Researchers Explore Gender Differences in Pain Research

Male and female brains really are different, due in part to the role of sex hormones each is secreting, researchers said at a conference on gender and pain held in Baltimore.

While this gender difference does not necessarily translate into a compulsion for collecting an overabundance of shoes or a fanatical love of Monday night football, it does explain one critical distinction: men and women feel pain differently.

"The balance tips towards more pain for females, i.e., lower thresholds and less tolerance," said Dr. Karen J. Berkley, a research professor of the Program in Neuroscience at Florida State University who spoke at the conference Wednesday at the University of Maryland Dental School.

In other words, women will report feeling pain sooner in tests and not endure as much pain as men.

Statistics show that women are also much more likely to be diagnosed with several chronic pain disorders like rheumatoid arthritis and fibromyalgia.

But before writing women off as the weaker sex, consider that men show greater anxiety about sustained low-level pain in some studies.

These mixed results show the difficulty of interpreting the role of gender across pain studies up to this point.

With no uniform guidelines on how to factor in gender when doing pain research, "We were all doing our own little thing and it was hard to relate the results," said Joel D. Greenspan, a professor in the Department of Biomedical Sciences at the University of Maryland Dental School.

Greenspan is also one of the three scientists organizing the conference who were referred to jokingly by Dr. Margaret M. McCarthy, who lectured on Wednesday, Sept. 27, as "the three musketeers of pain."

On Sept. 28 and 29, 33 prominent pain researchers from the United States, Europe and Canada were due to attend a closed-door session of the conference to create a set of "guidelines to guarantee consistency from study to study," said Greenspan. The guidelines will be submitted to an academic journal for publication.

Greenspan predicted that some of the recommendations will deal with documenting hormonal cycles when pain data is collected. Another recommendation might be to include both very old and very young subjects in studies, both age groups that are usually overlooked in pain experiments.

By standardizing pain research practices, scientists hope to better understand gender differences in pain perception and the role of hormonal influences.

Hormone levels are suspected to be a key factor in explaining pain differences and the brain's role in producing sex hormones lead McCarthy to declare that "the brain is really a gonad."

Future research will focus on whether certain pain-relievers are more effective in men or women.

"Does aspirin work better in men than women?" poses Berkley. "Maybe a better question is: Does it work differently? And is that a good thing or a bad thing?"

Ultimately, conference attendees see the research improving clinical diagnoses and treatment for both men and women in pain.

Understanding differences in how gender influences pain perception could raise legal issues as well, said Berkley.

Recent studies have shown that males may be more aggressively treated for pain than women. If doctors are more willing to prescribe painkillers to men, we must ask whether a "disservice is being done to women," Berkley said.

"We're not moving fast enough," Berkley said, speaking about the pace of pain and gender research.

"...we are at the tip of the iceberg and all of us feel the palpable frustration. We've accumulated all this data and something should come out of it."

The Capital News Service contributed to this report.