Effect of a Low-Dose Oral Contraceptive on Venous Endothelial Function in Healthy Young Women: Preliminary Results

Abstract

Giribela CRG, Rubira MC, Melo NR de, Plentz RDM, Angelis K de, Moreno H, Consolim-Colombo FM. Effect of a lowdose oral contraceptive on venous endothelial function in healthy young women: preliminary results. Clinics. 2007;62(2): 151-8.BACKGROUND: A possible increase in the incidence of venous thromboembolic events has been reported among users of third generation oral contraceptives. The objective of this study was to evaluate the effect of a low dose oral contraceptive (15 µg ethinyl estradiol/60 µg gestodene) on the venous endothelial function of healthy young women. METHODS: Prospective case control study using the dorsal hand vein technique. Venous endothelial function was evaluated at baseline and after 4 months in the oral contraceptive users group (11 women) and in a control group (9 women). After preconstriction of the vein with phenylephrine, dose-response curves for acetylcholine and sodium nitroprusside were constructed. RESULTS: In the contraceptive users group, a reduction occurred in the maximum venodilation response to acetylcholine and sodium nitroprusside after 4 months of oral contraceptive use, but this difference was not statistically significant (P > 0.05). No significant changes were detected in maximum venodilation responses to acetylcholine and sodium nitroprusside at the 4-month time point in the control group. CONCLUSION: This study found no significant impairment of endothelium-dependent or independent venodilation in healthy young women following oral contraceptive use. Further studies are necessary using the same methodology in a larger sample over a longer follow-up period.

Comparison of Postprandial Lipemia between Women who are on Oral Contraceptive Methods and Those who are not

“…Also based on the results of this study, it is plausible to infer that women in COG are more prone to forming arterial and venous thrombi. OC and the increased PPL, independently, increase the activation of the blood-coagulation factor VII and inhibit the action of plasminogen, and these factors are proven to favor the formation of venous and arterial thrombi 28 , 39 .…”

“…It is important to mention that millions of women in the world use OC 27 , and new formulas have been developed in order to reduce its adverse effects, especially those related to lipid metabolism 28 . In Brazil, the most prevalent contraceptive method until the age of 30 is the hormone pill 29 .…”

“…The longer the time of use, the stronger its effect on lipid profile 17 , 30 . Some studies report that three months are sufficient to cause changes in lipid metabolism 21 , 28 .…”

Bradykinin or Acetylcholine as Vasodilators to Test Endothelial Venous Function in Healthy Subjects

“…Because of the way in which the vasomotor response to acetylcholine or other agonists of the muscarinic receptors are evaluated, several studies have also utilized regional infusions of this substance, usually intra-arterial, to measure endothelium-dependent vasodilation. 2 , 14 , 15 The use of acetylcholine in this context has potential advantages: the simplicity of its use, its favorable cost and its well-known effects on the arterial endothelium. However, studies performed in the late 1980s that utilized acetylcholine as an endothelium-dependent vasodilator agent demonstrated that high-dose infusions of acetylcholine caused a vasoconstrictor effect in the venous endothelium.…”