- Email: [email protected]
Classification of polycystic ovary syndrome into three types according to response to human corticotropin-releasing hormone
FERTILITY AND STERILITYt VOL. 72, NO. 1, JULY 1999 Copyright ©1999 American Society for Reproductive Medicine Published by Elsevier Science Inc. Printed on acid-free paper in U.S.A.
POLYCYSTIC OVARY SYNDROME
Classification of polycystic ovary syndrome into three types according to response to human corticotropin-releasing hormone Yoshihito Kondoh, M.D., Tsuguo Uemura, M.D., Masahiko Ishikawa, M.D., Natsuko Yokoi, M.D., and Fumiki Hirahara, M.D. Department of Obstetrics and Gynecology, Yokohama City University School of Medicine, Yokohama, Japan
Objective: To evaluate disturbances of the hypothalamic-pituitary-adrenal axis in women with polycystic ovary syndrome (PCOS). Design: Retrospective cohort study. Setting: Yokohama City University, Yokohama, Japan. Patient(s): Sixty women with PCOS and 19 women with normal menstruation. Intervention(s): Administration of human corticotropin-releasing hormone (hCRH), dexamethasone suppression testing, and stimulation of ovulation with clomiphene citrate. Main Outcome Measure(s): Plasma cortisol and ACTH levels, plasma androstenedione and DHEAS levels, and ovulation rates. Result(s): In women with PCOS, plasma ACTH and cortisol levels were significantly higher and the plasma ACTH level after the administration of hCRH was higher than in controls. Based on the response to hCRH, patients with PCOS could be classified into three categories: those with a normal response to hCRH (group 1), those with an exaggerated response of ACTH to hCRH (group 2), and those with a high basal level of cortisol and a poor response to hCRH (group 3). In groups 2 and 3, DHEAS levels were significantly higher, suppression of androstenedione by dexamethasone was significantly greater, and ovulation rates with clomiphene citrate were significantly lower than in group 1. Conclusion(s): This classification provides insight into the underlying cause of PCOS and thus is useful in selecting appropriate treatment. (Fertil Sterilt 1999;72:15–20. ©1999 by American Society for Reproductive Medicine.) Key Words: Polycystic ovary syndrome (PCOS), ACTH, cortisol, hCRH
Received November 2, 1998; revised and accepted February 16, 1999. Reprint requests: Yoshihito Kondoh, M.D., Department of Obstetrics and Gynecology, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan (FAX: 8145-701-3536). 0015-0282/99/$20.00 PII S0015-0282(99)00195-8
The pathogenesis of polycystic ovary syndrome (PCOS) is poorly understood. Polycystic ovary syndrome can be caused by various factors, such as disproportionately high or low levels of gonadotropins, abnormal adrenal function (e.g., hyperandrogenism), and insulin resistance. Many studies have shown that some women with PCOS have adrenal abnormalities that affect androgen production (1, 2). However, the role of the corticotropin-releasing hormone (CRH)–ACTH system in patients with PCOS has received little attention. We evaluated the hypothalamic-pituitaryadrenal axis in women with PCOS by assessing their response to the administration of human CRH (hCRH). We also studied whether the response to hCRH could be used to predict the
outcome of and select the treatment of choice for women with PCOS.
MATERIALS AND METHODS Sixty patients with PCOS aged 17–37 years were enrolled at the outpatient clinic of Yokohama City University. Polycystic ovary syndrome was diagnosed according to the following criteria of the Japan Society of Obstetrics and Gynecology (3): [1] amenorrhea or oligomenorrhea with or without hirsutism; [2] a high plasma LH level associated with a low FSH level and an LH;FSH ratio of .1; and [3] bilaterally normal or enlarged ovaries with multiple small cysts, as assessed by transvaginal ultrasonography. Cushing’s syndrome was ruled out in pa15
tients with high plasma cortisol levels with the use of magnetic resonance imaging and hormone studies. Late-onset adrenal hyperplasia was excluded in patients with slightly higher levels of 17a-hydroxyprogesterone (.3 ng/mL) with the use of an ACTH stimulation test (4). Nineteen women with normal menstruation who were matched with the patients for age and body mass index were studied as controls. A detailed family history was obtained from all women. The patients received no medication for at least 3 months before the study. The study was approved by the Committee on the Ethics of Research on Human Subjects of the university. All women gave informed consent to participate in the study. In the early follicular phase or after progestin-induced menses, 100 mg of hCRH (Mitsubishi Kasai Corp., Tokyo, Japan) dissolved in physiologic saline was injected intravenously at 10:00 AM after 30 minutes of bed rest. Blood samples were taken from the radial vein 0, 30, and 60 minutes after treatment; the samples were placed on ice and centrifuged immediately. The plasma was stored at 220°C until assayed. After the hCRH test, the patients received 1 mg of dexamethasone once daily for 7 days. Levels of DHEAS, androstenedione, testosterone, and cortisol were measured before and after treatment with dexamethasone. Plasma concentrations of cortisol, DHEAS, testosterone, LH, FSH, prolactin, 17a-hydroxyprogesterone, and E2 were determined with the SPAC-S cortisol kit (Daiichi Radioisotope Laboratories Ltd., Tokyo, Japan), Coat-A-Count DHEA-S SO4 kit (Nippon DPC Corporation, Tokyo, Japan), Coat-A-Count total testosterone kit (Nippon DPC Corporation), SPAC-S LH kit (Daiichi Radioisotope Laboratories Ltd.), SPAC-S FSH kit (Daiichi Radioisotope Laboratories Ltd.), SPAC-S prolactin kit (Daiichi Radioisotope Laboratories Ltd.), DPC 17a-hydroxyprogesterone kit (Nippon DPC Corporation), and E2 kit “Daiichi” II (Daiichi Radioisotope Laboratories Ltd.), respectively. Androstenedione was measured with an RIA (Teikoku Hormone Manufacturing Co. Ltd., Tokyo, Japan), and ACTH was measured with an Allegro ACTH kit (Nichols Institute Diagnostics, Los Angeles, CA). All results are expressed as means 6 SE of the absolute values. The statistical significance of differences was determined by paired t-test and analysis of variance with Scheffe´’s post hoc test. Statistical analysis was done with StatView software (Abacus Concepts Inc., Berkeley, CA).
RESULTS Clinical and Hormonal Characteristics Table 1 shows the clinical and hormonal characteristics of the subjects. Age and body mass index did not differ significantly between the patients and the controls. The patients had significantly higher plasma concentrations of LH and prolactin than the controls. There was no difference in the 16
Kondoh et al.
Classification of PCOS by hCRH
plasma concentrations of FSH, 17a-hydroxyprogesterone, or E2 between the patients and the controls.
