Muscle size, strength, and physical function in response to augmented calorie delivery: A TARGET sub-study

Area of Science:

• Critical care medicine
• Nutritional support
• Muscle physiology

Background:

• Muscle loss is common in critically ill patients.
• Nutritional support aims to mitigate muscle wasting.
• The optimal calorie delivery for muscle preservation is unclear.

Purpose of the Study:

• To assess the impact of augmented calorie delivery on muscle mass, strength, and function in critically ill patients.
• To investigate if higher caloric intake can attenuate muscle loss during critical illness.

Main Methods:

• An exploratory sub-study of the TARGET trial included patients randomized to 1.0 or 1.5 kcal/ml enteral formulae.
• Muscle layer thickness (MLT) and handgrip strength were measured weekly.
• Physical function was assessed using the 'get up and go' and 6-min walk tests at 3 and 6 months post-discharge.

Main Results:

• The group receiving 1.5 kcal/ml received more calories but showed no significant difference in quadriceps muscle layer thickness compared to the 1.0 kcal/ml group at ICU discharge.
• No significant differences were observed in other muscle mass measures, handgrip strength, or 6-minute walk test results between groups.
• The 1.5 kcal/ml group demonstrated improved 'get up and go' test performance at 3 months.

Conclusions:

• Augmented calorie delivery did not significantly attenuate muscle loss or improve strength and function 6 months post-ICU.
• These findings suggest that higher caloric intake may not be sufficient to prevent muscle wasting in critical illness.
• Larger trials are warranted to explore the effects of augmented calorie delivery on muscle outcomes in critically ill populations.