The effect of estrogens on carbohydrate metabolism: Glucose, insulin, and growth hormone studies on one hundred and seventy-one women ingesting Premarin, mestranol, and ethinyl estradiol for six months

One hundred and seventy-one women were tested with a three-hour, 100 Gm. oral glucose tolerance test and then treated for 6 months with either Premarin, 1.25 mg., mestranol, 0.08 mg., or ethinyl estradiol, 0.05 or 0.5 mg. A second identical test was then done, and comparisons were made of the blood glucose, plasma insulin, and plasma growth hormone levels. The results were analyzed on the basis of the menstrual status, the pretreatment glucose status, and the type and dose of estrogen taken. There was a significant weight gain by the women in all groups. There were few significant changes found in either the group glucose values, the individual glucose tolerance curves, or the group plasma insulin levels. The tolerance curves improved slightly in the premenopausal women and deteriorated slightly in the postmenopausal women being treated. There was a significant fasting glucose rise for the Premarin group and a significant 2 hour insulin decrease for the mestranol group. The mean fasting ambulatory growth hormone levels were unchanged with Premarin therapy but increased with the mestranol and ethinyl estradiol treatment, although only the changes with mestranol were significant. In general, the type and dose of estrogen used made little difference in the glucose and insulin results. The significance of these findings with respect to the carbohydrate metabolic alterations reported in oral contraceptive users is noted.