Reduced Fibrinolytic Capacity Associated with Low Ratio of Serum Testosterone to Oestradiol in Healthy Coronary High-risk Men

In a study of 42 healthy, middle-aged men with high risk of coronary heart disease (CHD), we found a highly significant correlation between low ratio of serum testosterone to oestradiol and delayed clot lysis after venous stasis as measured with the euglobulin clot lysis time (ECLT). The upper normal limit of ECLT was set at 60 min. Half of the examined specimen, i.e. from 21 individuals, lysed as normal; 4 specimen lysed between 60 and 90 min, whereas the remaining 17 specimen did not lyse within 2 hours. Sixteen of these 17 individuals with the most defective fibrinolytic capacity belonged to the group of individuals with the lowest ratio of serum testosterone to oestradiol. The association was highly significant (p < 0.001). In comparison, the correlation between serum triglyceride concentration and the ratio of serum testosterone to oestradiol was significant at the 2% level, whereas serum cholesterol and this ratio were not associated. The significance of the findings remains obscure, but may be important for the incidence of CHD in men.