Role of decreased androgens in the ovarian response to stimulation in older women Fertil Steril Jan;99(1):5-11 Presented by Hsing-Chun Tsai

Outlines Part I: Effects of testosterone (T) on preantral and antral follicles Part II: How to improve ovarian response ? – Exogenous testosterone – DHEA – Aromatase inhibition (AI) – LH/HCG – Growth hormone (GH) / IGF-I

Effects of T on ovarian response Serum testosterone (T) decreases as age advances in premenopausal women, similar to AFC and AMH T response to hCG decreased with age -- > age- related decrease of T secretion from the theca tissue surrounding ovarian follicles J Clin Endocrinol Metab 2003

StudyPatientsResults Barbieri et al., normal cycling women undergoing IVF Baseline T correlated with # of retrieved oocytes after adjusting for age, BMI, smoking  Ovarian T plays a role in the ability of follicles to respond to FSH  Part of the decreased ovarian response with aging may be due to declining ovarian androgen production Dickerson et al., 2010 normal cycling women Free androgen index and insulin resistance correlated with the follicle count after stimulation Nardo et al., 2009 nonobese PCOS pt normal cycling control A positive relationship of AMH with T, free androgen index, and insulin resistance. Barbieri et al., 1984 insulin-sensitive low- responding pt without PCOS to obese, insulin-resistant pt with severe PCOS insulin stimulates T secretion from theca tissue Bioavailable T within the ovary may increase follicular response.

Effects of T on follicular response T stimulates earlier stages of follicular growth. (preantral & small antral follicles) Mechanisms: – Increasing FSH-receptor activity – Stimulating insulin-like growth factor-I (IGF-I)

FSH-receptor activity AR gene expression correlate with follicle growth, and T increases granulosa cell (GC) FSH receptor mRNA. Very strong correlations of follicular fluid T and GC androgen receptor mRNA with FSH receptor expression were found in 3~9 mm antral follicles in adult human ovaries.

insulin-like growth factor-I (IGF-I) T significantly increases # of primordial follicles, IGF-I (3X), and IGF-I receptor mRNA (5X). IGF-I may stimulate primary follicle development, and enhance oocyte metabolic activity and maturation in vitro. In human ovary, regulation of IGF action is complex. – IGF-binding proteins (IGFBPs) and IGFBP proteases within the follicle maximizing IGF action. IGF-IThecaGH regulate IGF-I systemically IGF-IIGranulosaFSH regulate IGF-II in granulosa

Growth hormone As co-gonadotropin therapy – Action on liver, increasing IGF-I systemically – Secondarily to enhance oocyte maturation, follicle growth and steroidogenesis – No direct action to increase expression of IGF and its receptor genes

Aim Hypothesis: intraovarian effects of bioavailable T act to cause a continuum of AFC and response from the poor responder to severe PCOS. Concept: decreasing thecal androgen production due to advancing age causes a progressive impairment of the aging ovary’s ability to respond to stimulation for fertility treatments.

Optimal health patients vs. PCOS with advancing age Success rate is relatively maintained in PCOS. – oocyte yield falls less with age compared with control – improved oocyte quality AFC predicts both oocyte quality and quantity. Fertility and Sterility Volume 99, Issue

How to increase intraovarian androgen exposure to promote FSH receptor expression and increase number of FSH-sensitive antral follicles ? growth-promoting actions are mediated by androgen receptor 10 days of T  similar to PCO state   impractical due to androgenic side effects GC

Testosterone

5 days of T patch (2.5mg) caused a progressively increasing circulating IGF-I even after T discontinuation. IGF-I level was significantly lower in the canceled cycles. Non-cancelled cycles Canceled cycles Day after T Day 5 of stimulationDay 7 of stimulation Day 9-10 of stimulation Day 2 of 5 days of T

T

Design: RCT Patients: 110 women ( ≦ 3 oocytes retrieved in prior cycle) Intervention: 12.5mg of T gel for 3 weeks vs. no treatment Results: – ↑ oocytes retrieved, grade 1 embryos, implantation rate and clinical pregnancy rate (>2X) – No patients reported any systemic or local adverse effects (changes in hair growth, voice pitch, or libido) – With lower level of systemic T, at least 3 weeks was required to increase ovarian response

Variables for therapeutic response Different brand of gel (different levels) The site and method of application The duration of treatment The dose of 12.5g for 3 weeks is very close to the threshold producing a response.

