Comparison of follicle-stimulating-hormone-stimulated dimeric inhibin and estradiol responses as indicators of granulosa cell function in polycystic ovary syndrome and normal women

The impact of polycystic ovary syndrome and body mass index on the absorption of recombinant human follicle stimulating hormone

PURPOSE

Women with polycystic ovary syndrome (PCOS) have an increased ovarian responsiveness to exogenous recombinant follicle stimulating hormone (rFSH) but also have high rates of obesity, which is known to affect serum FSH concentrations following exogenous injection. The purpose of this study was to compare rFSH absorption and ovarian response between lean and overweight/obese PCOS subjects and normo-ovulatory controls.

METHODS

Fourteen women with PCOS aged 18-42 years old with a BMI of 18.5-24.9 kg/m2 (normal) or 25.0-40.0 kg/m2 (overweight/obese) and eleven normo-ovulatory controls matched by age and BMI were included. After downregulation with oral contraceptives, participants were administered a single subcutaneous injection of 225 IU rFSH and underwent serial blood draws over 72 h.

RESULTS

Lean PCOS subjects exhibited a significantly higher area under the curve (AUC) of baseline-corrected serum FSH over 72 h when compared with overweight/obese PCOS subjects (183.3 vs 139.8 IU*h/L, p = 0.0002), and lean, normo-ovulatory women had a significantly higher AUC FSH when compared with overweight/obese, normo-ovulatory women (193.3 vs 93.8 IU*h/L, p < 0.0001). Within overweight/obese subjects, those with PCOS had a significantly higher AUC FSH compared with normo-ovulatory controls (p = 0.0002). Lean PCOS subjects similarly had the highest AUC of baseline-corrected estradiol (6095 pg h/mL), compared with lean normo-ovulatory subjects (1931 pg h/mL, p < 0.0001) and overweight/obese PCOS subjects (2337 pg h/mL, p < 0.0001).

CONCLUSION

Lean PCOS subjects exhibited significantly higher baseline-corrected FSH and estradiol levels following rFSH injection compared with overweight/obese PCOS subjects with similar ovarian reserve markers. Amongst overweight/obese subjects, those with PCOS had significantly higher FSH and E2 levels when compared with normo-ovulatory controls.

Reproductive and metabolic determinants of granulosa cell dysfunction in normal-weight women with polycystic ovary syndrome

OBJECTIVE

To determine the degree to which E₂ hyperresponsiveness to FSH and antimüllerian hormone (AMH) overproduction in normal-weight women with polycystic ovary syndrome (PCOS) correlate with increased antral follicle number (AFN), hyperandrogenism, and/or metabolic dysfunction.

DESIGN

Prospective cohort study.

SETTING

Academic medical center.

PATIENT(S)

Seven normal-weight women with PCOS (1990 National Institutes of Health criteria) ages 20-34 years and 13 age- and body mass index- (BMI-; 18.5-25 kg/m²) matched normoandrogenic ovulatory women were studied.

INTERVENTION(S)

All women underwent basal serum hormone and metabolic measurements, FSH stimulation testing with transvaginal ovarian sonography, frequently sampled IV glucose tolerance testing, and whole-body dual-energy x-ray absorptiometry.

MAIN OUTCOME MEASURE(S)

Serum hormone/metabolite levels, 24-hour serum E₂ response to 150 IU recombinant human (rh) FSH infusion, AFN, insulin sensitivity, and body mass measurements.

RESULT(S)

Serum E₂ responsiveness to rhFSH and AMH levels were greater in women with PCOS than in BMI- and age-matched control women, as were serum androgen levels, AFN, and abdominal fat mass. In all women combined, serum E₂ responsiveness to rhFSH was associated with AFN. Serum AMH levels, however, positively correlated with AFN but remained positively correlated with serum LH and free T levels and negatively correlated with total body fat and percent body fat, adjusting for AFN.

CONCLUSION(S)

In normal-weight women with PCOS, serum E₂ hyperresponsiveness to rhFSH represents increased AFN, while elevated serum AMH levels reflect opposing effects of stimulatory reproductive (hyperandrogenism and increased AFN) versus inhibitory metabolic (body fat) factors. Given the small number of subjects reported, additional follow-up studies are required to confirm these data.

