Effect of low-dose oral triphasic contraceptives on blood viscosity, coagulation and lipid metabolism.

ABSTRACT

PIP: Previous studies have documented an association between blood viscosity and risk factors for cardiovascular and thromboembolic disease. The present study assessed the impact of use of a low-dose, triphasic oral contraceptive (OC) containing ethinyl estradiol in combination with gestodene on the coagulation system, serum lipid metabolism, and blood viscosity. Enrolled were 10 OC users with no history of OC use before the study and 10 non-users. At 3 and 6 months after initiation of OC use, significant changes were recorded in partial thromboplastin time, fibrinogen, high density lipoprotein, and apolipoprotein A-1. Plasma viscosity was significantly increased during OC use, while whole blood viscosity and erythrocyte deformability remained unchanged. All alterations associated with OC treatment remained within the normal range of laboratory values, however. Thus, these findings suggest an absence of any significant OC effects on the hemostatic balance or lipid metabolism that might represent a risk factor for cardiovascular disease. Moreover, the measurement of blood viscosity may be a promising marker for monitoring thrombotic risk in women taking OCs given its apparent high sensitivity.