference, but what we seem to
be finding is that while education may be a part of the puzzle,
it is not adequate by itself," Sanchez continued. "Maybe we
should step back and take a closer look at how we are spending
our resources. One area that could be improved is better
implementation of guidelines for increasing the use of
medications we know save lives."
Patients with diabetes are twice as likely as the general
population to have acute coronary syndrome (ACS), a condition
characterized by blockages in coronary arteries that prevent
oxygen-rich blood from nourishing the heart, which can lead to
chest pain and possibly heart attack. Additionally, diabetic
patients with ACS have twice the death rate as ACS patients
For their study, the team enrolled 200 diabetic patients who
were treated at Duke University Hospital for ACS. At enrollment
each patient took a standardized test that measured his or her
knowledge related to diabetes. The 14-question assessment asked
about dietary and life style choices related to glycemic and
lipid control, as well knowledge of the effects of the disease
on other organ systems. Patients were then ranked as either
high-scoring or low-scoring.
Six months later the researchers correlated how each of the
groups scored with such clinical measurements as glycemic
control, cholesterol levels, body mass index (BMI) and death.
The only correlation, not surprisingly, was that
diabetes-related knowledge scores increased as years of
"However, even when we controlled for other potential
confounding factors as age, race, insulin requirements, and how
long patients had diabetes, we found no correlation between the
two groups and measurements of glycemic control, cholesterol
levels and BMI," Sanchez said.
Furthermore, in a subset of patients who returned
finger-stick blood samples, the team found no difference in
measurements of glycemic control. "We found this quite
interesting, since these patients had been hospitalized and
recovered from a life-altering event, yet there was no
difference between the groups in terms of glycemic
In terms of mortality, the high-scoring group had a 6-month
mortality rate of 6.2 percent, compared to 9.7 percent for the
low-scoring group. In terms of heart attacks, 15.5 percent of
the high-scoring group suffered at least one, compared to 19.4
percent for the low-scoring group. The differences in both the
death and heart attack rates were not statistically
significant, the researchers said.
Because of these findings, the researchers said that further
studies are needed to determine how best to allocate scarce
health care resources to reduce the cardiovascular risk factors
"Delays in identifying the disease, failure to begin
appropriate medications and inadequate dosing are all
well-documented shortcomings of our health care system,"
Sanchez said. He pointed out, for example, that on enrollment
to the study, only two-thirds of the patients were taking
medications that have been proven in clinical trials to improve
the outcomes for diabetics with heart disease. These drugs
include aspirin, beta blockers, ACE inhibitors and statins.
Duke cardiologist Kristin Newby, M.D., a senior member of
the research team, said that while patient noncompliance,
whether because of financial or psychosocial reasons, plays an
important role in the under-treatment of heart disease in these
patients, physicians' prescription of appropriate medications
and the health care delivery system must also play leading
roles in improving outcomes.
"These findings indicate that we may need to shift some of
our focus in managing diabetes and its complications," said
Newby. "Much of the diabetes efforts tend to focus on the
microvascular changes caused by the disease: the loss of
vision, kidney function or loss of limbs. However, heart
disease is the leading cause of death for diabetics.
"Although education and prevention of microvascular
complications are important, we need to markedly increase
efforts to ensure that health care systems are in place to
promote both the delivery of evidence-based care in accordance
with existing guidelines and long-term adherence to therapies
that are proven to prevent heart attacks and death from heart
disease," she said.
Other members of the team include Duke's Vic Hasselblad,
Ph.D., Mark Feinglos, M.D., and Mognus Ohman, M.D; and Darren
McGuire, M.D., University of Texas Southwestern Medical Center,
Dallas. All are members of the Duke Clinical Research