News di Alcologia

Diabete in agguato col binge drinking
di Roberta Lunghini

Il binge drinking alza il livello di resistenza all'insulina, con il conseguente rischio diabete. In particolare quello di tipo II. Secondo uno studio pubblicato sulla rivista Science Translational Medicine, infatti, il consumo smodato di bevande alcoliche in un intervallo di tempo piuttosto breve provoca un'infiammazione tissutale che distrugge la comunicazione ipotalamica coi recettori per l'insulina nel cervello. Un risultato al quale i ricercatori sono arrivati somministrando alcol (3 g/kg) a topi di laboratorio per tre giorni consecutivi. Si è visto, così, che questi animali si sono dimostrati insulino-resistenti fino a 54 ore dopo l'ultima dose di etanolo.

Abstract dell'articolo originale

Binge Drinking Induces Whole-Body Insulin Resistance by Impairing Hypothalamic Insulin Action
Claudia Lindtner, Thomas Scherer, Elizabeth Zielinski, Nika Filatova, Martin Fasshauer, Nicholas K. Tonks, Michelle Puchowicz and Christoph Buettner

Individuals with a history of binge drinking have an increased risk of developing the metabolic syndrome and type 2 diabetes. Whether binge drinking impairs glucose homeostasis and insulin action is unknown. To test this, we treated Sprague-Dawley rats daily with alcohol (3 g/kg) for three consecutive days to simulate human binge drinking and found that these rats developed and exhibited insulin resistance even after blood alcohol concentrations had become undetectable. The animals were resistant to insulin for up to 54 hours after the last dose of ethanol, chiefly a result of impaired hepatic and adipose tissue insulin action. Because insulin regulates hepatic glucose production and white adipose tissue lipolysis, in part through signaling in the central nervous system, we tested whether binge drinking impaired brain control of nutrient partitioning. Rats that had consumed alcohol exhibited impaired hypothalamic insulin action, defined as the ability of insulin infused into the mediobasal hypothalamus to suppress hepatic glucose production and white adipose tissue lipolysis. Insulin signaling in the hypothalamus, as assessed by insulin receptor and AKT phosphorylation, decreased after binge drinking. Quantitative polymerase chain reaction showed increased hypothalamic inflammation and expression of protein tyrosine phosphatase 1B (PTP1B), a negative regulator of insulin signaling. Intracerebroventricular infusion of CPT-157633, a small-molecule inhibitor of PTP1B, prevented binge drinking-induced glucose intolerance. These results show that, in rats, binge drinking induces systemic insulin resistance by impairing hypothalamic insulin action and that this effect can be prevented by inhibition of brain PTP1B.

Sci Transl Med 30 January 2013:
Vol. 5, Issue 170, p. 17

(Articolo pubblicato dal CUFRAD sul sito www.alcolnews.it