Effects of low-dose monophasic levonorgestrel with ethinyl estradiol preparation on serum lipid levels: A twenty-four-month clinical trial

OBJECTIVE: The aim of this 24-cycle study was to evaluate the effects on se rum lipid concentrations of an oral contraceptive preparation containing 10 0 mu g levonorgestrel and 20 mu g ethinyl estradiol. STUDY DESIGN: Forty-two healthy women were enrolled in a study designed to evaluate the effects on serum lipid concentrations of an oral contraceptive containing 100 mu g levonorgestrel and 20 mu g ethinyl estradiol. Lipid da ta were evaluated for 28 women who completed 24 cycles of treatment with a preparation of 100 mu g levonorgestrel with 20 mu g ethinyl estradiol for 2 1 days followed by placebo for 7 days. Concentrations of triglycerides, tot al cholesterol, high-density lipoprotein cholesterol, high-density lipoprot ein cholesterol subfractions 2 and 3, low-density lipoprotein cholesterol, and apolipoproteins A-1 and B were analyzed. Mean percentage changes from b aseline were tested for significance by means of paired Student t tests. RESULTS: Total cholesterol, high-density lipoprotein cholesterol, high-dens ity lipoprotein subfraction 2, and apolipoprotein A-1 concentrations were n ot significantly changed from baseline. Neither was the ratio of high-densi ty lipoprotein subfraction 2 to high-density lipoprotein subfraction 3. Mea n percentage increases in concentrations of triglyceride, high-density lipo protein subfraction 3, apolipoprotein B, and low-density lipoprotein choles terol and increases in the ratios of total cholesterol to high-density lipo protein cholesterol, low-density lipoprotein cholesterol to high-density li poprotein cholesterol, and apolipoprotein B to apolipoprotein A-1 were sign ificant (P < .05) at greater than or equal to 1 cycle. By cycle 24, however , only the concentration of high-density lipoprotein subfraction 3 remained significantly elevated. CONCLUSION: Changes in the plasma lipid profiles among women receiving mono phasic 100 mu g levonorgestrel with 20 mu g ethinyl estradiol were similar to those seen with other low-dose oral contraceptives, but by cycle 24 only 1 of 7 mean values remained significantly different from baseline.