Glucose trajectories in cystic fibrosis and their association with pulmonary function

Abstract

Background: The prevalence of cystic fibrosis-related diabetes is increasing. This condition is potentially responsible for respiratory decline.

Methods: At inclusion, then yearly (over three years), 111 children and 117 adults with cystic fibrosis had oral glucose tolerance and insulin tests at one (G1) and 2h (G2). KmL analysis identified homogeneous G1 and G2 glucose trajectories. A linear mixed model quantified the relationships between trajectories and FEV1 changes.

Results: In children, there were three G1 and four G2 trajectories and FEV1 decrease was not significantly different between G1 or G2 trajectories. In adults, two G1 and four G2 trajectories were identified and FEV1 change was estimated at -0.85/year (95% CI: [-1.54; -0.17], p=0.01) whatever the G1 trajectory and found significantly faster in the high and increasing G2 trajectory (-2.1/year, [-3.9; -0.2], p=0.03).

Conclusions: In case of persistent G2 abnormality, physicians should be alert for clinical deterioration and intensify patient surveillance.

Keywords: Body mass index; Cystic fibrosis-related diabetes; Oral glucose tolerance test; Pulmonary function.