Relationships Between Intravenous Glucose Loads, Insulin Responses and Glucose Disappearance Rate¹

Abstract

In order to evaluate the relation between insulin responses, glucose loads and glucose disappearance rate, normal subjects were given glucose doses from 0.5 to 40 g by rapid intravenous injection. A highly linear correlation was seen between dose and the rapidly attained peak plasma glucose level measured as either the mean of the 3-through 5-min (3-5') absolute (r=+.98) or 3-5' incremental (A) (r=+.98) glucose value, suggesting any of these parameters can be employed as an index of the glucose stimulus. Estimated from the 3-5' A plasma insulin levels, the early insulin response, which has been previously shown to be derived from a functional pool of stored insulin, increased in a nonlinear manner over the entire dosage range. In contrast, the total incremental insulin area increased linearly (r = +.85) with increasing glucose loads, suggesting that the total insulin output proportionally responds to the size of the glucose dose. Glucose tolerance measured as the glucose disappearance rate (KG) was also a nonlinear function of glucose dose and therefore was highly correlated (r = +.72) with the acute insulin response but less well with the total incremental insulin output. Furthermore, within the 20 g glucose dose, the KG was highly correlated with the acute insulin response (r= +.66) but not with total insulin output (r= +.04). These observations suggest that the storage pool of readily available insulin is small and finite and the magnitude of the response from this pool is an important determinant of intravenous glucose tolerance (KG). (J Clin Endocr 33: 409, 1971)

Between and within subject variation of the first phase insulin response to intravenous glucose

“…the total 0-10 min area under the curve (0-10' area; mU-1 -I. min 1), 2. the incremental 0-10 rain area above fasting concentrations [4], (A 0-10' area; mU.1-1.min ~) 3. the sum of the 1 and 3 min concentrations [1], (1'+3' insulin; mU/1) 4. the mean of the incremental 3 to 5 min values above fasting concentrations [5], (A 3-5' insulin; mU/1).…”

Glucose control of basal insulin secretion in diabetes

“…The normal B-cells are most responsive in the region of the overnight fasting glucose concentration [17]; if there were a decreased number of B-cells those remaining would have to function towards their maximal capacity [18]. This would result in a decreased capacity to respond to changes in plasma glucose, which would affect both the basal and stimulated insulin secretion.…”

Estimation of pancreatic IRI output rate and its relation to glucose tolerance in normal anaesthetized dogs

“…However , increased amounts of secreted IRI did not produce an increased action of insulin on BG level, glucose tolerance or glucose assimilation [10,40]. In man, a defective early phase IRI increase may indicate pre-diabetes [7,8]; and Lerner et al [25] showed some interaction between the early IRI increase and the glucose assimilation constants. Other authors found no correlation, or a contrary one, between such parameters in the peripheral blood [/, 30,39,40].…”