Anomeric specificity of glucose-induced insulin release in normal and diabetic subjects

The alpha- and beta-anomer of D-glucose (3.5 or 5.0 g) were injected intravenously in 15 normal subjects and 13 non-insulin-dependent diabetic patients with mild fasting hyperglycaemia. In the normal subjects, alpha-D-glucose increased more than beta-D-glucose the plasma insulin concentration. Thus, 2 min after injection of D-glucose, the concentration of insulin relative to paired basal value was 61% higher in response to alpha- than beta-D-glucose (p less than 0.05). In 8 diabetic subjects, the secretory response to D-glucose was insufficient to allow characterization of its anomeric specificity. In the remaining 5 diabetic patients, a preferential response to alpha-D-glucose was observed in 3 cases, but not so in the other 2 cases. These results indicate that glucose-stimulated insulin release is alpha-stereospecific in normal subjects. A possible perturbation of such a stereospecificity in certain diabetic subjects warrants more extensive investigation on its precise incidence and etiopathogenic significance.