PLASMA-LIPIDS AND HIGH-DENSITY LIPOPROTEINS DURING ORAL CONTRACEPTION WITH DIFFERENT COMBINATIONS OF ETHINYL ESTRADIOL AND LEVONORGESTREL

Seventy five menstruating women seeking contraceptive advice were randomly allocated to treatment with combined oral contraceptive containing either ethinyl estradiol 50 μg + levonorgestrel 250 μg (50/250), ethinyl estradiol 30 μg + levonorgestrel 150 μg (30/150) or ethinyl estradiol 50 μg + levonorgestrel 125 μg (50/125). The concentrations of cholesterol, triglycerides, phospholipids, high density lipoprotein (HDL)-cholesterol and HDL-phospholipids were determined after one, three and six months and compared to the mean of two determination of the same parameters before medication. Triglycerides increased by 18-42 percent after 1-6 months of treatment with 50/125. The HDL-cholesterol and HDL-phospholipids were reduced by 10 percent during 50/250 treatment. No other parameters showed any consistent alteration in any of the treatment groups. Raised triglyceride concentration and/or decreased HDL concentration increases the risk for cardiovascular disease. It is therefore suggested that in order to alter the HDL concentration a combined oral contraceptive agent should not contain more gestagen-androgen than corresponding to 125 -150 μg of levonorgestrel. To avoid a rise of the triglyceride level the weight relation between levonorgestrel and ethinyl estradiol should be about 5:1.; This study evaluates the effects of 3 different combinations of ethinyl estradiol (EE) and gestagen levonorgestrel on the plasma concentrations of some lipids and lipoproteins. 75 healthy menstruating women from the Dept. of Obstetrics and Gynecology of Linkoping University were randomly assigned to 3 different treatment groups and were given either 1) EE 50 ug + levonorgestrel 250 ug (50/250); 2) EE 30 ug + levonorgestrel 150 ug (30/150); or 3) EE50 ug + levonorgestrel 125 ug (50/125). Fasting blood samples were collected before medication and on the 20th or 21st treatment day of cycles 1, 3 and 6. No significant alterations of the mean blood pressure, blood hemoglobin concentrations or erythrocyte sedimentation rate were observed in any of the groups. After 1-6 months of treatment with 50/125, triglyceride increased by 18-42%. In the group treated with 50/250, HDL-cholesterol and HDC phospholipids were reduced by 10%. No other parameter exhibited any consistent changes in any of the treatment groups. Elevated triglyceride concentrations and/or decreased HDL concentration increases cardiovascular risk. So as not to alter the HDL concentration, it is recommended that a combined oral contraceptive should not contain more gestagen-androgen than corresponding to 125-150 ug. of levonorgestrel. A proportion of around 5:1 between levonorgestrel and EE may be needed to balance the changes of production and elimination of triglycerides.