Abstract Limited studies have explored the longitudinal alterations of fat-free mass (FFM), fat mass (FM), and phase angle (PhA) in the motor neuron disease (MND) population. This pilot longitudinal study investigated body composition changes via bioimpedance analysis (BIA) at time of diagnosis and gastrostomy. Nineteen patients ( n = 11, 57.9% females) were included. Statistically significant reductions in FFM median (IQR) 43.0 (17.8) kg to 42.1 (16.7) kg, p < 0.001 and PhA 4.6 (2.0)° to 4.5 (2.1)°, p = 0.012 were found. FFM ( p = 0.007, 95% CI 0.505, 1.32) and FM ( p = 0.024, 95% CI 0.160, 1.249) were significant predictors of weight change, with FFM accounting for 72% of the change. Larger longitudinal studies are needed to explore the clinical benefit associated with reducing pre-gastrostomy FFM loss in the MND population. In the interim, clinicians should consider monitoring body composition and implementing interventions aimed at preserving body weight and composition, particularly FFM, prior to gastrostomy placement.
Yang et al. (Sat,) studied this question.