Ageing and Endocrinology Flashcards
What are the pituitary hormones?
- Anterior pituitary hormone
- Posterior pituitary hormone
- secreyed from pituitary glands
What hormones are secreted from the anterior p gland?
- Gonadotropins (FSH and LH)
- Growth hormone
- prolactin
- Adrenocorticotropic hormone (ACTH from adrenal cortex)
- Thyroid stimulating hormone (TSH) - from thyroid gland
What does the posterior p gland regulate the production of ?
- oxytocin
- antiduretic hormone
What are some age related changes in the e system?
- some atrophy in most glands
- decreased secretion with age
What are the hormonal alterations most apparent in ageing?
- Glucose homeostasis ( type 2 diabetes increased risk)
- Reproductive function
- Calcium metabolism
- subtle alterations in :
- adrenal function, thyroid function
What is the effect of ageing on glucose homeostasis (pancreas) ?
- islets of Langerhans = little age related change
- Substantial decline in glucose tolerance
- Caused by decrease islets resposne to insulin secretion in response to blood glucose
- inaadewaute insulin production
- Decreased cell membrane responsiveness to insulin
- Increased insulin level in response to oral glucose (in some elderlu)
What are risk factors are assocaited with diabetes in ageing?
- Decreased physical activity , leading to :
- Increased adiposity
- Age effects on insulin action - leading to insulin resistance
- Medication
- Genetics , coexisting illness = decreased insulin secretion = impaired adaptation : No increase in insulin = leadinf to progression to IGT and Type 2 diabetes
- ## Age effects on Beta cells
What are some reprroductive system changes in ageing in women?
- Climacteric occurs = reproductive cap decreases
- Stops eventually = loss of oestrogen and progesterone . FSH and LH increase
- Transition from perimenopause to menopause (in 40s)
- Thinning and hraying of pubic hair
- Loss of subQ fat in external genitalis (look shrunken)]
- Ovaries and uterus decreases in size and weight
- skin - less elastic
- atrophy of vaginal tissues due to low estrogen levels = thinng and dryness occurs / agglutination of labia majora and minora may occur
What are some reproductive system changes in ageing in men?
- Testosterone decreases, testes become softer and smaller
- Erections = less firm and often require direct stimulation to retain rigidity
- still produce enough viable sperm to fertilise ova in older age
- Less seminal fluid may be ejaculated
- May not experience orgasms
- prostrate glaand enlarges: this often results in compression of the urethea which mau inhibit the flow of urine
Summary of changes in ageing?
- Menpause = low estrogen
- Andropause = low testosterone
- Andrenopause = low DHEA levels
- Somatopause: GH/IGF-1 = Low
What is andropause?
- Ageing of rep system
- Reduced sexual activity among elderly ppl
- Disease and condition associated witha dvancing age
- can manifest as :
- Impotence
- Gynecomastia
- Adenocarcinoma
- Hypertrophy prostate
- Testicular cancer
Why is vitd and calcium homeostasis important?
- maintaing bone mass
- burn turnover
- increased pth causes:
- -increased ca absorption in the gut
- Calcium reabsorption in renal tubules = less ca excretion
- Increase in bone turnover for availability of calcium
- leads to a rise in serum calcium to maintain calcium homeostasis
What is the effect of ageing on the Vit D pathway?
- reduced vit D ressistance = lesss absorption of calcium
- postreceptor defects e.g. in calcium transport proteins ‘
- Vit D resistance , increased adipocytes, increased protein turnover
-MAKE A DIAGRAM
What happens when there are lower ACTH and glucocorticoidm secretion?
- Increased cortisol production
- Patient may present with nausea and weight loss
- Stress in the elderly
- May not adapt to stress the same way
- pituitary and adrenal involvement
- Stress activation and feedback inhibition
- CRH in Alzheimer’s disease
What are the effects of ageing on the adrenal cortex?
-cortisol decline by 25% in elderlu
Plasma cortisol level unchanged
- Renal clearance of coritosl are diminished
- Responsiveness to ACTH does not decline
- Pituitary to cortisol feedback : does not
- Progesterone - aldosterone : decrease with age
- Affect attitudes, behavior or related physical factors
- Renin-aldosterone mechanism also decline with age ( reduction in bp and may increase risk of falling and dizziness)
