AZU1 and hereditary antithrombin deficiency: These interindividual variabilities are well known, and previous studies reported multiple factors, including obesity, aging, hepatic or renal disease, altered production of heparin-binding proteins, general heparin resistance, antithrombin deficiency, increased heparin clearance, elevated levels of heparin-binding proteins, and increased plasma levels of factor VIII, fibrinogen, and platelet factor 45–11.