Fibrinolysis and body build: Interrelationships between blood fibrinolysis, body composition and parameters of lipid and carbohydrate metabolism

Abstract

Summary Parameters of the blood fibrinolytic enzyme system, body build and fasting levels of plasma triglycerides, free fatty acids, cholesterol, insulin and glucose were measured in healthy males and females of varying degrees of body fatness. The fibrinolytic measurements included dilute blood clot lysis, [ 131 I]fibrin clot lysis, euglobulin and fibrin plate lysis, fibrinogen, plasminogen, antiplasmin and urokinase inhibitor levels and urokinase excretion. Highly significant inverse relationships were obtained between all the estimates of fibrinolytic activity and body fatness in both males and females. No relation was demonstrable between fibrinolysis and creatinine excretion or other indices of muscularity. Fibrinogen and plasminogen levels were significantly elevated in the more obese subjects. However, the fibrinolytic inhibitors, antiplasmin and urokinase inhibitor were not significantly related to body fatness. Significant negative correlations were found between fibrinolytic activity and plasma triglyceride and free fatty acid levels in males, and triglyceride, insulin and glucose levels in females. However, these relations (except with insulin in females) became insignificant when the effect of obesity was taken into account in regression analysis. The inverse relationship between fibrinolysis and body fatness appears to be due to a low level of circulating plasminogen activator and not to an increase in known inhibitors. It cannot be attributed to elevated fibrinogen levels or to changes in the lipid and carbohydrate parameters measured in the present study.