Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_2617_Библиотеки_им_академика_М_И_Перельмана

However, it is the most frequent endocrinopathy in women of childbearing age. The difculties in univocally dening PCOS stem from its etiology, which is still obscure in many respects, and the complex nature of this endocrinopathy. A shared opinion among experts in the eld is that the term “polycystic ovary syndrome” is misleading for the complex­ity of the hormonal aspects that characterize this condition. There is a consensus that the diagnosis of PCOS can be made based on at least two conditions: chronic anovularity, hyper­androgenemia (clinical or biochemical), and polycystic ovary morphology.

• Hyperandrogenism (clinical or biochemical) and chronic

testosterone before initiating any medical therapy that may interfere with circulating levels. The total testosterone assay should be accompanied by free testosterone because the lat­ter has greater diagnostic sensitivity for hyperandrogenism. However, there are critical analytical considerations that may limit the reliability of this test. Methodologically, free testos­terone can commonly be assayed by ELISA as long as the inter-assay imprecision assessed internally within the labora­tory remains below 10% and appropriate reference intervals are established in non-hyperandrogenic women. Alternatively, more accurate LC-MS/MS-based assays are now considered the gold standard for steroid hormonesmea­surement, although their use is restricted almost exclusively to clinical research in specialized laboratories. Compared to the free testosterone assay, some authors have proposed an approach based on SHBG with total testosterone. The ratio between total testosterone and SHBG indicates the amount of free hormone indirectly and is, therefore, a valuable tool to identify possible states of hyperandrogenism, especially when accurate dosages of free testosterone are not available. Epidemiological studies have shown that high levels of total testosterone and low levels of SHBG have a high positive predictive value for polycystic ovary syndrome, a condition also characterized by hyperandrogenism. In addition, reduc­ingcirculating SHBG can be considered a marker of insulin resistance to predict the onset of metabolic syndrome and gestational diabetes in women with PCOS.The signicance of Δ4-androstenedione and DHEA-S dosage in hirsut­ismpatients is still poorly understood. Δ4-androstenedione may be considered a pro-androgen; therefore, its circulating concentration may not reect the biological actions of theactive hormone.

Progesterone increases physiologically following ovulation. The serum dosage of progesterone in the lutein phase (21st day of the cycle) is used to conrm ovulation. In many cases, it is possible to have regular but anovulatory menstrual cycles, as in the case of PCOS, in which the nding of anovu­lation is one of the diagnostic criteria.

17-OH-progesterone, a progesterone derivative, does not have a precise biological role but is of particular diag­nostic importance because its circulating concentration,

both in basal conditions and after stimulation by synthetic ACTH, increases in cases of congenital adrenal hyper­plasia and, in particular, 21α-hydroxylase deciency. The 17-OH-progesterone assay is used in the etiological diag­nosis of hirsutism to identify a 21α-hydroxylase deciency.

In patients with hirsutism, FSH, LH, 17β-estradiol, and 17-OH-progesterone should be measured in addition to androgens. The prolactin and TSH assay excludes secondary forms of hyperprolactinemia and thyroid diseases. The most frequent cause of androgen excess is PCOS, which is associ­ated with increased cardio-metabolic risk, especially if accompanied by obesity. In this regard, therefore, it is neces­sary to investigate the presence, even in the past, of oligor­rhea or amenorrhea and to perform the dosage of progesterone in the lutein phase to document ovulation, since a signicant proportion of women with hirsutism have anovulatory cycles. In addition, the diagnostic approach also includes transvaginal ultrasonography to assess any polycystic mor­phology of the ovary. An evaluation of the cardio-metabolic prole should further investigatePCOS. In particular, it is necessary to assess carbohydrate tolerance by OralGlucose Tolerance Test(OGTT), BMI and abdominal circumference, complete lipid prole, and blood pressure.

The most frequent cause of secondary amenorrhea is preg­nancy. Therefore, the rst test is the β-hCG assay (Fig.25.38).

is normal, ovarian causes should be considered, such as ovar­ian hyperthecosis or androgen-secreting ovarian tumors, both conditions independent of LH.In case of mildly increased tes­tosterone levels, in addition to PCOS, non-classical congenital adrenal hyperplasia should also be considered by assaying, basal and after ACTH stimulation, 17-OH-progesterone, and Cushing’s syndrome. If testosterone is normal, free testoster­one should be assessed. In PCOS, hypersecretion of LH is typically observed with normal or slightly reduced levels of FSH, thus resulting in the typical increase in LH/FSH ratio. However, it is not recommended LH/FSH ratio as a diagnostic criterion, given the inuence of obesity on the pulsatility of their secretion. Beyond a marker of ovarian reserve, AMH is also considered a marker of the number of follicles in the ovary with polycystic morphology. However, its use in rela­tion to the diagnosis of PCOS is still controversial.