Sarcopenia - 2021: Pathophysiology, diagnosis, therapy

Area of Science:

• Geriatrics
• Muscle Physiology
• Metabolic Diseases

Background:

• Sarcopenia is a progressive skeletal muscle disorder characterized by loss of muscle mass and function.
• Initially considered age-related (primary sarcopenia), it also affects younger individuals with chronic diseases (secondary sarcopenia).
• It is linked to adverse outcomes and poor prognosis, necessitating a comprehensive understanding of its pathophysiology.

Purpose of the Study:

• To provide an overview of sarcopenia's pathophysiology, including contributing factors like physical inactivity, insulin resistance, and inflammation.
• To explore the roles of hepatokines and myokines in muscle damage.
• To examine the functional interconnections between muscle, adipose tissue, and the liver in conditions like non-alcoholic fatty liver disease and cirrhosis.

Main Methods:

• Diagnosis involves assessing muscle strength (e.g., hand grip strength), muscle mass (using DXA, BIA, CT, or MRI), and physical performance.
• Evaluation of underlying conditions is crucial for secondary sarcopenia.
• Pathophysiological mechanisms are reviewed, focusing on the imbalance between protein synthesis and proteolysis.

Main Results:

• Low muscle strength is the primary diagnostic indicator, with decreased physical performance signifying severe sarcopenia.
• Imaging techniques confirm muscle mass loss, aiding diagnosis.
• Understanding the interplay between liver, muscle, and adipose tissue is vital, particularly in liver diseases.

Conclusions:

• Regular physical activity from early adulthood, adequate protein-calorie intake, and pharmacotherapy (Vitamin D, testosterone, L-carnitine, BCAAs) are crucial for sarcopenia treatment and prevention.
• Addressing the underlying disease is essential for managing secondary sarcopenia.
• A holistic approach integrating lifestyle modifications and medical interventions is recommended.