Roles of Estrogen

Other Roles of Estrogen
Bone
Estrogen produced by the ovaries helps prevent bone loss and works together with calcium and other hormones and minerals to build bones. Osteoporosis occurs when bones become too weak and brittle to support normal activities.
Your body constantly builds and remodels bone through a process called resorption and deposition. Up until around age 30, your body makes more new bone than it breaks down. But once estrogen levels start to decline, this process also slows.
Thus, after menopause your body breaks down more bone than it rebuilds. In the years immediately after menopause, women may lose as much as 20 percent of their bone mass. Although the rate of bone loss eventually levels out after menopause, keeping bone structures strong and healthy to prevent osteoporosis becomes more of a challenge.
Vagina and Urinary Tract
When estrogen levels are low, as in menopause, the vagina can become drier and the vaginal walls thinner, making sex painful.
Additionally, the lining of the urethra, the tube that brings urine from the bladder to the outside of the body, thins. A small number of women may experience an increase in urinary tract infections (UTIs) that can be improved with the use of vaginal estrogen therapy.
Perimenopause: The Menopause Transition
Other physical and emotional changes are associated with fluctuating estrogen levels during the transition to menopause and the year after menopause occurs, called perimenopause. This phase typically lasts about five years for most women. Symptoms include:
Hot flashes -- a sudden sensation of heat in your face, neck and chest that may cause you to sweat profusely, increase your pulse rate and make you feel dizzy or nauseous. A hot flash typically lasts about three to six minutes, although the sensation can last longer and may disrupt sleep when they occur at night.
Irregular menstrual cycles
Breast tenderness
Exacerbation of migraines
Urinary stress incontinence
Mood swings
Estrogen Therapy
Estrogen therapy is used to treat certain conditions, such as delayed onset of puberty and menopausal symptoms such as hot flashes and symptomatic vaginal atrophy. Vaginal atrophy is a condition in which low estrogen levels cause a woman's vagina to narrow, lose flexibility and take longer to lubricate. Female hypogonadism or incomplete functioning of the ovaries, can also cause vaginal dryness, breast atrophy and lower sex drive, and is also treated with estrogen.
For many years, estrogen therapy and estrogen-progestin therapy were prescribed to treat menopausal symptoms, to prevent osteoporosis and to improve women's overall health. However, after publication of results from the Women's Health Initiative (WHI) in July 2002 and March 2004, the U.S. Food and Drug Administration (FDA) now advises health care professionals to prescribe menopausal hormone therapies at the lowest possible dose and for the shortest possible length of time to achieve treatment goals.
The WHI was a study of 27,000 women aged 50-79 taking estrogen therapy or estrogen/progesterone therapy who was followed for an average of five to six years. The study was unable to document that benefits outweighed risks when hormone therapy was used as preventive therapy.
Determining hormone status can be important in certain settings. For instance, estrogen and other hormones are prescribed to treat reproductive health and endocrine disorders (the endocrine system is the system in the body that regulates hormone production and function).
Some uses of hormone therapy include the following situations:
Delayed puberty
Contraception
Irregular menstrual cycles
Symptomatic menopause