Hypothalamic-pituitary, ovarian and adrenal contributions to polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a prevalent heterogeneous disorder linked with disturbances of reproductive, endocrine and metabolic function. The definition and aetiological hypotheses of PCOS are continually developing to incorporate evolving evidence of the syndrome, which appears to be both multifactorial and polygenic. The pathophysiology of PCOS encompasses inherent ovarian dysfunction that is strongly influenced by external factors including the hypothalamic-pituitary axis and hyperinsulinaemia. Neuroendocrine abnormalities including increased gonadotrophin-releasing hormone (GnRH) pulse frequency with consequent hypersecretion of luteinising hormone (LH) affects ovarian androgen synthesis, folliculogenesis and oocyte development. Disturbed ovarian-pituitary and hypothalamic feedback accentuates the gonadotrophin abnormalities, and there is emerging evidence putatively implicating dysfunction of the Kiss 1 system. Within the follicle subunit itself, there are intra-ovarian paracrine modulators, cytokines and growth factors, which appear to play a role. Adrenally derived androgens may also contribute to the pathogenesis of PCOS, but their role is less defined.

Decreased inhibin B responses following recombinant human chorionic gonadotropin administration in normal women and women with polycystic ovary syndrome

OBJECTIVE

To determine whether granulosa cells contribute to excess androgen production, by assessing inhibin B (Inh B) responses to hCG in women with polycystic ovary syndrome (PCOS) and in normal women.

DESIGN

Prospective study.

SETTING

Academic medical center.

PATIENT(S)

Twenty women with PCOS and 16 normal women.

INTERVENTION(S)

Blood samples obtained before and 24 hours after injection of 25 μg recombinant hCG (r-hCG).

MAIN OUTCOME MEASURE(S)

Basal and stimulated Inh B, E2, androstenedione (A), and T responses after r-hCG administration.

RESULT(S)

In normal and PCOS women, r-hCG induced a significant reduction of Inh B levels. Lowered Inh B responses were not related to body mass index, PCOS status, or age by multivariate regression. Recombinant hCG significantly increased serum A and E2 in both normal and PCOS women.

CONCLUSION(S)

In normal and PCOS women, Inh B production was decreased following r-hCG administration. These findings strongly suggest that in PCOS women androgen excess is not enhanced by LH-stimulated Inh B production.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00747617.

Polycystic ovary syndrome: effect and mechanisms of acupuncture for ovulation induction

Polycystic ovary syndrome (PCOS), the most common endocrine disorder among women of reproductive age, is characterized by the coexistence of hyperandrogenism, ovulatory dysfunction, and polycystic ovaries (PCO). PCOS also represents the largest part of female oligoovulatory infertility, and the management of ovulatory and menstrual dysfunction, comprises a third of the high costs of PCOS treatment. Current pharmacological and surgical treatments for reproductive symptoms are effective, however, associated with negative side effects, such as cardiovascular complications and multiple pregnancies. For menstrual irregularities and ovulation induction in women with PCOS, acupuncture has indicated beneficial effects. This review will focus on the results from randomized controlled acupuncture trials for regulation of menstrual dysfunction and for inducing ovulation in women with PCOS although there are uncontrolled trials with nonetheless interesting results. Animal experimental studies will be further discussed when they can provide a more mechanistic explanatory view.

Disordered follicle development

Alterations of ovarian follicle morphology and function have been well documented in women with PCOS. These include increased numbers of growing preantral follicles, failure of follicle growth beyond the mid-antral stage, evidence of granulosa call degeneration, and theca cell hyperplasia. Functional abnormalities include paradoxical granulosa cell hyperresponsiveness to FSH which is clinically linked to ovarian hyperstimulation during ovulation induction. In addition, there is likely a primary theca cell defect that accounts for the majority of excess androgen production in this disorder. The precise mechanisms responsible for altered follicle function are not completely clear. However, several factors appear to influence normal advancement of follicle development as well as impair ovarian steroidogenesis. These include intra- as well as extraovarian influences that distort normal ovarian growth and disrupt steroid production by follicle cells.

