Effects of body mass index on gastric motility in children with abdominal pain-predominant functional gastrointestinal disorders.

Abstract

INTRODUCTION: There is evidence that overweight children have a higher prevalence of functional gastrointestinal disorders (FGIDs) than normal-weight children. Objective of this study was to assess the effects of body mass index (BMI) on gastric motility abnormalities in children with abdominal pain-predominant FGIDs (AP-FGIDs). METHODS: Gastric motility parameters of 100 children with AP-FGIDs (61(61%) girls, mean age 8.0 years [SD 2.1years] and 50 healthy controls (30 (30%) boys, mean age 8.6 years [SD 1.9 years]) were assessed at the Gastroenterology Research Laboratory of Faculty of Medicine, University of Kelaniya, Sri Lanka, using a previously validated ultrasound method. AP-FGIDs were diagnosed using Rome III criteria. Fifty-four had functional abdominal pain, 23 had irritable bowel syndromes, 9 had functional dyspepsia, 8 had abdominal migraine and 6 had more than one AP-FGID. RESULTS: Patients with AP-FGIDs had significantly lower gastric emptying rate (44.9% vs. 59.5% in controls, p < 0.0001), frequency of antral contractions (8.29 vs. 9.44, p < 0.0001), amplitude of antral contraction (48.6% vs. 58.1%, p < 0.0001) and antral motility index (4.0 vs. 6.4, p = 0.001). Fasting antral size (FA) and antral area at 1minute (AA1) and antral area at 15 minutes (AA15) after ingestion of the liquid test meal were not significantly different. BMI of children with AP-FGIDs and controls were respectively 15.2 and 15.6 (p = 0.42). The correlations between BMI and AA1 (r = 0.29, p = 0.007), AA15 (r = 0.32, p = 0.003) and MI (r = 0.22, p = 0.038) in children with AP-FGIDs were significant. Patients with BMI <15Kg/m2 had a lower FA (1.5cm2 vs. 2.1cm2, p = 0.03), AA1 (8.9 cm2 vs. 10.7 cm2, p = 0.003) and AA15 (4.6 cm2 vs. 5.8 cm2, p = 0.01) than patients with BMI >15Kg/m2. CONCLUSIONS: BMI has an impact on certain gastric motility parameters in children with AP-FGIDs. However, it does not contribute to abnormalities seen in main gastric motility parameters such as gastric emptying.