S.A. Birk

Prospective Studies of Carbohydrate Metabolism in “Normal” Women Using Norgestrel for Eighteen Months

Studies of carbohydrate metabolism were conducted before and after 18 months of daily use of a 0.075-mg norgestrel preparation by 50 normal women. Each study involved a 3-hour oral glucose tolerance test. There was a significant increase in the weights of the women over the time of study. In addition, all of the plasma insulin values and all of the blood glucose values were significantly elevated at the 18-month test. All of the control glucose tolerance tests were normal initially, but eight (16%) of the glucose curves were abnormal at the 18-month test. These data suggest a systemic metabolic effect of norgestrel which may play a role in accelerating atherogenesis.

The effects of two years of mestranol treatment on carbohydrate metabolism

Twenty-nine menstrual age women who had a hysterectomy and oophorectomy were treated cyclically with 80 micrograms of mestranol per day for 2 yr. Their carbohydrate metabolism was evaluated prospectively by doing a 3 hr oral glucose tolerance test after a 100 g glucose load and measuring both blood glucose and plasma insulin levels. The tests were performed before drug treatment and after 2 yr of drug use. Those women that had a normal predrug test had some carbohydrate metabolism changes at the 2 yr test with significant elevations of the fasting, 1 and 2 hr blood glucose values, and also significant elevations of the 2 and 3 hr plasma insulin values. Those women with a borderline abnormal predrug test had no significant change in either parameter of carbohydrate metabolism however a trend toward similar changes was noted.

Carbohydrate metabolism studies in women using Brevicon, a low-estrogen type of oral contraceptive, for one year

A prospective study of carbohydrate metabolism was done in 12 normal women over 1 years time while they were using the low-estrogen type of oral contraceptive Brevicon, which contains 0.035 mg of ethinyl estradiol and 0.5 mg of norethindrone. The women had a 3-hour oral glucose tolerance test before starting the drug and then in 12 months, both blood glucose and plasma insulin levels were measured. After 1 year, there was no significant change in weight, blood pressure, or plasma insulin levels. There was a slight decrease in the fasting blood glucose value after 1 years use (67.5 +/- 1.5 versus 63.2 +/- 1.3 mg/dl). The other glucose values were unchanged. The importance of these data in terms of mechanisms of action of the steroids on metabolism and the safety of oral contraceptive usage is discussed.

Influence of HLA types on carbohydrate effects of a low-estrogen oral contraceptive.

The lymphocyte HLA types were determined for 13 women, who were then separated into a subgroup of those having a high risk for insulin-dependent diabetes mellitus (B8, B15, AW30) and a low-risk subgroup (B7, BW35). A 3-hour oral glucose tolerance test was conducted on each woman before starting on oral contraceptives (OC) and then 6 months after using them. Both blood glucose and plasma insulin levels were measured. The OC contained 0.035 mg of ethinylestradiol and 0.4 mg of norethindrone. There was a significantly higher 0.5-hour glucose value in the control test in the high risk group. There was a significant elevation of the 1-hour plasma insulin value in the 6-month test for the high-risk group. The usefulness of the HLA prescreening of women prior to use of OC needs more study.