Survival Rate After Trauma Higher For Women

BALTIMORE - Severely injured premenopausal women more likely
to survive severe trauma than men; sex hormones
disadvantage men, Johns Hopkins study suggests

Women who have been severely injured are 14
percent more likely to survive than similarly
injured men, according to a new Johns Hopkins
study, a difference researchers believe may be
due to the negative impact of male sex hormones on a traumatized immune system.

Published in the September issue of The Journal
of Trauma, the study is believed to be the
largest in humans to date to suggest a survival
disadvantage among men from male sex hormones, a
hypothesis that has been successfully tested in
mice. Both men and women have androgens (male sex
hormones, including testosterone) and estrogens,
but in different ratios that change over time.
The new findings could lead to ways to improve
survival in badly injured men, such as giving
androgen-blocking drugs to male patients who have been critically injured.

“Female sex hormones appear to give women better
resiliency to extreme injury, while male sex
hormones seem to worsen their survival after
severe trauma” says Adil H. Haider, M.D., M.P.H.,
an assistant professor of surgery at the Johns
Hopkins University School of Medicine and the
study’s leader. “And if we can come up with ways
to manipulate those hormones in men, for example
by temporarily blocking sex hormones, we may be
able to improve their survival.”

Haider and his colleagues analyzed information
from the National Trauma Data Bank on more than
48,000 patients who, between 2001 and 2005, were
severely injured and arrived at an emergency room
with low blood pressure, a sign of significant
blood loss. They split the data into three
categories children 12 years and younger, teens
and adults ages 13 to 64 and seniors age 65 and
older. In the younger patients, those whose sex
hormones hadnÂ’t developed yet, and in the older
patients, whose hormone activity was expected to
be significantly diminished, survival did not
vary based on gender. It was only the middle
group of 13-to-64-year-olds those most likely
to have had the highest levels of estrogen and
progestin or testosterone where women were
significantly more likely to survive. The
survival advantage was there even when factors
such as race, insurance status and source of injury were taken into account.

“The results of the study suggest that female sex
hormones provide an advantage and help women
survive after trauma,” he says. “As expected, the
female-to-male advantage is restricted to the
group likely to have more sex hormones, rather
than in the very young or the old.”

Scientists have long suspected that female sex
hormones have some kind of immune-enhancing
effect, Haider says, something which can be an
advantage in trauma but may lie behind the
greater prevalence of auto-immune disorders such
as lupus, which is seen primarily in women. After
trauma, sex hormones appear to have specialized
roles in regulating metabolic, cardiovascular and
immune reactions. There may be other mechanisms involved as well, Haider says.

The impetus for HaiderÂ’s study came about several
years ago, after Edward E. Cornwell III, M.D., a
former Johns Hopkins trauma surgeon and the
studyÂ’s senior investigator, treated a male
patient who arrived at the hospitalÂ’s emergency
department with multiple gunshot wounds to the
chest and the testicles, which were almost
completely destroyed by the shots. The patient
had a poor prognosis, but soon after surgery
showed a remarkable recovery, Haider recalls.
Aware of studies showing that male mice were less
likely to survive than female mice after severe
trauma and that castrated mice fared better,
surviving at rates similar to female mice
Cornwell suspected this patientÂ’s nearly
destroyed testicles and the lack of testosterone
production that resulted could have been a reason
why he survived his severe wounds.

Haider says he hopes this new study leads to
future research into the use of sex-based
therapies for severe trauma. He says trials
should be conducted to explore the survival
benefits of using drugs to temporarily block
androgens in severely injured or critically ill
men. He says such medications are used as part of
treatment for prostate cancer and donÂ’t have permanent effects in those men.

Other Johns Hopkins researchers involved in the
study include Joseph G. Crompton, M.D.; David T.
Efron, M.D.; and Elliott R. Haut, M.D.