The new study, reported in the current issue of the Archives of General Psychiatry, is the latest discovery in a three-decade-long series of experiments underway at the Ohio State University's Institute for Behavioral Medicine Research. The work is aimed at identifying and then explaining the ways psychological stress can affect human immunity.
Jan Kiecolt-Glaser, a professor of psychiatry and psychology, and partner Ronald Glaser, a professor of molecular virology, immunology and medical genetics, both at Ohio State, say the findings provide important recommendations for patients facing surgery.
"This shows specifically why it is so important that people be psychologically prepared for their surgeries," Kiecolt-Glaser explained.
Colleague Glaser added, "We have enough data now from all of our past studies to basically suggest that hospitals need to modify existing practices in ways that will reduce stress prior to surgery." Both researchers said such stress reduction could lead to shorter hospital stays -- with corresponding lower medical bills -- and a reduced risk of infections among patients.
The researchers focused on a group of 42 married couples who had been together an average of at least 12 years. Each couple was admitted into the university's General Clinical Research Center for two, 24-hour-long visits. The visits were separated by a two-month interval.
During each visit, both the husband and wife were fitted with a small suction device which created eight tiny uniform blisters on their arms. The skin was removed from each blister and another device placed directly over each small wound, forming a protective bubble, from which researchers could extract fluids that normally fill such blisters. The husbands and wives also completed questionnaires intended to gauge their level of stress at the beginning of the experiment. Lastly, each person was fitted with a catheter through which blood could be drawn for later analysis.
During the first visit, Kiecolt-Glaser said, each spouse was asked to talk for several minutes about some characteristic or behavior which he or she would like to change. This was a supportive, positive discussion.
"But during the second visit, we asked them to talk about an area of disagreement," she said, "something that inherently had an emotional element."
Both discussions were videotaped and those tapes were used to gauge the level of hostility present between the couples. Fluid accumulating at the individual wound sites and peripheral blood samples were also taken from each participant.
When the researchers analyzed the data, the results showed the following:
Wounds took a day longer to heal after the arguments than they did after the initial supportive discussion;
Couples who showed high levels of hostility needed two days longer for wound-healing, compared to couples whose hostility appeared low.
"Wounds on the hostile couples healed at only 60 percent of the rate of couples considered to have low levels of hostility," Kiecolt-Glaser said.
Blood samples from those highly hostile couples showed differences as well. The levels of one cytokine -- interleukin-6 (IL-6) -- increased one-and-a-half times over those in couples considered less hostile.
Cytokines are key elements in the human immune system
. They hold a delicate balance in maintaining the right immune response. Increased levels of IL-6 at the site of a wound stimulate the healing process but those same levels circulating throughout the bloodstream is a problem.
Sustained higher-than-normal levels of IL-6 have been linked long-term inflammation which, in turn, is implicated in a host of age-related illnesses. These include cardiovascular disease, osteoporosis, arthritis, type-2 diabetes, certain lymphoproliferative diseases and cancers, Alzheimers disease and periodontal disease, the researchers said.
"In our past wound-healing experiments, we looked at more severe stressful events," Kiecolt-Glaser said. "This was just a marital discussion that lasted only a half-hour.
"The fact that even this can bump the healing back an entire day for minor wounds says that wound-healing is a really sensitive process."
Glaser added, "This supports our long-held contention that even small changes in cytokine levels will have a marked effect on health."
William Malarkey, professor of internal medicine; Stanley Lemeshow, dean of the School of Public Health and director of the Center for Biostatistics, and postdoctoral researchers Tim Loving and Jeff Stowell also worked on the research.