Menopause-related blood pressure increase and its relationship to age and body mass index: the SIMONA epidemiological study

BACKGROUND: Menopause is commonly associated with some blood pressure (BP) rise, but cross-sectional or longitudinal studies completed so far were often too small and were unable to indicate whether this BP increase is really dependent on menopause, or was caused by age or changes in body mass index (BMI). METHODS AND RESULTS: The SIMONA study (Study on Hypertension Prevalence in Menopause in the Italian population) was a large cross-sectional study on 18 326 women of age range 46-59 years, consecutively seen by 302 practitioners all over Italy, and representing 60% of the women of that age in the National Health care list of those doctors. BP was measured three times in the seated position by the same automatic machine, and demographic and clinical data were taken. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were slightly but significantly higher in postmenopausal than premenopausal and perimenopausal women, but so were age and BMI. Within seven biannual strata, differences in age and BMI were minimized, but SBP/DBP remained significantly higher (by 3.4/3.1 mmHg) in postmenopausal than in premenopausal subjects in the youngest stratum (46-47 years), and was also significantly higher in the stratum 48-49 years. The differences remained significant after the exclusion of 1809 women with surgical menopause or 695 women with cardiovascular disease. Even when the confounding effects of age, BMI, smoking and contraceptive or replacement therapies were excluded by analysis of covariance, menopause was significantly and positively associated with SBP and DBP (approximately 2 mmHg difference in the age range 46-49 years). CONCLUSION: Menopause is associated with a slightly but significantly higher BP, even after adjustment for age and BMI, as well as other confounding factors, but the association is evident only in the younger end of the age range related to menopause.