Gastric motility following ingestion of a solid meal in a cohort of adult asthmatics

Abstract

Background/aims: Asthmatics have abnormal esophageal motility and increased prevalence of gastroesophageal reflux disease (GERD). The contribution of gastric motility is less studied. We studied gastric myoelectrical activity, gastric emptying (GE) and their association with GERD symptoms and vagal function in adult asthmatics.

Methods: Thirty mild, stable asthmatics and 30 healthy controls underwent real-time ultrasonography and 1 hour pre- and post-prandial cutaneous electrogastrography, following a test meal (480 kcal, 60% carbohydrate, 20% protein, 20% fat and 200 mL water). The percentage of normal slow waves and arrhythmias, dominant frequency and power, frequency of antral contractions, gastric emptying rate (GER) and antral motility index (MI) was calculated. Twenty-seven asthmatics underwent gastroscopy and in all subjects GERD symptoms were assessed by a validated questionnaire. Vagal function parameters were correlated with gastric motility parameters.

Results: The asthmatics (37% male; 34.8 ± 8.4 years) and controls (50% male; 30.9 ± 7.7 years) were comparable. None had endoscopic gastric pathological changes. Twenty asthmatics described GERD symptoms. Twenty-two (73.3%) asthmatics showed a hypervagal response. Compared to controls, asthmatics had delayed GER and lower MI, lower percentage of normal gastric slow waves, more gastric dysrythmias and failed to increase the post-prandial dominant power. There was no correlation of GE and cutaneous electrogastrography parameters with presence of GERD symptoms or with vagal function.

Conclusions: Asthmatics showed abnormal gastric myoelectrical activity, delayed GE and antral hypomotility in response to a solid meal compared to controls. There was no association with vagal function or GERD symptom status.

Keywords: Asthma; Gastric emptying; Gastroesophageal reflux.

Figure 1

Measurement of gastric emptying and motility using real-time ultrasonography. (A) A scan showing the plane used to obtain the cross-sectional antral areas. (B) A scan showing the antral area at 5 min after ingestion of the test meal. (C) A scan showing the antral area at 210 min after ingestion of the test meal. L, liver; PA, pyloric antrum; SMA, superior mesenteric artery; AO, aorta.

Figure 2

Gastric residual ratios after ingestion of the solid meal in asthmatics and controls. ^*P < 0.01 compared with controls (Mann-Whitney U test).

Figure 3

Motility index after ingestion of the solid meal in asthmatics and controls. ^*P < 0.05 compared to controls. ^**P < 0.01 compared to controls (Mann-Whitney U test).