Janice K. Kiecolt-Glaser, Ph.D., of Ohio State University, Columbus, and colleagues conducted a study to assess how hostile marital behavior affected a health outcome, wound healing, as well as the production of proinflammatory cytokine. The study included 42 healthy married couples, aged 22 to 77 years (average, 37 years old), married an average of 12.6 years. Couples were admitted twice to a hospital research unit for 24 hours. During the first admission, couples had a structured social support interaction, and during the second admission, they discussed a marital disagreement. Couples rated their behavior and responses. A vacuum pump was used to produce blisters on the arm. The blister wound was examined several times over a 12 day period to determine the degree of healing and blood was drawn to measure cytokine levels.

The researchers found that couples’ blister wounds healed more slowly following marital conflicts than after social support interactions. Couples who demonstrated consistently higher levels of hostile behaviors across both their interactions healed at 60 percent of the rate of low-hostile couples and had a median (midpoint) time to healing of one day longer.

Local cytokine production was lower at wound sites following marital conflicts than after social support interactions. High-hostile couples also produced relatively larger increases in cytokine values the morning after a conflict than after a social support interaction compared with low-hostile couples.

“These changes are important because both stressors and depression can sensitize the inflammatory response in such a way that they produce heightened responsiveness to stressful events as well as antigen challenge. Furthermore, more frequent or persistent stress-related changes in plasma levels of these key cytokines have broad implications for health; elevated levels of proinflammatory cytokines have been linked to a variety of age-related disease, including cardiovascular disease, osteoporosis, arthritis, type 2 diabetes mellitus, certain cancers, and frailty and functional decline. Moreover, inflammatory activation can enhance development of depressive symptoms. Thus, relationships characterized by hostility, repeated conflicts, and heightened [cytokine] levels could have negative consequences for both physical and mental health. Indeed, our data are consistent with the growing epidemiological evidence that marital stress is a risk factor for mental and physical health,” the authors write.

“If chronically hostile or abrasive relationships produce more frequent and more pronounced proinflammatory cytokine changes, then individuals in troubled relationships could be at greater risk over time,” the researchers conclude.