Preliminary report of the 13C-mixed triglyceride breath test to assess timing of pancreatic enzyme replacement therapy in children with cystic fibrosis

Background Despite guidelines suggesting pancreatic enzyme replacement therapy (PERT) should be taken before or during a meal, it is currently unknown whether this has benefits over administration after a meal in individuals with cystic fibrosis (CF). Methods 18 children with pancreatic insufficient CF were randomised to two ¹³C-mixed triglyceride (¹³C-MTG) breath tests to assess lipase activity with PERT administered 10 min before and 10 min after a meal. Results were expressed as percentage cumulative dose recovered (PCDR) of ¹³CO₂ and were compared with established values in healthy subjects. Gastric half emptying time (T½) was also assessed by a ¹³C-octanoate breath test. Results There was no difference in mean PCDR of ¹³CO₂ between taking PERT before versus after the meal (p = 0.68). Eleven subjects had a greater PCDR when PERT was taken before and 7 when PERT was taken after the meal. 6/8 subjects (75%) with a lower than normal PCDR at one time point normalised PCDR when PERT timing was changed. When PERT was taken after the meal, PCDR was higher in normal vs. fast T½ (p = 0.04). Conclusions Changing PERT timing can result in normalised lipase activity. Gastric emptying rate may influence optimal timing of PERT. Clinical Trial Registration Number — This study was undertaken prior to the registration process being a commonly required practice.