Experiencing stress increases a woman’s chance of developing cardiovascular disease, according to a Northwestern Medicine study that analyzed data from 82,000 women.
Kiarri Kershaw, PhD, MPH, ’12 GME, assistant professor in Preventive Medicine-Epidemiology, and colleagues used data from the Women’s Health Initiative, a national observational study with a large, multiethnic cohort of postmenopausal women.
“We found that women who reported experiencing more stressful life events and being in stressful relationships were more likely to develop coronary heart disease and stroke than women who reported fewer of these negative experiences after adjusting for socioeconomic and demographic characteristics,” said Kershaw.
The findings were published in the Journal of the American Heart Association.
To measure the baseline presence of stressful life events, the scientists looked at participants’ responses in a questionnaire about life changes. The women reported whether they had experienced over the past year occurrences such as a spouse’s death or serious illness, major money problems, divorce, conflict with children, losing a job or physical abuse.
The scientists evaluated social strain by looking at the women’s answers to questions about their social relationships: How many people important to you get on your nerves? How many of them ask too much of you?
Kershaw’s team then tracked incidence of coronary heart disease and stroke over 16 years of follow-up. They determined whether the associations between stress and cardiovascular disease could be explained by typical risk factors, such as smoking, alcohol use, poor diet and low physical activity.
“These relationships were almost entirely explained by traditional risk factors. These include health behaviors individuals may adopt to cope with stress and biological risk factors that may be affected by chronic stress,” said Kershaw. “In particular, we found that waist circumference and diabetes status accounted for the largest proportion of the relationship between each stress measure and coronary heart disease and stroke.”
Statistical analysis adjusted for age, race/ethnicity, education, income, marital status and depressive symptoms showed that high levels of social life events and social strain were significantly associated with higher incidences of the diseases compared to women with low stress scores.
Previous research has investigated the correlation between stress and cardiovascular disease, but this study is meaningful for several reasons: it broke down stress into two measures; it used a large cohort of women; and its conclusions stemmed from cardiovascular disease outcomes that were clinically confirmed.
“Our findings suggest targeted interventions to promote stress management may lower CVD risk in women,” said Kershaw.
This study was supported by NIH grant N01‐HC‐95164.