Objective: To study day-to-day variation of postprandial blood glucose and insulin increments in non-insulin-dependent diabetes mellitus (NIDDM) subjects and to analyze intra- and interperson variance of response.
Research design and methods: Ten NIDDM subjects attending the outpatient clinic at Aarhus Kommunehospital were studied. The subjects ate three meals of 90 g of white bread, with 7 days between tests.
Results: Mean +/- SD areas under the blood glucose response curve (above basal) over a 3-h period were 557 +/- 60, 569 +/- 74, and 565 +/- 67 mM x 180 min (NS), and areas under the insulin-response curve were 3350 +/- 448, 2815 +/- 359 and 3551 +/- 679 mU/L x 180 min (NS) on each of the three occasions. The 95% confidence intervals of blood glucose and insulin areas for the test meal repeated three times were 564 +/- 120 mM x 180 min and 3240 +/- 1645 mU/L x 180 min, respectively. Intra- and interperson components of variance were 25 vs. 75% (glucose) and 78 vs. 22% (insulin) of the total variance. The intraperson components of variance included all sources of variation other than between-person variation. There was no significant correlation between blood glucose and insulin response areas.
Conclusions: A valid estimate of the glycemic response in a single patient is obtained after a single meal. Because of the large between-person variation, paired data should preferably be used when comparing glycemic responses to different foods.