Peripheral muscle weakness in patients with chronic obstructive pulmonary disease

Area of Science:

• Pulmonary Medicine
• Muscle Physiology
• Exercise Science

Background:

• Peripheral muscle weakness is a common comorbidity in Chronic Obstructive Pulmonary Disease (COPD).
• This weakness can significantly impair exercise capacity in COPD patients.
• The underlying mechanisms and distribution of this weakness require further elucidation.

Purpose of the Study:

• To investigate the relationship between muscle strength and cross-sectional area (CSA) in COPD patients.
• To determine the distribution pattern of peripheral muscle weakness in COPD.
• To examine the correlation between muscle strength and the severity of lung disease in COPD.

Main Methods:

• Evaluated 34 COPD patients and 16 healthy controls.
• Assessed muscle strength and thigh muscle CSA using computed tomography.
• Analyzed the quadriceps strength/thigh muscle CSA ratio and compared muscle groups.

Main Results:

• COPD patients exhibited reduced muscle strength and thigh muscle CSA compared to controls.
• The quadriceps strength/thigh muscle CSA ratio was similar between groups, indicating muscle atrophy.
• Quadriceps weakness was more pronounced than shoulder girdle weakness and correlated with disease severity (FEV1).

Conclusions:

• Muscle weakness in COPD is primarily attributed to muscle atrophy rather than intrinsic strength deficits relative to muscle size.
• Peripheral muscle weakness distribution and its correlation with airflow obstruction suggest chronic inactivity contributes to muscle loss.
• These findings highlight the importance of addressing muscle deconditioning in COPD management.