Effects of hormone therapy on blood pressure and the renin-angiotensin system in postmenopausal women.
Observational studies have documented an association between lower rates of cardiovascular disease and hormone therapy (HT). Meanwhile, randomized clinical trials have documented increased rates of myocardial infarction and stroke in women receiving hormone therapy. These seemingly discordant findings have stimulated new research to examine estrogen's effects on the cardiovascular system, including its effects on blood pressure, regulation of the renin-angiotensin system (RAS), and the clinical consequences of hypertension. In the last 6 years several studies have better defined the mechanisms by which HT affect the RAS, blood pressure, and the clinical effects of hypertension. Recent studies documented increases in angiotensinogen synthesis and the suppression of active renin with estrogen replacement. Genotype may be a factor in determining the degree of suppression of angiotensin converting enzyme levels that occurs with estrogen therapy. Estrogen supplementation in postmenopausal women increases systemic angiotensin II, a potent vasoconstrictor. This vasopressor effect is attenuated by an estrogen-induced reduction of angiotensin II type 1 receptor expression. Renal blood flow reduction, in the absence of blood pressure changes, have been reported after estrogen replacement, and an increased risk of total stroke has been demonstrated in hypertensive women on HT compared to normotensive women on this therapy. Estrogen replacement affects many components of the RAS, but its effect on this system has little effect on blood pressure. Further studies are needed to describe the effects of estrogen replacement on abnormal vasculature and how these effects relate to myocardial infarction and stroke.
Prime
D D
DD
Cardiology Section, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA. dprime@wfubmc.edu
Brosnihan
K B
KB
Herrington
D M
DM
D000804:Angiotensin II / Q000378:metabolism; D000808:Angiotensinogen / Q000096:biosynthesis / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects*; D015914:Estrogen Replacement Therapy / Q000009:adverse effects; D005260:Female; D005838:Genotype; D006801:Humans; D017698:Postmenopause; D012079:Renal Circulation / Q000187:drug effects*; D012083:Renin / Q000187:drug effects / Q000378:metabolism; D012084:Renin-Angiotensin System / Q000187:drug effects*; D012307:Risk Factors
D000808:Angiotensinogen; D000804:Angiotensin II; D012083:Renin