Response of ACTH and Cortisol to hCRH The response of the ACTH level to treatment with hCRH was evaluated in the patients with PCOS and the control subjects. The plasma ACTH concentration was highest at 30 minutes and subsequently decreased in both the patients and the controls. Compared with the controls, the basal plasma ACTH concentration (P,.05) and the plasma ACTH concentration 30 minutes (P,.01) and 60 minutes (P,.05) after the injection of hCRH were significantly higher in the patients with PCOS (Fig. 1). The basal plasma cortisol concentration was significantly higher in the patients with PCOS (P,.05) than in the controls. The plasma cortisol concentration increased gradually in both groups after the injection of hCRH and was similar in the patients and the controls at 30 minutes and 60 minutes (Fig. 1).
Classification of PCOS According to the Response of ACTH and Cortisol to hCRH Various responses to hCRH were observed in the 60 women with PCOS. The basal concentrations of ACTH and cortisol and the net increases in these concentrations are shown in Figure 2. In patients whose basal cortisol concentrations were above the upper limit of normal (mean 6 2SD), the responses of cortisol and ACTH to the injection of hCRH generally were poor. Patients who had normal basal cortisol concentrations could be classified into two groups: those with a normal response and those with an exaggerated response of ACTH to hCRH. We therefore divided the patients with PCOS into three groups according to the basal level of cortisol and the response of ACTH to hCRH. Group 1 consisted of patients who had normal basal levels of cortisol and normal responses of ACTH to hCRH. Group 2 was comprised of patients in whom the net increase in ACTH was more than the mean 1 2SD of the control value. Group 3 consisted of patients in whom the basal cortisol level was higher than the mean 1 2SD of the control value. Figure 3 shows the responses of ACTH and cortisol to treatment with hCRH in the control group and the three groups of women with PCOS. In comparison with the controls, group 1 showed a similar response to hCRH, group 2 showed a significantly higher level of ACTH in response to hCRH, and group 3 showed a higher basal level of cortisol.
Androgen (DHEAS, Androstenedione, and Testosterone) Levels and Response to the Dexamethasone Suppression Test Table 1 shows the basal androgen levels in the study groups. In the PCOS group, the basal concentrations of DHEAS, a specific marker of adrenal androgen production, Vol. 72, No. 1, July 1999
TABLE 1 Clinical data and hormonal findings in patients with polycystic ovary syndrome and healthy women. Study group
Variable Age (y) BMI (kg/m2) No. (%) of obese patients† No. (%) of patients with hirsutism LH level (mIU/mL) FSH level (mIU/mL) PRL level (ng/mL) E2 level (pg/mL) DHEAS level (ng/mL) Androstenedione level (pg/mL) Testosterone level (ng/mL) 17a-OH progesterone level (ng/mL) Mean (6SE) percentage suppression of indicated hormone by dexamethasone DHEAS Androstenedione Testosterone Cortisol Ovulation rate with clomiphene citrate Pregnancy rate
Control (n 5 19)
PCOS (n 5 60)
Group 1 (n 5 37)
Group 2 (n 5 13)
Group 3 (n 5 10)
26.6 6 0.4 20.7 6 0.4 0 (0) 0 (0) 6.6 6 0.6 7.9 6 0.8 4.5 6 4.3 63.1 6 19.0 1,856 6 183 1.11 6 0.15 0.45 6 0.06 1.67 6 0.56
26.5 6 0.7 22.4 6 0.5 12 (20.0) 17 (28.3) 12.9 6 0.7‡ 7.7 6 0.4 6.5 6 0.4§ 96.7 6 15.9 2,566 6 204§ 1.61 6 0.09‡ 0.63 6 0.13 1.62 6 0.18
27.0 6 1.0 21.3 6 0.4 3 (8.1) 6 (16.2) 12.9 6 0.9 7.9 6 0.5 6.0 6 0.4 129.0 6 30.5 2,061 6 174 1.47 6 0.09§ 0.43 6 0.04 1.63 6 0.43
26.6 6 1.3 23.2 6 0.8* 4 (30.8) 5 (38.5) 12.8 6 1.4 7.9 6 0.8 8.4 6 0.8 63.1 6 16.9 2,820 6 403*§ 1.94 6 0.13*§ 0.91 6 0.38 1.51 6 0.24
24.6 6 1.1 23.7 6 1.9 5 (50.0) 6 (60.0) 13.0 6 2.4 7.9 6 0.8 6.0 6 0.9 76.9 6 16.9 3,217 6 440*§ 1.37 6 0.33 0.66 6 0.16 2.13 6 0.14
— — — — — —
— — — — 60.0 40.4
268.9 6 3.1 24.6 6 9.9 239.2 6 14.5 272.9 6 7.3 72.9 57.1
272.8 6 3.1 230.8 6 7.7* 231.7 6 20.0 284.8 6 5.4 38.5* 0\
272.2 6 9.8 236.3 6 10.3* 239.4 6 13.8 287.7 6 4.8 40.0* 25*
Note: Values are means 6 SE. BMI 5 body mass index; 17a-OH progesterone 5 17a-hydroxyprogesterone; PCOS 5 polycystic ovary syndrome; PRL 5 prolactin. * P,.05 (vs. group 1). † Obesity was defined as a BMI of .26 kg/m2. ‡ P,.1 (vs. control). § P,.05 (vs. control). \ P,.01 (vs. group 1).
and androstenedione were significantly higher than in the control group (P,.05 and P,.01, respectively).
higher in groups 1 and 2 than in the control group, and those in group 2 were significantly higher than those in group 1.
Compared with group 1 and the control group, groups 2 and 3 had significantly higher concentrations of DHEAS. Plasma androstenedione concentrations were significantly
Dexamethasone suppression tests were performed to determine whether the source of the hyperandrogenism was the adrenal gland or the ovary. The results are summarized in Table 1. The suppression rate of DHEAS did not differ among the three groups, but the suppression rate of androstenedione was significantly higher in groups 2 and 3 than in group 1.
FIGURE 1 Response of ACTH and cortisol levels to treatment with human corticotropin-releasing hormone (hCRH; 100 mg IV) in women with PCOS. Open circles indicate the mean 6 SE of the control group (n 5 19) and solid circles indicate the PCOS group (n 5 60). *P,.05 vs. control. **P,.01 vs. control.
