Oestrogen amplification of LH-RH response in the polycystic ovary syndrome and response to clomiphene

Oral contraceptives and the management of hyperandrogenism-polycystic ovary syndrome in adolescents

Appropriate management of polycystic ovary syndrome in adolescents depends on recognizing the syndrome, which can have a variety of presenting complaints and must be differentiated from other causes of hyperandrogenism, as well as not dismissed as "normal adolescence." Oral contraceptives have long been considered the first line of treatment by obstetrician/gynecologists and have many advantages in treating the aspects of PCOS that are most bothersome to teens. Because of the potential risk for cardiovascular disease, early diagnosis and management may be helpful in minimizing the risk of the early metabolic correlates of adult disease.

Three types of polycystic ovarian syndrome in relation to androgenic function

OBJECTIVE

To re-evaluate the concept of polycystic ovarian syndrome (PCOS) in view of androgenic function.

DESIGN

Patients were studied endocrinologically and ultrasonographically.

SETTING

This study was performed as a clinical investigation.

PATIENTS, PARTICIPANTS

Sixty-nine euprolactinemic anovulatory patients with luteinizing hormone (LH) hypersecretion and 18 normal volunteers were selected.

INTERVENTIONS

One hundred micrograms of LH-releasing hormone were administered.

MAIN OUTCOME MEASURE(S)

It was possible to divide PCOS patients into three types.

RESULTS

Patients with neither hirsutism nor elevation of serum androstenedione (delta 4) and/or testosterone (T) were designated as type I PCOS (n = 20). Patients without hirsutism but with elevated delta 4 and/or T were referred to as type II PCOS (n = 33). Patients with both hirsutism and elevation of delta 4 and/or T were defined as type III PCOS (n = 16). Concentrations of delta 4 appeared gradedly increasing in types I, II, and III in that order, whereas T concentrations were significantly higher in types II and III than in control. Ultrasonographically, cystic ovaries were found in 88%, 84%, and 100% of types I, II, and III patients, respectively.

CONCLUSIONS

It is postulated that each type may represent a subset of whole spectrum of PCOS from Stein-Leventhal syndrome to simple anovulation with LH hypersecretion.

Androstenedione concentrations following dexamethasone suppression: correlation with clomiphene responsiveness in women with polycystic ovary syndrome

It is difficult to predict clomiphene responsiveness in women with polycystic ovary syndrome (PCOS) but it has been suggested that women with evidence of excess adrenal androgen are less likely to respond to clomiphene. To investigate this further we performed a short Synacthen test following overnight dexamethasone suppression, using 11 beta-hydroxyandrostenedione (11-OHA) as a specific marker of adrenal androgen secretion in women with anovulatory infertility due to PCOS (n = 19) compared with a normal group (n = 7). Women with PCOS were subsequently divided into 2 groups according to whether or not they ovulated after clomiphene. On day 1 blood was taken at 9.00 hours for measurement of androstenedione (A), 11-OHA and cortisol, and 1 mg dexamethasone was given at 22.00 hours. On day 2 blood was taken at 9.00 hours and at 30 and 60 minutes after intravenous administration of 250 micrograms Synacthen. Before dexamethasone was given, concentrations of A but not of 11-OHA or cortisol were significantly higher in women with PCOS than in controls but there was no difference in A levels between clomiphene responders and non-responders. After 1 mg dexamethasone had been given, concentrations of A, 11-OHA and cortisol were suppressed in all 3 groups and there were no differences between the groups in the post-dexamethasone concentrations of 11-OHA or cortisol.(ABSTRACT TRUNCATED AT 250 WORDS)

The LH surge in humans: its mechanism and sex difference

There is a sex difference in the response to an estrogen challenge test in humans, but, unlike with rats, this sex difference is not permanently imprinted in the central nervous system. Estrogen is not only the important ovarian signal to trigger off the LH surge, but it also probably plays an important role in activating the positive estrogen feedback mechanism in humans. For an LH surge to occur, amplification of the hypothalamic signal (enhanced secretion of GnRH) as well as sensitization of the pituitary responsiveness to GnRH are required. It is unlikely that androgens per se are responsible for suppressing the positive estrogen feedback in humans and the possible role of another gonadal factor other than androgens remains speculative. The LH surge is a neuroendocrine phenomenon involved primarily in the process of ovulation and it is not correlated to sexual identity and orientation. Furthermore, how the hypothalamic-pituitary axis (HPA) responds to the estrogen challenge can be accounted for purely by its exposure to a different steroid milieu without reference to gender identity or sexual orientation of the subject.

