The effects of two triphasic oral contraceptives on carbohydrate metabolism in women during 1 year of use

Sixty-one women were randomly assigned to use one of two different triphasic oral contraceptives (OCs), for one year's time (Ortho Novum 777, Ortho Pharmaceutical Corp., Raritan, NJ, and Triphasil, Wyeth Laboratories, Philadelphia, PA), containing the progestins norethindrone and levonorgestrel, respectively. The carbohydrate metabolism was evaluated using the oral glucose tolerance test before OC use and at the end of the 12th month. Both plasma glucose and insulin levels were measured. The fasting glucose value in the norethindrone-containing OC group (777) was significantly lower at the 1-year testing. All other values were unchanged. These data demonstrate that the triphasic oral contraceptive preparations currently in use have minimal effects on carbohydrate metabolism.