|
ANDROGENS AND ESTROGENS IN WOMEN: RESTORING THE BALANCE
Vliet, E.L.
Founder, HER Place: Health Enhancement and Renewal for Women, Inc.
Dallas, TX and P.O. Box 64507, Tucson, AZ 85728, USA
Hormone therapy for menopause has been under attack since the publication
of the Women's Health Initiative in the United States
and the Million Women Study in the United Kingdom.
Both studies have serious limitations, yet have been
generalized to all ages of women needing hormones,
all types and routes of delivery for hormones, in
spite of decades of basic science studies in animal
models and humans, pharmacological research, epidemiological
and clinical studies that have shown marked differences
in outcomes and risks with different types and routes
of delivery. This presentation will briefly review
some of the critical flaws of each study that limit
applicability to all groups of women. Although the
focus for approved indications for hormone therapy
at menopause has been elimination of vasomotor symptoms,
atrophic vaginitis, and prevention of bone loss, a
wealth of basic science and clinical research over
the last five decades has demonstrated that ovarian
gonadal hormones play multiple metabolic, endocrine,
and neuroendocrine roles throughout the body. Loss
of these critical hormones at menopause sets the stage
for increased risk of metabolic syndrome and diabetes,
cardiovascular disorders, cognitive decline, immune
dysfunction, loss of muscle mass, adverse changes
in joints and connective tissue, among other effects.
This presentation will review key areas of research
that show such multiple effects of ovarian hormones
in women. This presentation will also discuss the
ways that different types of estrogen options for
hormone therapy have an impact on crucial androgen
balance in women. For example, oral conjugated equine
estrogens (e.g. Premarin, Prempro) have long been
known to increase sex hormone binding globulin (SHBG)
and decrease the free fraction of testosterone and
estradiol. Non-oral delivery systems can eliminate
most of the hepatic first pass effect on increased
SHBG production. Androgens, in balance with optimal
estradiol, play a critical role in women to maintain
lean body mass and reduce the progressive tendency
for postmenopausal women to gain fat mass as they
age. Progestins have been used for menopausal hormone
therapy primarily to reduce the risk of hyperplasia
and endometrial carcinoma from unopposed estrogen
in women with an intact uterus. Newer studies, clinical
and basic science, suggest that various types of progestins
have quite different risk profiles and ability to
attenuate the documented benefits of both androgens
and estrogens. For example, medroxyprogesterone acetate
has been shown to accelerate the clumping of abnormal
proteins in the CNS that lead to development of Alzheimer's,
but this effect was not seen with the progestin norethisterone
or the natural ovarian progestagen, progesterone.
Data will be presented to illustrate these important
differences in progestins, as well as the impact of
various types of estrogens on androgen balance. This
presentation will primarily focus on the clinical
relevance of this wealth of research and discuss practical
approaches for the clinician in assessing women and
developing hormone therapy approaches tailored to
the individual woman's health risks, clinical history,
biomedical markers, and personal preferences and health
goals. There will also be case vignettes of the differences
in objective markers and subjective patient responses
to various preparations of estrogens, progestins,
and androgens.
|
