Changes in lipid metabolism during 12 months of treatment with two oral contraceptives containing 30 micrograms ethinylestradiol and 75 micrograms gestodene or 150 micrograms desogestrel

The effect of two oral contraceptives containing 30 micrograms ethinylestradiol + 75 micrograms gestodene (EE/GSD) or 30 micrograms ethinylestradiol + 150 micrograms desogestrel (EE/DG) upon serum lipids and lipoproteins were measured in 11 women each on days 1, 10, and 21 of the first, third, sixth, and twelfth treatment cycle and compared to the levels on days 1, 10, and 21 of the preceding control cycle. There was no change in total cholesterol (CH) and phospholipids (PL), while total triglycerides (TG) were significantly elevated only during treatment with EE/GSD. After 3 and 6 months of intake of both oral contraceptives, a transitory increase in the TG content of very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL), and a decrease in LDL-PL was observed. After 12 months, VLDL-CH, VLDL-PL, and apolipoprotein B were significantly elevated, while VLDL-TG and all components of LDL were unchanged. Most of the components of high-density lipoprotein (HDL) were increased due to a rise in HDL3 and apolipoprotein A-II, while HDL2 and apolipoprotein A-I were not altered. There was no significant difference between the effects of the two preparations, although those of EE/GSD were mostly more pronounced. The time-dependent change in the effects of the oral contraceptives on various parameters of lipid metabolism demonstrates that the relevance of results of short-time studies may be questionable. There was also a significant alteration in some parameters between day 1 and 10 of the treatment cycles and a tendency to return to the pretreatment levels during the pill-free week, e.g., in total TG and in the PL component of VLDL, LDL and HDL. The increase in HDL, VLDL, and total TG reflects a slight preponderance of the effect of ethinylestradiol on lipid metabolism. The unchanged total CH and LDL-CH and the elevated HDL levels indicate that the risk of the development of atherosclerosis is in all probability not increased during treatment with both preparations.