Plasma Insulin and Glucose Responses of Healthy Subjects to Varying Glucose Loads During Three-hour Oral Glucose Tolerance Tests

Abstract

The plasma glucose and plasma immunoreactive insulin concentrations of twelve healthy, nonobese, adult subjects were compared following administration of oral glucose loads of 50, 75 and 100 gm., and 1.75 gm./kg. body weight. The time -of occurrence and the magnitude of maximal plasma glucose and insulin concentrations were unaffected by the 25 gm. increases in glucose load. The 50 gm. glucose load gave the smallest plasma glucose response during the three-hour tests and this response was statistically distinguishable from the plasma glucose responses due to the 100 gm. and 1.75 gm./kg. loads (p < 0.05). The plasma glucose responses due to the other loads did not differ from each other. Insulin responses, estimated by either summing all the plasma insulin values or by measuring the areas under the curves, increased approximately 35 per cent with the first 25 gm. glucose load increment (50 to 75 gm.) and 27 per cent with the second 25 gm. load increment (75 to 100 gm.) during the three-hour study. The differences in insulin responses between the 50 gm. load and the 100 gm. or 1.75 gm./kg. loads were highly significant (p < 0.01) while the difference between the insulin responses following the 75 gm. and 1.75 gm./kg. loads had lower significance (p < 0.05). Differences in insulin responses of the other loads were not significant. Increases in glucose loads above 120 gm. did not further increase the insulin response. This provides evidence that maximal insulin responses provoked by an oral glycemic stimulus alone in subjects are achieved with 100 gm. A wide range was observed in the plasma insulin concentrations among these healthy individuals for any given load, at any one time, and was probably due to biological variation.The fact that incremental changes in glucose load particularly influenced plasma glucose and insulin concentrations relatively late in the glucose tolerance tests, and that mean insulin peak concentrations did not differ, indicates that increasing glucose load results in a more prolonged insulinogenic stimulus rather than the acute release of greater quantities of insulin relatively abruptly. These studies provide evidence that the response associated with increasing glucose load is to some extent a function of the quantity of glucose ingested, and that the significant increases in insulin response commonly occur in association with concurrent alterations in plasma glucose concentrations. The results also indicate that the 50 gm. glucose load results in a different plasma glucose response than does the 100 gm. and 1.75 gm./kg. loads and consequently requires different criteria for interpretation of glucose tolerance testing.

Development of Cookie Test for the Simultaneous Determination of Glucose Intolerance, Hyperinsulinemia, Insulin Resistance and Postprandial Dyslipidemia

“…It is reported that various amounts of carbohydrate load (50-100 g, 30 g/square meter of body surface) does not influence the peak blood glucose levels at 1 h, but slightly lower 2 h glucose values were seen with a load of 50 g or 30 g square meter of body surface compared with 75 or 100 g loading [7,8]. Therefore, the time delay for the ingestion of the latter half of the cookie does not significantly influence the glucose level at peak and 2 hr.…”

Portal Diversion for the Treatment of Glycogen Storage Disease in Humans

“…Our first two patients had portacaval transposition; cnd-to-side portacaval shunt was used for the last 5. In Cases 3,4,6, and 7 parenteral hyperalimentation as described by Folkman et al,9 was used for 29, 13, 6, and 7 days. When performing the end-to-side portacaval shunts, all tributaries of the portal vein were ligated and divided from just above the pancreas to the division into the right and left portal branches.…”

“…Patients 3,4, and 5 had plasma somatotropin determinations after portal diversion. The same investigations were performed for an unoperated Sibling of patient 4 for whom portacaval shunt is planned.…”

Miglitol (Bay m 1099) has no extraintestinal effects on glucose control in healthy volunteers

“…To estimate the number of subjects to be included for valid interpretation of the results, available data on healthy volunteers were used [ 9]. Using a power of 95%, giving a two-sided significance level of 0.05, and the formula described by Fleiss [ 10], the required number of healthy volunteers to demonstrate relative to placebo a decrease of the area under the curve of the post-peak blood values of 10% after miglitol, as found by Joubert et al [ 3,4 ], was calculated to be 12.…”