Relationship between serum adipsin and the first phase of glucose-stimulated insulin secretion in individuals with different glucose tolerance.

AIMS/INTRODUCTION: To detect serum adipsin levels in individuals with different glucose tolerance, and investigate the relationship between adipsisn and the first phase of insulin secretion. MATERIALS AND METHODS: A total of 56 patients with newly diagnosed type 2 diabetes mellitus, 36 patients with impaired glucose tolerance (IGT) and 45 individuals with normal glucose tolerance were enrolled. Intravenous glucose tolerance tests were carried out to evaluate pancreatic ß-cell function. The serum levels of adipsin, interleukin-1ß and high-sensitivity C-reactive protein were assayed. RESULTS: Serum adipsin levels were significantly lower in the type 2 diabetes mellitus and the IGT patients than those in the normal glucose tolerance group (P < 0.05). The acute insulin response and area under the curve showed a progressive decrease in the normal glucose tolerance and IGT groups, and decreased to the lowest levels in the type 2 diabetes mellitus group (P < 0.05). Adipsin was found to be negatively correlated with waist-to-hip ratio, free fatty acid, fasting plasma glucose, 2-h postprandial plasma glucose, glycated hemoglobin, homeostasis model assessment of insulin resistance, interleukin-1ß and high-sensitivity C-reactive protein (P < 0.05 or P < 0.001), and positively correlated with homeostasis model assessment of ß-cell function, high-density lipoprotein cholesterol, the area under the curve of the first phase insulin secretion and acute insulin response (P < 0.05 or P < 0.001). Stepwise multiple regression analysis showed that homeostasis model assessment for ß-cell function and acute insulin response were independently related to adipsin (P < 0.05). CONCLUSIONS: Serum adipsin levels were lower in type 2 diabetes mellitus and IGT patients, and correlated with the first phase of insulin secretion. Adipsin might be involved in the pathology of type 2 diabetes mellitus.

Relationship between serum betatrophin levels and the first-phase of glucose-stimulated insulin secretion.

AIMS: To examine circulating betatrophin concentrations in subjects with different glucose tolerance status and to investigate the relationship between serum betatrophin levels and first-phase of glucose-stimulated insulin secretion. METHODS: Serum betatrophin concentrations were measured in 110 age- and sex-matched subjects: 47 newly diagnosed type 2 diabetes mellitus (T2DM), 29 impaired glucose tolerance (IGT) and 34 normal glucose tolerance (NGT). Oral glucose tolerance test and intravenous glucose tolerance test were performed to assess glucose tolerance and first-phase of glucose-stimulated insulin secretion. RESULTS: Serum betatrophin levels were significantly higher in the T2DM and IGT group than in the NGT group (2.10±1.16ng/mL vs 0.77±0.44ng/mL, 1.73±1.28ng/mL vs 0.77±0.44ng/mL; P<0.01). The AIR and AUC among the three groups showed a progressive decrease from the NGT to IGT group with the lowest value in the T2DM group (P<0.01). Betatrophin were found to be positively correlated with BMI, waist circumference (WC), homeostatic model assessment of insulin resistance (HOMA-IR) and triglyceride (TG), and inversely associated with HDL-c (all P<0.01), but not significantly correlated with 0-10min insulin the area under the curve (AUC) and acute insulin response (AIR) (P>0.05). Stepwise multiple regression analysis showed that HOMA-IR and TG were independently related to betatrophin (P<0.05). CONCLUSION: Serum betatrophin concentrations were higher in T2DM and IGT, and were closely related to glucolipid disorder, insulin resistance, but not related to the first-phase of glucose-stimulated insulin secretion.

Plasma vascular endothelial growth factor B levels are increased in patients with newly diagnosed type 2 diabetes mellitus and associated with the first phase of glucose-stimulated insulin secretion function of ß-cell.