FERTILITY & STERILITYt
Clinical Characteristics of the Three Groups of Women With PCOS Hirsutism, a clinical sign of hyperandrogenemia, was present in 16.2% of group 1, 38.5% of group 2, and 60% of group 3. Obesity was found in 8.1% of group 1, 30.8% of group 2, and 50% of group 3. Body mass index was significantly higher in group 2 than in group 1. The ovulation rate in response to the administration of clomiphene citrate was significantly higher in group 1 (72.9%) than in group 2 (38.5%) and group 3 (40%). The conception rate with the use of clomiphene citrate also was higher in group 1 (57.1%) than in group 2 (0) and group 3 (25%). 17
FIGURE 2 Basal levels (left) and responses (right) of ACTH and cortisol levels to treatment with human corticotropin-releasing hormone (hCRH) in women with POCS (n 5 60). Dotted lines indicate the mean 6 2 SD of the control group. Open triangles indicate group 1, solid circles indicate group 2, and solid triangles indicate group 3.
DISCUSSION In women with PCOS, hyperandrogenemia results from increased secretion of ovarian androgens, adrenal androgens, or both. Ovarian production of androgens is stimulated by elevated levels of LH, whereas the mechanism responsible for increased adrenal secretion of androgens is unclear. An altered response of adrenal androgen levels to ACTH was reported in women with PCOS (5, 6), but the role of the CRH-ACTH axis in this disease is poorly understood. The responses of ACTH and cortisol levels to treatment with CRH in women with PCOS first were described by Mongioi et al. (7). Although the responses of ACTH, cortisol, testosterone, and DHEA to ovine CRH (1 mg/kg of body weight) were normal in their study, the response of andro-
FIGURE 3 Responses of ACTH and cortisol levels to treatment with human corticotropin-releasing hormone (hCRH; 100 mg IV) in the three groups of women with PCOS and the control group. Open circles indicate the mean 6 SE of the control group (n 5 19). Open triangles indicate group 1, solid circles indicate group 2, and solid triangles indicate group 3. *P,.05 vs. control. **P,.01 vs. control.
stenedione was exaggerated. These findings suggested excessive adrenal production of androgens, at least in some patients with PCOS. Lanzone et al. (8) recently demonstrated that hCRH (1 mg/kg of body weight) induced exaggerated responses of ACTH and cortisol in patients with PCOS. Our results are partially consistent with those of Lanzone et al. (8), but they disagree with those of Mongioi et al. (7). These discrepancies may be due to differences in the criteria used to diagnose PCOS and the numbers of patients studied. Mongioi et al. (7) studied 9 patients with oligomenorrhea or amenorrhea who had an LH;FSH ratio of .2 or plasma androgen levels at the upper limit of normal. In contrast, we studied 60 patients with high plasma LH levels, low FSH levels, and an LH;FSH ratio of .1, excluding cases of Cushing’s syndrome. The inconsistencies between our results and those of previous studies also may involve genetic differences because androgen levels in Japanese women with PCOS are lower than those in European and American patients (9). Another important factor related to the dissimilar results is the heterogeneity of PCOS (10). We therefore classified PCOS into three types according to the response to treatment with hCRH and examined the relations between the type of PCOS and the clinical findings. Body mass index was higher in group 2 than in group 1, and hirsutism was more common in groups 2 and 3 than in group 1. The basal plasma androstenedione concentration was significantly higher in group 2 than in group 1. The basal plasma concentration of DHEAS, which is secreted mainly by the adrenal gland and is used as an index of increased adrenal androgen production (11), was significantly higher in groups 2 and 3 than in group 1. The dexamethasone suppression test, which can differentiate between ovarian and
18
Kondoh et al.
Classification of PCOS by hCRH
Vol. 72, No. 1, July 1999
adrenal causes of hyperandrogenism (12), revealed a significantly lower plasma androstenedione concentration in group 3 than in group 1 in our study. Obesity (13) and prolactin levels (14) also may influence adrenal androgen production, but Lanzone et al. (8) and Carmina et al. (15) reported no relation between CRHinduced responses and obesity, and we found no difference in prolactin levels among the three groups. Our clinical and laboratory findings also support disturbance of the CRH-ACTH-adrenal axis rather than the GnRHgonadotropin-ovarian axis in groups 2 and 3. Moreover, the increased adrenal androgen production in groups 2 and 3 seemed to arise from a disturbance of the CRH-ACTH system. The patients with PCOS in group 1 had normal basal cortisol concentrations and a normal response of ACTH to hCRH; their disease apparently involved ovarian androgen production without adrenal dysfunction. In group 2, the net increase in the ACTH level after treatment with hCRH exceeded the normal range of response, and the basal cortisol level was normal. Patients in this group were hypersensitive to hCRH at the pituitary level, which resulted in abnormal adrenal function. This type of PCOS is consistent with the findings of Lanzone et al. (8) and seems to involve hyperfunction of the hypothalamic-pituitary-adrenal axis, perhaps secondary to increased sensitivity to CRH at the pituitary level and consequent hypersecretion of ACTH. The reasons for the exaggerated response of ACTH to treatment with hCRH in women with PCOS remain unknown, but Lanzone et al. (16) reported that somatostatin might be involved in such endocrine disturbances because somatostatin analogues reduce this response. Moreover, Lanzone et al. (17) found that the hypothalamic-pituitaryadrenal axis in women with PCOS was hyperresponsive to naloxone compared with that of normal controls. These findings suggest that the hypothalamic pituitary system may be disturbed in patients with PCOS. Group 3 showed clinical and endocrinologic characteristics similar to those of patients with Cushing’s disease, such as high rates of obesity (50%) and hirsutism (60%), a significantly elevated DHEAS concentration, and significantly greater suppression of DHEAS by dexamethasone compared with group 1. However, group 3 had a high basal cortisol concentration and a normal or poor response of ACTH to hCRH. These responses differ from those seen in patients with Cushing’s disease and adrenal Cushing’s syndrome. In the former, high plasma ACTH and cortisol concentrations increase further in response to treatment with hCRH, and in the latter, low plasma ACTH and high cortisol concentrations show no response (18). The responses to treatment with hCRH in group 3 were similar to those reported in hirsute women by Carmina et al. (15), who demonstrated a blunted response of ACTH to CRH in the subgroup with increased adrenal sensitivity to FERTILITY & STERILITYt
