T1 L12 Endocrinology of ageing Flashcards
What is somatopause?
Decrease in growth hormone secretion with age
What is adrenopause?
Decrease in androgen secretion with age
What has a greater effect than hormonal influence on age?
Genetic
Environmental
Psychological
Co-morbidities
What shared symptoms do hypogonadism, GH deficiency and ageing cause?
Increased fat mass Increased visceral fat Sarcopaenia Decreased bone mineral density Decreased quality of life / mood Increased risk of cardiovascular disease
Describe how weight changes with age
Increases from the mid 30s until it plateaus between 50 and 70
Lean body mass decreases by 6-8% per decade from mid-30s
Describe how diet changes with age
Decreased total energy intake
Increased protein intake
Describe how insulin and glucose concentration change with age
Increased insulin resistance
Decreased peripheral glucose uptake
What are the 4 cardiovascular risk factors in metabolic syndrome?
Visceral obesity
Dyslipidaemia
Hyperglycaemia
Hypertension
Describe oestrogen levels pre and post-menopausal
Pre-menopausal: cycling
Post-menopausal: very low, constant levels
What is the average age of menopause?
50 ± 2 years
Genetics are a strong predictor for the age of menopause
What are the symptoms of menopause?
Hot flushes
Night sweats
What morbidity is associated with the menopause?
Increased risk of osteoporosis
Increased risk of coronary heart disease
Increased risk of sexual dysfunction
What are the benefits of post-menopausal HRT?
Treatment reduces symptoms
Decreases risk of osteoporosis and fractures during use
What are the risks of post-menopausal HRT?
Increased risk of venous thromboembolism
Increased risk of breast cancer
Increased risk of endometrial cancer - this is prevented if the HRT includes progesterone
Describe the relationship between the male gonadal axis and age
Decrease in testosterone concentration with age
At 75 years, the mean concentration of testosterone is 2/3 what it was at 25 years
Describe the effect of clinical hypogonadism
Decreased sexual function
Increased osteoporosis
Decreased muscle strength
What is the effect of testosterone treatment on bones?
Increased bone mineral density
No evidence that it decreases the risk of fractures
Why doesn’t testosterone treatment decrease the risk of bone fractures?
Fractures also depend on muscle strength and stability
What is the effect of testosterone treatment on body composition?
Increased lean body mass
Decreased fat mass
Increased muscle strength with supra-physiological dose
What are the risks of testosterone treatment?
Prostate (benign prostatic hypertrophy / cancer)
Erythropoiesis
Possible cardiovascular risk
Describe the relationship between the GH - IGF1 axis and age
Decrease in integrated GH concentration as age increases
Decreased IGF1 concentration with increasing age
What happens to body composition when GH treatment is given?
Increased lean body mass
Decreased fat mass
What are the potential risks of GH treatment?
Increased risk of cancer in the prostate, colon and breast
Increased risk of T2DM
What are the side effects of GH treatment?
Soft tissue oedema
Arthralgias
Carpal tunnel syndrome
Describe the relationship between cortisol and ageing
Higher trough levels with increasing age
Phase advance of diurnal rhythm (trough and peak occurs earlier)
Average levels of cortisol increase
Describe the relationship between DHEA and ageing
Decreases with age
What is an increase in DHEA associated with?
Increased quality of life
Increased bone mineral density
Decreased cognitive decline
Decreased coronary heart disease
Describe the relationship between the thyroid axis and ageing
Increase in TSH with age
T4 remains the same
Decrease in peripheral T4 to T3 conversion with age
Decrease in T3 concentration with age
What are the potential risks of giving T4 treatment?
Increased risk of osteoporosis and atrial fibrillation
Increased risk in elderly with atherosclerotic coronaries
What happens with insulin and glucose in starvation / anorexia nervosa?
Decrease in insulin
Decrease in glucose
Increase in insulin sensitivity
Where is leptin produced?
White adipose tissue
Leptin concentration correlates with BMI and body fat
What is the consequence of a decreased leptin concentration?
Increased food intake
Decreased energy expenditure
Decreased fertility
What happens to oestrogen / testosterone in starvation / AN?
Decrease in LH and FSH
Decrease in oestrogen / testosterone
Decrease in fertility (hypothalamic amenorrhoea)
Osteoporosis
What is kisspeptin?
Central mediator
KISS1 neurons are highly response to oestrogen
Metabolic influences on reproduction are mediated by leptin via the kisspeptin system (puberty, reproduction)
What happens to cortisol levels in starvation / AN?
Decrease
What is the relationship between thyroid function and starvation / AN?
TSH and T4 on lower limit of normal
Decreased T4 conversion to T3 –> decreased T3
Increased T4 conversion to reverse T3 –> increased reverse T3 (inactive)
Lower basal metabolic rate
Conserve energy
