Oral contraceptive use and blood pressure in a German metropolitan population.

The relationship between blood pressure (BP) and oral contraceptive (OC) use in women has been examined with the data from the Munich Blood Pressure Study (MBS), a cross-sectional study with follow-up of a random sample of 3198 Munich citizens aged 30-69 (response rate 69.3%). Multiple linear and logistic regression analyses were run with BP as the dependent variable and age, OC use, obesity, alcohol consumption, and smoking habit as the independent variables. All second and third order interactions between the independent variables were tested during a backward stepping procedure. OC use appeared as a significant main effect in most of the analyses. The coefficient of the OC variable was about 3 in the linear regression analyses for both systolic BP and diastolic BP, indicating an increase of about 3 mmHg in the systolic and diastolic BP of the OC users. An analysis of the change in BP after one year in relation to change in OC user status has also been made. It was observed that women ceasing to use OC had a clear decrease in BP while those starting to use OC had on average an increase in BP.