Introduction: Loss of lean body mass is common following radiotherapy in patients with head and neck squamous cell carcinoma (HNSCC) and may reduce maximal muscle strength and functional performance. However, the associations between lean body mass, muscle strength and functional performance are unclear and no studies in HNSCC patients have compared the levels of these variables to the levels seen in healthy individuals.
Purpose: The purpose of the present study was to investigate the associations between lean body mass, maximal muscle strength and functional performance in HNSCC patients and to compare the levels of these variables after radiotherapy and after progressive resistance training with the levels in healthy individuals.
Material and methods: Lean body mass (dual energy X-ray absorptiometry), maximal muscle strength (isokinetic dynamometry) and functional performance (10 m max gait speed, 30 s chair rise, 30 s arm curl, stair climb) from HNSCC patients from the DAHANCA 25 trials and data from 24 healthy individuals were included.
Results: Lean body mass and maximal muscle strength were significantly associated according to the gender and age-adjusted linear regression model (p < 0.0001). In addition, maximal muscle strength were associated with 30 s arm curl performance, 10 m max gait speed and 30 s chair rise (p < 0.0001). Multiple regression analyses showed that HNSCC patients expressed significant lower levels of the investigated variables after radiotherapy than healthy individuals (p < 0.0001), and that all differences were evened out after training.
Conclusions: Significant associations were found between lean body mass, maximal muscle strength and functional performance in HNSCC patients. Patients expressed lower levels of these variables compared with healthy individuals, suggesting that lean body mass is a clinically relevant health factor in HNSCC patients.