Autonomic and cardiovascular function in postmenopausal women: the effects of estrogen versus combination therapy.
OBJECTIVE
This study examined the effects of oral estrogen (ERT) alone versus oral estrogen/medroxyprogesterone acetate (HRT) therapy on cardiovascular function, as controlled by the autonomic nervous system.


METHODS
Forty-three postmenopausal women received ERT, HRT, or a placebo for 3 months in a double-blind, randomized, placebo-controlled study. Cardiovascular hemodynamics and heart rate variability were assessed at rest and during stress.


RESULTS
After 3 months of therapy, oral HRT significantly increased high-frequency power (P =.0002) and decreased total peripheral resistance (P =.04). The changes were evident at rest and during stress.


CONCLUSIONS
Our findings suggest that combination therapy produces a more favorable alteration of autonomic cardiovascular function than estrogen alone (ie, combination therapy increases vagal activity).
Farag
Noha H
NH
Department of Psychiatry, University of California, San Diego, UCSD Medical Center, 92103-0804, USA. nfarag@ucsd.edu
Nelesen
Richard A
RA
Parry
Barbara L
BL
Loredo
Jose S
JS
Dimsdale
Joel E
JE
Mills
Paul J
PJ
D000284:Administration, Oral; D000368:Aged; D001341:Autonomic Nervous System / Q000187:drug effects* / Q000502:physiology*; D001794:Blood Pressure / Q000187:drug effects; D002320:Cardiovascular Physiological Phenomena / Q000187:drug effects*; D004359:Drug Therapy, Combination; D004958:Estradiol / Q000627:therapeutic use*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D020249:Hormone Replacement Therapy; D006801:Humans; D017258:Medroxyprogesterone Acetate / Q000627:therapeutic use*; D008875:Middle Aged; D017698:Postmenopause / Q000502:physiology*; D045167:Progesterone Congeners / Q000627:therapeutic use*; D014621:Vagina / Q000187:drug effects / Q000502:physiology; D014655:Vascular Resistance / Q000187:drug effects
D045167:Progesterone Congeners; D004958:Estradiol; D017258:Medroxyprogesterone Acetate