Longitudinal changes in insulin sensitivity, insulin secretion, beta cell function and glucose effectiveness during development of non-diabetic hyperglycemia in a Japanese population

Insulin sensitivity and insulin secretion are mutually related such that insulin resistance is compensated by increased insulin secretion. A correct judgement of insulin secretion therefore requires validation in relation to the insulin sensitivity in the same subject. Mathematical analyses of the relationship between insulin sensitivity and insulin secretion has revealed a hyperbolic function, such that the product of the two variables is constant. This product is usually called the disposition index. Several techniques may be used for its estimation such as data derived from the frequently sampled i.v. glucose tolerance test, the oral glucose tolerance test or the glucose-dependent arginine stimulation test or the euglycemic hyperinsulinemic clamp technique in combination with a test on insulin secretion. Using these techniques the compensatory increase in beta cell function in insulin resistance has been verified in obesity, in pregnancy and after glucocorticoid administration as has the defective beta cell function as the underlying cause of impaired glucose tolerance and type 2 diabetes. Similarly, combined analysis of insulin sensitivity and insulin secretion has shown a down-regulation of beta cell function in increased insulin sensitivity accompanying weight reduction in obesity and following exercise. Acknowledging this inverse relationship between insulin secretion and insulin sensitivity therefore requires estimation of both variables for correct assessment in any individual.

Download Full-text

Ethnic differences in beta cell function occur independently of insulin sensitivity and pancreatic fat in black and white men

BMJ Open Diabetes Research & Care ◽

10.1136/bmjdrc-2020-002034 ◽

2021 ◽

Vol 9 (1) ◽

pp. e002034

Author(s):

Meera Ladwa ◽

Oluwatoyosi Bello ◽

Olah Hakim ◽

Fariba Shojaee-Moradie ◽

Maria Linda Boselli ◽

...

Keyword(s):

Insulin Secretion ◽

Insulin Sensitivity ◽

Beta Cell ◽

Ethnic Differences ◽

Beta Cell Function ◽

Cell Function ◽

White Men ◽

Black And White ◽

Pancreatic Fat ◽

Postprandial Insulin

IntroductionIt is increasingly recognized that type 2 diabetes (T2D) is a heterogenous disease with ethnic variations. Differences in insulin secretion, insulin resistance and ectopic fat are thought to contribute to these variations. Therefore, we aimed to compare postprandial insulin secretion and the relationships between insulin secretion, insulin sensitivity and pancreatic fat in men of black West African (BA) and white European (WE) ancestry.Research design and methodsA cross-sectional, observational study in which 23 WE and 23 BA men with normal glucose tolerance, matched for body mass index, underwent a mixed meal tolerance test with C peptide modeling to measure beta cell insulin secretion, an MRI to quantify intrapancreatic lipid (IPL), and a hyperinsulinemic-euglycemic clamp to measure whole-body insulin sensitivity.ResultsPostprandial insulin secretion was lower in BA versus WE men following adjustment for insulin sensitivity (estimated marginal means, BA vs WE: 40.5 (95% CI 31.8 to 49.2) × 103 vs 56.4 (95% CI 48.9 to 63.8) × 103 pmol/m2 body surface area × 180 min, p=0.008). There was a significantly different relationship by ethnicity between IPL and insulin secretion, with a stronger relationship in WE than in BA (r=0.59 vs r=0.39, interaction p=0.036); however, IPL was not a predictor of insulin secretion in either ethnic group following adjustment for insulin sensitivity.ConclusionsEthnicity is an independent determinant of beta cell function in black and white men. In response to a meal, healthy BA men exhibit lower insulin secretion compared with their WE counterparts for their given insulin sensitivity. Ethnic differences in beta cell function may contribute to the greater risk of T2D in populations of African ancestry.

Download Full-text

Treatment failures: A common problem in the management of patients with type II diabetes

Acta Endocrinologica ◽

10.1530/acta.0.104s131 ◽

1983 ◽

Vol 104 (4_Suppl) ◽

pp. S131-S135

Author(s):

Leif Groop ◽

Risto Pelkonen

Keyword(s):

Insulin Secretion ◽

Insulin Sensitivity ◽

Beta Cell ◽

Special Interest ◽

Type Ii Diabetes ◽

Beta Cell Function ◽

Cell Function ◽

Type Ii ◽

Secondary Failure ◽

Secondary Drug Failure

ABSTRACT. Secondary failure is a common problem in the treatment of patients with type II diabetes. The underlying mechanisms are reviewed, and special interest is focused on the assessment of insulin secretion and insulin sensitivity. Impaired beta-cell function seems to be the major cause of secondary drug failure in patients with normal weight, whereas insulin resistance is of greater importance in obese patients. The importance of Cpeptide determinations to detect patients needing insulin is emphasized. The concept of progressive deterioration of beta-cell function with time in type II diabetes is challenged. Different treatment modalities for the management of patients with secondary drug failure are discussed and special interest is focused on the combination of insulin and sulfonylureas in the management of secondary failure patients with slightly impaired insulin secretion. Key words: secondary drug failure, type II diabetes, Cpeptide, insulin sensitivity, oral antidiabetic drugs, insulin therapy.

Download Full-text