dexamethasone. Moreover, the responses in group 3 were similar to those in patients with depression (19) or anorexia nervosa (20). In such patients, an abnormality at or above the level of the hypothalamus has been suggested to cause hypersecretion of CRH, because continuous IV infusion of a high dose of CRH in normal volunteers produces a 24-hour pattern of cortisol secretion similar to that seen in patients with depression and anorexia nervosa (21). These findings suggest that the PCOS in group 3 may have been due to hypersecretion of CRH. Clomiphene citrate is an estrogen antagonist that is widely used to induce ovulation in patients with chronic anovulation associated with PCOS. In this study, ovulation rates with the use of clomiphene citrate were significantly higher in group 1 (72.9%) than in group 2 (38.5%) and group 3 (40%). These findings are consistent with a decreased rate of ovulation in patients with high concentrations of DHEAS (10) and androstenedione (22). Classification of PCOS according to our criteria facilitates the selection of the most appropriate therapy for ovulation induction. Clomiphene citrate, which blocks inappropriate estrogen feedback mechanisms, is the therapy of choice for group 1, whereas adrenal suppression alone or in combination with clomiphene citrate is recommended for groups 2 and 3. We believe that our system of classifying PCOS is more useful for treatment selection than classifying the disease solely on the basis of elevated androgen levels. However, the patients in group 2 and 3 must be evaluated further to determine the treatment regimen best suited for each patient. It also should be noted that the pregnancy rate was significantly higher in group 1 than in group 2 or group 3. In summary, women with PCOS had a significantly greater increase in the level of ACTH in response to treatment with hCRH than did healthy women. Based on the response to hCRH, we classified PCOS into three types: an ovarian type, an ACTH-hyperresponsive type, and a hypercortisolism type. This classification provides insight into the underlying cause of PCOS and is useful in selecting appropriate treatment. References 1. Kandeel F, London D, Butt W, Danila N, Rudd B, Ssdeghian S, et al. Adrenal function in subgroups of the PCO syndrome assessed by a long ACTH test. Clin Endocrinol (Oxf) 1980;13:601–12. 2. Loughlin T, Cunningham S, Moore M, Culliton M, Smith P, McKenna T. Adrenal abnormalities in polycystic ovary syndrome. J Clin Endocrinol Metab 1986;62:142–7. 3. Japan Society of Obstetrics and Gynecology. Reports of the Committee on Reproduction and Endocrinology. Acta Obstetrica et Gynecologica Japonica 1993;45:1359 – 67. 4. New MI, Lorenzen F, Jerner AJ, Kohn B, Oberfield SE, Pollack MS, et al. Genotype steroid 21-hydroxylase deficiency: hormonal reference data. J Clin Endocrinol Metab 1983;57:320 – 6. 5. Ayers J. Differential responses to adrenocorticotropin hormone stimulation in polycystic ovarian disease with high and low dehydroepiandrosterone sulfate levels. Fertil Steril 1982;37:645–9. 6. Rosenfield R, Barnes R, Cara J, Lucky A. Dysregulation of cytochrome P450c17* as the cause of polycystic ovarian syndrome. Fertil Steril 1990;53:785–91. 7. Mongioi A, Macchi M, Vicari E, Fornito M, Calogero A, Riccioli C, et al. Pituitary and adrenal response to ovine corticotropin-releasing hor-
19
8.
9.
10. 11. 12.
13.
14. 15.
20
mone in women with polycystic ovarian syndrome. J Endocrinol Invest 1988;11:637– 40. Lanzone A, Petraglia F, Fulghesu AM, Ciampelli M, Caruso A, Mancuso S. Corticotropin-releasing hormone induces an exaggerated response of adrenocorticotropic hormone and cortisol in polycystic ovary syndrome. Fertil Steril 1995;63:1195–9. Aono T, Miyazaki M, Miyake A, Kinugawa T, Kurachi K, Matsumoto K. Responses of serum gonadotropins to LH-releasing hormone and oestrogens in Japanese women with polycystic ovary. Acta Endocrinol Copenh 1977;85:840 –9. Hoffmann D, Lobo R. Serum dehydroepiandrosterone sulfate and the use of clomiphene citrate in anovulatory women. Fertil Steril 1985;43: 196 –9. Lobo R, Paul W, Goebelsmann U. Dehydroepiandrosterone sulfate as an indicator of adrenal androgen function. Obstet Gynecol 1981;57:69 – 73. Abraham G, Maroulis G, Boyrs S, Buster J, Magyar D, Elsner C. Predictive value of dexamethasone (DXE) suppression test in the clinical response to hyperandrogenized patients to endocrine therapy. Obstet Gynecol 1981;57:158 – 65. Komindr S, Kurtz B, Stevens M, Karas J, Bittle J, Givens J. Relative sensitivity and responsivity of serum cortisol and two adrenal androgens to alfa-adrenocorticotropin-(1–24) in normal and obese, nonhirsute, eumenorrheic women. J Clin Endocrinol Metab 1986;63:860 – 4. Lobo R, Kletzky O, Kaptein E, Goebelsmann U. Prolactin modulation of dehydroepiandrosterone sulfate secretion. Am J Obstet Gynecol 1980;138:632– 6. Carmina E, Levin J, Malizia G, Lobo R. Ovine corticotropin-releasing
Kondoh et al.
Classification of PCOS by hCRH
16.
17.
18. 19.
20. 21.
22.
factor and dexamethasone responses in hyperandrogenic women. Fertil Steril 1990;54:245–50. Lanzone A, Fulghesu AM, Guido M, Cucinelli F, Caruso A, Mancuso S. Somatostatin treatment reduces the exaggerated response of adrenocorticotropin hormone and cortisol to corticotropin-releasing hormone in polycystic ovary syndrome. Fertil Steril 1997;67:34 –9. Lanzone A, Guide M, Ciampelli M, Fulghesu A, Pavone V, Proto C, et al. Evidence of a disturbance of the hypothalamic-pituitary-adrenal axis in polycystic ovary syndrome: effect of naloxone. Clin Endocrinol (Oxf) 1996;45:73–7. Fukata J, Shimizu N, Imura H, Hibi I, Tanaka K, Tanaka T, et al. Human corticotropin-releasing hormone test in patients with hypothalamo-pituitary-adrenocortical disorders. Endocr J 1993;40:597– 606. Gold P, Loriaux D, Roy A, Kling M, Calabrese J, Kellner C, et al. Responses to corticotropin-releasing hormone in the hypercortisolism of depression and Cushing’s disease: pathophysiologic and diagnostic implications. N Engl J Med 1986;314:1329 –35. Gold P, Gwirtsman H, Augerinos P, Nieman L, Gallucci W, Kaye W, et al. Abnormal hypothalamic-pituitary-adrenal function in anorexia nervosa. N Engl J Med 1986;314:1335– 42. Schulte H, Chrousos G, Gold P, Booth JD, Oldfield EH, Cutler GB Jr, et al. Continuous administration of synthetic ovine corticotropin-releasing factor in man: physiological and pathophysiological implications. J Clin Invest 1985;75:1781–5. Takahashi K, Ozaki T, Uchida A, Kitao M, Yamasaki H. Transvaginal ultrasonic assessment of the response to clomiphene citrate in polycystic ovary syndrome. Fertil Steril 1994;62:48 –53.
