Many researchers have proposed that certain personality types are more likely to develop high blood pressure. But in fact, the relationship between personality and high blood pressure may be less clear-cut than previously understood, suggest the results of a new study.
"No evidence from this study supports the hypertensive personality hypothesis," said lead author Joseph E. Schwartz, PhD, of the department of psychiatry at State University of New York, Stony Brook.
Previous studies have found those with high blood pressure to be angrier, more anxious, more depressed and more Type A than those with normal blood pressure. Studies have also found characteristics such as restrained aggression, inner tension and submissiveness to be associated with high blood pressure.
According to Schwartz and colleagues, the findings of such studies may be misleading for several reasons. Obtaining accurate blood pressure measurements is inherently difficult, since many individuals test differently in a clinical environment. "As many as 20 percent of all patients diagnosed with hypertension may have 'white coat' hypertension," said Schwartz, referring to the phenomenon whereby blood pressure rises as a direct response to having it measured. Also, many studies fail to screen study participants for other cardiovascular diseases, which may skew results.
Another problem with previous studies on blood pressure and personality is their lack of consistency, according to the researchers. Some studies used standard psychological tests, some didn't. Some studies measured anger expression and not anger suppression, and some studies measured a range of variables while others measured only one or two, like anger and anxiety, for example. "This variability makes cross-study comparisons difficult," said Schwartz.
Using popular standardized tests, Schwartz and colleagues measured a wide range of behaviors in 283 men, including anger, anger expression, anxiety, hopelessness and submissiveness. They also measured the study participants' blood pressure in several ways, including using a monitor that took ongoing measurements for 24 hours.
Those with mild hypertension were no more likely to possess the tested characteristics than those with normal blood pressure, the researchers found. The study results are published in the January/February issue of the journal Psychosomatic Medicine.
One study limitation is that their study participants -- who tended to be healthy, employed, white men -- may not resemble others with hypertension in terms of psychological traits, the researchers noted. Studies of women, and of black men, have found associations between anger and blood pressure, for example.
Personality may indeed play some role in the development of high blood pressure, the researchers speculated, perhaps to enhance or reduce the effects of genetic predisposition. Situational factors probably do play a role, noted the researchers. In an earlier publication from this study, Schwartz and colleagues found that men in highly demanding jobs with little decision-making power were more likely to have hypertension.
"The relationship between psychological variables and hypertension, if one exists at all, is probably quite complex," Schwartz concluded.
This research was supported in part by grants from the National Heart, Lung and Blood Institute and the American Heart Association.
Psychosomatic Medicine is the official bimonthly peer-reviewed journal of the American Psychosomatic Society. For information about the journal, contact Joel E. Dimsdale, MD, at (619) 543-5468.
Posted by the Center for the Advancement of Health