Abstract

PIP: Many studies have demonstrated a correlation between serum lipid concentrations and the high risk of developing cardiovascular disease. Further, oral contraceptives (OCs) are known to change lipid metabolism. The extent of the change depends on the dose and structure of the estrogen and gestagen, however. Many researchers studying the effect of OCs on lipid metabolism have encountered numerous sources of variability in their studies, such as age of the subjects, smoking, daily variations in serum lipid concentration, and whether samples were stored before analysis and for how long. Since there are many sources of variability, the results of any study should not be accepted uncritically. Published studies of OCs with 30ug ethinyl-estradiol and 150 ug levonorgestrel, serum low density lipoprotein (LDL) cholesterol concentration was lowered in 12 and unchanged in 13. On the other hand, results of studies for the triphasic OC containing ethinyl-estradiol and levonorgestrel were more consistent--this triphasic OC produced no change in either serum LDL cholesterol or high density lipoprotein (HDL) cholesterol concentrations. As for ethinyl-estradiol combined with 150 ug desogestrel, 15 studies showed an increase in serum HDL cholesterol concentration and 4 with no change, and 9 reported no change in serum LDL cholesterol concentration and 2 with a decrease. Further, research shows that changes in lipid metabolism appear not to be progressive with continued use of OCs, and the lipids revert to their pretreatment concentrations after stopping OC use. Despite inconclusive evidence of increased cardiovascular risk with OC use, physicians should prescribe formulations containing the lowest dose consistent with efficacy and acceptability.