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Currently, there are no data in the literature regarding the pathophysiological mechanisms involved in the rapid resolution of type 2 diabetes after bariatric surgery, which was reported as an additional benefit of the surgical treatment for morbid obesity. With this question in mind, insulin sensitivity, using euglycemic-hyperinsulinemic clamp, and insulin secretion, by the C-peptide deconvolution method after an oral glucose load, together with the circulating levels of intestinal incretins and adipocytokines, have been studied in 10 diabetic morbidly obese subjects before and shortly after biliopancreatic diversion (BPD) to avoid the weight loss interference. Diabetes disappeared 1 week after BPD, while insulin sensitivity (32.96 ± 4.3 to 65.73 ± 3.22 µmol ⋅ kg fat-free mass-1 ⋅ min-1 at 1 week and to 64.73 ± 3.42 µmol ⋅ kg fat-free mass-1 ⋅ min-1 at 4 weeks; P < 0.0001) was fully normalized. Fasting insulin secretion rate (148.16 ± 20.07 to 70.0.2 ± 8.14 and 83.24 ± 8.28 pmol/min per m²; P < 0.01) and total insulin output (43.76 ± 4.07 to 25.48 ± 1.69 and 30.50 ± 4.71 nmol/m²; P < 0.05) dramatically decreased, while a significant improvement in β-cell glucose sensitivity was observed. Both fasting and glucose-stimulated gastrointestinal polypeptide (13.40 ± 1.99 to 6.58 ± 1.72 pmol/l at 1 week and 5.83 ± 0.80 pmol/l at 4 weeks) significantly (P < 0.001) decreased, while glucagon-like peptide 1 significantly increased (1.75 ± 0.16 to 3.42 ± 0.41 pmol/l at 1 week and 3.62 ± 0.21 pmol/l at 4 weeks; P < 0.001). BPD determines a prompt reversibility of type 2 diabetes by normalizing peripheral insulin sensitivity and enhancing β-cell sensitivity to glucose, these changes occurring very early after the operation. This operation may affect the enteroinsular axis function by diverting nutrients away from the proximal gastrointestinal tract and by delivering incompletely digested nutrients to the ileum. Diabetes 55:2025-2031, 2006 [ABSTRACT FROM AUTHOR]

OBJECTIVE -- The purpose of this study was to elucidate the mechanisms of diabetes reversibility after malabsorptive bariatric surgery. RESEARCH DESIGN AND METHODS-- Peripheral insulin sensitivity and β-cell function after either intravenous (IVGTT) or oral glucose tolerance (OGTT) tests and minimal model analysis were assessed in nine obese, type 2 diabetic subjects before and 1 month after biliopancreatic diversion and compared with those in six normal-weight control subjects. Insulin-dependent whole-body glucose disposal was measured by the euglycemic clamp, and glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were also measured. RESULTS -- The first phase of insulin secretion after the IVGTT was fully normalized after the operation. The disposition index from OGTT data was increased about 10-fold and became similar to the values found in control subjects, and the disposition index from IVGTT data increased about 3.5-fold, similarly to what happened after the euglycemic clamp. The area under the curve (AUC) for GIP decreased about four times (from 3,000 ± 816 to 577 ± 155 pmol ⋅ 1-1. min, P < 0.05). On the contrary, the AUC for GLP1 almost tripled (from 150.4 ± 24.4 to 424.4 ± 64.3 pmol ⋅ 1-1 ⋅ min, P < 0.001). No significant correlation was found between GIP or GLP1 percent changes and modification of the sensitivity indexes independently of the route of glucose administration. CONCLUSIONS -- Restoration of the first-phase insulin secretion and normalization of insulin sensitivity in type 2 diabetic subjects after malabsorptive bariatric surgery seem to be related to the reduction of the effect of some intestinal factor(s) resulting from intestinal bypass. [ABSTRACT FROM AUTHOR]

OBJECTIVE -- The purpose of this study was to clarify the effects of maternal obesity on insulin sensitivity and secretion in offspring. RESEARCH DESIGN AND METHODS-- Fifty-one offspring of both sexes of obese (Ob group) and 15 offspring of normal-weight (control group) mothers were studied. Plasma glucose, insulin, and C-peptide were measured during an oral glucose tolerance test (OGTT). Insulin sensitivity was calculated using the oral glucose insulin sensitivity index, and insulin secretion and β-cell glucose sensitivity were computed by a mathematical model. Fasting leptin and adiponectin were also measured. Body composition was assessed by dual-X-ray absorptiometry. RESULTS -- No birth weight statistical difference was observed in the two groups. Of the Ob group, 69% were obese and 19% were overweight. The Ob group were more insulin resistant than the control group (398.58 ± 79.32 vs. 513.81 ± 70.70 ml[sup -1] ⋅ min[sup -1] ⋅ m[sup -2] in women, P < 0.0001; 416.42 ± 76.17 vs. 484.242 ± 45.76 m1[sup -1] ⋅ min[sup -1] ⋅ m[sup -2] in men, P < 0.05). Insulin secretion after OGTT was higher in Ob group than in control group men (63.94 ± 21.20 vs. 35.71 ± 10.02 nmol ⋅ m[sup -2], P < 0.01) but did not differ significantly in women. β-Cell glucose sensitivity was not statistically different between groups. A multivariate analysis of variance showed that maternal obesity and offspring sex concurred together with BMI and β-cell glucose sensitivity to determine the differences in insulin sensitivity and secretion observed in offspring. CONCLUSIONS-- Obese mothers can give birth to normal birth weight babies who later develop obesity and insulin resistance. The maternal genetic/epigenetic transmission shows a clear sexual dimorphism, with male offspring having a higher value of insulin sensitivity (although not statistically significant) associated with significantly higher insulin secretion than female offspring. [ABSTRACT FROM AUTHOR]