VARIATION OF POSTPRANDIAL PLASMA-GLUCOSE, PALATABILITY, AND SYMPTOMS ASSOCIATED WITH A STANDARDIZED MIXED TEST MEAL VERSUS 75 G ORAL GLUCOSE

OBJECTIVE- To compare within-subject variability of plasma glucose mea sured 2 h after a glucose tolerance test (GTT) with that of plasma glu cose measured 2 h after administration of a standardized test meal (di abetes screening product [DSP], Ceapro, Edmonton, Alberta, Canada) and to determine the relationship between the mio sets of plasma glucose measurements. RESEARCH DESIGN AND METHODS- Plasma glucose and insulin responses of 36 overnight-fasted subjects (10 lean normal, 9 obese nor mal, 9 with impaired glucose tolerance [IGT], and 8 with mild diabetes ) were studied on eight different mornings after they consumed 75 g or al glucose or 50 g carbohydrate from the DSP. Each test meal was repea ted four times by each subject. Within-subject coefficients of variati on (CVs) (CV = 100 X SD/mean) of plasma glucose concentrations 2 h aft er administration of the GTT and DSP were compared by repeated measure s ANOVA and linear regression analysis. RESULTS- Mean plasma glucose 2 h after administration of the DSP (D) was linearly related to that 2 h after the GTT (G): G = 1.5 x D - 1.6 (r = 0.97. P < 0.0001). The CV of 2-h plasma glucose was significantly lower after administration of the DSP 10.5 +/- 1.0%, than after the GTT, 12.7 +/- 1.18% (P = 0.025). The effect of test meal on CV differed in different groups of subject s (P = 0.018), with the largest difference found in IGT subjects, in w hom the CV after DSP administration was 47% less than after the GTT (P = 0.0005). The DSP was significantly more palatable and produced fewe r adverse symptoms than the GTT. CONCLUSIONS- Plasma glucose concentra tions measured 2 h after DSP administration are closely related to tho se measured 2 h after the GTT but are more consistent than the 2-h pos t-GTT concentrations within the critical IGT range. This finding sugge sts that measurement of plasma glucose 2 h after administration of the DSP may allow more precise discrimination among normal glucose levels , IGT, and diabetes than measurement of plasma glucose 2 h after the G TT.