Single-cell expression analysis of BMP15 and GDF9 in mature oocytes and BMPR2 in cumulus cells of women with polycystic ovary syndrome undergoing controlled ovarian hyperstimulation

PURPOSE

To detect expression of bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) in oocytes, and their receptor type 2 receptor for BMPs (BMPR2) in cumulus cells in women with polycystic ovary syndrome (PCOS) undergoing in vitro fertilization (IVF), and determine if BMPR2, BMP15, and GDF9 expression correlate with hyperandrogenism in FF of PCOS patients.

METHODS

Prospective case-control study. Eighteen MII-oocytes and their respective cumulus cells were obtained from 18 patients with PCOS, and 48 MII-oocytes and cumulus cells (CCs) from 35 controls, both subjected to controlled ovarian hyperstimulation (COH), and follicular fluid (FF) was collected from small (10-14 mm) and large (>18 mm) follicles. RNeasy Micro Kit (Qiagen) was used for RNA extraction and gene expression was quantified in each oocyte individually and in microdissected cumulus cells from cumulus-oocyte complexes retrieved from preovulatory follicles using qRT-PCR. Chemiluminescence and RIA assays were used for hormone assays.

RESULTS

BMP15 and GDF9 expression per oocyte was higher among women with PCOS than the control group. A positive correlation was found between BMPR2 transcripts and hyperandrogenism in FF of PCOS patients. Progesterone values in FF were lower in the PCOS group.

CONCLUSION

We inferred that BMP15 and GDF9 transcript levels increase in mature PCOS oocytes after COH, and might inhibit the progesterone secretion by follicular cells in PCOS follicles, preventing premature luteinization in cumulus cells. BMPR2 expression in PCOS cumulus cells might be regulated by androgens.

Inhibin secretion in women with the polycystic ovary syndrome before and after treatment with progesterone

OBJECTIVES

It has been suggested that inhibin secretion is altered in women with the polycystic ovary syndrome (PCOS). However, the contribution of a preceding luteal phase has not been taken into account. The aim of the present study was to investigate whether progesterone in the context of a simulated luteal phase affects basal and FSH-induced inhibin secretion in women with PCOS and elevated LH.

METHODS

Ten women with PCOS and 8 normally cycling women participated in an experimental procedure (Exp) involving the administration of a single injection of recombinant FSH (450 IU sc). In the women with PCOS, the procedure was performed before (Exp 1) and after a 20-day treatment with progesterone (Exp 2), while in the normal women on day 2 of the cycle (Exp 3). Inhibin A and B levels were measured in blood samples taken before and 24 hours after the FSH injection.

RESULTS

Basal LH levels were significantly higher and inhibin A levels were significantly lower in the PCOS group compared to the control group, while inhibin B levels were comparable in the two groups. In the PCOS group, after treatment with progesterone inhibin A and LH but not inhibin B levels decreased significantly (p < 0.05). After the FSH injection, inhibin A and B levels increased significantly in the women with PCOS (Exp 1 and Exp 2) but not in the control women (Exp 3).

CONCLUSIONS

In women with PCOS, as compared to control women, the dissimilar pattern of inhibin A and inhibin B secretion in response to FSH appears to be independent of a preceding simulated luteal phase. It is possible that compared to normal ovaries, the PCOS ovaries are less sensitive to endogenous LH regarding inhibin A secretion and more sensitive to exogenous FSH stimulation in terms of inhibin A and inhibin B secretion.

Comparison of inhibin B and estradiol responses to intravenous FSH in women with polycystic ovary syndrome and normal women

BACKGROUND

Inhibin B (Inh B) is produced by pre-antral and early antral follicles whereas estradiol (E(2)) is a product of follicles undergoing antrum formation. This temporal distinction is evident in the patterns of Inh B and E(2) release earlier and later during the follicular phase of the menstrual cycle, respectively. However, in previous studies of women with polycystic ovary syndrome (PCOS) and normal controls, release of these granulosa cell (GC) products appears to be simultaneous in response to FSH stimulation. In order to reconcile these disparate findings, we conducted dose-response studies in both PCOS women and normal controls to determine whether GC product responses were due to the amount of FSH administered. In addition, we compared FSH-stimulated responses in PCOS women at various stages of recovery following ovarian suppression with a long-acting GnRH agonist to examine whether Inh B and E(2) responses reflected the level of ovarian follicle activity (i.e. circulating E(2) levels).

