Insulin secretion and impaired glucose tolerance

One-Time Injection of Parathyrin Increases Glucose Tolerance

“…In our view calcitonin decreasing Ca 2+ entry to ß-cells provokes the decreasing of its sensitivity to glucose and by this way decreases the number of functioning ß-cells as a result there are insulin resistance and glucose intolerance. It should be noted that the decreasing sensitivity to glucose of secret mechanisms and the decrease of number of functional ß-cells are found in the patients with 2 type diabetes mellitus [23,24]. A. Mari [25] considers that the decreasing of ß-cells sensitivity to glucose is the dominate defect in glucose intolerance.…”

Insulin secretion and impaired glucose tolerance. Reply to Jenkins AB, Campbell LV [letter]

“…It is the existence of a physiological inverse relationship between beta cell function (β) and insulin sensitivity (S i ) that makes glucose (G) relatively constant, as G is determined by β and S i (assuming that glucose appearance, R in in Eq. 1 of Jenkins and Campbell [1], is of minor importance). If, conversely, β and S i were unrelated, G would not be equally constant, but obviously the lack of the β-S i relationship would be the primary fact and not a consequence of a relationship masked by large variations in G.…”

“…the nature and physiological meaning of these relationships. They say that the disposition index 'theory was originally developed to explain the hyperbolic relationship between insulin secretion and insulin sensitivity, which within our model is an intrinsic property resulting from the underlying physiology requiring no additional mechanistic explanation' [1]. It seems to us that this view ignores the cause-effect relationship.…”

“…To the Editor: Drs Jenkins and Campbell recall a basic equation of glucose homeostasis (equation 1 in Jenkins and Campbell [1]) that is indeed useful for understanding the interrelationships between beta cell function, insulin sensitivity and glucose tolerance. This equation illustrates well their critique of the disposition index, on which we have also expressed some reservations [2,3].…”

Does exercise have a role in the management of gestational diabetes mellitus?

“…12,14 However, it is now clear that the result of this correction (the so-called Disposition Index) is no more than an alternative way of expressing the level of glycaemia, and its use has the effect of obscuring the crucial independent role of impaired insulin secretion in the pathogenesis of GDM and type 2 diabetes. 11,15,16 So far there is little evidence for beneficial effects on insulin secretion in any of the existing diabetes therapies, and some evidence that some drugs exacerbate its decline. 17 GDM differs from type 2 diabetes in its rapid onset and usual reversal, postpartum, consistent with a triggering role of the metabolic and hormonal stresses associated with pregnancy.…”