INTRODUCTIONInsulin resistance in latent autoimmune diabetes in adults (LADA) patients is controversial. The aim of this study was to evaluate insulin resistance and its related factors (metabolic syndrome parameters) among subjects with LADA and glutamic acid decarboxylase antibodies (GADA) negative diabetes, as well as the impact of these factors on insulin resistance.

MATERIALS AND METHODSGADA levels were investigated in 1140 diabetic patients aged between 30 and 70 years. Insulin resistance and metabolic syndrome parameters were assessed in LADA and GAD-negative diabetic patients by general linear model. In addition, the impact of metabolic syndrome factors on insulin resistance was assessed in LADA and glutamic acid decarboxylase (GAD)-negative diabetic patients.

RESULTSLADA was diagnosed in 33 subjects from 1140 Malaysian diabetic patients (prevalence = 2.9%). The results showed that LADA patients had higher insulin resistance and high density lipoprotein cholesterol (HDLc) (P = 0.003 and 0.00017 respectively) and lower body mass index (BMI) (P = 0.007) compared to GAD-negative diabetic patients. The HDLc was associated with decreased insulin resistance in LADA patients (P = 0.041), whereas HbA1c, triacylglycerides (TG) and waist were associated with increased insulin resistance in GAD-negative diabetic patients (P = 3.6×10⁻¹², 1.01×10⁻⁵ and 0.004 respectively). HbA1c was highly associated with decreasing β-cell function in both LADA (P = 0.009) and GAD-negative diabetic subjects (P = 2.2×10⁻²⁸).

CONCLUSIONInsulin resistance is significantly higher in LADA than GAD-negative diabetic Malaysian subjects.

Adult ; Antibodies ; blood ; Diabetes Mellitus, Type 1 ; blood ; metabolism ; Female ; Glutamate Decarboxylase ; immunology ; Humans ; Insulin Resistance ; Male ; Middle Aged

OBJECTIVETo investigate the role of T cell and its subsets in the induction of insulitis and type 1 diabetes mellitus (T1DM) in BALB/c mice.

METHODSAutoimmune diabetes mellitus was developed by intraperitoneal injection of 40 mg/kg streptozotocin (STZ) daily for 5 consecutive days in BALB/c mice as sources of donor cells. Spleen cells from diabetic mice were then cultured for 7 days in the stimulation of interleukin-2 (IL-2) to harvest diabetogenic T cells, which were subsequently transferred into normal BALB/c mice recipients. MTT, ELISA, and HE staining were used to analyze the lymphocyte proliferation, cytokine (IL-2, interferon-gamma, IL-4, and IL-10) levels, and pathological changes in pancreatic islets.

RESULTSAs few as 3 x 10(6) diabetogenic T cells successfully induced diabetes mellitus in recipients pretreated with STZ twice, whereas transfer of equal amount of normal splenocytes, T cell-depleted diabetogenic splenocytes, or diabetogenic CD4+ T cells alone in recipients receiving STZ twice pretreatment was proved not to induce diabetes mellitus either. A markedly increased lymphocyte proliferation, high levels of interferon-gamma and IL-2 in the supernatants of diabetogenic T cells were observed. In addition, a markedly enhanced lymphocyte proliferation, a high level of interferon-gamma secretion in serum, and numerous lymphocytes infiltration in pancreatic islets were detected in the diabetic mice induced by diabetogenic T cells transfer.

CONCLUSIONSA novel T1DM murine model is established in STZ-pretreated BALB/c mice by adoptive transfer of diabetogenic T cells. CD4+ T cells with interferon-gamma may promote the onset of diabetes mellitus.

Animals ; Blood Glucose ; metabolism ; Cytokines ; immunology ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; Diabetes Mellitus, Type 1 ; immunology ; pathology ; Disease Models, Animal ; Islets of Langerhans ; cytology ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred BALB C ; T-Lymphocytes ; cytology ; immunology

OBJECTIVETo explore the relationship between the T cell subsets and glucose level and first-phase insulin secretion function in patients with type 2 diabetes mellitus (T2DM).

