LAUSR

Introduction Previous cross-sectional studies have reported lower ventilatory and aerobic function (peak oxygen uptake, VO2peak) during exercise in people with cystic fibrosis related diabetes (CFRD), compared to non-CFRD counterparts. Given that VO2peak is highly predictive of mortality, and the pancreas is one of the earliest affected organs in CF, there is a necessity to identify the interaction between exercise parameters and glycaemic status - particularly over time, which has implications for disease management in CFRD. Objectives To examine differences in ventilatory and exercise-based changes (including VO2peak) in people with CF, of differing glycaemic status. Methods Annual review data, including cardiopulmonary exercise testing and pulmonary function tests, were retrospectively analysed in n = 82 people with CF. Data was analysed in two ways: 1) three groups; normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and CFRD, and 2) a dichotomous division of NGT versus a combined IGT + CFRD group. Data was analysed at baseline (T0) and one-year follow up (T1). Analysis of variance, with Bonferroni-corrected post-hoc tests determined significant differences between variables at different time points. Results At baseline, absolute forced expiratory volume in one second (FEV1) and VO2peak were significantly reduced (p =0.01) in the CFRD (n = 19) group compared to NGT (n = 58). At T1, a reduced relative peak power (W.kg-1, p = 0.05), VO2peak (p = 0.03) and gas exchange threshold (p = 0.02) were observed from T0 in the combined group (n = 24) compared to the NGT group (n = 58). No change in VO2peak was identified over time, however, a significant decrease was discovered for FEV1 (%pred) in the NGT group between T0 and T1 (p = 0.02). Conclusions Patients with CFRD have a reduced aerobic and ventilatory function compared to non-CFRD counterparts. Whilst a decrease in lung function was observed longitudinally, no change in VO2peak was found, thus alluding to how aerobic and ventilatory functions provide different clinical organ and systemic outcomes in CF. Future research building upon these findings should assist with future management strategies to increase the longevity and quality of life of those with CFRD.