Vol. 72, No. 1, July 1999
POLYCYSTIC OVARY SYNDROME
Classification of polycystic ovary syndrome into three types according to response to human corticotropin-releasing hormone Yoshihito Kondoh, M.D., Tsuguo Uemura, M.D., Masahiko Ishikawa, M.D., Natsuko Yokoi, M.D., and Fumiki Hirahara, M.D. Department of Obstetrics and Gynecology, Yokohama City University School of Medicine, Yokohama, Japan
Objective: To evaluate disturbances of the hypothalamic-pituitary-adrenal axis in women with polycystic ovary syndrome (PCOS). Design: Retrospective cohort study. Setting: Yokohama City University, Yokohama, Japan. Patient(s): Sixty women with PCOS and 19 women with normal menstruation. Intervention(s): Administration of human corticotropin-releasing hormone (hCRH), dexamethasone suppression testing, and stimulation of ovulation with clomiphene citrate. Main Outcome Measure(s): Plasma cortisol and ACTH levels, plasma androstenedione and DHEAS levels, and ovulation rates. Result(s): In women with PCOS, plasma ACTH and cortisol levels were significantly higher and the plasma ACTH level after the administration of hCRH was higher than in controls. Based on the response to hCRH, patients with PCOS could be classified into three categories: those with a normal response to hCRH (group 1), those with an exaggerated response of ACTH to hCRH (group 2), and those with a high basal level of cortisol and a poor response to hCRH (group 3). In groups 2 and 3, DHEAS levels were significantly higher, suppression of androstenedione by dexamethasone was significantly greater, and ovulation rates with clomiphene citrate were significantly lower than in group 1. Conclusion(s): This classification provides insight into the underlying cause of PCOS and thus is useful in selecting appropriate treatment. (Fertil Sterilt 1999;72:15–20. ©1999 by American Society for Reproductive Medicine.) Key Words: Polycystic ovary syndrome (PCOS), ACTH, cortisol, hCRH
Received November 2, 1998; revised and accepted February 16, 1999. Reprint requests: Yoshihito Kondoh, M.D., Department of Obstetrics and Gynecology, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan (FAX: 8145-701-3536). 0015-0282/99/$20.00 PII S0015-0282(99)00195-8
The pathogenesis of polycystic ovary syndrome (PCOS) is poorly understood. Polycystic ovary syndrome can be caused by various factors, such as disproportionately high or low levels of gonadotropins, abnormal adrenal function (e.g., hyperandrogenism), and insulin resistance. Many studies have shown that some women with PCOS have adrenal abnormalities that affect androgen production (1, 2). However, the role of the corticotropin-releasing hormone (CRH)–ACTH system in patients with PCOS has received little attention. We evaluated the hypothalamic-pituitaryadrenal axis in women with PCOS by assessing their response to the administration of human CRH (hCRH). We also studied whether the response to hCRH could be used to predict the
outcome of and select the treatment of choice for women with PCOS.
MATERIALS AND METHODS Sixty patients with PCOS aged 17–37 years were enrolled at the outpatient clinic of Yokohama City University. Polycystic ovary syndrome was diagnosed according to the following criteria of the Japan Society of Obstetrics and Gynecology (3): [1] amenorrhea or oligomenorrhea with or without hirsutism; [2] a high plasma LH level associated with a low FSH level and an LH;FSH ratio of .1; and [3] bilaterally normal or enlarged ovaries with multiple small cysts, as assessed by transvaginal ultrasonography. Cushing’s syndrome was ruled out in pa15
tients with high plasma cortisol levels with the use of magnetic resonance imaging and hormone studies. Late-onset adrenal hyperplasia was excluded in patients with slightly higher levels of 17a-hydroxyprogesterone (.3 ng/mL) with the use of an ACTH stimulation test (4). Nineteen women with normal menstruation who were matched with the patients for age and body mass index were studied as controls. A detailed family history was obtained from all women. The patients received no medication for at least 3 months before the study. The study was approved by the Committee on the Ethics of Research on Human Subjects of the university. All women gave informed consent to participate in the study. In the early follicular phase or after progestin-induced menses, 100 mg of hCRH (Mitsubishi Kasai Corp., Tokyo, Japan) dissolved in physiologic saline was injected intravenously at 10:00 AM after 30 minutes of bed rest. Blood samples were taken from the radial vein 0, 30, and 60 minutes after treatment; the samples were placed on ice and centrifuged immediately. The plasma was stored at 220°C until assayed. After the hCRH test, the patients received 1 mg of dexamethasone once daily for 7 days. Levels of DHEAS, androstenedione, testosterone, and cortisol were measured before and after treatment with dexamethasone. Plasma concentrations of cortisol, DHEAS, testosterone, LH, FSH, prolactin, 17a-hydroxyprogesterone, and E2 were determined with the SPAC-S cortisol kit (Daiichi Radioisotope Laboratories Ltd., Tokyo, Japan), Coat-A-Count DHEA-S SO4 kit (Nippon DPC Corporation, Tokyo, Japan), Coat-A-Count total testosterone kit (Nippon DPC Corporation), SPAC-S LH kit (Daiichi Radioisotope Laboratories Ltd.), SPAC-S FSH kit (Daiichi Radioisotope Laboratories Ltd.), SPAC-S prolactin kit (Daiichi Radioisotope Laboratories Ltd.), DPC 17a-hydroxyprogesterone kit (Nippon DPC Corporation), and E2 kit “Daiichi” II (Daiichi Radioisotope Laboratories Ltd.), respectively. Androstenedione was measured with an RIA (Teikoku Hormone Manufacturing Co. Ltd., Tokyo, Japan), and ACTH was measured with an Allegro ACTH kit (Nichols Institute Diagnostics, Los Angeles, CA). All results are expressed as means 6 SE of the absolute values. The statistical significance of differences was determined by paired t-test and analysis of variance with Scheffe´’s post hoc test. Statistical analysis was done with StatView software (Abacus Concepts Inc., Berkeley, CA).
RESULTS Clinical and Hormonal Characteristics Table 1 shows the clinical and hormonal characteristics of the subjects. Age and body mass index did not differ significantly between the patients and the controls. The patients had significantly higher plasma concentrations of LH and prolactin than the controls. There was no difference in the 16
Kondoh et al.
Classification of PCOS by hCRH
plasma concentrations of FSH, 17a-hydroxyprogesterone, or E2 between the patients and the controls.
