The Association of Grip Strength, Body Mass Index, and Lung Function in Youth with Cystic Fibrosis.

Compared with body mass index (BMI), lean body mass and fat-free mass are strongly associated with lung function in children and adolescents with cystic fibrosis (CF). Methods of measuring body composition in youth with CF are often unreliable, expensive, or not clinically feasible. Grip strength (GS), a measure of muscle function, is used as a surrogate for muscle mass and is an indicator of nutrition status.