Measures of body habitus are associated with lung function in adults with cystic fibrosis: A population-based study

Background: Body habitus differences may explain some of the variation in lung function between individuals with cystic fibrosis (CF). We tested the hypothesis that measures of lean muscle mass and obesity are independently associated with lung function in CF. Methods: Cross-sectional study design using UK CF registry data from 2096 clinically stable adults. Results: Serum creatinine and BMI were positively and independently associated with FEV₁ and FVC. One standard deviation increment in serum creatinine was associated with an FEV₁ increase of 171ml (95% confidence intervals CI: +116 to +227ml) in males and 90ml (95% CI: +46 to +133ml) in females. Compared to the reference group of 20-24.9kg/m², those with a BMI<20kg/m² had lower FEV₁ with values of -642ml (95%CI: -784 to -500ml) for males and -468ml (95%CI: -564 to -372ml) for females. Conclusions: Prospective studies and controlled trials are required to ascertain if these associations have therapeutic potential in modifying disease progression.