Animal models for study of polycystic ovaries and ovarian atresia

In the human, polycystic ovaries are generally accompanied by normal or elevated levels of serum LH, normal or slightly depressed FSH and by high levels of circulating estrogens and androgens. If the excess androgen secretion is reduced by one of several methods, ovulatory cycles are usually restored. Several animal model systems have been proposed for the study of the pathophysiology of the polycystic ovarian syndrome. These include neonatal androgenization, hCG administration to hypothyroid rats, injection of estradiol valerate and maintaining animals in constant light. In a model developed in this laboratory, pubertal or adult rats were treated with the weak androgen, dehydroepiandrosterone (DHA), to induce polycystic ovaries. This treatment also altered the blood levels of LH and FSH but the effect on gonadotropins and on the formation of the degenerative follicles was fully reversed following discontinuation of the androgen injections. The polycystic ovaries of the DHA-treated animals were steroidogenically more active than controls raising the possibility that the DHA was acting directly on the ovary in addition to an action on the pituitary-hypothalamus axis. In order to study the direct effect of androgens on the ovary, another animal model was developed in which immature, hypophysectomized rats were injected with pregnant mare serum gonadotropin (PMSG) to initiate follicular growth followed by a single injection of dihydrotestosterone (DHT). The androgen caused follicular atresia and decreased the number of ova shed in response to ovulation induction with hCG. The suppressive effects of DHT were entirely prevented by concomitant treatment with estradiol. The studies with DHT were continued using another batch of PMSG, but the DHT-induced increase in the rat of atresia and suppression of induced ovulation were no longer seen. However, when this same batch of PMSG was given with estrogen or with the antiandrogen flutamide, there was less atresia and the growth of follicles was actually enhanced. Based on these studies, it was postulated that the second batch of PMSG had greater LH activity than the first preparation and that the LH has stimulated endogenous androgen production. The ovarian follicles which appeared to be most susceptible to this DHT effect were small to medium in size and had a low capacity to synthesize estrogen. This possibility was confirmed in another animal model system in which immature rats were injected with PMSG and 4 separate injections of DHT and then sacrificed at several time points over the next 8 days.(ABSTRACT TRUNCATED AT 400 WORDS)

Prevalence of polycystic ovaries in women with anovulation and idiopathic hirsutism

Polycystic ovaries were defined with ultrasound imaging in a series of 173 women who presented to a gynaecological endocrine clinic with anovulation or hirsutism. Polycystic ovaries were found in 26% of women with amenorrhoea, 87% with oligomenorrhoea, and 92% with idiopathic hirsutism--that is, hirsutism but with regular menstrual cycles. Fewer than half the anovulatory patients with polycystic ovaries were hirsute, but in 93% of cases there was at least one endocrine abnormality to support the diagnosis of polycystic ovaries--that is, raised serum concentrations of luteinising hormone, raised luteinising hormone: follicle stimulating hormone ratio, or raised serum concentrations of testosterone or androstenedione. This study shows that polycystic ovaries, as defined by pelvic ultrasound, are very common in anovulatory women (57% of cases) and are not necessarily associated with hirsutism or a raised serum luteinising hormone concentration. Most women with hirsutism and regular menses have polycystic ovaries so that the term "idiopathic" hirsutism no longer seems appropriate.

