The PCOS Plan. Jason Fung
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Название: The PCOS Plan
Автор: Jason Fung
Издательство: Ingram
Жанр: Здоровье
isbn: 9781771644617
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·acne,
·lowered tone of voice,
·menstrual irregularities, and
·clitoral enlargement (in severe cases).
The feature most commonly associated with PCOS is hirsutism, which affects an estimated 70 percent of women with PCOS. Just as with men, more testosterone increases the growth of facial and body hair in certain areas, such as the face, legs, chest, back, and buttocks. At the same time, higher levels of testosterone can cause hair loss on the scalp, which leads to crown-pattern or male-pattern baldness. In women with hyperandrogenism, this hair gain and loss becomes very obvious.
An estimated 15 to 30 percent of PCOS patients develop acne, though it has only recently been recognized as a symptom of hyperandrogenism. Among women who complain of acne, 40 percent are eventually diagnosed with PCOS, so it is important to keep it in mind.5 Deepening of the voice and enlargement of the clitoris indicate severe hyperandrogenism.
Serum androgen levels can be measured through blood testing. The most useful blood tests for hyperandrogenism determine levels of serum testosterone and DHEA-S (dehydroepiandrosterone sulfate), another type of androgen. These hormones fluctuate throughout the day and throughout the menstrual cycle, making it harder to define normal and abnormal ranges. Nevertheless, 75 percent of women with PCOS will have an abnormal value, if you look hard enough. Because high testosterone levels are not part of the diagnostic criteria (only clinical manifestations of it are), most clinicians do not bother to administer these blood tests.
It is worth noting that androgens also act as precursors to female sex hormones (estrogens) in both men and women. Excess adipose (fat) tissue can convert testosterone into estrogen, causing breast enlargement in both men and women. This process accounts for the very obvious “man boob” phenomenon seen in some older and obese men; it is much less obvious in women. There are ethnic differences in sensitivities to androgens, with white people being the most sensitive and Asians being the least.
Menstrual irregularities
Dr. John Nestler from Virginia Commonwealth University estimates that “if a woman has fewer than eight menstrual periods a year on a chronic basis, she probably has a 50 to 80 percent chance of having polycystic ovary syndrome based on that single observation.”6 Irregular, absent, or rare menstrual cycles are all common symptoms of PCOS. An estimated 85 percent of women with PCOS suffer menstrual irregularities.7 During the normal menstrual cycle, the human egg develops from the primordial follicle. It grows during the first half of the menstrual cycle and then is released into one of the fallopian tubes to be carried to the uterus, where it awaits fertilization by the sperm. Ovulation is the release of the egg from the ovary. Irregular menstrual cycles are caused by the failure of ovulation. In PCOS, the main menstrual problems are anovulation and oligo-ovulation. Anovulation means a complete lack of ovulation and oligo-ovulation refers to a lower-than-normal rate of ovulation.
Figure 2.1. Follicle development in a normal menstrual cycle
When normal ovulation does not occur, then menstrual cycles may be completely absent (amenorrhea) or may last longer than usual (oligomenorrhea). But even having a regular cycle does not mean that ovulation has occurred normally, especially in women with other evidence of hyperandrogenism. Twenty to 50 percent of women with signs of excess testosterone and regular periods still have evidence of anovulation. This lack of ovulation will result in difficulty conceiving and infertility. PCOS is associated with recurrent miscarriages, and it is the most common cause of infertility in industrialized nations.
When I was trying to conceive, I often bought over-the-counter ovulation prediction kits that use urine strips to test for luteinizing hormone (LH). This hormone spikes just before a woman ovulates and indicates that it’s baby-making time! During many of my infertile months, I noticed the same thing as many of my infertile patients do. Even when I had a menstrual cycle, whether it was regular or not (much longer than 28 days), I did not have an LH surge. In other words, I was not ovulating.
Polycystic ovaries
Follicles are collections of cells in the ovary. During a normal menstrual cycle, many follicles begin to develop and one eventually becomes the human egg that is released into the uterus at the time of ovulation. The other follicles usually shrivel up and are reabsorbed into the body. When these follicles fail to shrivel up, they become cystic and show up on an ultrasound as ovarian cysts.
The Rotterdam criteria define polycystic ovaries as being the presence of 12 or more follicles measuring 2 to 9 mm in diameter in each ovary. Two main factors influence the number of cysts. Small (2–5 mm) follicles are related to the serum androgen level and larger (6–9 mm) follicles are related to both serum testosterone and fasting insulin levels. Because 20 to 30 percent of otherwise normal women may have multiple cysts on their ovaries, the mere presence of cysts is not enough to make the diagnosis of PCOS. And there is no correlation between the number of cysts and the severity of PCOS.
WHEN WHAT LOOKS LIKE PCOS IS NOT
DESPITE THE REASONABLY clear diagnostic criteria for PCOS, certain populations present with symptoms that fit the Rotterdam criteria but do not necessarily indicate PCOS. Certain conditions, too, can look a lot like PCOS but have completely different causes and associated treatments.
Misdiagnosis in adolescents
Making the diagnosis of PCOS in adolescents is particularly tricky because irregular cycles, hyperandrogenism, and polycystic ovaries can all be found during normal puberty.
When girls first begin to menstruate (called menarche), their cycles are commonly irregular and may not always be accompanied by ovulation. In the United States, the median age of menarche is 12.4 years. The period of irregular cycles often lasts for two years or more, and the cycle intervals typically range from 21 to 45 days (average of 32.2 days). This average is quite close to the 35-day cycle that is defined as oligomenorrhea, or infrequent menstrual cycles in women of childbearing age.
Normal puberty and the irregular cycles seen in PCOS overlap significantly. To avoid overtreatment and unnecessary worry, clinicians should generally wait until the third year after menarche to confirm a diagnosis of PCOS in teens. By that time, 60 to 80 percent of girls have cycles that are 21 to 34 days long, which is typical of a normal adult cycle.
Blood testing of androgens in adolescents does not distinguish unusually high levels, because normal levels are not well defined in this age group. During puberty, there is a normal physiological increase in testosterone levels that peaks a few years after menarche. This increased testosterone leads, for example, to the familiar problem of acne during teenage years that improves or disappears in later adult years. The presence and the severity of this temporary increase in acne do not predict a later diagnosis of PCOS.
Polycystic ovaries, too, are difficult to diagnose during adolescence. In adult women, a transvaginal ultrasound, in which the ultrasound probe is inserted into the vagina, provides the clearest images of the ovary. However, this technique is usually avoided in adolescent girls, which makes the radiological diagnosis more difficult. In studies where ultrasounds were performed, 26 to 54 percent of asymptomatic adolescent girls had polycystic ovaries by imaging.8
Special care must be taken in labeling a patient with PCOS during their teen years, and it is often prudent to wait until after adolescence to make the diagnosis since it is not an urgent СКАЧАТЬ