The Ageing Endocrine Systems Flashcards

1
Q

What is meant by ‘compression of morbidity’?

A

Popular with geriatricians - aim is that illness and disability squeezed into a short period at the end of life

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2
Q

What is the endocrine system?

A

Made up of organs + tissues that produce hormones

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3
Q

What is a hormone?

A
  • A chemical messenger
  • Released into the bloodstream from one location to target other organs or tissues
  • Amino acid or steroid based
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4
Q

How does the hypothalamus link the nervous system to the endocrine system?

A

Via the pituitary gland

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5
Q

Where is the central circadian clock located in the hypothalamus?

A

Suprachiasmatic nucleus

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6
Q

What changes occur as a result of the ageing hypothalamus?

A
  • Circadian rhythm diminishes with age
  • Decreased sleep + disturbed sleep/wake cycle
  • Diminished appetite
  • Poor thermoregulation
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7
Q

Is it the posterior or anterior pituitary that produces its own hormones?

A

Anterior pituitary produces its own hormones. Posterior pituitary stores hormones made in the hypothalamus.

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8
Q

mnemonic: GOAT FLAP

Which hormones does the pituitary gland produce? Which of these two are produced by the posterior pituitary?

A
  • Growth hormone (GH)
  • Oxytocin
  • Anti-diuretic hormone (ADH)
  • Thyroid stimulating hormone (TSH)
  • Follicle stimulating hormone (FSH)
  • Luteinising hormone (LH)
  • Adrenocorticotropic hormone (ACTH)
  • Prolactin
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9
Q

What is growth hormone also known as?

A

Somatotropin

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10
Q

What is the action of growth hormone?

A
  • Causes production of IGF-1 from liver
  • Involved in protein, fat + carbohydrate metabolism (gluconeogenesis, muscle growth, bone growth)
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11
Q

What happens to growth hormone levels with age?

A
  • Growth hormone decreases with age
  • GH secretion from pituitary declines progressively after puberty -> decreased levels of IGF-1
  • Decreased muscle mass + bone density
  • Somatopause
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12
Q

What are advantages of replacing growth hormone?

A
  • Increased lean body mass
  • Decreased adipose tissue
  • Increased bone density
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13
Q

What are limitations of replacing growth hormones?

A
  • Has to be given subcutaenously
  • Difficult dosing
  • Side effects - hyperglycaemia, oedema, arthralgia
  • Increased IGF-1 can increase malignancy
  • Cost
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14
Q

Which is the active hormone released from the thyroid?

A

T3 - causes most of the metabolic effects

(T4 is a peripheral storage of thyroxin and just gets converted to T3)

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15
Q

What changes occur regards to the thyroid gland with age?

A
  • TSH increases
  • T4 levels remain unchanged
  • Increased levels of thyroid antibodies (autoimmune)
  • Both hyperthyroidism and hypothyroidism more prevalent - many undiagnosed
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16
Q

What is sick euthyroid syndrome and what is it caused by?

A
  • Abnormal TFTs in patients unwell with non-thyroid systemic disease
  • Caused by:
  • > reduced TSH secretion
  • > lower thyroid hormone binding
  • > reduced peripheral T4 -> T3 (so T4 remains normal)
  • These^ reverse once underlying illness improves
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17
Q

What are clinical features of hypothyroidism?

A
  • Hearing loss
  • Psychosis, depression, coma
  • Loss of outer eyebrows + dry, brittle hair
  • Thick, coarse features
  • Goitre, hoarse voice
  • Congestive cardiac failure, bradycardia, hypertension
  • Slow reflexes, myalgia, carpel tunnel
  • Ataxia, anorexia, overweight, constipation, menorrhagia
  • Cold intolerance
  • Oedema
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18
Q

What are clinical features of hyperthyroidism?

A
  • Restlessness, malaise, irritability, psychosis
  • Goitre, bruit
  • Opthalmoplegia, exopthalmos
  • Periorbital oedema
  • Heat intolerance
  • Tachycardia, AF, hypertension, CCF, SoB
  • Tremor, palor, erythema, onycholysis
  • Thirst, weight loss, poor appetite, d&v
  • Proximal myopathy, pretibial myxoedma
19
Q

What is the visible difference between exophthalmos and proptosis?

A
  • Exophthalmos = eye protruding from orbit (can see white above AND below pupil)
  • Proptosis = eye bulging out, can cause chemosis
20
Q

Why is thyroid disease tricky to detect in the elderly?

