Menopause
The formal definition of menopause is the permanent cessation of menses, clinically defined as 12 months after a woman’s last menstrual period. It marks the end of a woman’s normal ovarian function.
2. When does menopause usually occur?
The median age for the last menses is defined at 51.4 years. There is large variability in the exact age at which menopause occurs. A genetic component appears to be involved because women often experience menopause around the same time as their mother or sister, but there are numerous examples of circumstances when this does not hold true. It also appears that women in Asia may experience menopause at an earlier age (42–49 years old).
3. How is menopause diagnosed clinically?
In a woman who is more than 45 years old, 12 months of secondary amenorrhea is sufficient to diagnose menopause. Although a pelvic examination may reflect some atrophy of the vaginal mucosa, this is not always remarkable. Generally, there are elevations in both follicle-stimulating hormone (FSH), which rises significantly (approximately 10- to 20-fold), and luteinizing hormone (LH), which has a more modest rise (approximately 3-fold). It is generally considered that an FSH level higher than 40 IU/L indicates ovarian failure, but these levels are not reliable for diagnosis because in certain circumstances these hormones may be elevated before menopause.
Menopause should not be thought of as occurring suddenly, but rather as a transitional process over time. Perimenopause (also called menopause transition) describes the transition toward menopause, in which women’s cycles can vary in frequency and severity. Menopause symptoms often begin to appear during this time.
5. Physiologically, what determines the timing of menopause?
The absence of ovarian oocytes signals the cessation of menstruation in women. Oocyte numbers decline throughout a woman’s life; they actually peak in number in utero and decline quite rapidly before birth, by which time approximately 80% of oocytes have been lost. Exhaustion of oocytes causes cessation of menses.
6. What is premature ovarian failure?
Ovarian failure is considered premature when it occurs in women who are less than 35 years old. Symptoms are very similar to those experienced by women entering menopause. There can be several causes of this condition, including autoimmune disorders, chromosomal defects, chemotherapy treatment, and some unknown causes. The incidence of this condition is estimated at 0.3% within the United States.
7. What are the symptoms of menopause?
The hallmark symptom of menopause, which often occurs during the perimenopause transition, consists of hot flashes. During these episodes, which last seconds to minutes, the woman experiences a tremendous warming of her body, often with accompanying redness of the skin and sweat production. Menopausal women often describe this variable temperature control as occurring at night, a condition termed “night sweats.” Other symptoms that are less prevalent include the following: insomnia; short-term memory loss or “mental fogginess”; a loss of “youthfulness” to the skin, hair, and nail cells; and skin and vaginal dryness.
8. Will all women experience menopause symptoms?
It is estimated that most women (approximately 85%) will experience some types of vasomotor symptoms with menopause. These can vary greatly in severity; the most severe symptoms usually occur in women who have had their ovaries surgically removed, thereby transitioning to what has been called “instant menopause.”
9. Do menopausal symptoms last indefinitely?
Generally, menopausal symptoms are worst during perimenopause or the first few years after menopause. Most women are able to tolerate these symptoms after approximately 3 to 5 years. Some women, however, continue to suffer from hot flashes and other menopause symptoms 10 years or longer after menopause occurs, at almost the same severity as when the symptoms first appeared.
10. What physiologic changes accompany menopause?
Loss of bone calcium, increased rates of coronary artery disease, skin and vaginal atrophy, hot flashes, and alterations in the lipid profile (mainly increased triglycerides and low-density lipoprotein cholesterol, and decreased high-density lipoprotein cholesterol) all occur through and after menopause.
11. What estrogens are present in a woman’s body?
Women naturally have three different estrogens present in varying amounts: estrone (E1), estradiol (E2), and estriol (E3). Estradiol is the most potent of the three estrogens, binds equally to both the α- and β-estrogen receptors, and converts freely back and forth with estrone in the body. Some evidence suggests that estrone has a higher carcinogenic risk compared with the other estrogens, possibly because of its higher affinity to the α-estrogen receptor (approximately 5:1 α:β). Estriol is a metabolite of estradiol and estrone and will not convert back to E1 or E2 once formed, but rather is excreted out through the urine. It has a higher selective binding to the β-estrogen receptor (3:1 β:α).
12. What is the predominant circulating estrogen during and after menopause?
Estradiol, or E2, is the most abundant estrogen in a woman’s body during reproductive years, and it is produced by the ovaries. During menopause, this production wanes and then stops, and estrone, or E1, becomes the dominant estrogen, converted in adipose tissue from androstenedione, which is secreted from the adrenal glands.
13. There was a major shift in managing women at menopause after the Women’s Health Initiative (WHI) trial. Why did this occur?
