The effects of long-acting injectable contraceptives on carbohydrate metabolism.

Carbohydrate metabolism, as assessed by the intravenous glucose tolerance test (i.v.-GTT), was studied in 19 healthy, non-lactating women who received injectable contraceptives containing either medroxyprogesterone acetate (DMPA) (10 subjects) or norethisterone enanthate (Net-En) (9 subjects). Tests were made prior to treatment and at intervals over a period of 15 months thereafter. Results obtained indicate that carbohydrate metabolism is not impaired by either of the two progestogens, and neither pyruvate nor cortisol concentrations changed significantly over the period of observation. However, the insulin release in response to glucose loading underwent interesting alterations during treatment. These abnormalities returned promptly to normal after withdrawal of treatment.