Heparin Cofactor Activity and Antithrombin III Concentration in Plasma Related to Age and Sex

Abstract

Heparin cofactor activity and antithrombin III (At-III) concentration were measured in plasma from 219 healthy men and 177 women. Narrow ranges for heparin cofactor activity and At-III concentration were found. The standard deviation for heparin cofactor activity in men and women was 8.6 and 10.1, respectively, and for At-III concentration, 10.4 and 12.5. In men, mean heparin cofactor activity and mean At-III concentration decreased significantly with increasing age. In women, mean heparin cofactor activity and mean At-III concentration tended to be lower in fertile age. Hereditary At-III deficiency was detected in 1 individual.