Dynamics of insulin secretion in obesity and diabetes

Abstract

Insulin resistance and compensatory hyperinsulinemia are commonly present in obesity. The biochemical mechanisms responsible for the maintenance of basal hypersecretion of insulin are reviewed in this article. Under basal, fasting and fed conditions the hyperinsulinemia of obesity largely depends on increased insulin secretion, without any alteration of the temporal secretion. This suggests that the functioning beta cell mass is enhanced, but normal regulatory mechanisms are maintained. A number of alterations in b-cell function are present in conditions of impaired glucose tolerance which precede the onset of overt diabetes.

Sirtuin 3 regulates mouse pancreatic beta cell function and is suppressed in pancreatic islets isolated from human type 2 diabetic patients

“…3g, h). Since insulin resistance would normally be expected to result in islet compensation and increased insulin secretion [1][2][3][4], these results, taken together, suggest partially impaired islet function. Interestingly, in this model, islet Sirt3 mRNA expression was mildly but non-significantly increased in HFD animals (Fig.…”

“…This leads to hyperglycaemia, glucose intolerance and onset of type 2 diabetes [1][2][3][4]. Hence, an understanding of the mechanisms responsible for reduced beta cell function and mass is essential for the development of strategies to prevent the onset of overt type 2 diabetes.…”

“…Type 2 diabetes develops when pancreatic beta cells lose the ability, through loss of function and mass, to compensate for insulin resistance [1][2][3][4]. This leads to hyperglycaemia, glucose intolerance and onset of type 2 diabetes [1][2][3][4].…”

Longitudinal variation of circulating irisin after an energy restriction‐induced weight loss and following weight regain in obese men and women

“…However, the direct association observed between irisin and insulin together with the inverse correlation between irisin and ghrelin, a circulating orexigenic hormone with opposite pattern that of insulin, could suggest that irisin circulating levels in obesity may represent a compensatory response to the hyperglycemia but acquiring a reduced irisin sensitivity, such as insulin (Polonsky, 2000) and leptin (Montez et al, 2005) resistance, which is commonly present in obesity. Fig.…”

High Dose Flaxseed Oil Supplementation May Affect Fasting Blood Serum Glucose Management in Human Type 2 Diabetics

“…The response of the pancreas to insulin insensitivity is to increase the blood serum concentration of insulin [9][10][11] However this rise in insulin levels seldom compensates completely for the insulin insensitivity and consequently blood serum glucose concentrations rise [12][13][14][15] . A rise in blood serum glucose concentrations rise causes an increase in glycosylated HbA1c as there is an increased ratio of glucose to hemoglobin concentration thus allowing the glycosylation process to occur at a higher rate [16][17][18][19] .…”