A prospective, one-year study on the effects of two long acting injectable contraceptives (depot-medroxyprogesterone acetate and norethisterone oenanthate) on serum and lipoprotein lipids.

Two parenterally administered progestins (depot medroxyprogesterone acetate, DMPA, 150 mg/12 weeks and norethisterone oenanthate, NET, 200 mg/8 weeks respectively) were given to women seeking contraceptive advice. Before treatment and after 1, 6, 7, 12 and 13 months blood samples were taken. In serum and in the ultracentrifugally separated lipoprotein fractions the levels of total and free cholesterol, triglycerides and phospholipids were assayed, as were the apolipoprotein A1 and B levels in serum. At the end of the study NET had induced a decrease in all lipid components of the HDL (high density lipoprotein) fraction of approximately 30% and tended to increase LDL (low density lipoprotein) lipids. DMPA also decreased HDL-lipids, approximately 15%. There was also a transient decrease in apolipoprotein A1 after one month in both patient groups. From epidemiological studies it is inferred that low HDL-levels and high LDL-levels are independent risk factors for the development of atherosclerosis and cardiovascular disease. Thus our findings might indicate an adverse effect in this respect of long term treatment with these progestins, particularly with NET.