METHODS

Women with PCOS, 18-35 years (n = 23), and normal ovulatory controls, 18-35 years (n = 10) were recruited for study. Dose-responses were assessed over 24 h following intravenous administration of 0 (saline), 37.5, 75 and 150 IU of recombinant human FSH (r-hFSH) in PCOS and normal women. In addition, E(2) and Inh B responses to 150 IU of r-hFSH were assessed at baseline and 4, 6 and 8 weeks following suppression of ovarian steroidogenesis by a long-acting GnRH agonist in PCOS women.

RESULTS

In PCOS women and normal controls, serum Inh B and E(2) exhibit similar and simultaneous dose-responsiveness to FSH stimulation. During recovery from ovarian suppression, basal and stimulated Inh B release appear to be restored earlier than that of E(2) in PCOS women.

CONCLUSIONS

These findings are consistent with the notion that, in PCOS women, the level of ovarian follicle activity largely determines the earlier release of Inh B compared with E(2).

Characterization of functionally typical and atypical types of polycystic ovary syndrome

CONTEXT

The typical polycystic ovary syndrome (PCOS) phenotype includes 17-hydroxyprogesterone (17OHP) hyperresponsiveness to GnRH agonist (GnRHag) testing. Functionally atypical PCOS lacks this feature.

OBJECTIVE

The hypothesis was tested that the typical PCOS ovarian dysfunction results from intrinsically increased sensitivity to LH/human chorionic gonadotropin (hCG) due to a flaw in FSH action. PARTICIPANTS/DESIGN/INTERVENTIONS/MAIN OUTCOME MEASURES: After phenotyping a cohort of 60 women, steroid and inhibin-B responses to gonadotropins were evaluated in representative typical (n = 7) and atypical (n = 5) PCOS and healthy controls (n = 8). Submaximal hCG testing before and after an FSH test dose was performed in random order before and after prolonged ovarian suppression by depot GnRHag.

SETTING

The study was performed at a Clinical Research Center.

RESULTS

Of our PCOS cohort, 68% were the typical type. Typical PCOS had 17OHP hyperresponsiveness and, unlike controls, significant androgen and estradiol responses to hCG. FSH increased inhibin-B and did not inhibit free testosterone or enhance estradiol responsiveness to hCG, all unlike controls. After ovarian suppression, 17OHP, androstenedione, and inhibin-B responsiveness to gonadotropin testing persisted. Atypical PCOS had significantly higher body mass index but lower ovarian volume and plasma free testosterone than typical PCOS. Steroid responses to hCG were insignificant and similar to controls. FSH suppressed free testosterone but stimulated inhibin-B. The estradiol level after combined hCG-FSH was subnormal. Free testosterone was less GnRHag suppressible than in typical PCOS.

CONCLUSIONS

Typical PCOS is characterized by intrinsic ovarian hypersensitivity to hCG to which excessive paracrine FSH signaling via inhibin-B may contribute. Atypical PCOS is due to a unique type of ovarian dysfunction that is relatively gonadotropin hyposensitive.

[Serum inhibin B in polycystic ovary syndrome as a potential marker of ovarian dysfunction]

INTRODUCTION

Polycystic ovary syndrome (PCOS) is one of the most common causes of anovulation, infertility and hyperandrogenism, and the prevalence of this condition in women of reproductive is 5-10%. The growth of early ovarian antral follicles is arrested and dominant follicle selection is disturbed in this syndrome.

OBJECTIVE

The aim of this study is to investigate whether inhibin B serum concentrations represent the extent of ovarian abnormalities in patients with PCOS.

METHOD

Inhibin B serum concentrations on the third day of spontaneous menstrual cycle and other endocrine characteristics were compared between 20 patients with PCOS and 19 healthy women in the control group.

