The effects of oral contraceptives on plasma lipids and lipoproteins

It has been well documented that low-density lipoproteins and intermediate-density lipoproteins play a role in the development of atherosclerosis. Data also indicate that high-density lipoproteins (HDLs), have potentially antiatherogenic effects. The individual estrogen and progestogen components of oral contraceptives (OCs) have been shown to affect plasma lipoproteins in both cross-sectional and longitudinal studies. This effect depends on both the type of steroid used and the dose of each of the OC components. Estrogen and progestogen have opposing effects on lipoprotein physiology. Estrogens raise the level of HDL cholesterol, while progestogens tend to lower HDL levels. Thus, in OC formulations, as the ratio of estrogen to progestogen increases in favor of estrogen, there is a greater increase in HDL cholesterol--a potentially beneficial effect. Although there is no direct evidence that favorable lipoprotein changes produced by OCs are cardioprotective, the physician prescribing an OC should minimize adverse lipoprotein effects by prescribing a balanced low-dose, low-impact formulation.