Musculoskeletal pathology - Sarcopenia

Question 1

Define ‘sarcopenia’.

Answer 1

A syndrome characterised by progressive loss of muscle mass, strength and function. This carries a risk of adverse outcomes such as poor quality of life, disability and death.

Question 2

Describe the prevalence of sarcopenia.

Answer 2

No difference between genders
Incidence of sarcopenia increases with age
1-29% for older adults living in the community
10% for adults living in acute hospital setting
14-33% for adults living in a care environment

Question 3

Describe the stages of sarcopenia.

Answer 3

Pre-sarcopenia
- decreased muscle mass

Sarcopenia

• decreased muscle mass
• loss of muscle strength or performance

Severe sarcopenia

• decreased muscle mass
• loss of muscle strength and performance

Question 4

How is sarcopenia diagnosed?

Answer 4

Diagnosis is based on:

• muscle mass
• muscle strength & function

Gait speed is measured first.

If gait speed is low, muscle mass is measured.
Low muscle mass = sarcopenia
Average muscle mass = no sarcopenia

If gait speed high, grip strength is measured
Average grip strength = no sarcopenia
Low grip strength = muscle mass measured
Average muscle mass = no sarcopenia
Low muscle mass = sarcopenia

Question 5

Explain the various mechanisms of muscle wasting.

Answer 5

Decrease in muscle strength and muscle mass can be attributed to:

Malnutrition caused by:

• increased energy requirement
• decreased intake
• malabsorption

Cachexia caused by:

• hyper-metabolic state
• proinflammatory cytokines
• starvation

Sarcopenia caused by:

• sedentary lifestyle
• age related hormones
• neurodegenerative disease

Question 6

How is sarcopenia prevented/treated?

Answer 6

Exercise is the single most effective prevention/treatment method for sarcopenia.

Adequate protein in the diet - older people should aim to have 1-1.2g protein per kg body weight per day. Should be spread out evenly across the day.

Pharmacological treatment includes:

• testosterone or selective androgen receptor modulators (SARMS)
• growth hormones

Question 7

Explain the causes of sarcopenia.

Answer 7

The cause of sarcopenia is multifactorial.

Lifestyle/environment

• lack of physical activity
• decline in nutrient intake

Age related

• Decrease in neuromuscular junctions
• Decrease in hormones related to muscle maintenance
• Increased in inflammatory pathways