A
  • Symptoms are non-specific and often mistaken for the ‘normal ageing’ process
  • Examination is difficult as thyroid may be shrunken + kyphotic posture
  • Overlapping presentation of hypo- + hyper-thyroidism in elderly (confusion, depression, incontinence etc)
21
Q

What does the adrenal cortex produce?

A
  • Aldosterone
  • Cortisol
22
Q

What does the adrenal medulla produce?

A

Catecholamines (adrenaline + noradrenaline)

23
Q

What happens to adrenal function with age (specifically cortisol)?

A
  • Cortisol is the stress hormone
  • Levels increase with age
  • Diurnal variation in cortisol is altered in elderly
  • Chornically elevated levels have been implicated with numerous age-related conditions eg. cog impairment, CVD
24
Q

What is menopause and when does it occur?

A
  • Cessation of menstruation due to ovarian failure
  • 45-55
25
What hormone changes occur post-menopause?
* Oestrogen levels fall * FSH and LH increase initially + then fall
26
What are the immediate post-menopausal symptoms?
* Hot flushes * Insomnia * Altered mood * Atrophy of oestrogen responsive tissue
27
What are the long term symptoms/impacts of menopause?
* Increased cardiovascular risk * Rapid loss of skeletal mass + bone mass * Vasomotor instability * Psychological symptoms * Loss of libido
28
When should hormone replacement therapy be used?
* menopausal symptoms where the risk:benefit ratio is favourable * For women with early menopause
29
What are the benefits of HRT?
* Improve **vasomotor symptoms** * Reduction in **osteoporosis** * Improve **sleep + mood** * Reduce risk of **colorectal cancer** * Reduce risk of **cardiovascular disease**
30
What are risks of HRT?
* Small inc risk of **breast, ovarian + endometrial cancer** * Increased risk of **venous thromboembolism** * Increased risk of **stroke** * Increased risk of **cholecystitis** * **Side effects** eg. bloating, breakthrough bleeding, breast tenderness
31
What are non-HRT options?
* Atrophic vaginitis - use topical oestrogens * Clonidine (a-stimulant) may reduce hot flushes (though can inc BP)
32
What happens to gonadal function in ageing men?
* Testosterone levels decrease w age * Decreased libido * Reduced muscle strength + bone mineral density
33
Should we replace testosterone in the elderly?
* Consider for patients w symptoms of hypogonadism and/or markedly reduced levels of testosterone * Can improve bone mineral density, muscle mass, libido, mood etc * BUT REMEMBER, **contraindicated in prostate cancer, increased risk of heart disease**
34
What changes occur with glucose metabolism in ageing?
* Beta cell function declines * Glucose-induced insulin release is delayed + smaller * Peripheral insulin resistance increases * ----\> increased impaired glucose tolerance + progression to T2DM
35
What are secondary causes of diabetes mellitus?
* Steroids * Thiazides * Pancreatitis * Cushings disease * Hyperthyroidism
36
Diabetes mellitus is difficult to diagnose in the elderly due to symptoms sometimes being related to 'ageing', what are these symptoms?
* Glucosuria + polyuria occur later * Impaired thirst (polydipsia occurs later) * Presentation: coma, delirium, thrush, cellulitis, weight loss, urinary incontinence, general malaise, vascular disease, peripheral neuropathy
37
What are microvascular complications of diabetes?
* Diabetic retinopathy * Diabetic nephropathy * Diabetic neuropathy
38
What are macrovascular complications of diabetes?
* Stroke * Heart disease * Peripheral vascular disease
39
What are limitations to treating diabetes in the elderly?
* Risk of **drug-induced hypoglycaemia**, confusion falls + fractures * LT benefits of treatment **unknown** in frail or \>80 * Practical difficulties with **administering** insulin * Full **compliance** with dietary change or insulin not always possible * Dietary change could cause loss of **QoL**
40
What changes occur in regards to parathyroid gland function and associated hormones, with age?
* **PTH rises with age** * Reduced **sunlight exposure** * Post menopausal **reduced hydroxylation** of Vit D * Reduced effect of PTH (altho counterbalanced by PTH rise) * Diminished capacity of **skin** to convert cholesterol to Vit D
41
Ageing leads to a decrease in overall bone mineral density, leading to which disease?
Osteoporosis
42
Summary Q: Which 2 hormones increase with age?
* Cortisol * PTH * (TSH gradually does) The rest decrease and T4 remains unchanged
43
What are easy, cheap yet important tests used to screen in the elderly?
* TFTs * Vit D * Ca * Haematinics (iron, b12, folate)