Early response of selected haemostatic and haematological parameters to physical activity in young women - the potential impact of oral contraceptives

Introduction and objective. Exercise (submaximal) in untrained subjects can modify haemostasis toward hypercoagulability, especially among women using oral contraceptives (OC). The aim of this study was to investigate whether this can be explained by platelet haemostasis and changes in the generation of membrane microparticles. Materials and method. Young, healthy women (n=60) were divided into 2 equal groups: a study group OC (+) who had used OC for >3 months, and controls who had never used oral contraceptives OC(-). Exclusion criteria: those with systematic daily physical activity. Participants were subjected to treadmill exercise (Cardiac Diagnostic System; model CH2000) using the Bruce protocol/ AHA guidelines. Platelet aggregation with arachidonic acid (ASPI test) or ADP (ADP test), membrane microparticle (MP) activity, plasma coagulation times (APTT/PT) and blood count were determined before and 45 minutes after exercise. Results. Before exercise, the OC(+) group had slightly higher platelet aggregation (ADP test), significantly lower MP activity, slightly lower PLT and slightly higher PDW rate. Exercise caused slight inhibition of platelet aggregation (ASPI test), and significant decrease in MP activity – only in the OC(-) group. After exercise, in both groups there was a significant decrease in PLT and increase in WBC, more pronounced in OC(+) group. Conclusions. Submaximal exercise was beneficial for haemostasis in women not using hormonal contraception, associated primarily with reduced MP activity. No beneficial effects of physical activity were found for women using hormonal contraceptives, possibly associated with a hypercoagulable state, and higher reactivity of blood platelets under the influence of the use of contraceptives.