PURPOSE: To detect plasma vascular endothelial growth factor B (VEGF-B) in individuals with different glucose tolerance and investigate the relationship between plasma VEGF-B levels and the first phase of glucose-stimulated insulin secretion. METHODS: A cross-sectional study was conducted involving 45 patients with newly diagnosed type 2 diabetes mellitus (T2DM), 37 patients with impaired glucose regulation (IGR), and 39 Normal glucose tolerance (NGT) subjects, all of whom underwent intravenous glucose tolerance test. Plasma VEGF-B levels were assayed by ELISA. The first phase of insulin secretion was evaluated by acute insulin response (AIR), the area under the curve of the first-phase (0-10 min) insulin secretion (AUC) and glucose disposition index (GDI). RESULTS: The T2DM and IGR groups had higher plasma VEGF-B levels than the NGT group (P < 0.01). Plasma VEGF-B levels were negatively correlated with AIR, AUC, GDI, HOMA-ß (P < 0.01), and positively correlated with plasma glucose, HbA1c, triglyceride, free fatty acid (FFA), fasting insulin, and HOMA-IR (P < 0.01). Logistic regression analysis revealed that higher VEGF-B levels [145.59-180.07 pg/ml, OR 3.55 (95% CI 1.05-12.02) and >180.07 pg/ml, OR 3.64 (95% CI 1.16-11.42)] were related to a greater probability of ß-cell hypofunction, compared with low VEGF-B levels (<145.59 pg/ml). After adjusting for triglyceride or FFA, the association between VEGF-B levels and ß-cell hypofunction disappeared (P > 0.05). CONCLUSIONS: Our study provides evidence that plasma VEGF-B levels were higher in patients with newly diagnosed T2DM, and were strongly associated with glucose and lipid metabolism and the first-phase insulin secretion function of ß-cells. VEGF-B may be involved in the mechanism of ß-cell dysfunction in T2DM.

Relationship between oxidative stress and the first-phase of glucose-stimulated insulin secretion from pancreatic β cell in individuals with different glucose tolerance / 中华内分泌代谢杂志

The relationship between oxidative stress and the first-phase of pancreatic β cell insulin secretion in subjects with different statuses of glucose tolerance was explored. Fasting adiponectin, 8-hydroxydeoxyguanosin ( 8-OHdG), malondialdehyde ( MDA ), superoxide dismutase ( SOD ), insulin area under the curve ( AUC ) from 0 to 10 min, and AIR3-5 were measured. The levels of oxidative stress-related markers were elevated, the activities of superoxide dismutase,adiponectin, and first-phase of insulin secretion were reduced with the disease progression. MDA and 8-OHdG were negatively correlated with adiponectin, homeostasis model assessment β cell function index ( HOMA-β ),AUC ,and AIR3-5. SOD was positively correlated with adiponectin, HOMA-β, AUC, AIR3-5. The plasma 8-OHdG and SOD were independently associated with AIR3-5. Oxidative stress exerts a significant effect on the first phase of pancreatic β cell insulin secretion, which may contribute to the pathogenesis of type 2 diabetes.

Relationship between angiotensin Ⅱ and pancreatic islet β cell secretion function in patients with type 2 diabetes mellitus / 中华内分泌代谢杂志

