AHA: Contraceptive Pill Linked to Atherosclerosis

ORLANDO, Nov. 6 -- Oral contraceptives may raise arterial atherosclerosis 20% to 30% for every decade of use, researchers from Belgium reported here.
Action Points
Caution patients that the authors of this study suggested that cardiovascular risk from hormonal contraceptive use may be managed with lifestyle changes and may not be a reason for discontinuing use.
This study was published as an abstract and presented orally at a conference. These data and conclusions should be considered to be preliminary as they have not yet been reviewed and published in a peer-reviewed publication.
However, women should not discontinue use of the pill solely on the basis of findings from the European population-based study, cautioned Ernst Rietzschel, M.D., of Ghent University, at the American Heart Association meeting.
Rather, it suggests that physicians should monitor cardiovascular risk for women prescribed oral contraceptives and counsel them on ways to manage the atherosclerotic risk through lifestyle changes, commented Nieca Goldberg, M.D., of New York University, acting as an AHA spokesperson.
Despite all the controversy surrounding hormone replacement therapy, little attention has been paid to hormonal contraceptives, "a drug therapy taken by far more women for a far longer time of use with far higher doses of estrogen," Dr. Rietzschel said.
What scrutiny there has been with the pill has primarily focused on thrombotic risk, and there has been almost no research on long-term outcomes, he added.
So he and colleagues studied a random sample of 1,301 apparently healthy women ages 35 to 55 from the Erpe-Mere region in Belgium. They all underwent ultrasound imaging of atherosclerosis of the bilateral carotid and femoral arteries. Women reported oral contraceptive use, which was validated with their primary care physician.
Overall, patient characteristics were similar to the Belgian population and reflected low cardiovascular risk.
More than 81% of the participants reported hormonal contraceptive use for at least a year, which closely matched the 82% rate for women ages 15 to 44 in the United States reported by the CDC. The average duration of use was 13 years.
The prevalence of unilateral carotid artery plaque rose significantly for each additional decade of contraceptive exposure (odds ratio: 1.17, 95% confidence interval: 1.00 to 1.33, P0.05). The same association was seen for femoral artery plaque (OR: 1.28, 95% CI: 1.10 to 1.47, P0.01).
Using a more specific and stringent criterion -- bilateral atherosclerosis -- the same associations were seen with even higher point estimates for harm (OR: 1.42 for carotid plaque and 1.34 for femoral plaque, both P0.05), "consistent with a true effect."
Many women in the study were exposed to all three generations of oral contraceptives that have come on the market during the almost 40 years since the first was introduced.
Although participants did not report which contraceptives they used and at what doses, part of the atherosclerotic risk was "almost certainly" from the older generations, which are known to raise LDLs and lower HDLs, Dr. Rietzschel said.
All three generations, though, are known to raise blood pressure by 4 to 9 mm Hg.
"It's very unlikely that a drug that raises blood pressure…will not impact vasculature," he said.
If effectively replicated, the findings suggested "we may need to change the way we look at oral contraceptives" to include the accumulation of atherosclerosis over time, Dr. Rietzschel said.
This will provide women an opportunity for better cardiovascular prevention, he concluded. "There's an enormous amount of things you can do to reduce that risk."
Dr. Rietzschel reported no conflicts of interest. Dr. Goldberg reported no relevant conflicts of interest.
Additional source: American Heart Association meetingSource reference: Rietzschel E, et al "Anticonceptive Drug Use And Increased Carotid and Femoral Plaque Prevalence: Population Data From Asklepios" AHA meeting 2007; Abstract 3614.