Objective: To determine whether abnormal gastric emptying is responsible for the inability of pancreatic enzyme replacement therapy (PERT) to normalize fat digestion in patients with cystic fibrosis (CF) who are pancreatic-insufficient. Study design Gastric emptying of a solid meal and pancreatic lipase function were assessed in 10 children with CF and 12 healthy control subjects with noninvasive breath tests using (13)C-octanoic acid and (13)C-mixed triglyceride, respectively. Lipase function was assessed in the subjects with CF with and without PERT.
Results: Without PERT, the lipase activity for the patients was less than that for the control subjects (P<.001); however, with PERT, 40% of the patients had a normalized lipase function. There were no differences between the mean gastric emptying rates of the patients with CF and the control subjects (P>.05), but there was a negative correlation between gastric half emptying time and percentage improvement in (13)C-mixed triglyceride results of the patients with CF with pancreatic enzymes compared with placebo (P<.05), with patients with slow gastric emptying having less improvement with PERT.
Conclusions: The success of PERT in improving pancreatic lipase activity is reduced in patients with slow gastric emptying, which could explain the variations in improvement of fat digestion with enzyme supplementation.