DHEA (Dehydroepiandrosterone) In gonadotropin-stimulated F, almost 50% of follicular fluid T was shown from circulating DHEA sulfate.

Adrenal production of DHEA drops about 50% from 25 to 45 y/o  age-related decline of DHEA could be contributing to reduced circulating and intraovarian T in older infertile women. In older women, 50mg of DHEA doubled the circulating T level.

Study heterogeneity

Aromatase inhibitor blocking the conversion of T to E Fertil Steril, 84 (2005) – Letrozole groups (71) (2.5mg daily, 5 days) compared with control (76) – higher levels of follicular fluid T and androstenedione (80.3 vs pg/mL and 57.9 vs mg/mL) – higher number of oocytes retrieved (6.1 vs. 4.3) – higher implantation rate (25% vs. 9.4%)

LH/HCG Small daily doses can increase thecal androgen production (insulin, IGF-I) ↔ large doses cause down-regulation of LH/hCG receptor ↑ basal LH levels correlated with higher IVF success Durnerin et al. (2008): long-protocol, daily 300IU of rLH for 7 days before stimulation (76) vs. control (71) – Small antral F: 8.8 vs. 7.3 (p<.007) – Fertilized oocytes: 7 vs. 5.5 (p<.03) – r-LH in standard IVF showed a possible modest clinical benefit

Meldrum, D.R (1995): In markedly hypogonadotropic women, and mini- dose hCG may be a more practical alternative to recombinant LH to promote normal follicle maturation in GnRH antagonist protocol. Case report: hCG has LH activity to enhance FSH-induced folliculogenesis LH not available in US, daily 50IU hCG should be examined to increase antral follicles in low responders.

Growth hormone/IGF-I IGF-I synergized with … – FSH  inducing GC aromatase activity – LH  stimulates thecal androgen production GH before initiation of ovarian stimulation would be expected to improve the ovarian response.

Daily GH 4mg (12IU) sc from D21 of preceding cycle with GnRHa until the day of hCG T + lower dose of GH  more affordable

Daily 8 IU of GH (Saizen) sc from day 7 of exogenous gonadotrophin administration till the day of hCG

routine use  no difference in outcome & adverse events poor responder  significant difference in both live birth rates and pregnancy rates without increasing adverse events (OR 5.39, 95% CI and OR 3.28, 95% CI ) heterogeneity

Older women with good ovarian reserve with no response to adequate T  IGF-I for mediating T effects on follicle response

12 pts, average at 42 y/o 12-d of transdermal T (2.5 mg per patch), followed by 7 days of gonadotrophin Opposing data No improvement

Discussion What we want to know ? – How to explain lower IGF-I levels in poor responders and women failing to conceive with IVF ? (characteristics for older women) – Is lower IGF-I level due to lower circulating GH or reduced hepatic IGF-I production ? – Mechanism of action of IGF-I – Roles of IGF-II, IGFBPs and IGFBP proteases in folliculogenesis

Age and definitions of poor responder vary among studies. Whether the intervention increase delivery rates? Additive effects ?  combinations of intervention? Low-dose hCG + letrozole T gel + T patch + GH during final follicle maturation  ovarian T  improve ovarian response

Best widely accepted interventions to improve both response to stimulation and the quality of oocytes and embryos in older women undergoing IVF deficient systemic IGF-I level  intraovarian T levels  FSH receptor expression

Conclusion Ovarian testosterone increases the response of antral follicles to stimulation, declines with age, and has effects mediated or potentiated by insulin-like growth hormone I (IGF-I). T, DHEA, LH/hCG, AI, GH  alone or in combination for enhancing oocyte yield with fertility treatments, particularly in older reproductive-age women

Thank You !