Gastric bypass surgery leads to marked improvements in glucose tolerance and insulin sensitivity in obese type 2 diabetes; the impact on glucose fluxes in response to a physiological stimulus - such as a mixed meal (MTT) - has not been determined. We administered an MTT to 12 obese type 2 diabetic patients (T2D) and 15 obese nondiabetic subjects (ND) before and one year after surgery (10 T2D and 11 ND) using the double-tracer technique and modeling of ß-cell function. In both groups postsurgery, tracer-derived appearance of oral glucose was biphasic, a rapid increase followed by a sharp drop, a pattern that was mirrored by postprandial glucose levels and insulin secretion. In diabetic patients, surgery lowered fasting and postprandial glucose levels; peripheral insulin sensitivity increased in proportion to weight loss (∼30%), ß-cell glucose sensitivity doubled but did not normalize (viz. 21 nonsurgical obese and lean controls). Endogenous glucose production, however, was less suppressed during the MMT as the combined result of a relative hyperglucagonemia and the rapid fall in plasma glucose and insulin levels.We conclude that, in type 2 diabetes bypass surgery changes the postprandial response to a dumping-like pattern, improves glucose tolerance, ß-cell function, and peripheral insulin sensitivity but worsens endogenous glucose output in response to a physiological stimulus.
|Autori:||Camastra, Stefania; Muscelli, E; Gastaldelli, A; Holst, Jj; Astiarraga, B; Baldi, Simona; Nannipieri, Monica; Ciociaro, D; Anselmino, M; Mari, A; Ferrannini, Eleuterio|
|Titolo:||Long-term effects of bariatric surgery on meal disposal and beta-cell function in diabetic and nondiabetic patients.|
|Anno del prodotto:||2013|
|Digital Object Identifier (DOI):||10.2337/db13-0321|
|Appare nelle tipologie:||1.1 Articolo in rivista|