1,5-Anhydro-D-glucitol--a novel type of sugar in the human organism.

1,5-Anhydroglucitol is a six-carbon chain monosaccharide in C1-chair conformation with an oxygen ring in pyran position. The compound is a component of normal human blood serum. The concentration in serum fluctuates within a narrow range in a normal population. Very low serum concentrations are found in patients with diabetes mellitus. In insulin-dependent (type 1) diabetes with a long history of disease the concentration of 1,5-anhydroglucitol remains low in spite of improvement of glycaemic control by intensification of treatment, whereas in non-insulin dependent (type 2) diabetes the concentration gradually increases towards normal levels concomitantly with improvement in glycaemic control. The serum 1,5-anhydroglucitol concentration may be useful as an indicator of glycaemic control in patients with non-insulin dependent diabetes. Urinary excretion of 1,5-anhydroglucitol in normal subjects is very low inferring that the compound is efficiently reabsorbed by tubular cells. During glucosuria, induced by glucose tolerance test in human or streptozotocin administration in rats the 1,5-anhydroglucitol excretion is temporarily increased, which may be attributable to a competition between 1,5-anhydroglucitol and glucose for renal tubular transporters. Data so far obtained indicate that 1,5-anhydroglucitol may be either actively or passively transported through the cell membrane, depending on the cell type. Gas-liquid chromatography is the method of choice in the measurement of the low concentrations of 1,5-anhydroglucitol present in biological samples.