Now, new research appearing in the May issue of Health Psychology suggests there may be good reason to also look at the role that learned behavioral factors might play in the development of hypertension, or high blood pressure.
"What was interesting is that we were not only seeing physiological reactivity differences [in children of parents with hypertension], we also saw differences in learned behavior," says Nicole L. Frazer, lead author of the study.Frazer is an assistant professor in the department of family medicine at Uniformed Services University of the Health Sciences in Maryland. She conducted the study while she was a doctoral candidate in clinical psychology at West Virginia University.
Frazer and her colleagues looked at 64 white undergraduate students between the ages of 18 and 46. Half were men and half women. Half within each gender group reported a parental history of hypertension while half did not.
The participants were asked to complete different mentally stressful tasks. They included subtracting backwards by sevens from the numbers 500, 613 and 518, and performing interpersonal role-playing.
The role-playing involved a three-minute session in which two people tried to resolve a conflict. The study participants were told that their goal was to reach a compromise. The other role player, who was not a study participant, was instructed not to reach a compromise.
Blood pressure, heart rate and behavioral responses were measured for each study participant throughout the trial.
The children of parents with hypertension had a greater increase in systolic blood pressure during the mental tasks, and engaged in more negative verbal and nonverbal behavior during the role-playing. Negative verbal behavior included using more put-downs, and nonverbal behaviors included eye-rolling, sighing and lack of eye contact, Frazer says.
What was surprising was that subsets within the group of children of hypertensive parents had differing responses. One saw their blood pressure rise, while the other resorted to the negative verbal/nonverbal responses.
"The offspring of hypertensives who responded with exaggerated cardiovascular response were not the same group of offspring who responded with negative or nonverbal behavior," Frazer says.
Determining who's at risk for hypertension might need to involve looking at behavioral responses as well as cardiovascular responses to stress, Frazer says: "It is interesting to speculate whether they constitute comparable risk factors for essential hypertension or heart disease."
The question is, what does this mean in real life?
"It has been difficult to relate what happens in the lab to what happens in real life," says Dr. Thomas Pickering, director of the integrative and behavioral cardiovascular health program at Mount Sinai School of Medicine in New York City. "It's very hard to establish a connection between the two."
This doesn't mean that everyone with hypertensive parents should sign up for yoga or assertiveness training.
"This [study] raises a lot of questions," Frazer says. "If you did teach offspring of hypertensives better social skills, relaxation and assertiveness, would that decrease their chances of developing hypertension?"
"Future research will have to look at how behavioral responses are linked to" the development of diseases, Frazer notes. "We have to now look prospectively at whether these types of behaviors or family environments are linked to disease endpoints, and then that would give us more data."