10. Menopause

Question 1

why does menopause occur

Answer 1

ovarian depletion of follicles… cessation of ovulation/menstrual cycles

Question 2

explain the hormonal changes leading to the features of the menopause

Answer 2

1. decreased primary follicle no… decreased no. of ovarian gonadotrophin Rs… decreased ovarian sensitivity to LH and FSH…
2. decreased oestrogen (and inhibin) secretion… increased anovulatory cycles…
3. decreased -ve feedback on hypothalamus and AP… increased FSH and LH secretion (esp. FSH)

Question 3

describe the 4 phases of the menopause

Answer 3

1. pre-menopause (40+ yrs)
   Time prior to menopause when changes in menstrual cycle start to occur:
   
   • decreased oestrogen, increased LH and FSH
   • follicular phase shortens
   • increased anovulatory cycles… decreased fertility
2. peri-menopause (transition menopause)
   Characterised by physiological changes associated with end of repro. capacity - regression of ovarian function
3. menopause (45-55 yrs)
   Permanent cessation of menstruation for 12 consecutive months, caused by ovarian follicle dev. failure
4. post-menopause
   Time after 12 consecutive mths of amenorrhea

Question 4

what is premature ovarian failure

Answer 4

cessation of menstruation (gradual or abrupt) due to ovarian follicle depletion before age 40 (occurs idiopathically in 5% women)

Question 5

why does onset of menopause cause dysfunctional uterine bleeding

Answer 5

1. Anovulation… no corpus luteum… no progesterone…
2. variable oestrogen levels (also produced by aromatase in other tissues, eg adipose) cause endometrium to keep thickening (hyperplasia)…
3. late menstrual period followed by irregular bleeding and spotting

Question 6

what is the effect of increased oestrogen on the cardiovascular system

Answer 6

1. peripheral vasodilation and transient increased body temp… hot flushes and sweating (which can then lead to insomnia, fatigue, irritability and headaches)
2. increased BP and metabolism changes… gradual increase in CVD and stroke risk
   • increased total serum cholesterol and triglycerides, decreased HDL-cholesterol
   • increased insulin resistance… decreased carb tolerance

Question 7

describe the changes in reproductive organs during the menopause

Answer 7

Ovaries: atrophy and become smaller… decreased oestrogen secretion (although substantialy increased gonadotrophin levels maintain ovarian androgen secretion - then converted to oestrogen by aromatase in ovary and adipose)

Uterus: myometrium atrophies, endometrium regresses

Thinning of cervix (becomes flush with vagina) and loss of vaginal rugae

Vulva: decreased fat in labia majora, decreased mons pubic and decreased pubic hair (final decrease testosterone)

Breast: become flat and shrivelled in thin women, or flabby and pendulous in heavy women

Question 8

describe the effect of increased oestrogen on bone

Answer 8

increased osteoclast activity… increased calcium loss from bone in 1st 5yrs after menopause onset… decreased bone density… osteoporosis and fractures

Question 9

describe the changes stimulated by the menopause on the digestive system

Answer 9

decreased motor activity of digestive tract… constipation and bloating

Question 10

describe the changes stimulated by the menopause on the urinary system

Answer 10

1. decreased collagen synthesis… weakening of vaginal walls and pelvic floor… increased stress incontinence and pelvic organ prolapse
2. epithelial lining of urethra and bladder becomes drier, thinner and less elastic… increased risk of UTIs

Question 11

what are the benefits of hormone-replacement therapy

Answer 11

replaces hormones produced by ovaries (oestrogen and progesterone) to limit effects of deficiency, e.g. limits risk of:

• osteoporosis
• pelvic organ prolapse and stress incontinence

Question 12

what are the disadvantages of hormone-replacement therapy

Answer 12

HRT moderately increases risk of:

• breast cancer
• ovarian cancer
• endometrial cancer - Oe-only replacement should only be given to Ps having had hysterectomy. Other Ps should also be given progesterone replacement as this limits proliferation of endometrium caused by unopposed Oe.
• thromboembolism (eg stroke) - due to pro-thrombotic effects of oestrogen