Effects of Oral Contraceptives and Obesity on Protein C Antigen

Abstract
In 24 women using oral contraceptives, protein C antigen was higher than in 24 women of the same age and of the same degree of obesity who were not using OC. In the pooled data for all 48 women, there was an increase in protein C of about 1% (of standard) for each 1.0 mm increase in skinfold thickness. Protein C tends to be high rather than low in circumstances predisposing to thrombosis.