Postprandial hypotension occurs frequently in diabetes; the fall in blood pressure is greatest after ingestion of carbohydrate, particularly glucose and, in type 2 diabetes, is related to the rate of gastric emptying. The aim of this study was to determine whether slowing of gastric emptying by guar gum reduces the fall in blood pressure after oral glucose in patients with type 2 diabetes. Eleven type 2 patients managed by diet alone, age 61.9 ± 1.3 years, had measurements of gastric emptying, blood pressure, blood glucose, and serum insulin on two occasions after ingestion of 300 ml water containing 50 g glucose, with or without 9 g guar gum. The magnitude of the fall in blood pressure was less (P < 0.05)="" and="" gastric="" emptying="" slower="">P < 0.05)="" after="" guar.="" blood="" glucose="">P < 0.05)="" and="" serum="" insulin="">P < 0.01)="" concentrations="" were="" lower="" after="" guar.="" the="" magnitude="" of="" the="" fall="" in="" systolic="" blood="" pressure="" was="" related="" to="" gastric="" emptying="" of="" glucose="" at="" 30="" min="" on="" the="" control="" day="">r = 0.67, P < 0.05).="" we="" conclude="" that="" guar="" gum="" attenuates="" the="" fall="" in="" blood="" pressure="" after="" oral="" glucose="" in="" patients="" with="" type="" 2="" diabetes="" mellitus,="" presumably="" by="" slowing="" glucose="">