Low-dose guar improves diabetic control.

Twenty diabetic outpatients (12 non-insulin-treated and 8 insulin-treated) were given guar granulate in a dose of 10 g daily for two months in order to study the effect on glycaemic control and lipid levels. Mean glycosylated haemoglobin levels (HbA1c%) fell from 11.1 +/- 2.0% pre-guar to 10.5 +/- 2.2% (P less than 0.001) after one month on guar and to 10.1 +/- 2.3% (P less than 0.0001) after two months. Following discontinuation of guar, HbA1c% rose to 11.1 +/- 2.5% (P less than 0.002). However, there were no significant changes in fasting blood glucose, 1 h postprandial blood glucose following a test meal, 24 h urinary glucose excretion or in lipid levels. Gastrointestinal side effects occurred in 4 patients during treatment with guar. Four patients reduced their dose of insulin and 2 patients reduced their dose of sulphonylurea therapy during this time because of symptoms suggestive of hypoglycaemia. We suggest that the low dose of guar used in this study may help improve glycaemic control in diabetic patients and that this may be achieved with a low incidence of gastrointestinal side effects.