Sarcopenia and osteoporosis are both common age-related musculoskeletal disorders among the elderly.
The roots of Sarcopenia come from the Greek word sarx- meaning flesh and penia- meaning loss.
Sarcopenia:

• Gradual deterioration of skeletal muscle mass;
• Decrease in muscle strength, power and endurance and
• Low physical performance.
• Poor co-ordination and balance ability

The prevalence of sarcopenia in the aging population in Hong Kong is approximately 11.2% in men and 7.6% in women. Higher prevalence is observed in those with other co-morbidities such as cognitive impairment, cancer, renal failure, chronic obstructive pulmonary disease, heart failure etc.

Progressive muscle wasting and muscle strength decline with aging are major determinants for functional decline, fall and subsequent fracture risk. It is associated with increased dependency, poor quality of life and increased health and social care usage.

The selective loss of fast acting muscles also leads to poor co-ordination and poor response, thus increase risk of falls which result in injuries

Poor reserve to major illness and serious injuries

The rate of skeletal muscle loss can be affected by genetic, environmental and lifestyle factors such as:

1. Age-related:
   • Decrease in circulating hormones such as testosterone, causing a protein synthesis-breakdown imbalance and degradation of muscle protein.
   • Apoptosis.


2. Decrease physical activity:
   • Sedentary lifestyle.
   • Bed rest.


3. Malnutrition:
   • Imbalance diet from inadequate food intake.
     Low protein intake: < 1.2g/kg /day.
     Low vitamin D intake: < 20µ/day.
     Low caloric intake: <21cal/kg.
   • Malabsorption.
   • Gastrointestinal disorders.
   • Medications.


4. Disease related:
   • Comorbidities, such as cancer, renal disease etc.
   • Cognitive impairment.

• People aged 60 years or older.
• Malnutrition/ Imbalance diet.
• Bed rest/ Sedentary lifestyle.
• Cognitive impairment.
• Low body mass index (BMI) <18.5.
• Comorbidities/ Chronic diseases.
• Lack of physical exercise in early life developmental stage.

• Decrease in muscle mass, muscle strength and endurance.
• Disability and functional decline.
• Increase risk of falls, subsequent fracture and mortality.
• Loss of independence.
• Decrease insulin sensitivity.
• Decrease energy expenditure.

• Reduced gait speed.
• Low muscle mass.
• Muscle weakness.
• Early fatigue.
• Poor muscle strength and endurance.
• Impaired mobility.
• Weight loss