Biomaterial Database

[The effect of age on glucose tolerance and B cell secretion]. 1997

K Dembe, and W Karnafel, and P Pacuła

Katedra i Klinika Gastroenterologii i Chorób Przemiany Materii AM w Warszawie.

The aim of the study was to evaluate glucose tolerance, B cell secretion and hepatic clearance of insulin during the process of aging. 100 subjects of both sexes, in age range of 17 to 92 years and with BMI < 27 kg/m2 were studied. All subjects were divided in 4 groups according to age: 18 patients were in age from 17 to 59 years (group I--mean 46 +/- 12 (SD) years, 23 patients in age from 60 to 69 years (group II--mean 64 +/- 3 years), 33 patients in age from 70 to 79 years (group III--mean 75 +/- 3 years), 26 patients in age from 80 to 92 years (group IV--mean 84 +/- 4 years). In all participants oral glucose tolerance test (75 g) and the i.v. glucagon test (1 mg) were carried out and blood glucose, serum insulin (IRI) and C-peptide (CP) were measured. Hepatic clearance of insulin was calculated from the serum CP/IRI ratio. With advanced age the increase in fasting glycaemia (group I 4.25 +/- 0.6, group IV 4.7 +/- 0.5 mM, p = 0.02) and after applied stimuli, and a decrease in fasting (group I 0.6 +/- 0.2, group IV 0.35 +/- 0.13 nM, p < 0.05) and stimulated serum CP with no differences in serum IRI concentrations between groups was observed. Consequently the serum CP/IRI ratio decreased from 10 +/- 3.8 in group I to 5.4 +/- 1.7 in group IV (p < 0.05) indicating reduced insulin clearance in liver, probably as a compensatory adaptation to the deterioration of B cell secretory activity.

UI	MeSH Term	Description	Entries
D007328	Insulin	A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).	Iletin,Insulin A Chain,Insulin B Chain,Insulin, Regular,Novolin,Sodium Insulin,Soluble Insulin,Chain, Insulin B,Insulin, Sodium,Insulin, Soluble,Regular Insulin
D007515	Islets of Langerhans	Irregular microscopic structures consisting of cords of endocrine cells that are scattered throughout the PANCREAS among the exocrine acini. Each islet is surrounded by connective tissue fibers and penetrated by a network of capillaries. There are four major cell types. The most abundant beta cells (50-80%) secrete INSULIN. Alpha cells (5-20%) secrete GLUCAGON. PP cells (10-35%) secrete PANCREATIC POLYPEPTIDE. Delta cells (~5%) secrete SOMATOSTATIN.	Islands of Langerhans,Islet Cells,Nesidioblasts,Pancreas, Endocrine,Pancreatic Islets,Cell, Islet,Cells, Islet,Endocrine Pancreas,Islet Cell,Islet, Pancreatic,Islets, Pancreatic,Langerhans Islands,Langerhans Islets,Nesidioblast,Pancreatic Islet
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D001786	Blood Glucose	Glucose in blood.	Blood Sugar,Glucose, Blood,Sugar, Blood
D002096	C-Peptide	The middle segment of proinsulin that is between the N-terminal B-chain and the C-terminal A-chain. It is a pancreatic peptide of about 31 residues, depending on the species. Upon proteolytic cleavage of proinsulin, equimolar INSULIN and C-peptide are released. C-peptide immunoassay has been used to assess pancreatic beta cell function in diabetic patients with circulating insulin antibodies or exogenous insulin. Half-life of C-peptide is 30 min, almost 8 times that of insulin.	Proinsulin C-Peptide,C-Peptide, Proinsulin,Connecting Peptide,C Peptide,C Peptide, Proinsulin,Proinsulin C Peptide
D005260	Female		Females
D005951	Glucose Tolerance Test	A test to determine the ability of an individual to maintain HOMEOSTASIS of BLOOD GLUCOSE. It includes measuring blood glucose levels in a fasting state, and at prescribed intervals before and after oral glucose intake (75 or 100 g) or intravenous infusion (0.5 g/kg).	Intravenous Glucose Tolerance,Intravenous Glucose Tolerance Test,OGTT,Oral Glucose Tolerance,Oral Glucose Tolerance Test,Glucose Tolerance Tests,Glucose Tolerance, Oral
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man