Reduced gains in fat and fat-free mass, and elevated leptin levels in children and adolescents with cystic fibrosis

Aim: Bodyweight is an important prognostic indicator in children with cystic fibrosis (CF), but the relationships between body composition and clinical outcomes are less clear. We have investigated the role of leptin (a potential satiety factor) and changes in body composition, height and weight with respect to age and clinical outcome. Methods: 143 children (77 boys) with CF and a median age (range) of 5.99 (2.27-17.98) y were followed with annual measurements of height, weight, skinfolds, forced expiratory volume (FEV1), Shwachman score assessment and fasting blood sample. Our control group comprised 40 children (20 boys, 20 girls) aged 8.6-10.2 y at recruitment who were participating in a longitudinal study of growth and puberty. Results: SD scores for height, weight and BMI decreased with age; fat and fat-free mass was lower in both sexes compared to controls. Shwachman score decreased with age in both sexes and was related to fat-free mass in girls, and to both fat-free and fat mass in boys. FEV1 decreased with age only in boys and was related to fat-free mass. Leptin levels by age and by fat mass were higher in CF children compared to controls. Conclusion: Despite improvements in management, contemporary children with CF still gain less body fat and fat-free mass and are shorter than controls. The higher leptin levels we observed may be due to stimulatory effects of inflammatory cytokines and we postulate that they may contribute to the anorexia, poor weight gain and growth of these children.