Response of ACTH and Cortisol to hCRH The response of the ACTH level to treatment with hCRH was evaluated in the patients with PCOS and the control subjects. The plasma ACTH concentration was highest at 30 minutes and subsequently decreased in both the patients and the controls. Compared with the controls, the basal plasma ACTH concentration (P,.05) and the plasma ACTH concentration 30 minutes (P,.01) and 60 minutes (P,.05) after the injection of hCRH were significantly higher in the patients with PCOS (Fig. 1). The basal plasma cortisol concentration was significantly higher in the patients with PCOS (P,.05) than in the controls. The plasma cortisol concentration increased gradually in both groups after the injection of hCRH and was similar in the patients and the controls at 30 minutes and 60 minutes (Fig. 1).
Classification of PCOS According to the Response of ACTH and Cortisol to hCRH Various responses to hCRH were observed in the 60 women with PCOS. The basal concentrations of ACTH and cortisol and the net increases in these concentrations are shown in Figure 2. In patients whose basal cortisol concentrations were above the upper limit of normal (mean 6 2SD), the responses of cortisol and ACTH to the injection of hCRH generally were poor. Patients who had normal basal cortisol concentrations could be classified into two groups: those with a normal response and those with an exaggerated response of ACTH to hCRH. We therefore divided the patients with PCOS into three groups according to the basal level of cortisol and the response of ACTH to hCRH. Group 1 consisted of patients who had normal basal levels of cortisol and normal responses of ACTH to hCRH. Group 2 was comprised of patients in whom the net increase in ACTH was more than the mean 1 2SD of the control value. Group 3 consisted of patients in whom the basal cortisol level was higher than the mean 1 2SD of the control value. Figure 3 shows the responses of ACTH and cortisol to treatment with hCRH in the control group and the three groups of women with PCOS. In comparison with the controls, group 1 showed a similar response to hCRH, group 2 showed a significantly higher level of ACTH in response to hCRH, and group 3 showed a higher basal level of cortisol.
Androgen (DHEAS, Androstenedione, and Testosterone) Levels and Response to the Dexamethasone Suppression Test Table 1 shows the basal androgen levels in the study groups. In the PCOS group, the basal concentrations of DHEAS, a specific marker of adrenal androgen production, Vol. 72, No. 1, July 1999
TABLE 1 Clinical data and hormonal findings in patients with polycystic ovary syndrome and healthy women. Study group
Variable Age (y) BMI (kg/m2) No. (%) of obese patients† No. (%) of patients with hirsutism LH level (mIU/mL) FSH level (mIU/mL) PRL level (ng/mL) E2 level (pg/mL) DHEAS level (ng/mL) Androstenedione level (pg/mL) Testosterone level (ng/mL) 17a-OH progesterone level (ng/mL) Mean (6SE) percentage suppression of indicated hormone by dexamethasone DHEAS Androstenedione Testosterone Cortisol Ovulation rate with clomiphene citrate Pregnancy rate
Control (n 5 19)
PCOS (n 5 60)
Group 1 (n 5 37)
Group 2 (n 5 13)
Group 3 (n 5 10)
26.6 6 0.4 20.7 6 0.4 0 (0) 0 (0) 6.6 6 0.6 7.9 6 0.8 4.5 6 4.3 63.1 6 19.0 1,856 6 183 1.11 6 0.15 0.45 6 0.06 1.67 6 0.56
26.5 6 0.7 22.4 6 0.5 12 (20.0) 17 (28.3) 12.9 6 0.7‡ 7.7 6 0.4 6.5 6 0.4§ 96.7 6 15.9 2,566 6 204§ 1.61 6 0.09‡ 0.63 6 0.13 1.62 6 0.18
27.0 6 1.0 21.3 6 0.4 3 (8.1) 6 (16.2) 12.9 6 0.9 7.9 6 0.5 6.0 6 0.4 129.0 6 30.5 2,061 6 174 1.47 6 0.09§ 0.43 6 0.04 1.63 6 0.43
26.6 6 1.3 23.2 6 0.8* 4 (30.8) 5 (38.5) 12.8 6 1.4 7.9 6 0.8 8.4 6 0.8 63.1 6 16.9 2,820 6 403*§ 1.94 6 0.13*§ 0.91 6 0.38 1.51 6 0.24
24.6 6 1.1 23.7 6 1.9 5 (50.0) 6 (60.0) 13.0 6 2.4 7.9 6 0.8 6.0 6 0.9 76.9 6 16.9 3,217 6 440*§ 1.37 6 0.33 0.66 6 0.16 2.13 6 0.14
— — — — — —
— — — — 60.0 40.4
268.9 6 3.1 24.6 6 9.9 239.2 6 14.5 272.9 6 7.3 72.9 57.1
272.8 6 3.1 230.8 6 7.7* 231.7 6 20.0 284.8 6 5.4 38.5* 0\
272.2 6 9.8 236.3 6 10.3* 239.4 6 13.8 287.7 6 4.8 40.0* 25*
Note: Values are means 6 SE. BMI 5 body mass index; 17a-OH progesterone 5 17a-hydroxyprogesterone; PCOS 5 polycystic ovary syndrome; PRL 5 prolactin. * P,.05 (vs. group 1). † Obesity was defined as a BMI of .26 kg/m2. ‡ P,.1 (vs. control). § P,.05 (vs. control). \ P,.01 (vs. group 1).
and androstenedione were significantly higher than in the control group (P,.05 and P,.01, respectively).
higher in groups 1 and 2 than in the control group, and those in group 2 were significantly higher than those in group 1.
Compared with group 1 and the control group, groups 2 and 3 had significantly higher concentrations of DHEAS. Plasma androstenedione concentrations were significantly
Dexamethasone suppression tests were performed to determine whether the source of the hyperandrogenism was the adrenal gland or the ovary. The results are summarized in Table 1. The suppression rate of DHEAS did not differ among the three groups, but the suppression rate of androstenedione was significantly higher in groups 2 and 3 than in group 1.
FIGURE 1 Response of ACTH and cortisol levels to treatment with human corticotropin-releasing hormone (hCRH; 100 mg IV) in women with PCOS. Open circles indicate the mean 6 SE of the control group (n 5 19) and solid circles indicate the PCOS group (n 5 60). *P,.05 vs. control. **P,.01 vs. control.
