It's not just donuts that can put a "donut" around your middle.
Depression, or the physiological changes that result from depression, may be
able to do so as well.
This is the message from a study conducted by Dutch and American
researchers published in the December 2008 Archives of General
Psychiatry.
The study included more than 2,000 community-dwelling older individuals
(aged 70 to 79) living in the Memphis, Tenn., and Pittsburgh areas. They were
evaluated at the start of the study for depression. Also at that time, and
five years later, they were assessed for both overall obesity and abdominal
obesity.
The yardsticks used to measure overall obesity included body mass index and
percentage of body fat as measured by dual-energy X-ray absorptiometry. The
yardsticks used to measure abdominal obesity included waist circumference and
visceral fat as measured by computed tomography.
Finally, at the end of five years, the researchers looked to see whether
there were any links between baseline depression and the later development of
either overall obesity or of abdominal obesity, after taking
sociodemographics, lifestyle, diseases, and other possibly confounding factors
into consideration.
The researchers found no significant link between baseline depression and
later overall obesity. But they did find a link between baseline depression
and abdominal obesity.
"The most important finding was that older individuals with depressed
symptoms were twice as likely to gain visceral fat as were nondepressed older
persons," Nicole Vogelzangs told Psychiatric News. Vogelzangs,
the study's lead investigator, is a doctoral student at VU University Medical
Center in Amsterdam. The results suggest that "depression may promote
visceral fat accumulation," Vogelzangs and her group wrote in their
study report.
One could argue that depression leads to abdominal obesity because
depressed people tend to have unhealthy lifestyles. However, the researchers
do not think that this argument holds since they took lifestyle factors, such
as smoking, alcohol use, and a reduced level of physical activity, into
consideration during their analyses. True, the researchers did not factor in
diet, but if overeating led to abdominal obesity, then it should also have led
to overall obesity, they reasoned.
"There are many studies showing a cross-sectional relationship
between depression and obesity—that is, people with depressive symptoms
or depressive disorders are more overweight or obese—and a smaller
number of studies showing a longitudinal relationship—that is, people
with depressive symptoms or depressive disorders are more likely to become
overweight or obese," Gregory Simon, M.D., told Psychiatric
News. "What's new here is the finding that depression is linked to
increases in abdominal fat." Simon, a psychiatrist and researcher at the
Group Health Center for Health Studies in Seattle, has studied the
relationship between depression and obesity (Psychiatric News,
September 16, 2005).
This new finding is important for two reasons, Simon explained."
First, abdominal fat is much more strongly associated with developing
serious health problems like diabetes and heart disease than is obesity in
general. Second, this finding suggests that hormonal changes, especially
increase in stress-related hormones, may explain how depression increases risk
of obesity and obesity-related health problems."
Indeed, some studies have shown that depression, at least in a subset of
patients, leads to elevated concentrations of the stress hormone cortisol, and
that cortisol can promote the accumulation of visceral fat by activating the
enzyme lipoprotein lipase and by inhibiting lipid movement.
Some crucial questions about the subject still remain to be answered. For
example, can depression fatten the "middles" of middle-aged people
as well as of seniors? And how often, and for how long, must one be depressed
to put one's abdomen in jeopardy of expansion?
The study was funded by the U.S. National Institutes of Health and the
Young Academy of the Royal Netherlands.
An abstract of "Depressive Symptoms and Change in Abdominal
Obesity in Older Persons" is posted at<http://archpsyc.ama-assn.org/cgi/content/abstract/65/12/1386>.▪