Effect of posture on glucose tolerance after gastric surgery.

Oral glucose tolerance after either partial gastrectomy or vagotomy and pyloroplasty for duodenal ulcer was markedly affected by posture. Peak blood glucoses and the degree of reactive hypoglycaemia were greater in the erect than in the supine position. This is probably due to positional changes in gastric emptying, and our findings support the view that after gastric surgery alteration in gastric emptying rate is the main factor responsible for the change in oral glucose tolerance.