Today's oral contraceptives have lower doses of hormones than those of the past, but when combined with smoking, they may still pose a significant risk of heart disease, new research suggests.
"Even today the latest types of oral contraceptives with lower doses of hormones than those of decades ago appear to have harmful effects when combined with smoking and stress," says Mary C. Davis, Ph.D., of Arizona State University, who reports the results of her research in the March issue of Health Psychology.
Davis investigated the links between oral contraceptive use and changes in blood content and dynamics when smokers and nonsmokers respond to acute stress, measuring its effects on stress-related changes in blood levels of cholesterol, triglycerides, and fibrinogen, a protein essential to blood coagulation that is implicated in atherosclerosis. This is the first study to offer data on how smoking and oral contraceptives intersect with acute stress to increase fibrinogen in the blood.
Davis administered two psychological stress tests to 52 women smokers and nonsmokers, half of whom were using oral contraceptives. After some of them smoked or puffed on an unlit cigarette, each of them was asked to deliver a four-minute speech defending themselves against a false accusation, and then to perform an endless mathematical task as fast and accurately as they could for eight minutes.
One of the principal findings was that oral contraceptive users had significantly greater cardiovascular reactivity to stress, but only if they were also smokers. The study also reports a modest but significant increase in lipid and fibrinogen levels during stress.
Total cholesterol and triglyceride levels increased up to 5 percent in response to stress among those who smoked, but increased only slightly or decreased among those who did not smoke. Stress-related increases in fibrinogen were apparent among all of the women.
The research generated a wealth of data for further research into the causal mechanisms and long-term consequences of acute stress-related increases in lipids and fibrinogen.
Grant support for the research was provided by the Arizona Disease Control Research Commission and a faculty grant-in-aid.
Health Psychology is the official, peer-reviewed research journal of the Division of Health Psychology (Division 38), American Psychological Association. For information about the journal, please contact its editor, David Krantz, Ph.D., at 301-295-3273.
Posted by the Center for the Advancement of Health http://www.cfah.org. For information about the Center, contact Petrina Chong pchong@cfah.org, 202-387-2829.
Journal
Health Psychology