No gender differences in growth patterns in a cohort of children with cystic fibrosis born between 1986 and 1995.

BACKGROUND & AIMS: A higher mortality rate at young ages has been reported in cystic fibrosis (CF) girls compared to boys. The reasons of this gap remain unclear but may be related to a different evolution of the disease, in terms of growth and lung function throughout childhood and adolescence. This study aimed at investigating gender differences in growth patterns in a cohort of children with CF through a longitudinal study, and as secondary objectives, to evaluate gender differences in forced expiratory volume in one second (FEV1 ) trend and transplant-free survival.

METHODS: We performed an historical cohort study of 203 CF patients born between 1986 and 1995. Weight and height were recorded from the time of CF diagnosis to the age of 18 years. Generalized estimated equations were used to evaluate the effect of gender on changes in z-score of BMI-for-age and z-score of height-for-age and FEV1 . Transplant-free survival to age 18 was computed by the Kaplan-Meier estimator.

RESULTS: Girls did not show a worse growth pattern as compared to boys. The odds of being underweight [Odds Ratio (OR) for girls: 0.85, 95% CI: 0.51; 1.39] or stunted [OR for girls: 0.79, 95% CI: 0.42; 1.49] were not significantly different between genders. FEV1 trend was also similar in boys and girls, as well as the probability of surviving to age 18 without receiving lung transplantation (boys: 0.88, 95% CI: 0.82-0.95, girls: 0.92, 0.87-0.98, P = 0.26).

CONCLUSIONS: In a cohort of children with CF born between 1986 and 1995, no gender differences in growth patterns were observed. This finding suggests that CF girls and boys have benefited equally from the advances in treatments that have occurred over the last three decades.