The relationship between regional body composition and quantitative strength in facioscapulohumeral muscular dystrophy (FSHD)

This study determines in facioscapulohumeral muscular dystrophy (FSHD) and able-bodied controls (1) the regional body composition and (2) the correlation between regional lean tissue mass and the corresponding regional strength. This is a cross-sectional, criterion standard, case-control study at a university based neuromuscular disease clinic. A dual-energy X-ray absorptiometry (DEXA) scanner was used to obtain regional body composition measurements in 14 FSHD and anthropometrically matched control pairs. A dynamometer determined peak isometric strength for the elbow and knee. Compared to controls, FSHD subjects showed increased regional fat tissue mass (p < 0.001-0.017), decreased regional lean tissue mass (p < 0.001-0.010), and decreased strength (p < 0.001-0.020). There was a correlation between quantitative strength and lean tissue mass for both FSHD and controls (r = 0.791-0.906; p < 0.001). FSHD subjects have higher regional fat tissue mass and lower regional lean tissue mass despite similar BMI and anthropometrics. Regional lean tissue mass correlates with strength.