title: Hormone replacement therapy reduces mean 24-hour blood pressure and its variability in postmenopausal women with treated hypertension.
abstract: BACKGROUND
  The rate and severity of hypertension increase dramatically after menopause. Complications seem to be more frequent and marked in hypertensive patients with greater blood pressure (BP) variability, and antihypertensive treatment does not easily reduce this variability. The effect of hormone replacement therapy (HRT) on BP and its variability is not well understood in moderate to severe hypertension, but estrogen may have calcium channel-blocking properties. Cardiovascular events occur more frequently in the morning, likely in part because of a rise in BP.
  
  
  METHODS
  We prospectively studied 34 postmenopausal women with treated hypertension (mean age = 53 years) and receiving a cyclic combination of estradiol and norgestrel for 19 weeks with 24-h ambulatory BP monitoring.
  
  
  RESULTS
  Mean daily BP and its variability decreased significantly with HRT (149.3 +/- 6.1 mm Hg vs. 140.3 +/- 8.5 mm Hg [p < 0.001]; diastolic: 95.4 +/- 4.7 mm Hg vs. 92.4 +/- 7.2 mm Hg [p < 0.05]). There was also a significant decrease in the early morning BP values after HRT (154.0 +/- 6.9 mm Hg vs. 145.6 +/- 11.0 mm Hg [p < 0.001]; diastolic: 98.0 +/- 4.8 mm Hg vs. 95.1 +/- 10.0 mm Hg [p < 0.05]). Subjects who were taking calcium channel blockers (n = 11) had only half the reduction in 24-h systolic BP compared with those who were not taking calcium channel blockers (5.3 mm Hg vs. 10.5 mm Hg), and the reduction in those who were taking calcium channel blockers failed to reach statistical significance.
  
  
  CONCLUSIONS
  Our results demonstrate that HRT may have a role in decreasing the severity of hypertension, and the mechanism of its action might be through calcium channels.
authors.affiliation: 2nd Department of Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: B
authors.initials: B
authors.lastname: Szekacs
authors.forename: Z
authors.initials: Z
authors.lastname: Vajo
authors.forename: N
authors.initials: N
authors.lastname: Acs
authors.forename: P
authors.initials: P
authors.lastname: Hada
authors.forename: L
authors.initials: L
authors.lastname: Csuzi
authors.forename: J
authors.initials: J
authors.lastname: Bezeredi
authors.forename: Z
authors.initials: Z
authors.lastname: Magyar
authors.forename: E A
authors.initials: EA
authors.lastname: Brinton
mesh_terms: D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology*; D002121:Calcium Channel Blockers / Q000627:therapeutic use; D004958:Estradiol / Q000494:pharmacology; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D008875:Middle Aged; D009644:Norgestrel / Q000494:pharmacology; D017698:Postmenopause / Q000502:physiology*; D045167:Progesterone Congeners / Q000494:pharmacology; D011446:Prospective Studies
chemical_list: D002121:Calcium Channel Blockers; D045167:Progesterone Congeners; D009644:Norgestrel; D004958:Estradiol