LESS VARIATION OF POSTPRANDIAL BLOOD-GLUCOSE AFTER STARCHY TEST MEALSTHAN ORAL GLUCOSE

To compare the variability of glycaemic responses after starchy test m eals versus oral glucose (GTT), 10 normal overnight fasted subjects to ok 75g glucose, 50g carbohydrate from white bread or 50g carbohydrate from a prototype diagnostic oat bar on separate days. Finger-prick blo od was taken before and 1/4, 1/2, 3/4, 1, 1 1/2 and 2h after starting to eat. Each test was repeated 3 times by each subject in random order . Coefficients of variation (CV=100xSD/mean) of blood glucose values f or repeated tests within subjects were compared by ANOVA. After GTT, 2 h blood glucose, 5.4+/-0.5 mmol/L, was significantly greater than afte r bread, 4.6+/-0.2, and oat bar, 4.4+/-0.2 (p<0.05). After GTT, 7 of t he 10 subjects had 2h blood glucose CV >7%, but after bread 7 of 10, a nd after oat bar 8 of 10 had CV <7%. The mean CV of 2h blood glucose a fter GTT, 12.9+/-2.8%, was 2-3 times greater than after bread, 5.2+/-0 .8%, or oat bar, 4.7+/-0.9% (p<0.01). The results suggest that starchy test meals may allow more precise assessment of carbohydrate toleranc e than GTT despite lower glycaemic responses. Further studies in a wid er range of subjects are required to confirm this.