Abstract 3002: Long Term Oral Contraceptive Use is an Independent Risk Factor for Arterial Stiffening

Abstract

Oral contraceptives (OC) are among the most frequently used drugs in the world with approximately 100 million women worldwide taking OC. In contrast to the active controversy surrounding hormone replacement therapy, little attention has been focused on OC, a drug therapy taken by far more women for far longer time periods. We describe the population effects of current and long-term OC exposure on a prognostically well validated marker of arterial stiffness: carotid-femoral pulse wave velocity (PWV). The Asklepios study is a representative sample (2524 apparently healthy M/F volunteers, aged 35–55 years, 1301 women) from the Belgian general population, free from overt cardiovascular disease. The subjects were extensively screened (biochemistry, lifestyle, cardiac and vascular echography, arterial tonometry). PWV was measured from flow patterns registered by Doppler echography in the femoral and carotid arteries. Of 1301 women (median age 45.7 y), 27.4% were actively taking OC. In contrast past use of OC is far more prevalent with 81% of women having taken OC for at least 1 year. The median duration of exposition in these women was 13 years. Age-adjusted PWV was higher in women currently taking OC: 6.75 versus 6.55 m/s (difference 0.19 ± 0.09 m/s; p = 0.034). However, current OC users also had higher blood pressures (BP): systolic BP (+4.4 ± 0.9 mmHg; p < 0.001), diastolic BP (+2.3 ± 0.6 mmHg; p < 0.001). After adjustement for BP, the difference in PWV between current OC users and non-users became non-significant: 6.60 versus 6.62 m/s (difference 0.02 ± 0.09 m/s; p = 0.814). In contrast, duration of OC use is a significant determinant of PWV, even after adjustement for age, BP, lipid levels, body size, heart rate, drug therapy (lipid-lowering, antihypertensive), glycemic status and smoking: F = 6.1; p = 0.013. Per 10 years of OC exposure PWV increased by 0.1 m/s (0.02– 0.18; p = 0.013). Use of OC is associated with increased vascular stiffness in women. Current use is associated with increased PWV because OC’s increase blood pressure, long-term use (probably through structural remodelling of the vessels) is an independent determinant of PWV, increasing PWV by 0.10 m/s per 10 years exposure.