Polycystic Ovary Syndrome

François PralongDivision of Endocrinology

Association of clinical and/or biochemical evidence of androgen excess with chronic anovulation

Heterogeneous condition with a spectrum of clinical/biochemical features

Estimated prevalence : 25% of all women, full blown syndrome in ~5% of women of reproductive age

Definition

· Hirsutism (95%), acne, alopecia· Enlarged ovaries (95%)· Sterility (75%)· Amenorrhea (55%)· Obesity (40%)· Dysmenorrhea (28%)· Chronic anovulation (20%)

Clinical presentation

PCOS: THE TEXTBOOK VIEW I

Pathogenic hypothesisAbnormal hormonal feedback mechanisms

PCOS: THE TEXTBOOK VIEW I

Hypothalamus

Ovaire

Surrénale

Tissuadipeux

PCOS: THE TEXTBOOK VIEW IIPathogenic hypothesisObesity and insulin resistance

PCOS: A DEVELOPMENTAL VIEW

Adapted from S Franks, 2002

InsulinLH

ANDROGENS

Puberty

•Hirsutism•Acne•Alopecia

Gonadotropin Secretion in PCOS

Increased LH secretion:•Ratio of LH/FSH: 2-3/1•Prevalence: 30 to 90% !

Importance of assessing LH secretion in relation to recent menses

Pituitary

GnRH

LH, FSH

E2,T

GnRH

LH

FSH

GnRHneurons

InhibitionFacilitation

Gonadotrophs

Childhood years

LH

GnRHneurons

InhibitionFacilitation

Gonadotrophs

Post-pubertal Period

LH

Metabolic signals

Adapted from S Franks, 2002

InsulinLH

ANDROGENS

Puberty

?

•Hirsutism•Acne•Alopecia

Possible Mechanisms of Abnormal LH Secretion in PCOS

Altered sex steroid feedback:

•Increased spontaneous LH pulse amplitude

•Increased LH response to GnRH

•Normal FSH response to GnRH

Inherent neuroendocrine abnormality

Study of 5 teenage, post-pubertal girls with PCOS, compared to age-matched controls

Diagnostic criteria:•Chronic anovulatory syndrome•Exclusion of other virilizing syndromes (Cushing, CAH…)•Normal TFTs and PRL

NEJM 309, 1983

Abnormality present in 4 of 5 patients

NEJM 309, 1983

Study of 12 women with PCOS, compared to 21 normal controls

Diagnostic criteria:•Perimenarchal onset of oligo/amenorrhea•Hirsutism and/or acne•Raised LH/FSH ratio•Raised T/androstenedione levels

•E2 lower than controls in MFP and LFP•Estrone higher than controls in EFP and MFP, lower in LFP

J Clin Endocrinol Metab 66, 1988

Normal PCOS

J Clin Endocrinol Metab 66, 1988

J Clin Endocrinol Metab 66, 1988

Study of 13 women (aged 11-18) with hyperandrogenism, compared to 28 aged-matched normal controls

Patients from Adolescent Medicine/Repro Endo clinics, UCSDDiagnostic criteria:

•Chief complaint: hirsutism•No hormonal medication for 3 months

J Clin Endocrinol Metab 79, 1994

J Clin Endocrinol Metab 79, 1994

J Clin Endocrinol Metab 79, 1994

Study of 61 women with PCOS, compared to 24 normal controls (EFP)

Diagnostic criteria:•Chronic oligoamenorrhea (<9 cycles/yr) or amenorrhea•Hyperandrogenism (clinical or biochemical)•Exclusion of late-onset CAH•Normal TFT and PRL•Off all medication for at least 2 months

J Clin Endocrinol Metab 82, 1997

J Clin Endocrinol Metab 82, 1997

J Clin Endocrinol Metab 82, 1997

J Clin Endocrinol Metab 82, 1997

J Clin Endocrinol Metab 82, 1997

High prevalence of gonadotropin secretion abnormalities in PCOS patients

Important associations between the elevated LHsecretion and recent ovulation or LH pulse frequency,

but NOT sex steroids

Strong association between LH pulse frequency and pool LH levels or LH/FSH ratio may suggest an etiologic relationship

J Clin Endocrinol Metab 82, 1997

CONCLUSIONS

Rapid GnRH pulse frequency probably has a role in the abnormal LH secretion pattern in PCOS

Marshall and Eagleson, 1999

CONCLUSIONS

Rapid GnRH pulse frequency probably has a role in the abnormal LH secretion pattern in PCOS

The defect in hypothalamic GnRH secretion seems to be intrinsic to PCOS patients

Could there be a role of elevated insulin levels/insulin resistance in this abnormal GnRH

secretion pattern?

