Earlier screening, diagnosis and treatment of type
2 diabetes may decrease the risk
of heart problems like heart attacks and death, suggest new results from a
The timing of the diagnosis and the start of treatment appeared
more important than the actual intensity of treatment, the researchers report
in Diabetes Care.
"Actually, though it seems intuitive, the evidence for
screening for type 2 diabetes is really not strong," said lead author Dr.
William H. Herman of the University of Michigan in Ann Arbor.
"The ideal study to look at screening for diabetes would be
to screen a large population, diagnose and treat half, and to not tell other
half that they have diabetes and follow them over time and compare
outcomes," Herman told Reuters Health by phone. "Of course that study
would be ethically unacceptable."
Type 2 diabetes, sometimes referred to as adult-onset diabetes, is when the body's cells are resistant to insulin or the body doesn't make enough of the
hormone, so glucose remains in the bloodstream and can climb to dangerously
high levels. Insulin gives glucose - or blood sugar - access to the body's
cells to be used as fuel.
Read: Symptoms of diabetes
Diabetes screening for
people at risk
The U.S. Preventive Services Task Force (USPSTF), a
government-backed panel on preventive healthcare, recently proposed an updated
recommendation to screen people for abnormal blood sugar and type 2 diabetes if
they are at an increased risk. That includes anyone age 45 and older.
One way to try to estimate the benefit of early screening is to
use a computer model, which simulates the progression of diabetes and its complications, resulting health
problems, quality of life and costs.
For the new estimates, Herman and his coauthors used data from a
large European study of people age 40 to 69 without known diabetes who were
screened and treated for the condition. In the original study, some
participants who tested positive were treated intensively while other were
treated routinely, and the authors found no difference in cardiovascular
outcomes or death five years later.
The researchers used a computer model known as the Michigan Model
to estimate what may have happened to the participants over the same five year
period if they had not been screened, and their diabetes diagnoses had been
delayed by three or six years.
If screening was delayed by three years, the researchers estimated
that about 11 percent of people would likely experience a heart problem within
five years, compared to about 8 percent when screening wasn't delayed.
If screening was delayed by six years, they estimated that about
13 percent of participants would experience a heart problem over the five
Read: Diagnosing diabetes
Validity of the model
The USPSTF would not include a modelling study like this in its
reviews, Herman said.
Richard Kahn of the University of North Carolina School of
Medicine in Chapel Hill told Reuters Health he disagrees with the new findings.
"We don't know very much about the model whatsoever,"
based on what is included in the paper, said Kahn, who was previously the chief
scientific and medical officer of the American Diabetes Association.
The Michigan Model may not reflect actual biology or the way
diabetes progresses for all people, he said.
Kahn has also researched the potential benefit of earlier
screening for diabetes, and "I would be hard pressed to believe the three
years makes a big difference."
Appropriate therapy must begin at diabetes diagnosis, but the
exact point when screening happens is less important, he said.
Instituting more screening earlier in life would be costly, and
may not have enough benefit to outweigh the cost, he said. A similar debate has
centred on mammography for younger women in recent years.
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