Blood pressure often decreases when you are with a spouse or significant other, dropping below levels associated with talking to friends or even being alone, according to a new study. "An intriguing possibility … is that the effects of partner interactions on [blood pressure] may partially account for the association between marital status and cardiovascular health," says Brook B. Gump, Ph.D., of the State University of New York at Oswego, referring to previous studies that have shown married men and women have less heart disease.
In the study of 117 subjects monitored continuously over 6 days, Gump and colleagues found that systolic and diastolic blood pressure measurements were lower during periods of interaction with a significant other than during interaction with any other person.
Systolic blood pressure, expressed as the first number in a blood pressure reading, refers to the pressure in the arteries during contractions of the heart, and diastolic, the second number, refers to the pressure in the arteries in between each contraction.
The study is published in the May issue of Psychosomatic Medicine.
The researchers found that subjects' blood pressure did not vary greatly among different social situations, only on the order of 1 to 1.5 mm Hg, but the changes were consistent and statistically significant. On a population-wide basis, these small effects may have substantial impact, they say.
"Given that most interactions with a well-established partner are safe or predictable, a partner's presence may act as a classically conditioned safety signal. Nonpartner interactions, however, because they may occur less frequently and involve greater uncertainty, may be more likely to be associated with a defense reaction or heightened vigilance," Gump says.
They also found that periods of talking were associated with a rise in blood pressure, although the increases were smaller when the subjects were with their partner than when talking with someone else. Talking was also largely responsible for the difference in blood pressure between interaction with someone other than a partner and alone time.
Surprisingly, the lower blood-pressure effects of partner interactions were about the same in subjects with less satisfying relationships than those with more satisfying relationships. However, those with less satisfying relationships spent less time with their partners, Gump says.