Thigh muscle mass and function in patients treated with glucocorticoids

Area of Science:

• Endocrinology
• Sports Medicine
• Rehabilitation Science

Background:

• Glucocorticoid therapy is associated with proximal skeletal muscle wasting.
• Previous studies in rats suggest physical training may mitigate muscle loss.
• The efficacy of physical training in reversing glucocorticoid-induced muscle wasting in humans remains unestablished.

Purpose of the Study:

• To investigate the effects of moderate physical training on muscle mass and function in human patients treated with glucocorticoids.
• To quantitatively assess changes using computed tomography (CT) and isokinetic dynamometry.
• To determine if physical training can reverse glucocorticoid-induced muscle wasting.

Main Methods:

• Quantitative assessment of mid-thigh muscle area and fat/muscle ratio using computed tomography (CT).
• Measurement of thigh muscle strength and endurance using an isokinetic dynamometer (Cybex II).
• A 50-day isokinetic training program was implemented in a subset of patients.

Main Results:

• Prednisone-treated patients exhibited significantly reduced mid-thigh muscle area (20-45%) and increased fat/muscle ratio (25-100%) compared to controls.
• Thigh muscle strength and work output were reduced by 20-30% in patients on prednisone.
• Fifty days of isokinetic training led to increased muscle area, decreased fat area, and normalized strength and endurance.

Conclusions:

• Glucocorticoid-induced muscle wasting is a significant concern in patients.
• Moderate physical training, specifically isokinetic training, can effectively reverse muscle wasting and functional deficits.
• Increasing physical activity represents a viable strategy to counteract the catabolic effects of glucocorticoids on skeletal muscle.