Effect of second and third generation oral contraceptives on lipid metabolism in the absence or presence of the factor V Leiden mutation.

Abstract

OBJECTIVES: The effect of a second and third generation oral contraceptive and of the progestagens used in these pills on lipid metabolism was studied in the absence or presence of the factor V Leiden mutation. DESIGN: A single centre, double blind randomized trial. SETTING: University Medical Centre. SUBJECTS: A total of 51 women without and 35 women with the factor V Leiden mutation. INTERVENTIONS: A second generation (30 microg ethinylestradiol/150 microg levonorgestrel) or a third generation (30 microg ethinylestradiol/l 50 microg desogestrel) oral contraceptive. After two cycles of use and a wash-out period of two cycles, the participants received the corresponding progestagen-only preparation containing 150 microg levonorgestrel or 150 microg desogestrel. MAIN OUTCOME MEASURES: Mean difference in changes between the treatment groups on total cholesterol, HDL, LDL, triglycerides and total/HDL cholesterol ratio. RESULTS: Compared with levonorgestrel, desogestrel-containing oral contraceptives caused in women without the factor V Leiden mutation significant changes in HDL (0.43; 95% confidence interval [CI] 0.25-0.61), LDL (-0.55; 95% CI -0.90 to -0.20), triglycerides (0.19; 95% CI 0.06-0.32) and total/ HDL cholesterol ratio (-0.87; 95% CI -1.21 to -0.53). When the progestagen-only preparations were used, differential changes were found for HDL (0.16; 95% CI 0.03-0.29), LDL (-0.31; 95% CI - 0.56 to -0.05) and total/HDL cholesterol ratio (-0.55; 95% CI -0.84 to -0.26). Desogestrel-only caused changes opposite to those of desogestrel-containing oral contraceptives. For cholesterol and triglycerides, this effect was also found for levonorgestrel-only in comparison with levonorgestrel-combined oral contraceptives. Levonorgestrel appeared to induce the effect on HDL. Almost all results were similar for women with the factor V Leiden mutation. CONCLUSION: It appears that desogestrel counteracts the effects of oestrogens to a lesser extent than levonorgestrel. Desogestrel-containing oral contraceptives have therefore a more favourable influence on cholesterol metabolism in comparison with levonorgestrel-containing oral contraceptives.