Interaction of oral contraceptive use with the effects of age, exercise habits and other cardiovascular risk modifiers on metabolic risk markers.

An analysis was undertaken to determine whether combined oral contraceptive (OC) use interacts with the effects of potential cardiovascular risk modifiers (age, body mass index, cigarette smoking, alcohol intake, exercise habit, family histories of heart disease or diabetes, number of pregnancies and duration of OC use) on blood pressure and lipid, lipoprotein, glucose and insulin risk markers for cardiovascular disease. Relationships between risk modifiers and risk markers were compared between non-users (n = 418) and users of low-estrogen dose OC (n = 925, categorised according to progestin content as monophasic levonorgestrel, triphasic levonorgestrel, norethindrone or desogestrel). OC use diminished the adverse effects of age on glucose tolerance. Aerobic exercise had a particularly beneficial effect on triglyceride levels and OGTT insulin response in OC users. The rise in HDL and HDL2 cholesterol concentrations with alcohol intake seen in non-users was diminished in OC users. Increasing duration of use of a desogestrel combination was associated with increasing HDL cholesterol concentrations. No adverse effects of risk modifiers on metabolic risk markers and blood pressure were augmented by OC use, and some were even diminished.