"Since these studies have been done in men, we decided that we would look to see if there was a similar relationship in women," said the study's lead author Christine M. Albert, M.D., M.P.H., assistant professor at Harvard Medical School, Boston.
Albert and colleagues studied data from the Nurses' Health Study, a large survey about heart disease risk factors, menopausal status and lifestyle factors that has polled nurses across the U.S. every two years since 1976. In 1988, Nurses' Health Study authors surveyed 72,359 women who had no history of heart disease about phobic anxieties. They measured phobic anxiety using the Crown-Crisp index (CCI), which ranks the degree of phobic anxiety on a scale of 1 to 16, with higher scores indicating higher anxiety. These questions were used:
Answers were Never/Not at all, Sometimes/Moderately or Often/Very/Yes.
The women's level of anxiety was classified into four groups based on their scores: 0-1, 2, 3, or 4 or higher. During the 12 years of follow-up, there were 97 sudden cardiac deaths, 267 coronary heart disease deaths, and 930 non-fatal heart attacks.
"We examined the relationship between the score on the phobia index and the subsequent risk of having coronary heart disease events," said Albert, who also works as an electrophysiologist and cardiologist at Massachusetts General Hospital and an epidemiologist at the Brigham and Women's Hospital in Boston.
"We found that women who suffered most from phobic anxiety -- those who scored four or greater on the survey -- were at a marginally increased risk of dying suddenly from coronary heart disease in general compared to those in the lowest quarter of the population," she said. A higher score on the CCI was associated with an increased risk for sudden cardiac death and fatal heart disease, but not non-fatal heart attack. Specifically, the women with a CCI greater than four had a 59 percent increased risk of sudden cardiac death, and a 31 percent increased risk of fatal coronary heart disease compared with those who scored zero or one.
These risks were lower after controlling for other cardiac risk factors linked to phobic anxiety such as high blood pressure, diabetes and high cholesterol. However, even after controlling for these risk factors, a trend toward increased risk for sudden cardiac death persisted. The authors conclude that associations between anxiety and other cardiac risk factors might account for some, but not all, of the risk linked to phobic anxiety.
"In other words, women who had high levels of phobic anxiety also were more likely to smoke, have hypertension and hypercholesteremia," she said. It is not known whether phobic anxiety makes women more likely to develop other risk factors for heart disease or whether these risk factors lead to higher levels of phobic anxiety.
While this study suggests a link between phobic anxiety and risk of coronary death among women, it did not look at whether treating the anxieties would have a positive impact on death from heart disease. Still, Albert suggested that consumers and their health care providers should consider that women who suffer from phobic anxieties are at elevated risk of death from heart disease and should, at the very least, try to control their other potential heart disease risk factors.
"One of the reasons that we did this study is that anxiety disorders, and phobic disorders in particular, tend to be more common in women," Albert said. "It's estimated that 5 percent of the population has anxiety disorders and as many as 15 percent will meet criteria for a phobic disorder. If the association we observed between phobic anxiety and sudden cardiac death in our study is causal, greater recognition and perhaps treating these disorders in women may lower their risk of dying from heart disease, especially from sudden cardiac death." Co-authors are Claudia U. Chae, M.D.; Kathryn M. Rexrode, M.D., M.P.H.; JoAnn E. Manson, M.D., D.P.H.; and Ichiro Kawachi, M.D., Ph.D. Statements and conclusions of study authors that are published in the American Heart Association scientific journals are solely those of the study authors and do not necessarily reflect association policy or position. The American Heart Association makes no representation or warranty as to their accuracy or reliability.
NR02 – 1017 (Circ/Albert)