RESULTS

Inhibin B concentrations were not significantly different between women with PCOS and women in the control group. In patients with PCOS there was statistically significant correlation between serum inhibin B and LH (r = 0.514; p = 0.021).There were no positive correlations between inhibin B and others endocrine parameters in patients with PCOS (FSH, E2,T, androstenedione).

CONCLUSION

Inhibin B serum concentrations on the third day of spontaneous menstrual cycle in women with PCOS are not different from the concentrations in healthy women. Serum Inhibin B levels in patients with PCOS are only slightly correlated with the endocrine markers of the disease so it could not represent the magnitude of ovarian dysfunction in this syndrome.

Increased intrafollicular androgen levels affect human granulosa cell secretion of anti-müllerian hormone and inhibin-B

OBJECTIVE

To evaluate whether the follicular fluid concentrations of anti-müllerian hormone (AMH), inhibin-B, and P become affected by androgen priming before controlled ovarian hyperstimulation and IVF/intracytoplasmic sperm injection (ICSI) treatment, extending our previous study.

DESIGN

Prospective nonrandomized clinical study.

SETTING

University hospital.

PATIENT(S)

Patients (N = 45) undergoing IVF/ICSI treatment received androgen priming before controlled ovarian hyperstimulation.

INTERVENTION(S)

All patients received cetrorelix, 3 mg SC, on cycle day 2 and 5. Group I (n = 15) received no other pretreatment. Group II (n = 15) received 2.5 mg once daily of letrozole from cycle day 2 through 8. Group III (n = 15) received letrozole as group II plus 1,250 IU hCG on cycle day 2.

MAIN OUTCOME MEASURE(S)

Follicular fluid concentrations of AMH, inhibin-B, and steroids.

RESULT(S)

Follicular fluid concentrations of AMH were significantly higher in group III than in groups I and II (2.6 +/- 0.3 vs. 1.6 +/- 0.2 and 1.5 +/- 0.4 ng/mL. Concentrations of inhibin-B were significantly lower in group II and III as compared with group I (27 +/- 4, 27 +/- 3 versus 46 +/- 6 ng/mL, respectively). Follicular fluid P concentrations remained similar in all groups.

CONCLUSION(S)

Granulosa cell production of AMH was significantly augmented and inhibin-B production was significantly reduced by a highly specific pharmacologically induced increase in the intrafollicular androgen levels, suggesting a dual action of androgen on follicular growth and development.

Increased androgen response to follicle-stimulating hormone administration in women with polycystic ovary syndrome

CONTEXT

In women with polycystic ovary syndrome (PCOS), excess ovarian androgen production is driven by increased LH secretion. Studies conducted in animals suggest that the granulosa cell may influence LH-stimulated theca cell androgen production.

OBJECTIVE

The objective of this study was to determine whether FSH enhances androgen production in women with PCOS compared with that of normal women.

DESIGN

A prospective study was conducted to compare androgen production in response to FSH in two groups of women.

SETTING

The study was conducted in a General Clinical Research Center in a tertiary academic medical center.

PATIENTS

Women with PCOS, 18-35 yr (n = 20), and normal ovulatory controls, 18-35 yr (n = 10), were recruited for study.

INTERVENTIONS

Serial blood samples were obtained over a 24-h period after an iv injection of recombinant human FSH (150 IU).

MAIN OUTCOME MEASURES

The main outcome measures were serum 17-hydroxyprogesterone (17-OHP), androstenedione (A), dehydroepiandrosterone (DHEA), testosterone (T), and inhibin B (Inh B) responses after FSH administration.

RESULTS

Basal serum 17-OHP, A, and T levels were markedly increased in women with PCOS compared with that observed in normal women. Basal DHEA and Inh B levels were similar to those of normal controls. After FSH injection, PCOS women demonstrated enhanced production of 17-OHP, A, DHEA, and Inh B, whereas in normal women no increases were observed. T levels declined slightly in both groups.

CONCLUSIONS

These findings provide evidence that, in PCOS women, theca cell androgen production is enhanced by FSH administration and suggest a granulosa-theca cell paracrine mechanism.