Risk factors for uterine fibroids: reduced risk associated with oral contraceptives

Risk factors for pathologically confirmed uterine leiomyomas (fibroids) were investigated using data from the Oxford Family Planning Association study, a long term follow up study of women using various methods of contraception. For each of 535 women who had had a fibroid an individual control was selected who matched the patient on age, date of entry into the cohort, and family planning clinic at recruitment and who was alive (and still being followed up) at the date the patient underwent surgery for fibroids. Case-control analysis showed that reproductive experiences were closely linked to development of fibroids. Risk of fibroids decreased consistently with increasing number of term pregnancies; women with five term pregnancies had only a quarter of the risk of women who had had none. Risk also decreased consistently with increasing duration of oral contraceptive use; the risk of fibroids was reduced by some 31% in women who had used oral contraceptives for 10 years. Risk was strongly related to weight: women who weighed under 55 kg had a particularly low risk, and overall the risk rose roughly 21% for each 10 kg increase. Cigarette smoking was associated with a decreased risk of fibroids; smokers of 20 cigarettes a day had a risk roughly two thirds that of non-smokers. These risk factors have all previously been identified as risk factors for endometrial cancer; this strongly suggests that the underlying risk factor is "unopposed" oestrogen.

Does testosterone affect the normal menstrual cycle?

In order to throw further light on the role of androgens in the aetiology of the polycystic ovary syndrome (PCO) we have examined the effect of artificially increasing serum testosterone levels on menstrual function in a group of ovulating women. Six women were studied who had either severe premenstrual syndrome or loss of libido for which they were treated with 100 mg testosterone by s.c. implantation. All had regular menstrual cycles. For 1 month before implantation serum LH, FSH, oestradiol (E2), progesterone and testosterone were measured three times per week. All women showed normal cyclical variation of LH, FSH, E2 and progesterone. Following implantation, three times weekly blood samples were taken during the first and third cycles. No patient had any disturbance of menstrual pattern. All continued to show cyclical changes of LH, FSH, E2 and progesterone. Serum E2 and progesterone were lower but not significantly so in the luteal phase of the treated cycles. This was despite a mean serum testosterone which rose from 1.3 to 7.1 nmol/l at the end of the third week following implantation and to 4.1 nmol/l at the end of the third month. Sex hormone binding globulin levels fell as expected by 18.5% during the first cycle. The lack of significant effect of a markedly elevated serum testosterone level on cyclical hormone changes is indirect evidence that in PCO the primary cause of the menstrual disturbance is not excessive production of ovarian or adrenal testosterone.

Increased DHEAs levels in PCO syndrome: evidence for the existence of two subgroups of patients

In 49 patients affected by PCO syndrome the serum levels of dehydroepiandrosterone-sulphate (DHEAs) were determined and correlated with the clinical presentation and the endocrine pattern. Twenty-three patients (47%) had high DHEAs levels (h-DHEAs patients). They presented a milder clinical presentation (low incidence of amenorrhea) than PCO patients with normal DHEAs levels (n-DHEAs patients). In h-DHEAs patients the finding of a normal DHEAs response to ACTH and of slightly increased 170HP serum levels suggested that the elevation of serum DHEAs was not due to an adrenal enzymatic deficiency but to a tonic hyperstimulation of the adrenals. Two subgroups of h-DHEAs patients were identified: in the first subgroup, PRL and estrone levels were increased and probably explained the DHEAs hypersecretion; in the second subgroup, the endocrine pattern was very similar to that observed in n-DHEAs patients and a clear explanation for DHEAs increase was not found, although the possibility of an exaggerated secretion of some pituitary hormones with adrenal androgen stimulating activity must be considered.

