# Changes in body composition and phase angle from diagnosis to gastrostomy, in motor neuron disease patients: a longitudinal study

## TL;DR

This study tracks body composition changes in motor neuron disease patients from diagnosis to gastrostomy, finding significant declines in fat-free mass and phase angle.

## Contribution

The study provides novel longitudinal data on body composition and phase angle changes in motor neuron disease patients using bioimpedance analysis.

## Key findings

- Fat-free mass and phase angle significantly decreased from diagnosis to gastrostomy.
- Fat-free mass was the strongest predictor of weight change in motor neuron disease patients.
- The study suggests monitoring body composition could help preserve weight and fat-free mass before gastrostomy.

## 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.