Effect of Estradiol / Norethindrone Acetate on 24-Hour Blood Pressure Profile in Postmenopausal Women

Objective: Framingham Heart Study found increased risk of cardiovascular events that occurs after menopause. Staessen found that menopause is associated with elevated blood pressure (BP), increased left ventricular wall thickness, decreased systolic performance, and decreased nocturnal BP fall. In the Italian population of SIMONA study, a significant increase in both systolic BP and diastolic BP was found in more than 18 000 Italian postmenopausal women, aged 46–59 years, compared to premenopausal and perimenopausal women. A growing body of evidence indicates that hormone replacement therapy (HRT) is beneficial in postmenopausal women. It is associated with symptomatic improvement: regulation of dysfunctional uterine bleeding, prevention of atrophic changes in the urogenital tract, a lower risk of osteoporosis and Alzheimer's disease, reduction of arterial stiffness, improvement in endothelium-dependent vasodilatation, a normalization of lipid profile, reduction of BP. Design and method: Design of the ongoing study in our Infertilty Center at the Institute of Endocrinology, we examined the effects of estradiol / norethindrone acetate on 24-h ambulatory blood pressure (ABPM) in 221 hypertensive postmenopausal women (HPMW, 51+/-2 mean+/-SE years, BMI 22.72±2.87kg/m 2 ). Validated, Meditech ABPM 05 ambulatory blood pressure monitor was used to obtain 24-h BP before and after six months therapy with estradiol / norethindrone acetate. Most women did not change antihypertensive treatment during the study. Results: After six months on HRT BP was lowered by an average of 1 mmHg systolic and 2 mmHg diastolic per day and per night BP was lowered by an average of 2 mmHg systolic and 1 mmHg diastolic. BP reductions were not significantly lower with regard to systolic or diastolic BP before initiation of HRT nor to action on day and night-time BP. Conclusions: BP reduction in HPMW after six months receiving estradiol / norethindrone acetate may lower the physicians concern that hypertension might worsen if they prescribe estradiol / norethindrone acetate. We propose a large international prospective study to confirm that an appropriate HRT in postmenopausal women lowers ABPM values and normalize a blunted nocturnal BP decline.