Lecture 28: menopause

Question 1

Why menopause?

Answer 1

Blessing of the modern life - fixed number of follicles

Senescence - to protect ageing women from the hazards of childbirth

Group selection - Protects the human gene pool against birth defects that are higher in older follicles

Good mother/grandmother theory - To provide extended care of offspring

Question 2

Timing of menopause? Childbirth?

Answer 2

It’s a consequence of ovaries running out of follicles, and occurs between 50-52 years (POF<40 in 1% and Early Meno. = 40-45

Defined as the stopping of menstrual bleeding

Towards the end you have to increase FSH to get the same ovulation (20-30 lost daily increasing in the last 10 years with only about 400 ovulating in a lifetime)

Some studies suggest that most women have their last child 10 years before menopause.

Question 3

Timing of menopause - variation?

Answer 3

In well nourished populations there is menopause independent of racial background - Poorly nourished women have earlier menopause

Women who smoke have an earlier menopause of 1-2 years

Parity, maritial status and the age of menarche (debatably) do not appear to influence the timing of menopause

Mothers and daughters have a similar age at menopause

Question 4

Andropause?

Answer 4

Thought to be between 40-55

Thought to be a decline in the level of testosterone - may be acompanied by changes in attitude and mods, fatigue, loss of libido and energy levels

Question 5

Timeline of cycles?

Answer 5

Question 6

Perimenopausal changes?

Answer 6

The time of erratic hormone fluctuations

Climacteric : relates to physical and emotional symptoms associated with the perimenopause

5-10% do not experience a transition phase of any significance and abruptly cease menstrual activity

Follicle level reduces below the critical threshold and inhibin B (from granulosa cells) begins to decline increasing FSH levels in D0-6 accelerating follicle loss

Question 7

Hormonal changes during perimenopause?

Answer 7

The higher FSH plasma levels stimulates greater proportion of primordial follicles to enter each follicular wave.

From about 20-40 up to around 80 being lost each day

increased TWINNING - more than one one follicle = non-identical twins

Question 8

Features of the perimenopause?

Answer 8

• Irregular cycles
• Annovulatory cycles are common (longer the cycle the more chance it is annovulatory)
• Gonadotrophs often elevated (especially FSH- can be detected in young women with POF)
• Oestrogen levels are often high (early perimenopause) or can be low in (late perimenopause)
• Unpredictable hormone patterns
• loss of androgen levels may be related to loss of libido
• ovulation is always possible
• Contraception is difficult - but pregnancy is rare.

Question 9

Postmenopausal estrogen production?

Answer 9

Estrogen is from extraglandular production. This is mainly done in the stromal cells of adipose tissue, by aromatisation of androstenedione secreted from the adrenal cortex.

Oestradiol is made from aromatisation of oestrone but only in small amounts. Oestrone is weekly oestrogenic having about 1/10 the effect of oestradiol

Question 10

Perimenopausal symptoms?

Answer 10

These symptoms usually follow the onset of the menopausal transition but they may preceed it and they sometimes continue for a time after menopause.

Vasomotor - hot flushes and night sweats often with palpatations, weakness and faintness

GU symptoms - atrophic changes, reduction in lubrication, rise in pH, dysparunia or incontinence

Reduction in size of uterus and breast density (good for mamography screening)

Increased bone loss

depression, anxiety, mental confusion, loss of libido

Question 11

HRT?

Answer 11

hormone replacement therapy

Great for reducing symptoms of menopause

Will - increase risk of breast or uterine cancer, heart disease, stroke and alzheimer’s disease.