Hyperinsulinism

Hypoglycemia may occur when there is too much insulin in die bloodstream in relation to the available glucose (hyperinsulinism). Hypoglycemia may occur ... 

Nestorowicz, A., Wilson, B.A., Schoor, K. P., Inoue, H., Glaser, B., Landau, H., Stanley, C.A., Thornton, P.S., Clement, J. P., Bryan, J., Aguilar-Bryan, L. and Permutt, M.A. (1996) Mutations in the sulonylurea receptor gene are associated with familial hyperinsulinism in Ashkenazi Jews. Human Molecular Genetics, 5, 1813-1822. 

Insulin production takes place in the islet tissue of the pancreas, and the individual variation in the amount of this tissue is large. It is estimated that a substantial percentage of the pancreases in a population (78 per cent in one study) 13 have from 0.9 to 3.5 per cent of islet tissue. Those individuals having less than 0.9 per cent are likely to be diabetics, and those having more than 3.5 per cent are likely to be actual or potential sufferers from hyperinsulinism. 14... 

Severe hypoglycemia caused by hyperinsulinism may occur in cases of insulin overdose, when food intake is decreased or delayed, during periods of excessive exercise, or in patients with brittle diabetes. 

Severe hypoglycemia caused by hyperinsulinism may occur with insulin overdose, decrease or delay of food intake, or excessive exercise and in those with brittle diabetes. 

Glucagon has also been used to stimulate insulin and C-peptide secretion, to see whether the islets still produce insulin, as a stimulatory test during pheochromocytoma, hyperinsulinism, and Zollinger-Ellison syndrome, or as an additive in upper gastrointestinal X-ray investigations (0.5-1 mg). It has been used in myocardial infarction, although its inotropic effects may present a risk. It has also been used to treat overdoses with beta-blockers (3) and calcium channel blockers (4), although its efficacy in such cases has only been demonstrated in animals (5) and to treat overdose with tricyclic antidepressants (6,7). 

Diazoxide can cause hyperglycemia and diabetes mellitus and has been used to treat hyperinsulinism in infancy, although its use may be hazardous (329,330). 

Abu-Osba YK, Manasra KB, Mathew PM. Complications of diazoxide treatment in persistent neonatal hyperinsulinism. Arch Dis Child 1989 64(10) 1496-500. 

Luef G, Abraham I, Trinka E, Alge A, Windisch J, Daxenbichler G, Unterberger I, Seppi K, Lechleitner M, Kramer G, Bauer G. Hyperandrogenism, postprandial hyperinsulinism and the risk of PCOS in a cross sectional study of women with epilepsy treated with valproate. Epilepsy Res 2002 48(1-2) 91-102. 

Sulfonylurea receptor cloned, associated with hyperinsulin secretion maps to chromosome 1 lpl5.1 38... 

Glaser B, Chiu KC, Liu L, Anker R, Nestorowicz A, Cox NJ, Landau H, Kaiser N, Thornton PS, Stanley CA. Recombinant mapping of the familial hyperinsulinism gene to an 0.8CM region on chromosome llpl5.1 and demonstration of a founder effect in Ashkenazi Jews. Hum Mol Genet 1995 4(5) 879-886. 

Loss-of-function alleles of the gene encoding the a subunit of the ATP-gated K+ channel shown in Figure 23-29 lead to a condition known as congenital hyperinsulinism—persistently high levels of insulin in the blood. 

Oral diazoxide (Proglycem) increases serum glucose level by inhibiting insulin release from the beta cells and stimulating release of epinephrine (Adrenalin) from the adrenal medulla. Oral diazoxide is used to treat chronic hypoglycemia caused by hyperinsulinism resulting from islet cell cancer or hyperplasia. It is not for hypoglycemic reactions. 

Hereditary fructose intolerance Leucine hypersensitivity Endogenous hyperinsulinism Reye s syndrome Idiopathic... 

Although this disorder is not usually expressed in childhood, several affected preadolescents have been described. Clinical presentations in adult patients include eruptive xanthomas, lipemia retinalis, pancreatitis, and abnormal glucose tolerance with hyperinsulinism. Premature atherosclerotic complications are not as commonly seen as with FH. This heterogeneous syndrome appears to be inherited in an autosomal dominant mode, but its genetic basis is yet to be elucidated. 

B. Glaser, P. Kesavan, M. Heyman, et al. Familial hyperinsulinism caused by an activating glucokinase mutation. New England Journal of Medicine 338,226(1998). 

C. A. Stanley, Y. K. Lieu, B. Y. L. Hsu, et al. Hyperinsulinism and hyperammonemia in infants with regulatory mutations of the glutamate dehydrogenase gene. New England Journal of Medicine 338, 1352 (1998). 

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