Wk. 7 L2 Sarcopenia

Question 1

LO

Answer 1

1. Describe common causes of sarcopenia
2. Describe changes that are found in sarcopenia
3. Explain the impact of sarcopenia in hormone-deprived populations

Question 2

Changes with ageing

Answer 2

Muscle mass:
- peaks in young adulthood, then plateaus and declines
- Strength declines faster than mass

Grip strength:
- increased and peak in early adult life
- maintained throughout midlife, and declines afterwards

Gait speed:
- increases quickly in early life, then slowly decreases after teenage year

Question 3

Sarcopenia

Answer 3

Progressive and generalised skeletal muscle disorder involving the accelerated loss of muscle mass and function

Associated with increased adverse outcomes including falls, functional decline, frailty, and mortality

Question 4

Diagnosis

Answer 4

Involves measuring at least two parameters related to:
- Muscle mass,
- Muscle strength (e.g., grip strength),
- Physical performance (e.g., gait speed)

There are different cut-offs, leading to varying prevalence between studies

Question 5

Causes

Answer 5

Common causes of sarcopenia:
– Nutritional (malnutrition)
– Inactivity
– Diseases
– Iatrogenic (medical treatment)

Question 6

Skeletal Muscle Organization

Answer 6

Large nucleated myofibres composed of myosin and actin filaments, organised into sarcomeres

Fast and slow twitch fibres
Type 1 = slow
Type 2 = fast

Question 7

Myofibers change

Answer 7

Cellular changes in sarcopenic muscles:
- Reduction in the size and number of myofibers
- Transition of muscle fibers from type I (slow) to type II (fast) myofibers
- Reduced satellite cells in type II (fast) muscle fibers
- Fat infiltration due to inactivity.

Question 8

Hormonal changes across lifespan

Answer 8

Women naturally experience a decline in (E2) and (T) production after menopause

In healthy men, there is no sharp decline in gonadal hormones, but there is increased variability in T levels.

When men experience sharp a decline in T and E2 levels: orchiectomy, hormone-suppressing medication, testicular injuries

Question 9

Sarcopenia after menopause

Answer 9

• Prevalence increases after menopause, potentially related to hormonal decline

Estrogen plays a role in muscle strength
generation, but not mass maintenance

Question 10

Sarcopenia in men

Answer 10

T deprivation causes muscle atrophy and increased adiposity in men
strength may decrease due to atrophy
Walking and balance may change, increasing the risk of falling