Role of Brain Insulin Receptor in Control of BodyWeight and Reproduction

15

20

25

30

35

40 Body weightG

ram

ms

6 10 14 18 23Age (weeks)

0

20

40

60

80 Leptin

ng/m

L

* **

15

20

25

30

35

40 Body weight

Gra

mm

sWT KO WT KO

Male Female

**

120100806040200

WAT

mg/

g B

W

*

**

150

100

50

0

Food uptake

mg/

g B

W

WT KO WT KO

Male Female

**

Brüning et al., Science 289, 2000

Role of Brain Insulin Receptor in Control of BodyWeight and Reproduction

Spermcount

0

0.1

0.2

0.3

0.4

0.5

Plasma LH

* **

ng/m

L

0

10

20

30

40

Plasma LH one hr afteri.p GnRH agonist

*

ng/m

L

WT KO WT KO

Male Female

WT KO WT KO

Male Female

46

8101214

*

WT KO

Brüning et al., Science 289, 2000

Euglycemic hyperinsulinemic clamp studies in mice

Insulin infusion Glucose 15 % infusion

Glycemia

Insulin Stimulates GnRH Secretion In Vivo

2.5 5.5 20

LH (n

g/m

L)

0,0

0,2

0,4

0,6

0,8

1,0P<0.01

Glucose (mM) 5.5Insulin - + + +

Burcelin et al, Endocrinology 2003

Insulin Stimulates GnRH Secretion In Vitro

0 5 10 15 20 25 30 35 40 45 50

GnR

H (p

g/m

L)

10

20

30

40

Glucose 0.5 mM Glucose 20 mM

Fractions

Insulin 2.5 mg/mL Insulin 2.5 mg/mL

Basal 0.5 1 2.5 50

50

100

150

200

250

300

350

A

B

C*

**

GnR

H (%

of B

L)

Insulin (mg/mL) Burcelin et al, Endocrinology 2003

Insulin stimulates the expression of the GnRH gene

GnR

H m

RN

A(%

of c

ontr

ols)

0

100

200

300

6 hours24 hours

Ct Ins

* *

Burcelin et al, Endocrinology 2003

Hypothalamic GnRH neurons express a functional insulin receptor

A

B

M B HT Gnv-3A

B M B HT Gnv-3

Vollenweider et al, Bern 2003

Insulin signaling and GnRH transcriptionInsulin

IRS P85

P110

Insulin receptor

Grb2Sos

Ras

Raf

Shc

ERK 1/2

PI3 Kinase

GnRH

Hypothalamic neurons

?

Akt

ERK1/2 activation (Phospho ERK) in primary hypothalamic cells

0

100

200

300

2 min 5 min 10 min 30 min

p-ER

K/to

tal E

RK(%

ove

r ba

sal)

n = 5-6

*

*

Time

PI-3 kinase activation

0

450

900

Basal 5 min 15 min 30 min 60 min 120 min

*

*

*

**

PI3

kina

se a

ctiv

ity

(% o

ver

basa

l)IP IRS-1

PI3-kinase

0

125

250

Basal 5 min 15 min 30 min 60 min 120 min

**

**

PI3

kina

se a

ctiv

ity

(% o

ver

basa

l)

IP IRS-2PI3-kinase

Time (min)

ERK1/2 (Phospho ERK) and Akt (Phospho-Akt) activation in GnV-3 cells

0

500

1000

1500

2000

1 min 5 min 10 min 30 min

p-ER

K1/2

/ERK

(% o

ver

basa

l )

n = 5-6*

* *

ERK 1/2

0

350

700

Basal 5 min 15 min 60 min

Akt

p-A

kt/A

kt(%

ove

r ba

sal)

*

**

**

Time Time

The insulin effect on GnRH gene expression is dependent upon Erk1/2 activation in primary hypothalamic neurons

GnRH mRNA levels

Ct Ins Ins + PD PD DMSO

% o

f CT

0

100

200

300

400

500 ** *

The insulin effect on GnRH gene expression is independent of PI3-kinase activation in primary hypothalamic neurons

CT Ins Ins + Wort Wort DMSO

% o

f CT

0

50

100

150

200

250

300

GnRH mRNA

Treatment options

•Oral contraception: retablish menstrual cycles, decrease hyperandrogenism

•Association with an anti-androgen

•Insulin sensitizers: metformin, thiazolidinediones

Usually good clinical response to clomiphene citrate when seeking fertility

Division of EndocrinologyLausanneMicheline GlauserMarie-Jeanne VoirolMarco GiacominiEinar CastilloRoberto SalviRolf Gaillard

Department of Medicine andBotnar Center of ClinicalInvestigationPeter VollenweiderPascal Nicod

Institute of Pharmacology andToxicology, LausanneBernard Thorens

University of ToulouseRémy Burcelin