Does blood pressure differ between users and non-users of hormone replacement therapy? The Women's Health in the Lund Area (WHILA) Study

Objective: To examine whether blood pressure over 24 h differed between postmenopausal women receiving and not receiving hormone replacement therapy. Methods: One group of hormone replacement postmenopausal women (n = 32) and one group of non-hormone replacement (n = 32) postmenopausal women underwent non-invasive 24-h ambulatory blood pressure monitoring. They were randomly selected among the 2000 firstly screened women in an ongoing project in Lund, Sweden. The study was designed to detect a difference of 5 mmHg in diastolic blood pressure over 24 h with a power of 80% and 5% significance (two-tailed test). Results: The hormone replacement women had a mean (SD) office blood pressure of 128/76 (12/8) mmHg and the non-hormone replacement 126/78 (16/8) mmHg. Mean ambulatory blood pressure over 24 h, day and night, in the hormone replacement group was 121/72 (11/7), 126/76 (12/8), 111/64 (11/7) mmHg. The corresponding values in the non-hormone replacement group were 118/72 (12/7), 124/77 (12/7), and 107/64 (13/7) ( p > 0.40 for diastolic blood pressure and p > 0.20 for systolic blood pressure). Mean heart rate over 24 h was 71 (7) and 73 (8) beats/min in the hormone and non-hormone replacement groups, respectively. Conclusion: There was no difference in blood pressure or heart rate between the hormone replacement and non-hormone replacement postmenopausal women, either over 24 h or during the day or night. Hormone replacement in postmenopausal women seems not to have an influence on blood pressure, but of course we are aware that this is a cross-sectional study, which has its limitations.