Comparative study of the effect of oral contraceptives containing 50 μg of estrogen and those containing 20 μg of estrogen on adrenal cortical function

Abstract

Because the adrenal cortex is an endocrine gland essential to life, its function was studied in women who were taking an oral contraceptive that contained either 50 μg or 20 μg of estrogen. Of 32 healthy women studied, 18 used an oral contraceptive that contained 50 μg of estrogen, and 14 used an oral contraceptive that contained 20 μg of estrogen. With 50 μg of estrogen, the total plasma cortisol level rose significantly, the level of urinary cortisol excretion did not change significantly, and the levels of 17-ketosteroids and 17-ketogenic steroids were significantly reduced. With 20 μg of estrogen, there were no significant changes in the levels of total plasma cortisol, urinary cortisol excretion, and the excretion of 17-ketosteroids and 17-ketogenic steroids. Thus, adrenal cortical function was altered in women who used an oral contraceptive that contained 50 μg of estrogen, but there was no significant effect with the use of an oral contraceptive that contained only 20 μg of estrogen. Our findings confirm previous ones in regard to the effects of 50 μg of estrogen on adrenal cortical function, although no studies had been carried out previously on the effects of 20 μg of estrogen.