Effect of Two Synthetic Estrogens on the Level of Serum Protein-Bound Iodine in Men and Women With Atherosclerotic Heart Disease

Forty-three postmenopausal women with ischemic heart disease were treated with placebo or with 0.005–0.04 mg. of ethinyl estradiol daily for one to eleven months. Seventy-two men with ischemic heart disease were treated with placebo, or 0.01–0.50 mg. of ethinyl estradiol daily, or 10–80 mg. of Manvene daily for one to eleven months. The concentration of serum protein-bound iodine (PBI) was determined before and after initiation of treatment. The results were as follows: 1) The average increase in PBI concentration over the baseline level was 1.7 μg. per 100 ml. for women and 2.1 μg. per 100 ml. for men receiving ethinyl estradiol, and 2.0 μg. per 100 ml. for men receiving Manvene. 2) Ethinyl estradiol in dosages less than 0.005 mg. daily in women, or 0.02 mg. daily in men, was apparently no more effective than placebo in raising the PBI level. 3) Ethinyl estradiol in the dosages used was about 5 to 6 times more active in raising the PBI level in women than in men.