Regular monthly menstrual cycles are a part of every woman's life for more than thirty years. Sometimes menstrual periods make an unexpected visit, sometimes they are very heavy, and sometimes they do not show up at all. Bone loss occurs much more rapidly when women reach the age where periods skip, then stop for good. The end of periods with transition to menopause may be a welcome relief for many women who view menstrual periods as “the curse.”
I liked the practice portrayed in Anita Diamant's novel The Red Tent. Women gathered in one place, “the red tent,” with other women who were all cycling together for the duration of their periods. They were off the hook for all of their duties during that time—wishful thinking for modern times!
Problems may arise when teens and younger women have only irregular, unpredictable periods. Some teens may fail to start their first period, others may have periods that come regularly for a while but then stop. Adult women with a history of menstrual disorders during their teenage years have decreased bone density when compared to their same-age peers. Women typically in their thirties who experience pelvic pain or infertility may have a problem called “endometriosis.” Medicines that treat this condition have profound effects on bone. This section highlights the connections between bone health and women who have menstrual disturbances.
NO PERIODS
Loss of menstrual periods, called amenorrhea, may be a sign that something is wrong. The associated lack of estrogen and other hormones can cause bone loss. As few as three months without a period may cause bone loss. The longer you go without having a period, the lower your bone density. This may be caused by increased bone loss and, in adolescents and young adults, by failure to accrue new bone, as well. The pattern of bone loss is dependent on the type of bone. Bone loss occurs first in the higher turnover bone of the spine. A longer duration of five to six years of amenorrhea is associated with changes in the dense cortical bone of the hip.
The teenager with amenorrhea gains bone throughout adolescence. However, the amount of bone mass is lower compared with regularly menstruating teenagers. The absence of periods for an extended time makes it unlikely that optimal peak bone mass will be achieved.
What Is Amenorrhea?
The word “amenorrhea” is a compound word constructed from three Greek roots: a = no; men = month; rhoia = flow. No monthly flow. In this section, the term refers to no menstrual period during the expected time between puberty and menopause. This is abnormal in a woman who is neither pregnant nor in the months immediately following delivery.
Amenorrhea is categorized into two types:
Primary amenorrhea is a delay in the start of menstruation (no menstrual period by the age of sixteen-and-a-half years).
Secondary amenorrhea is the absence of a menstrual cycle for at least three to six consecutive months in a woman who has previously menstruated.
Some causes include decreased body weight or weight loss, endocrine and other medical disorders, certain medicines, strenuous exercise, and even stress.
SPORTS, WEIGHT, AND MENSTRUAL PERIODS
Menstrual problems are expected in young, very lean athletes. We think of these young women as healthy but they are the most likely group to have menstrual problems. Athletic girls tend to experience their first period later than nonathletic girls. The average age of first menstrual period in healthy American girls is twelve years. Athletes who participate in a wide variety of sports typically have their first periods one to two years later.
The delay may be due to insufficient nutrition, the stress of training, or low levels of body fat. Alternatively, it may just reflect the athletes' physique, which tends to be slender with low levels of fat. However, athletes who begin training before age twelve may experience a later start of periods compared with girls who begin training after their first period occurs.
Prolonged amenorrhea may lead to diminished bone mass from the associated decrease in estrogen secretion. A decrease in frequency or intensity of training may allow resumption of regular periods. However, most athletes view the loss of periods as a blessing—no worries about cramps or bleeding, which might negatively impact their performance.
Participation in sports where a thin appearance is required can also put girls at risk. Women who participate in lightweight rowing at the international level cannot individually exceed 130 pounds, and the average weight for the entire crew of the boat is 126 pounds. They need to “make weight.” At rowing events, all participants are weighed at check-in to make sure the weight requirement is met. Women's wrestling, which was added to the Olympics in 2004, is gaining popularity in the US; participants have weight-class requirements they must meet. Other sports, such as gymnastics, figure skating, diving, synchronized swimming, ballet, and ballroom dancing, though they do not have weight requirements, do encourage maintenance of a thin, lean body shape.
Athletes participating in these sports and activities may have a tendency to decrease their dietary intake as a way to lose weight. Sometimes the weight loss is too much and they end up “underweight.” Most girls do not realize that their eating habits have repercussions that will ultimately reduce their physical performance. Exercising intensely and not eating enough calories is harmful. Periods may become irregular or just stop. The subsequent bone loss puts them at risk for immediate problems such as stress fractures. When disordered eating, amenorrhea, and “osteoporosis” occur together, it is called the “female athlete triad.” The common manifestations of this triad are weight loss, irregular periods or no periods, and stress fractures.
Even girls who begin their periods at a later age and have a lower weight during their teen years have lower bone density when compared with their peers. Practically every teenage girl is trying to lose weight, even if they are normal weight or underweight. Weight loss is also associated with amenorrhea. It may be a function of how much body fat is present. Weight loss may be from excessive dietary restrictions as well as malnutrition. Weight gain usually restores regular menstrual cycles and hormone levels that result in increased bone density.
Teens should be counseled about how nutrition is a necessary fuel for their physical activities and health. Adolescence is a delicately balanced and hormonally supercharged time. Get help if you need it.
ENDOMETRIOSIS
Any woman who has menstrual periods can develop endometriosis, but it is most common among women in their thirties and forties. The name comes from the word for the lining of the uterus or womb, “endometrium.” Endometriosis occurs when this tissue grows outside of the uterus on other structures, typically in the pelvis or abdomen. These endometrial cell “implants” cycle as if they are still contained in the uterus. Therefore, this condition typically causes pain with menstrual periods, but pelvic pain may be constant as well. Some women may have no symptoms at all. It is commonly found during an infertility evaluation, and it may be present in almost half of women with infertility.
There is no cure for endometriosis. Treatments are focused on pain relief and promoting fertility. Since estrogen appears to promote the growth of endometriosis, medical therapy is directed at reducing estrogen by causing amenorrhea. These hormonal treatments include birth control pills, Depo-Provera, or other progesterone preparations, and medicines that chemically cause “temporary menopause.”
Medicines of this type include a daily nasal spray (Synarel®), an implant put under the skin once a month (Zoladex®), and a shot once a quarter (Lupron®). Lupron is the most commonly used. Called gonadotrophin-releasing hormone agonists or GnRH agonists, these treatments target the master gland, the pituitary, to decrease production of the messenger hormone that stimulates the ovary. As a result, estrogen levels drop dramatically. Similar to menopause, regular periods stop and symptoms such as hot flashes, poor sleep, and vaginal dryness occur.
In addition, bone loss from the spine occurs rapidly, just as though your ovaries had been surgically removed. These agents are used for an average of six months. Even though it is a short time, bone loss of 2 to 7 percent is common during a six-month course of GnRH agonist therapy. Once these are stopped, estrogen levels rapidly return to normal. However, bone density may take up to twelve to twenty-four months to return to normal. Once the medicines are stopped, monthly periods return, along with the potential to get pregnant. However, if pain with endometriosis had been a problem, it may recur. Careful monitoring of bone density is needed if consecutive six-month courses of therapy are used. Sometimes a small amount of estrogen is “added back” along with these drugs to counter the side effects and bone loss. However, it is difficult to find a dose that protects the body from substantial bone loss but does not interfere with the treatment of endometriosis.
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The Bare Bones
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