FERTILITY & STERILITYt
Clinical Characteristics of the Three Groups of Women With PCOS Hirsutism, a clinical sign of hyperandrogenemia, was present in 16.2% of group 1, 38.5% of group 2, and 60% of group 3. Obesity was found in 8.1% of group 1, 30.8% of group 2, and 50% of group 3. Body mass index was significantly higher in group 2 than in group 1. The ovulation rate in response to the administration of clomiphene citrate was significantly higher in group 1 (72.9%) than in group 2 (38.5%) and group 3 (40%). The conception rate with the use of clomiphene citrate also was higher in group 1 (57.1%) than in group 2 (0) and group 3 (25%). 17
FIGURE 2 Basal levels (left) and responses (right) of ACTH and cortisol levels to treatment with human corticotropin-releasing hormone (hCRH) in women with POCS (n 5 60). Dotted lines indicate the mean 6 2 SD of the control group. Open triangles indicate group 1, solid circles indicate group 2, and solid triangles indicate group 3.
DISCUSSION In women with PCOS, hyperandrogenemia results from increased secretion of ovarian androgens, adrenal androgens, or both. Ovarian production of androgens is stimulated by elevated levels of LH, whereas the mechanism responsible for increased adrenal secretion of androgens is unclear. An altered response of adrenal androgen levels to ACTH was reported in women with PCOS (5, 6), but the role of the CRH-ACTH axis in this disease is poorly understood. The responses of ACTH and cortisol levels to treatment with CRH in women with PCOS first were described by Mongioi et al. (7). Although the responses of ACTH, cortisol, testosterone, and DHEA to ovine CRH (1 mg/kg of body weight) were normal in their study, the response of andro-
FIGURE 3 Responses of ACTH and cortisol levels to treatment with human corticotropin-releasing hormone (hCRH; 100 mg IV) in the three groups of women with PCOS and the control group. Open circles indicate the mean 6 SE of the control group (n 5 19). Open triangles indicate group 1, solid circles indicate group 2, and solid triangles indicate group 3. *P,.05 vs. control. **P,.01 vs. control.
stenedione was exaggerated. These findings suggested excessive adrenal production of androgens, at least in some patients with PCOS. Lanzone et al. (8) recently demonstrated that hCRH (1 mg/kg of body weight) induced exaggerated responses of ACTH and cortisol in patients with PCOS. Our results are partially consistent with those of Lanzone et al. (8), but they disagree with those of Mongioi et al. (7). These discrepancies may be due to differences in the criteria used to diagnose PCOS and the numbers of patients studied. Mongioi et al. (7) studied 9 patients with oligomenorrhea or amenorrhea who had an LH;FSH ratio of .2 or plasma androgen levels at the upper limit of normal. In contrast, we studied 60 patients with high plasma LH levels, low FSH levels, and an LH;FSH ratio of .1, excluding cases of Cushing’s syndrome. The inconsistencies between our results and those of previous studies also may involve genetic differences because androgen levels in Japanese women with PCOS are lower than those in European and American patients (9). Another important factor related to the dissimilar results is the heterogeneity of PCOS (10). We therefore classified PCOS into three types according to the response to treatment with hCRH and examined the relations between the type of PCOS and the clinical findings. Body mass index was higher in group 2 than in group 1, and hirsutism was more common in groups 2 and 3 than in group 1. The basal plasma androstenedione concentration was significantly higher in group 2 than in group 1. The basal plasma concentration of DHEAS, which is secreted mainly by the adrenal gland and is used as an index of increased adrenal androgen production (11), was significantly higher in groups 2 and 3 than in group 1. The dexamethasone suppression test, which can differentiate between ovarian and
18
Kondoh et al.
Classification of PCOS by hCRH
Vol. 72, No. 1, July 1999
adrenal causes of hyperandrogenism (12), revealed a significantly lower plasma androstenedione concentration in group 3 than in group 1 in our study. Obesity (13) and prolactin levels (14) also may influence adrenal androgen production, but Lanzone et al. (8) and Carmina et al. (15) reported no relation between CRHinduced responses and obesity, and we found no difference in prolactin levels among the three groups. Our clinical and laboratory findings also support disturbance of the CRH-ACTH-adrenal axis rather than the GnRHgonadotropin-ovarian axis in groups 2 and 3. Moreover, the increased adrenal androgen production in groups 2 and 3 seemed to arise from a disturbance of the CRH-ACTH system. The patients with PCOS in group 1 had normal basal cortisol concentrations and a normal response of ACTH to hCRH; their disease apparently involved ovarian androgen production without adrenal dysfunction. In group 2, the net increase in the ACTH level after treatment with hCRH exceeded the normal range of response, and the basal cortisol level was normal. Patients in this group were hypersensitive to hCRH at the pituitary level, which resulted in abnormal adrenal function. This type of PCOS is consistent with the findings of Lanzone et al. (8) and seems to involve hyperfunction of the hypothalamic-pituitary-adrenal axis, perhaps secondary to increased sensitivity to CRH at the pituitary level and consequent hypersecretion of ACTH. The reasons for the exaggerated response of ACTH to treatment with hCRH in women with PCOS remain unknown, but Lanzone et al. (16) reported that somatostatin might be involved in such endocrine disturbances because somatostatin analogues reduce this response. Moreover, Lanzone et al. (17) found that the hypothalamic-pituitaryadrenal axis in women with PCOS was hyperresponsive to naloxone compared with that of normal controls. These findings suggest that the hypothalamic pituitary system may be disturbed in patients with PCOS. Group 3 showed clinical and endocrinologic characteristics similar to those of patients with Cushing’s disease, such as high rates of obesity (50%) and hirsutism (60%), a significantly elevated DHEAS concentration, and significantly greater suppression of DHEAS by dexamethasone compared with group 1. However, group 3 had a high basal cortisol concentration and a normal or poor response of ACTH to hCRH. These responses differ from those seen in patients with Cushing’s disease and adrenal Cushing’s syndrome. In the former, high plasma ACTH and cortisol concentrations increase further in response to treatment with hCRH, and in the latter, low plasma ACTH and high cortisol concentrations show no response (18). The responses to treatment with hCRH in group 3 were similar to those reported in hirsute women by Carmina et al. (15), who demonstrated a blunted response of ACTH to CRH in the subgroup with increased adrenal sensitivity to FERTILITY & STERILITYt
