Physiological variations in blood glucose concentration affect oesophageal motility and sensation in normal subjects

Background/aims: a marked elevation in the blood glucose concentration (approximate to 15 mmol L-1) slows oesophageal peristalsis. Recent studies indicate that changes in blood glucose within the normal postprandial range affect gastric motility and emptying. The aim of this study was to investigate whether such alterations in blood glucose also affect oesophageal motility. Methods: in eight healthy subjects oesophageal motility and sensation to balloon distension were measured on two separate days while blood glucose concentrations were stabilized with an insulin-glucose clamp at 4 mmol L-1 and 8 mmol L-1. Results: peristaltic velocity in the proximal oesophagus and over the oesophagus as a whole was faster at a plasma glucose concentration of 8 mmol L-1 compared with those at 4 mmol L-1 (proximal 3.3 +/- 0.3 cm s(-1) vs 2.6 +/- 0.2 cm s(-1), P < 0.05, total 3.1 +/- 0.2 cm s(-1) vs 2.7 +/- 0.2 cm s(-1), P < 0.005) but there were no differences in wave amplitude or duration, or basal lower oesophageal sphincter pressure (LOSP). The threshold for initial perception of oesophageal distension was lower at a plasma glucose of 8 mmol L-1 (2.9 +/- 0.5 mL vs 4.9 +/- 1.0mL, P < 0.05). Conclusions: physiological variations in plasma glucose concentration influence oesophageal motility and sensation. These observations suggest that in order to minimize effects of varying plasma glucose levels on oesophageal motility, manometry should be performed under the same lasting or fed conditions when oesophageal motor function is evaluated.