Impact of glucagon-like-peptide-1 receptor agonist therapy on pulmonary function in people with cystic fibrosis who achieve normal body mass index.

Background: Glucagon-like-peptide-1 receptor agonists (GLP-1 RA) and glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 receptor agonists (GIP/GLP-1 RA) are being explored for use in people with CF (pwCF) and CF-related diabetes. In pwCF who are overweight or obese, GLP-1 RA and GIP/GLP-1 RA may offer additional benefits beyond glycemic control, including potential benefits in lung function. However, there is a paucity of evidence regarding the impact of these medications on pulmonary function in pwCF and whether the associated weight loss adversely affects lung function.

Methods: This study is the first to describe the impact of GLP-1 RA and GIP/GLP-1 RA on lung function in pwCF who experienced weight loss and had a normal-range body mass index (BMI) of 18.5-24.9 kg/m². Our cohort consists of 13 pwCF (12 females, 1 male; aged 23-46 years) treated with GLP-1 RA or GIP/GLP-1 RA for a median duration of 16 months (range 3-50 months).

Results: Subjects experienced 11.1 kg median weight loss (-15.5 % median weight reduction); median BMI reduced from 26.2 kg/m² to 21.7 kg/m². Eleven of thirteen subjects had an increase in FEV1 (median, 10.8 %) and all subjects had an increase in FVC (median, 10.6 %). There was no difference in median number of pulmonary exacerbations between groups.

Conclusions: Future multi-center studies are needed to investigate the efficacy and tolerability of GLP-1 RA therapy in pwCF. If these agents are shown to be safe and effective in pwCF with normal-range BMI, then current BMI targets in pwCF may need to be revisited.