The dynamic interaction between steroids and gonadotropins in the mammalian ovulatory cycle

The interrelationship between steroid hormone secretion and gonadotropin secretion during the human menstrual cycle is a set of complex interactions. The temporal relationship between estradiol and progesterone secretion, the preovulatory surge of gonadotropins and the time of ovulation, has been studied extensively. The median time interval between the first rise of estradiol, progesterone, LH and FSH, and ovulation has been estimated to be 82.5 hr, 7.8 hr, 32 hr and 21.1 hr, respectively. The median time interval between peak blood concentrations of estradiol, LH and FSH, and the time of ovulation is estimated to be 24, 16.5 and 15.3 hr. There is considerable individual variation in the above mentioned estimates. The rising levels of blood estradiol that are secreted by the maturing ovarian follicles appear to be the primary trigger for the surge of gonadotropins leading to ovulation. In the experimental animal, the estrogen effect takes place at the level of the hypothalamus in the release of LHRH and at the level of the pituitary in increasing its sensitivity to LHRH. There appears to be a good correlation between the nuclear translocation of occupied estrogen receptors in the hypothalamus and the pituitary and the manifestation of estrogen effects. In the human, a rise in progesterone begins to take place after the first rise in LH has occurred. Progesterone appears to have both a stimulatory and inhibitory effect on gonadotropin secretion in the experimental animal and the human. Thus it exerts a fine-tune modulatory influence of estrogen effects which include enhancement of the estradiol induced gonadotropin surge, and perhaps the initiation of the midcycle FSH surge in the human. The abrupt termination of the preovulatory gonadotropin surge is difficult to explain because the pituitary gland is not depleted of its gonadotropin content or its capacity to secrete gonadotropins. Preliminary results suggests that progesterone by exerting its inhibitory influence may be responsible for the termination of the gonadotropin surge. This hypothesis, however, needs careful confirmation. The effects of progesterone may be manifested at higher brain centers, the hypothalamus and the pituitary, and may involve not only the release of LHRH but also an alteration of the pulsatile pattern of release of LHRH. The recognition of these components, along with the presence and control of LHRH degrading enzymes in the hypothalamus and the pituitary, emphasize the complexity of the system and the need for further work to gain a better understanding of the steroidal regulation of gonadotropin secretion.

Pituitary and ovarian responses to LHRH stimulation in women with clinical features of the polycystic ovary syndrome

The gonadotrophin release and the changes in ovarian and adrenal steroid levels following the administration of a low dose of LHRH were assessed in a group of women with clinical features of the polycystic ovary syndrome (PCO syndrome). The results were compared with those obtained in a group of normal ovulatory women. A significant increase in LH and FSH levels and a decrease in cortisol concentrations were demonstrated in both study groups following the administration of LHRH. The LH response was significantly exaggerated in the PCO group when compared with the control women. The estrone and estradiol levels did not change in either group. The androstenedione and testosterone concentrations did not change or decreased in the control group, whereas an increase of these hormones was seen in the PCO group. In the PCO group a positive correlation between the LH response and the androstenedione response was noticed. These findings indicate that the hyperandrogenic state encountered in PCO patients is at least in part of ovarian origin.

Hormonal characteristics of women with clinical features of the polycystic ovary syndrome

The aim of the present study was to determine whether a group of patients selected on the basis of clinical features only is characterized by the typical hormonal findings as discussed in the literature concerning the PCO-syndrome. PCO patients had oligomenorrhea, secondary amenorrhea or otherwise evidence of chronic anovulation, as well as hirsutism and/or obesity. Control women had regular menstrual cycles and a normal body weight. Since androgen and estrogen production in women depends on the stage of follicular development, an effort was made to obtain endocrinological data under standardized conditions. Under well-defined circumstances the PCO group (n = 20) had higher LH levels and lower FSH levels as compared with the control group (n = 10). Consequently the LH/FSH ratio was significantly elevated in the PCO group. Serum estrone and estradiol levels were significantly elevated in the PCO group, as were the serum levels of androstenedione and testosterone. Despite these differences a marked degree of overlap existed in the PCO patients and the control women for gonadotropin, estrogen and androgen levels. It was concluded that although the presence of polycystic ovaries in the investigated PCO group of women was not confirmed by laparoscopy, laparotomy or histological examination of the ovaries, these women had basal endocrinological characteristics similar to those found in well-proven PCO patients reported in the literature.