Objective To investigate the relationship between angiotensin Ⅱ and pancreatic islet β cell secretion function under different glucose tolerance statuses. Method Forty-two patients with newly diagnosed type 2diabetes mellitus ( DM group), 38 subjects with impaired fasting glucose/impaired glucose tolerance ( IFG/IGTgroup) ,and 40 normal control subjects (NGT group) underwent intravenous glucose tolerance test. Fasting plasma angiotensin Ⅱ ( Ang Ⅱ ) and adiponectin were assayed by ELISA. Acute insulin response from 3 to 10 min( AIR3-10 ),the area under the curve( AUCⅠ ) and the peak concentration of the first-phase ( 0-10 min) insulin secretion, the area under the curve of the second-phase( 10-120 min) insulin secretion( AUCⅡ), homeostasis model assessment for β cell function index(HOMA-β) and homeostasis model assessment for insulin resistance index(HOMA-IR) were calculated to explore the relationship with Ang Ⅱ. Result ( 1 ) The levels of Ang Ⅱ in DM group and IFG/IGT group were significantly higher than that in NGT group( P＜0.05 ). The AIR3-10, AUCⅠ and peak concentration, AUCⅡ ,adiponectin in DM group and IFG/IGT group were significantly lower than those in the NGT group ( P＜0. 05), and these results were more significantly reduced in DM group compared with those in IFG/IGT group. (2) Ang Ⅱ was negatively correlated with AIR3-10, AUCⅠ and the peak concentration, AUCⅡ, adiponectin, HOMA-β ( P＜0. 01 ), and positively correlated with fasting blood glucose,2 h blood glucose after glucose loading, fasting insulin, HOMA-IR (P＜0. 05 ). (3)Multiple stepwise regression analysis showed that Ang Ⅱ was independently associated with AUCⅠ and AUCⅡ.Conclusion Ang Ⅱ was an independent factor that affected the insulin secretion function of pancreatic islet βcells. Ruling out the effect of blood pressure, body position, drugs, and other factors, high levels of Ang Ⅱ could predict the dysfunction of pancreatic islet β cell as well as insulin resistance in patients with type 2 diabetes.

Relationship between adiponectin and the first phase of glucose-stimulated insulin secretion from pancreatic β-cell in patients with type 2 diabetes mellitus / 中华内分泌代谢杂志

Objective To investigate the relationship between adiponectin and the first-phase of pancreatic P-cell insulin secretion in subjects with different statuses of glucose tolerance. Methods Thirty-seven patients with newly diagnosed type 2 diabetes mellitus (DM) , 30 patients with abnormal glucose tolerance (IGR) , and 40 normal control subjects (NGT) underwent intravenous glucose tolerance test (IVGTT). Fasting adiponectin and proinsulin (PI) was assayed by EL1SA. Fasting free fatty acid ( FFA) was measured by colorimetry. Insulin area under the curve ( AUC ) , incremental AUC (iAUC) from 0 min to 10 min, AIR3-5, homeostasis model assessment for insnlin resistance (HOMA-IR) , and for β cell function ( HOMA-p) were calculated. The relationship between adiponectin and AUC, iAUC, AIR3-5, proinsulin, FFA, and HOMA-IR was explored. Results (1) The levels of AUC, iAUC, AIR3-5, and adiponectin in DM group and IGR group were significantly lower than those in NGT group (P<0.05), reduced in DM group than those in IGR group(P<0.05). (2) The levels of PI in DM group and IGR group were significantly higher than that in NGT (P<0.05). (3) Adiponectin was positively correlated with HOMA-p,AUC,iAUC,AIR3-5, and HDL-C,while negatively correlated with proinsulin, HOMA-IR, and LDL-C. (4) Proinsulin was positively correlated with HOMA-IR. (5 ) Multiple regression stepwise analysis showed that adiponectin was independently associated with AUC. Conclusions Adiponectin was an independent factor affecting the first phase of pancreatic p-cell insulin secretion. Low adiponectin level could predict the dysfunction of the first phase pancreatic p-cell secretion as well as insulin resistance in patients with type 2 diabetes.

First-phase insulin secretion and its components in the first-degree relatives of type 2 diabetics / 中华内分泌代谢杂志

Objective To investigate the changes of first-phase insulin secretion and its components in the first-degree relatives of Chinese type 2 diabetics with normal glucose tolerance and their correlation with type 2 diabetes. Methods The first-degree relatives of type 2 diabetes (Group B, n=35), newly diagnosed type 2 diabetic patients (Group C, n=35) and health subjects (Group A, n=21) were recruited. Immune reactive insulin (IRI), proinsulin (PI), and true insulin (TI) were determined during intravenous glucose tolerance test (IVGTT) in each subjects. IRI was determined with radioimmunoassay kit, while PI and TI with ELISA kits. Results (1) For the fasting sera, the levels of IRI and PI showed significant differences (both P