Muscle atrophy

A pathological reduction in skeletal muscle mass and muscle fiber cross-sectional area, resulting in decreased muscle strength, reduced physical performance, and impaired functional capacity.

Causes

• Prolonged immobility

  • Bed rest

  • Sedentary lifestyle

  • Prolonged weightlessness during spaceflight

  • Limb immobilization after injury or surgery

• Neurological disorders causing impaired neural stimulation of muscle

  • Amyotrophic lateral sclerosis (ALS)

  • Spinal muscular atrophy (SMA)

  • Spinal cord injury

  • Peripheral nerve damage

  • Stroke

  • Multiple sclerosis

• Systemic disease-related causes

  • Cancer-related cachexia

  • Heart failure

  • Chronic obstructive pulmonary disease (COPD)

  • HIV infection

  • Chronic kidney disease

  • Prolonged inflammatory catabolic state

• Corticosteroid therapy

• Age-related muscle loss (sarcopenia)

  • Reduced physical activity

  • Hormonal changes (testosterone)

• Nutritional and metabolic causes

  • Malnutrition

  • Protein deficiency

  • Vitamin deficiencies

  • Malabsorption disorders

  • Severe chronic illness causing catabolic metabolism

• Primary muscle diseases: Muscular dystrophies, inflammatory myopathies