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 microgram or 20 microgram of estrogen. Of 32 healthy women studied, 18 used an oral contraoceptive that contained 50 microgram of estrogen, and 14 used an oral contraceptive that contained 20 microgram of estrogen. With 50 microgram 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 microgram 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 microgram of estrogen, but there was no significant effect with the use of an oral contraoceptive that contained only 20 microgram of estrogen. Our findings confirm previous ones in regard to the effects of 50 microgram of estrogen on adrenal cortical function, although no studies had been carried out previously on the effects of 20 microgram of estrogen.
PIP: The effect of oral contraceptives (OCs) containing 50 mcg vs those containing 20 mcg of ethinyl estradiol (EE) on adrenal cortex function was assessed. From a total of 32 women studied, 18 used the 50-mcg EE OC and 14 used the 20-mcg preparation. Blood and urine specimens were obtained at the start of the trial and in 3-month intervals for 9 months thereafter, and total plasma cortisol, urinary cortisol excretion, urinary 17-ketosteroids excretion, and urinary ketogenic steroids excretion were assayed. In women using the 50-mcg OC, the total plasma cortisol level rose significantly after 3, 6, and 9 months of OC use with no significant difference between the mean values of these periods. Urinary cortisol excretion level did not change significantly after 3, 6, and 9 months of use. Urinary levels of 17-ketosteroids and 17-ketogenic steroids were significantly reduced after 3, 6, and 9 months of OC use; however again means were not statistically significantly different. In the 20-mcg OC group, the measured substances did not change significantly after 3, 6, and 9 months, confirming the previously reported findings that adrenal cortical function was affected during use of high-dose EE OCs.