Gastric meal accommodation studied by ultrasound in diabetes. Relation to vagal tone

Disturbed gastric meal accommodation may cause abdominal symptoms in patients with functional dyspepsia and diabetes mellitus who have poor vagal control of gastric motility. In the present study we aimed to explore the relation between gastric meal accommodation and vagal tone in diabetic patients with vagal neuropathy.

Twenty patients with diabetes (DM) (insulin-dependent type; 10 men and 10 women, aged 35.3 +/- 7.6 years) and 20 healthy controls (HC) (10 men and 10 women; aged 34.7 +/- 10.7 years) were studied. Proximal gastric size was assessed with ultrasound in a sagittal area and a frontal diameter. Distal gastric (antrum) size was assessed in a sagittal area. Vagal tone was assessed non-invasively by recording of respiratory sinus arrhythmia (RSA) in beats per minute.

Proximal sagittal area was significantly (P = 0.03) smaller in DM (18.5 +/- 5.5 cm2) than in HC (22.2 +/- 4.6 cm2). Proximal frontal diameter did not differ significantly (P = 0.60) between DM and HC (5.9 +/- 1.1 cm versus 5.7 +/- 0.8 cm). Antral area, too, did not differ significantly (P = 0.59) between DM and HC (14.5 +/- 4.1 cm2 versus 13.6 +/- 5.8 cm2). Proximal/distal meal distribution ratio, defined as proximal sagittal area/distal sagittal area, was significantly (P = 0.05) smaller in DM (6.8 +/- 0.6) than in HC (9.9 +/- 5.5). Vagal tone was significantly (P = 0.03) lower in DM (4.5 +/- 1.9 beats/min) than in HC (6.3 +/- 2.7 beats/min). Vagal tone tended (r = 0.33, P = 0.06) to correlate with proximal sagittal area in DM and HC pooled. Vagal tone correlated (r = 0.34, P = 0.05) with proximal frontal diameter in DM and HC pooled. A significant negative correlation (r = -0.39, P = 0.03) was observed between vagal tone and antral area in DM and HC pooled.

Patients with diabetes and low vagal tone have an impaired postprandial gastric meal distribution characterized by a small proximal stomach and a small proximal/distal meal distribution ratio.