Endocrine Abstracts

Aim: This study aimed to evaluate changes in growth, body composition and bone health in children and adolescents with CF following treatment with Kaftrio.

Methods: Retrospective study including children with CF who had dual energy X-ray absorptiometry (DXA) prior to starting Kaftrio and after one year of therapy as part of their routine care. DXA lean mass index (LMI: defined as DXA lean mass/height²) and fat mass index (FMI: defined as DXA fat mass/height²) were converted to standard deviation scores (SDS) based on LMI and FMI centiles from a cohort of healthy school children from Glasgow. DXA total body less head bone mineral content (TBLH-BMC) and DXA lumbar spine bone mineral apparent density (LS-BMAD) were converted to a SDS based on published UK normative data. TBLH-BMC was adjusted for bone area, age and sex. A control group (age and sex matched) of children with CF, not receiving CFTR modulator therapy, were used at baseline and follow-up.

Results: 23 children were included in the study group and 24 in the control group with mean age of 10.4 and 10.7 years respectively. At baseline, mean LMI SDS was significantly lower than a healthy population for both the study group (-1.39, P < 0.01) and the control group (-1.48, P < 0.01). Mean FMI SDS was significantly higher than a healthy population; study group (1.68, P < 0.001) and control group (1.22, P = 0.002). Mean TBLH-BMC SDS, was lower than a healthy population for the study group (-0.93, P < 0.001) and the controls (-0.87, P < 0.001). Mean LS-BMAD SDS showed no significant differences to a healthy population in either study or control groups. Treatment with Kaftrio did not result in significant changes in SDS for height, BMI, FMI, LS-BMAD, or TBLH-BMC compared to the control group at one year follow-up. A significant decrease in LMI SDS was found in the study group (-0.64) compared to control group (0.20) (P = 0.005).

Conclusion: Children with CF have abnormalities in bone health and body composition which did not improve following one year treatment with a CFTR modulator. Further research with larger sample sizes and longer follow-up durations is warranted to understand the clinical impact of Kaftrio.