Pathological mechanisms in polycystic ovary syndrome: modulation of LH pulsatility by progesterone

The pulsatile discharge of luteinizing hormone (LH) in nine patients with polycystic ovary syndrome (PCO) and nine patients with amenorrhoea but without PCO, who exhibited LH discharge in response to oestrogen provocation, were studied by 4-h measurement of gonadotrophin pulsatility before and after a course of progesterone injections. No significant differences were found in the gonadotrophin pulsatility patterns of the two groups, although the LH/FSH ratio rose significantly in the patients without PCO after progesterone but not in the patients with PCO, suggesting an abnormality of FSH storage. The ability to discharge gonadotrophins in response to oestrogen provocation has been reported to be present in patients with greater than or equal to 3 LH pulses in a 4-h study period. This, however, was not demonstrated in five of the nine PCO patients despite the presence of 'normal' gonadotrophin pulsatility patterns.

The feminisation of gonadotrophin responses in intact male transsexuals

In castrated animals and hypogonadal men other workers have shown an LH surge following oestrogen administration similar to that found in the normal female. However, there is no evidence that this can be achieved in intact males. We have therefore studied male transsexual patients before and after chronic oestrogen therapy given for at least three months to feminise the body habitus before undergoing plastic surgery. Subjects were assessed for the acute effects of oestradiol valerate on sex steroid hormone levels and gonadotrophin responses to gonadotrophin releasing hormone. The results showed that longterm treatment could transform the normal male pattern of a suppressive effect of oestrogen on gonadotrophin release to one where the oestrogen increased LH levels and amplified the effect of LHRH on gonadotrophin release. This pattern is similar to that found in normal women and indicates that longterm oestrogen treatment to males can feminise gonadotrophin responses.

Acth function in women with the polycystic ovarian syndrome

Serum androgen levels, including dehydroepiandrosterone sulphate (DHAS) which is thought to be solely of adrenal origin, are elevated in women with the polycystic ovarian syndrome. We have investigated the possibility that this may be due to a mild form of congenital adrenal hyperplasia by measuring basal and stimulated levels of ACTH in women with this condition and have compared them to levels in normal women. We found no difference in the diurnal rhythm of ACTH between patients and normal subjects nor any difference in stimulated levels achieved after a single-dose oral metyrapone test. Thus there is no evidence from this study to support the idea that these patients might have congenital adrenal hyperplasia. There are two alternative hypotheses to explain the elevated DHAS levels. They may be associated with the high oestrogen levels, which interfere with the enzyme 3 beta-hydroxysteroid dehydrogenase, or there may be alteration of the factors controlling adrenal androgen secretion.

Oestrogen stimulated neurophysin in pregnancy and lactation

Serum concentrations of oestrogen stimulated neurophysin (ESN) were measured throughout pregnancy in thirty-one women and until 6 weeks post-partum in a further twenty-three. During pregnancy ESN rose progressively and values during labour were similar to those immediately before delivery. There were significant correlations (P less than 0.05) between serum ESN and oestradiol values measured in samples from four patients. After delivery the concentration of ESN fell rapidly to the range for non-pregnant women by 5 days post-partum, whether the mothers lactated or not, and remained fairly constant for the next 6 weeks. Bromocriptine or metoclopramide, drugs which affect prolactin secretion, were without effect on ESN values. At 8 days post-partum in sixteen of the eighteen patients studied there was an increase in ESN concentration 30 min after suckling commenced. At 6 weeks similar changes occurred in five of the ten subjects studied. In contrast, at 8 days there was no significant change in ESN in four mothers who bottle fed their babies over the 90 min studied. The relationship between ESN and hormonal changes during pregnancy and lactation is discussed in the light of these results.