dexamethasone. Moreover, the responses in group 3 were similar to those in patients with depression (19) or anorexia nervosa (20). In such patients, an abnormality at or above the level of the hypothalamus has been suggested to cause hypersecretion of CRH, because continuous IV infusion of a high dose of CRH in normal volunteers produces a 24-hour pattern of cortisol secretion similar to that seen in patients with depression and anorexia nervosa (21). These findings suggest that the PCOS in group 3 may have been due to hypersecretion of CRH. Clomiphene citrate is an estrogen antagonist that is widely used to induce ovulation in patients with chronic anovulation associated with PCOS. In this study, ovulation rates with the use of clomiphene citrate were significantly higher in group 1 (72.9%) than in group 2 (38.5%) and group 3 (40%). These findings are consistent with a decreased rate of ovulation in patients with high concentrations of DHEAS (10) and androstenedione (22). Classification of PCOS according to our criteria facilitates the selection of the most appropriate therapy for ovulation induction. Clomiphene citrate, which blocks inappropriate estrogen feedback mechanisms, is the therapy of choice for group 1, whereas adrenal suppression alone or in combination with clomiphene citrate is recommended for groups 2 and 3. We believe that our system of classifying PCOS is more useful for treatment selection than classifying the disease solely on the basis of elevated androgen levels. However, the patients in group 2 and 3 must be evaluated further to determine the treatment regimen best suited for each patient. It also should be noted that the pregnancy rate was significantly higher in group 1 than in group 2 or group 3. In summary, women with PCOS had a significantly greater increase in the level of ACTH in response to treatment with hCRH than did healthy women. Based on the response to hCRH, we classified PCOS into three types: an ovarian type, an ACTH-hyperresponsive type, and a hypercortisolism type. This classification provides insight into the underlying cause of PCOS and is useful in selecting appropriate treatment. References 1. Kandeel F, London D, Butt W, Danila N, Rudd B, Ssdeghian S, et al. Adrenal function in subgroups of the PCO syndrome assessed by a long ACTH test. Clin Endocrinol (Oxf) 1980;13:601–12. 2. Loughlin T, Cunningham S, Moore M, Culliton M, Smith P, McKenna T. Adrenal abnormalities in polycystic ovary syndrome. J Clin Endocrinol Metab 1986;62:142–7. 3. Japan Society of Obstetrics and Gynecology. Reports of the Committee on Reproduction and Endocrinology. Acta Obstetrica et Gynecologica Japonica 1993;45:1359 – 67. 4. New MI, Lorenzen F, Jerner AJ, Kohn B, Oberfield SE, Pollack MS, et al. Genotype steroid 21-hydroxylase deficiency: hormonal reference data. J Clin Endocrinol Metab 1983;57:320 – 6. 5. Ayers J. Differential responses to adrenocorticotropin hormone stimulation in polycystic ovarian disease with high and low dehydroepiandrosterone sulfate levels. Fertil Steril 1982;37:645–9. 6. Rosenfield R, Barnes R, Cara J, Lucky A. Dysregulation of cytochrome P450c17* as the cause of polycystic ovarian syndrome. Fertil Steril 1990;53:785–91. 7. Mongioi A, Macchi M, Vicari E, Fornito M, Calogero A, Riccioli C, et al. Pituitary and adrenal response to ovine corticotropin-releasing hor-
19
8.
9.
10. 11. 12.
13.
14. 15.
20
mone in women with polycystic ovarian syndrome. J Endocrinol Invest 1988;11:637– 40. Lanzone A, Petraglia F, Fulghesu AM, Ciampelli M, Caruso A, Mancuso S. Corticotropin-releasing hormone induces an exaggerated response of adrenocorticotropic hormone and cortisol in polycystic ovary syndrome. Fertil Steril 1995;63:1195–9. Aono T, Miyazaki M, Miyake A, Kinugawa T, Kurachi K, Matsumoto K. Responses of serum gonadotropins to LH-releasing hormone and oestrogens in Japanese women with polycystic ovary. Acta Endocrinol Copenh 1977;85:840 –9. Hoffmann D, Lobo R. Serum dehydroepiandrosterone sulfate and the use of clomiphene citrate in anovulatory women. Fertil Steril 1985;43: 196 –9. Lobo R, Paul W, Goebelsmann U. Dehydroepiandrosterone sulfate as an indicator of adrenal androgen function. Obstet Gynecol 1981;57:69 – 73. Abraham G, Maroulis G, Boyrs S, Buster J, Magyar D, Elsner C. Predictive value of dexamethasone (DXE) suppression test in the clinical response to hyperandrogenized patients to endocrine therapy. Obstet Gynecol 1981;57:158 – 65. Komindr S, Kurtz B, Stevens M, Karas J, Bittle J, Givens J. Relative sensitivity and responsivity of serum cortisol and two adrenal androgens to alfa-adrenocorticotropin-(1–24) in normal and obese, nonhirsute, eumenorrheic women. J Clin Endocrinol Metab 1986;63:860 – 4. Lobo R, Kletzky O, Kaptein E, Goebelsmann U. Prolactin modulation of dehydroepiandrosterone sulfate secretion. Am J Obstet Gynecol 1980;138:632– 6. Carmina E, Levin J, Malizia G, Lobo R. Ovine corticotropin-releasing
Kondoh et al.
Classification of PCOS by hCRH
16.
17.
18. 19.
20. 21.
22.
factor and dexamethasone responses in hyperandrogenic women. Fertil Steril 1990;54:245–50. Lanzone A, Fulghesu AM, Guido M, Cucinelli F, Caruso A, Mancuso S. Somatostatin treatment reduces the exaggerated response of adrenocorticotropin hormone and cortisol to corticotropin-releasing hormone in polycystic ovary syndrome. Fertil Steril 1997;67:34 –9. Lanzone A, Guide M, Ciampelli M, Fulghesu A, Pavone V, Proto C, et al. Evidence of a disturbance of the hypothalamic-pituitary-adrenal axis in polycystic ovary syndrome: effect of naloxone. Clin Endocrinol (Oxf) 1996;45:73–7. Fukata J, Shimizu N, Imura H, Hibi I, Tanaka K, Tanaka T, et al. Human corticotropin-releasing hormone test in patients with hypothalamo-pituitary-adrenocortical disorders. Endocr J 1993;40:597– 606. Gold P, Loriaux D, Roy A, Kling M, Calabrese J, Kellner C, et al. Responses to corticotropin-releasing hormone in the hypercortisolism of depression and Cushing’s disease: pathophysiologic and diagnostic implications. N Engl J Med 1986;314:1329 –35. Gold P, Gwirtsman H, Augerinos P, Nieman L, Gallucci W, Kaye W, et al. Abnormal hypothalamic-pituitary-adrenal function in anorexia nervosa. N Engl J Med 1986;314:1335– 42. Schulte H, Chrousos G, Gold P, Booth JD, Oldfield EH, Cutler GB Jr, et al. Continuous administration of synthetic ovine corticotropin-releasing factor in man: physiological and pathophysiological implications. J Clin Invest 1985;75:1781–5. Takahashi K, Ozaki T, Uchida A, Kitao M, Yamasaki H. Transvaginal ultrasonic assessment of the response to clomiphene citrate in polycystic ovary syndrome. Fertil Steril 1994;62:48 –53.
Vol. 72, No. 1, July 1999