A two-year clinical study of the effects of two triphasic oral contraceptives on plasma lipids.

ABSTRACT

PIP: The first 24-cycle study of the metabolic effects of triphasic oral contraceptives (OCs) recorded significant changes in lipid values, yet none of these values moved outside the normal range. Included in the study were 69 non-smoking Canadian women 19-29 years of age with no history of obesity, diabetes, or alcohol misuse. Subjects were randomly assigned to receive either an ethinyl estradiol-norethindrone formulation (Ortho 7/7/7) or an ethinyl estradiol-levonorgestrel preparation (Triphasic). 25 controls underwent periodic blood samplings for lipid and lipoprotein levels. The only significant change recorded among controls was a 42% increase in the plasma apo B level resulting from changes in the low density lipoprotein (LDL) apo B subfraction. In the Ortho 7/7/7 and Triphasic groups, both plasma and LDL triglycerides were increased above baseline and above values for controls at the 24-month point. In Ortho 7/7/7 acceptors, LDL cholesterol increased by 28%, high density lipoprotein (HDL) decreased by 11%, and plasma cholesterol increased by 14%; other cholesterol levels decreased significantly. In the Triphasic group, HDL decreased by 8%, but no other significant changes occurred. Apo A1 increased by 15% in the Ortho 7/7/7 group, but not among Triphasic users; all apo B values increased significantly in both treatment groups. Although these changes in lipid profiles among triphasic OC users do not seem to increase the risk of cardiovascular disease, there is potential for adverse health effects when other cardiovascular risk factors, especially smoking, are present.