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Men with a common genetic variant produce more than twice as
much of a hormone known to increase blood pressure and blood
sugar when they are angry, according to researchers from Duke
University Medical Center.

The findings, presented today at the American Psychosomatic
Society's annual scientific meeting, shed more light on the
notion that stress can trigger physiological changes that
result in the development of cardiovascular disease and type 2
diabetes.

"We know that emotional stress can lead to negative health
outcomes but our goal with this study was to obtain a better
understanding of the biological mechanisms behind this
phenomenon," says Redford Williams, MD, director of Duke's
Behavioral Medicine Research Center and study co-author.

Researchers analyzed variants of serotonin receptor genes,
which regulate effects of the neurotransmitter serotonin on
emotions and physical functions, including levels of the stress
hormone cortisol.

"We looked at specific points along a cascade of events,"
says Stephen Boyle, PhD, study co-author. "Serotonin is
processed in the brain and controls the release of cortisol by
the adrenal grand. Cortisol is known to stimulate the
production of glucose and makes the influence of adrenaline
more pronounced."

Researchers measured cortisol in two blood samples taken
from 41 men. One sample was collected during a five-minute
resting period and the other during five-minutes when they
described a recent event in their lives that made them
angry.

Men with common variants of one of the serotonin receptor
genes (5HTR2C) had increased cortisol production when recalling
a situation that made them angry.

One of those variants was associated with an average
increase in cortisol that was more than twice as large (70
pg/ml vs. 30 pg/ml) when compared with men possessing the other
variant of the same gene.

"Interestingly, one of the genetic variants associated with
a prominent affect on cortisol production is also known to
alter the amount of receptor protein the gene makes," says
Williams. "This tells us that this variant is a strong
candidate to be responsible for the findings we observed."

"This work may provide a clearer understanding of the
genetic and environmental factors that combine to put some men
at greater risk for developing increased belly fat, type 2
diabetes and cardiovascular disease," adds Boyle.

The next phase of research will study large samples of
people to determine if men with the genetic variant associated
with larger cortisol responses to anger seen in this study are
more likely to develop type 2 diabetes or cardiovascular
disease.

The research was supported by a grant from the National
Heart, Lung and Blood Institute.

Additional members of the research team include Christopher
Potocky, MS, Beverly Brummett, PhD, Cynthia Kuhn, PhD,
Anastasia Georgiades, PhD, Ilene Siegler, PhD, and Allison
Ashley-Koch, PhD.