Menopause
In the United States, the cessation of menstruation, menopause, normally occurs between 40 and 60 years of age. The initial symptoms include irregular menstrual cycles, anovulation, and hot flashes. A dramatic decline in the levels of progesterone and estrogen also occurs at this time. Estradiol values decline to sub-functional levels after menopause. In some women, maintaining adequate estrogen levels after menopause may alleviate the typical symptoms of menopause, but hormone replacement therapy may increase a woman’s risk of developing endometrial cancer. 59 A decrease in progesterone levels prior to menopause also results in a reduced anti-estradiol effect. The inability of a pre-menopausal woman’s body to maintain the secretory activity of the endometrium leads to endometrial hyperplasia, irregular bleeding, and related conditions. The information provided by FHP concerning hormone levels can provide guidance in hormone replacement therapy.
Endometrial stimulation by estrogen can lead to the development of cancer, and the risk increases in proportion to the length of time involved. The information provided by CPMP concerning hormone levels can provide guidance in hormone replacement therapy. There is no way to overstate the importance of monitoring hormone therapy on a regular basis and performing physical examinations prior to beginning therapy and at least annually thereafter.
Menopausal bleeding can develop in women with or without hormone replacement therapy. Because of the increased incidence of endometrial adenocarcinoma, endometrial sampling should be performed as soon as possible. Cyclic courses of progestogens have been used to arrest heavy menopausal bleeding and reverse hyperplasia of the endometrium.
There is good evidence for photoperiod dependence and/or melatonin responsiveness in the initiation and evolution of certain cancers, particularly hormone-dependent cancers. Because of its powerful oncostatic effects and its estrogen-blocking ability, melatonin demonstrates particular promise in the treatment of breast cancer. Numerous studies have reported an inverse correlation between melatonin levels and the growth of estrogen-receptive positive tumors. Used in conjunction with tamoxifen to modulate cancer endocrine therapy, melatonin shows marked ability to influence estrogen receptor expression and inhibit breast cancer cell growth. Moreover, researchers surmised that melatonin might induce objective tumor regressions in metastatic breast cancer patients refractory to tamoxifen alone.
Following menopause, a decrease in estrogen levels produces several distinct changes in female physiology. For sexually active women, intercourse can become uncomfortable or painful because vaginal lubrication is reduced with the decrease in estrogen and the epithelium becomes progressively thinner, producing a condition known as atropic vaginitis. Hormone replacement therapy or the use of water-soluble lubricants can provide relief in such cases.
Lower levels of estrogens can also influence skin aging, affect memory, alter lipid metabolism, and accelerate rate of bone loss. Vasomotor symptoms, at least among women in the industrialized Western countries, include hot flashes, which can also be ameliorated by estrogen replacement.
Progesterone also decreases at this point in the female life cycle. Lower levels of this hormone have been associated with dysfunctional uterine bleeding and may play a role in osteoporosis and other age associated conditions. To reduce some of the side effects of estrogen replacement therapy, especially the increased risk of endometrial hyperplasia adenocarcinoma, progesterone is often combined in hormone replacement therapy.
For women as well as men, testosterone maintains libido. Imbalances of testosterone in postmenopausal women are associated with various forms of coronary heart disease and cardiovascular events, including myocardial infarction. In addition to influencing muscle mass and weight loss, testosterone also plays a role in the production of several other hormones.