Adrenal function in subgroups of the PCO syndrome assessed by a long ACTH test

Fifteen patients with the polycystic ovarian (PCO) syndrome were classified into Group A (n = 6) and Group B (n = 9) based on their LH responses to LHRH before and at 44 and 92h after administration of oestradiol benzoate. Adrenal function in both groups was assessed by comparing the hormone responses to ACTH (0.5mg twice daily for 4 days) with those obtained in nine normally ovulating women during the early follicular phase of their cycles. In Group A patients there was no significant difference from normals in the serum concentration of dehydroepiandrosterone sulphate (DHAS), 17 alpha-hydroxy-progesterone (17-OHP) or androgens (testosterone and dihydrotestosterone). In contrast, the serum concentrations in Group B were significantly higher (P less than 0.01) for each of these steroids before ACTH, and remained higher at 2 and 4 days for DHAS, but not for the other two steroids. The concentration of oestrone was significantly higher (P less than 0.05) in Group B patients before, and 2 days after, ACTH, while in Group A patients higher concentrations (P less than 0.02) were found only after 2 days. The concentrations of oestradiol, on the other hand, were not different from normal in either group before ACTH and became lower than normal in both groups at 2 days and remained lower at 4 days in Group B. The concentration of cortisol was within the normal range throughout in Group A, but was lower than normal after 4 days in Group B patients (P less than 0.05). The ratios between the sums of concentrations of DHAS to cortisol on days 2 and 4 (P less than 0.001) or 17-OHP to cortisol (P less than 0.05) were elevated in Group B compared with normal subjects. LH, FSH and prolactin values were normal throughout in Group A, but in Group B patients the mean value for LH was significantly elevated before ACTH and at 4 days after ACTH (P less than 0.02).

Is "benign intracranial hypertension" really benign?

Hypothalamic-hypophyseal insufficiency has been found in seven of eight patients with so-called benign intracranial hypertension, of whom four showed an inadequate adrenal response to stress. The syndrome of benign intracranial hypertension cannot therefore be considered entirely benign and patients should receive full endocrinological assessment and follow up.

Oestrogen modulation of gonadotrophin and prolactin release in women with anovulation and their responses to clomiphene

An LHRH test was performed before and at both 44 and 92 h after the administration of 2.5 mg oestradiol benzoate in eleven patients with hyperprolactinaemia, eight with idiopathic secondary amenorrhoea and seven with oligomenorrhoea. The basal serum hormone concentrations and the responses to LHRH were compared with the same tests performed on ten normal subjects during the early follicular phase of their menstrual cycles (days 4--6). Mean basal concentrations of oestradiol in each group of patients and oestrone in those with hyperprolactinaemia were significantly lower than in the normal subjects. The mean concentration of prolactin in women with secondary amenorrhoea remained lower than in the normal women throught the tests (P less than 0.05). The LH and FSH responses to LHRH before oestrogen in patients with hyperprolactinaemia and of FSH in those with secondary amenorrhoea, were greater than in the normal subjects (P less than 0.001). After oestrogen treatment the responses were similar in all groups except in those with oligomenorrhoea where LH and FSH responses at 44 h (P less than 0.05 and P less than 0.01 respectively) and LH responses at 92 h (P less than 0.01) were lower than in normal controls. The responses at 92 h in all groups were greater than at 44 h (amplification) but the amplification at 92 h and at 44 h compared to the pre-treatment responses, tended to be lower in each group of patients compared to the normal controls. In the hyperprolactinaemic group of patients there was a negative correlation between the basal prolactin concentration and the gonadotrophin amplifications at 92 h (P less than 0.01), and a positive correlation between the basal oestrone levels and the amplifications at 92 h (P less than 0.01). The results of the oestrogen amplification test in eleven of the non-hyperprolactinaemic anovular patients were compared with the ovulatory response to 100 mg clomiphene given for 5 days. Six showed a normal oestrogen amplification and they all ovulated. Two patients failed to show greater amplification at 92 than at 44 h and required human chorionic gonadotrophin (HCG) as well as clomiphene to ovulate. The other three showed a diminished LH amplification at 92 h; they required 200 mg clomiphene and showed a prolonged follicular phase. The responses of the hyperprolactinaemic patients to clomiphene were poor and there was a negative correlation between prolactin concentration and oestrogen production (P less than 0.01). All ten hyperprolactinaemic patients treated with bromocriptine ovulated and eight conceived. The oestrogen amplification test appears to have some value in predicting the subsequent response to clomiphene in non-hyperprolactinaemic anovular women.