Metabolic effects of two low-dose triphasic oral contraceptives containing ethinyl estradiol and levonorgestrel or gestodene.

A well-known triphasic oral contraceptive (OC) containing ethinyl estradiol (EE) plus levonorgestrel (LNG) was compared with a triphasic containing the same dose of EE in combination with a 14% smaller dose of a new progestogen gestodene (GTD), in a prospective study of 24 and 20 healthy young women, respectively. Serial determinations of lipids, lipoproteins, and carrier proteins, and repeated standardized oral glucose tolerance tests (OGTTs) were conducted during 12 months of OC use. All lipid concentrations recorded before and during both treatments were strictly within the normal range. After 12 months, no significant fluctuations were observed in levels of total cholesterol, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, and apolipoprotein A1; concentrations of total triglycerides, phospholipids, and apolipoprotein B were slightly but significantly increased; the epidemiologically important ratios of HDL-cholesterol:total cholesterol and apolipoprotein A1:apolipoprotein B were not significantly changed, while the ratio of LDL-cholesterol:HDL-cholesterol was significantly decreased at 12 months of use of the GTD triphasic. SHBG levels (+ 100% over basal during use of the LNG-OC and + 200% with the GTD-OC) and transcortin (+ 100% over basal) increased early and remained stable. During use of the LNG-OC, glucose tolerance was strictly unchanged, while insulin response to a 75-g glucose load was transiently increased at 6 months (area under the curve [AUC] + 29%) before returning to normal at 12 months. During GTD-OC treatment, glucose tolerance was slightly impaired (AUC + 14%) at 6 months but back to normal at 12 months, while insulin response during OGTT was completely unaltered.(ABSTRACT TRUNCATED AT 250 WORDS)