Postprandial glycaemic and hormone responses to meals with different nutrient compositions and their heterogeneity were evaluated in 16 non-insulindependent diabetic patients and 5 healthy volunteers. Five kinds of nutrient stimulation-75 g glucose, a Japanese mixed meal (400 kcal, carbohydrate 60%, protein 14%, fat 26%), a high protein meal (300 kcal, C 26%, P 64%, F 10%), a high fat meal (300 kcal, C 23%, P 5%, F 72%) and 20 giv glucose-was given to each subject. On the average, in both normal and diabetic subjects, the increases in plasma glucose (PG) and insulin (IRI) were the largest with the oral glucose load and the smallest with the high protein meal. The ratio of increase in IRI and PG (ΣΔIRI/ΣΔPG) was the highest with the high protein meal and the lowest with the oral glucose load.ΣΔIRI with the high protein meal and the high fat meal were the same in normal and diabetic subjects. However, each of the 16 NIDDM patients and 5 normal volunteers exhibited a different pattern of response to the nutrient stimuli and no definite subgroup could be classified. There was no correlation between metabolic responses and family history of diabetes mellitus, duration of diabetes, body mass index and fasting plasma glucose.
The present results suggest the nearly intact capacity of insulin secretion in NIDDM in response to a high protein or high fat meal and the difficulty of subclassification in NIDDM according to the glycaemic and hormone responses to the different nutrient stimuli.