Study findings show that there is a link between the use
of antidepressant drugs and diabetes, investigators here
at the 66th Scientific Sessions of the American Diabetes
Association announced. This is the first report of such
an association, they say.
Depression is two- to three-times higher in diabetics than
in the general population. In addition, 10 percent to 15
percent of the U.S. population takes antidepressants, "and
the numbers are increasing," Dr. Richard R. Rubin of The
Johns Hopkins University School of Medicine in Baltimore,
Maryland, told meeting attendees Saturday.
Dr. Rubin, a co-investigator with the Diabetes Prevention
Program Research Group, presented findings for 3,187 trial
participants with elevated blood glucose values, indicating
that they were pre-diabetic. Of these subjects, 5.7 percent
reported regular use of antidepressants at the beginning
of the study. Elevated scores on the Beck Depression Inventory,
a common test used to diagnose depression, were found for
10.3 percent.
Patients were randomly assigned to one of three subgroups:
metformin therapy, intended to prevent the onset of diabetes;
intensive lifestyle modification; or placebo. The average
length of patient follow-up was 3.2 years.
High scores on the Beck Depression Inventory alone did
not predict the development of diabetes. However, after
the influence of weight, and metabolic and demographic factors
of the subjects at the beginning of the study was factored
in, the investigators found that antidepressant use did
predict diabetes. Patients in the placebo group had almost
twice the risk of developing diabetes and those in the intensive
lifestyle modification arm had almost three-times the risk.
No increased risk of diabetes was associated with depression
in patients in the metformin subjects.
"We don't have a clue" as to why the association exists,
Dr. Rubin stated. In their abstract, the investigators note
that the mechanism "does not appear to be increased weight
or fasting plasma glucose or insulin levels."
Metformin acts primarily in the liver, and may change the
body's response to antidepressants. "Or, the drug could
be a marker for something else," Dr. Rubin suggested.
If the findings are confirmed in further studies, "it would
have enormous public health implications," he commented.
"In the meantime, patients should not stop taking their
antidepressants. They have been proven to have tremendous
relief, but those at risk of diabetes should have their
blood sugar monitored frequently and perhaps -- perhaps
-- begin oral anti-diabetic treatment early."
Dr. Rubin emphasized that patients in this study were all
at very high-risk for developing diabetes.
