The muscle-bone in children and adolescents with and without cystic fibrosis

Puberty is a crucial period for rapid changes in bone mineral, size, geometry, and microarchitecture. The mechanostat theory postulates that increased mechanical loading will affect bone phenotype and strength during development and in later life. Individuals with cystic fibrosis(CF) have an increased risk of developing osteoporosis and fragility fractures in young adulthood, which may be caused by poor growth. The aim was to investigate whether sex and disease status modified the relationship between: 1) puberty and bone, and 2) muscle and bone. This would contribute to the understanding of how sex(malesvs.females) and disease group(CFvs.controls) alters the relationship between bone and muscle in children and adolescents as they transition through puberty and who, on a population level, differ in the prevalence of osteoporosis and risk of fracture in later life. This observational study used novel imaging and muscle assessment techniques to measure bone and muscle parameters in White Caucasian children and adolescents, aged 8 to 16 years, living in the UK, with children with CF(n=65) and controls(n=151). Anthropometry and pubertal status were assessed. Dual energy x-ray absorptiometry, peripheral quantitative computed tomography(pQCT), high-resolution pQCT, and jumping mechanography were used to measure bone and muscle outcomes. ANCOVA with Scheffé post hoc and multiple linear regression tests were performed. Data were adjusted according to the research aims and included covariates; sex, disease group, pubertal stage, age, quadratic age, height, weight, maximum force(Fmax), and maximum power(Pmax). Data are presented as beta-coefficient(%) and p-value, with the significance level set to p