Oral contraception in diabetic women. A cross-over study on serum and high density lipoprotein (HDL) lipids and diabetes control during progestogen and combined estrogen/progestogen contraception.

Twenty-three young women with insulin-dependent diabetes were randomly allocated to contraceptive treatment with either a progestogen only (Lynestrenol 0.5 mg) (LYN) or a combined oral contraceptive (OC) (ethinyl estradiol 50 micrograms + lynestrenol 2.5 micrograms) (EE + LYN). After six months treatment the medication was withdrawn for at least two months, after which the patients were placed on the other preparation. Diabetes control and serum and high density lipoprotein (HDL) lipids were assessed before and after 1, 3 and 6 months of treatment. Low-dose LYN administration did not alter the insulin requirement, blood glucose or body weight while the combined EE + LYN treatment increased the insulin requirement (p less than 0.01) without altering blood glucose or body weight. Low-dose LYN reduced serum triglycerides (p less than 0.001), serum cholesterol (p less than 0.001) and serum phospholipids (p less than 0.01) without affecting HDL lipids, while EE + LYN gave an inconsistent increase in serum triglycerides (p less than 0.01) but no change in HDL lipids. These findings confirm our earlier results and we conclude that EE + LYN influences diabetes control slightly more (although still not seriously) than the low-dose LYN. It is suggested that insulin-dependent diabetics (in contrast to non-diabetics) are more sensitive to the influence of 19-norprogestogens than to alkylated estrogens, with respect to lipid metabolism.