The affairs of the heart may actually affect the affairs of the heart in ways previously not understood.
"Growing evidence suggests that the quality and patterns of one's social relationships may be linked with a variety of health outcomes, including heart disease," says Thomas Kamarck, professor of psychology and Biological and Health Program Chair in the University of Pittsburgh Kenneth P. Dietrich School of Arts and Sciences. He is an author of a new study that correlates unhappy marital interaction with thicker carotid arteries and a higher risk of cardiovascular disease.
"The contribution of this study is in showing that these sorts of links may be observed even during the earliest stages of plaque development [in the carotid artery]," Kamarck continues, "and that these observations may be rooted not just in the way that we evaluate our relationships in general but in the quality of specific social interactions with our partners as they unfold during our daily lives."
Nataria Joseph, who recently completed a postdoctoral fellowship under Kamarck, is the lead author of the paper, published this month in the journal Psychosomatic Medicine. Given the size of the effect in the study and the relationship between carotid artery plaque and disease, Joseph's findings, made at Pitt, indicate that those with marital interactions light on the positive may have an 8.5 percent greater risk of suffering heart attack or stroke than those with a surfeit of good feelings.
Joseph, who is now at the VA Greater Los Angeles Healthcare System, says, "These findings may have wider implications. It's another bit of support for the thought that marital or serious romantic relationships play a significant role in overall health. Biological, psychological, and social processes all interact to determine physical health."
The study included 281 healthy, employed, middle-aged adults who were married or living with a partner in a marital-like relationship. Their interactions were monitored hourly over the course of four days, with the partners rating their interactions as positive or negative.
Carotid artery thickness was also measured. Those partners reporting more negative interactions were found to have thicker carotids. Joseph says that these associations could not be accounted for by other behavioral or biological risk factors and were also independent of marital interaction frequency, nonmarital social interaction, or personality factors. The findings were consistent across age, sex, race, and education level.
There are limitations to the study, Joseph says, because it is a cross-sectional study with all the data collected at one point in time. Causality, therefore, has not been proven, though a strong correlation has been established.
"What it does show," she says, "is that health care providers should look at relationships as a point of assessment. They are likely to promote health or place health at risk."