Glucose tolerance affects pubertal growth and final height of children with cystic fibrosis

There are few data about the impact of cystic fibrosis-related diabetes (CFRD) on growth. We analyzed 17 children with cystic fibrosis (CF) presenting with newly diagnosed CFRD during puberty, in comparison with a matched control group of 52 CF children with normal glucose tolerance (NGT). Anthropometric evaluation showed that body mass index at CFRD diagnosis was significantly reduced in children with CFRD, in comparison with children with NGT (CFRD: -0.48 ± 1.08 vs. NGT: 0.2 ± 0.99; P=0.01), and the same difference remained evident at the end of follow up (CFRD: -0.49 ± 0.95 vs. NGT: 0.13 ± 0.89; P=0.04). Height standard deviation score (SDS) at baseline was slightly but not significantly lower in CFRD children (CFRD: -0.71 ± 0.83 vs. NGT: -0.25 ± 1.08; P=0.08), while final height SDS was significantly reduced (CFRD: -1.61 ± 1.12 vs. NGT: -0.61 ± 1.15; P=0.003). Mean final height SDS of the whole group was lower than mean target height SDS (final height SDS: -0.86 ± 1.2 vs. target height SDS: -0.3 ± 0.85; P<0.001). Target adjusted final height was lower in CFRD children, although the difference between CFRD and NGT children did not reach statistical significance (CFRD: -0.8 ± 1.03 vs. NGT: -0.47 ± 0.9; P=0.09). Pubertal growth and final height are negatively affected by CFRD. Intensive insulin treatment does not appear to be effective in normalizing growth, even when treatment is started early in the course of the disease, before the onset of clinical deterioration.