Background: Many studies have analysed the relation between cardiovascular risk factors and oral contraceptive use in adult women, whereas information on the possible health effects of oral contraceptive use during adolescence is lacking.
Design: The effect of current contraceptive pill use on blood pressure and serum total cholesterol concentration was studied in a cross-sectional sample of 120 adolescent girls with a mean age of 17.4 years.
Methods: After the girls had rested for 5 minutes in the sitting position, trained study nurses measured blood pressure three times consecutively using a mercury sphygmomanometer. The nurses also administered a questionnaire gathering information on the use of oral contraceptives, smoking and parental social class. In the morning blood samples were taken for the measurement of serum total cholesterol.
Results: Mean age (+/-SD) was 17.4+/-0.8 years. Blood pressure averaged (+/-SD) 108.7+/-9.9 systolic and 68.0+/-8.2 mmHg diastolic. Serum total cholesterol was 4.5+/-0.7 mmol/l. Forty-nine girls (41%) were taking the contraceptive pill. Of these, 44 (90%) were on a combination of ethinyloestradiol (20-35 microg) and a progestogen, four (8%) on anti-androgens (35 microg) and one (2%) only on a progestogen. After adjustment for age, body mass index, smoking and alcohol status systolic blood pressure was 4.6 mmHg higher (95% CI 1.2-8.1; P<0.001) in current pill users than in girls not currently on the pill (111.4 versus 106.8 mmHg). Adjusted for the aforementioned covariates, diastolic blood pressure was not related to pill use (68.2 versus 67.8 mmHg; P=0.7). Serum total cholesterol was 0.43 mmol/l (95% CI 0.18-0.60; P=0.001) higher among girls using oral contraceptives (4.7 versus 4.3 mmol/l), irrespective of whether or not the model was adjusted for age, body mass index, smoking and alcohol status.
Conclusions: In 17-year-old girls, the use of oral contraceptives was associated with a nearly 5 mmHg higher systolic blood pressure and a 0.4 mmol/l higher level of serum total cholesterol. The long-term prognostic implications of our findings remain to be elucidated.