Relation between pancreatic lipase activity and gastric emptying rate in children with cystic fibrosis

Abstract 

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 ¹³C-octanoic acid and ¹³C-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 ¹³C-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.

Abbreviations:  ¹³C-MTG, 1,3-distearyl, 2[carboxyl-13C]octanoyl glycerol [¹³C-MTG], CF, Cystic fibrosis, GEC, Gastric emptying coefficient, PERT, Pancreatic enzyme replacement therapy, t_1/2, Gastric half emptying time, t_lag, Lag phase