METHODSWe determined the oral glucose tolerance (OGTT), insulin release test(IRT), body mass index(BMI), glycohemoglobin A1c (HbA1c), T lymphocyte subsets (CD4(+),CD8(+)), and activity of natural kill(NK) cell and ⊿I(30)/⊿G(30) in 78 newly diagnosed T2DM patients, 60 impaired glucose tolerance (IGT) patients, and 60 normal controls.

RESULTSDM and IGT patients had significantly lower levels of CD4(+), CD4(+)/CD8(+)ratio, activity of NK cell, and ⊿I(30)/⊿G(30) and significantly higher levels of HbA1c and CD8(+)compared with normal controls(all P<0.05). Patients in DM group had significantly lower level of CD4(+),⊿I(30)/⊿G(30) and significantly higher levels of FBG and HbA1c compared with IGT group. There was no significant difference in terms of CD8(+), CD4(+)/CD8(+)ratio, and activity of NK cell between IGT and DM groups, whereas CD4(+) T cells were negatively correlated with FBG and HbA1c and positively with ⊿I(30)/⊿G(30) . Multiple regression stepwise analysis showed that CD4(+) was independently associated with HbA1c and ⊿I(30)/⊿G(30).

CONCLUSIONT2DM patients tends to have disorders in cellular immunity, which is correlated with blood glucose level and the insulin secretion function.

Adult ; Aged ; Blood Glucose ; metabolism ; Diabetes Mellitus, Type 2 ; blood ; immunology ; Female ; Humans ; Immunity, Cellular ; Insulin ; blood ; Male ; Middle Aged ; T-Lymphocyte Subsets ; immunology

OBJECTIVETo analyze the significance of Fas-FasL in NOD insulitis and to explore the mechanism of the autoimmune diabetes.

METHODSThirty-two female NOD mice, 3-32 weeks of age, were selected. The blood glucose concentrations were recorded. The pathological data were obtained from the HE staining of the pancreatic sections and the immunohistochemical staining, in which insulin, Fas, FasL, CD8 were detected.

RESULTSDiabetes was found from the age of 14 weeks. In normal islets, insulin + cells accounted for (59.37 +/- 1.21)%, and some islet cells were observed expressing Fas. At the age of 6 weeks, insulitis lesions could be found. The average score of insulitis tended to rise with the increasing age (P < 0.0005). Meanwhile, insulin + cells decreased (P < 0.0005), and correlated negatively with scoring (P < 0.05). Fas+ islet cells increased (P < 0.0005), correlated positively with scoring (P < 0.01). In insulitis lesions, islet cells expressed FasL that increased gradually (P < 0.0005) and correlated positively with scoring (P < 0.01). The infiltrating cells were all Fas negative. But these mononucleated cells showed the expression of FasL and CD8, both increasing gradually (P < 0.0005). Furthermore, there was certain correlation between the expression of some antigens: in islet cells, between Fas and insulin (negative, P < 0.01), insulin and FasL (negative, P < 0.01), and Fas and FasL (positive, P < 0.01). In the infiltrating cells, the expression of CD8 was correlated with FasL (positively, P < 0.01); it was also found that there was a negative correlation between Fas+ islet cells and CD8+ mononucleated cells (P < 0.05).

CONCLUSIONTo sum up, there may be some important and complicated effects by Fas-FasL on the damage of beta cells and the regulation of autoreactive T cells in NOD insulitis, which will facilitate further studies in human type 1 diabetes.

Animals ; Autoimmune Diseases ; etiology ; immunology ; metabolism ; Diabetes Mellitus, Experimental ; etiology ; immunology ; Fas Ligand Protein ; Female ; Inflammation ; immunology ; metabolism ; Insulin ; blood ; Islets of Langerhans ; immunology ; metabolism ; Membrane Glycoproteins ; physiology ; