Reduction of ovarian
steroids at menopause leads to significant changes in the urogenital tract. These changes often worsen with time, particularly in nonsmokers, affecting up to 38% of menopausal women. Urogenital symptoms that clearly respond to
estrogen therapy include
atrophic vaginitis, dryness, and accompanying
dyspareunia.
Estrogen reduces
urinary tract infections in women plagued by frequent recurrence. The sensation of urgency improves with
estrogen but
urge incontinence improvement is similar to that with placebo. Stress incontinence does not improve with
estrogen. Until recently, vaginal
therapy was reserved for local symptoms. Rings make systemic vaginal
therapy acceptable and even preferred by some users. Vaginal delivery, like other parenteral
therapies, bypasses the gastrointestinal tract, with less anticipated impact on
lipids,
globulins, clotting, and fibrinolytic factors. Evidence of a lowered risk of
venous thromboembolism is reviewed. Options for
estrogen therapy include native, synthetic, or biologically derived
estrogens delivered by cream, gel, insert (
pessary), ring, or
tablet. Even the lowest dose
estradiol (7.5 mug daily or 25 mug twice per week) shows evidence of systemic absorption. In long-term placebo-controlled studies, bone density was better preserved and
lipid profiles were more favorable. Therefore, even these low dose
therapies should be opposed by occasional
progestogen to prevent
endometrial carcinoma. Intermittent
therapy is best given for a minimum of 12 days based on laboratory data. Less frequent dosing, although preferred by patients, likely confers a slightly increased risk of
hyperplasia. No combination
estrogen/
progestogen vaginal product is currently available. The best dose to reduce risk of endometrial pathology adequately in the lower dose
therapies will be defined not only by the dose and potency of the exogenous
estrogen but by the individual is body habitus and lifestyle choices.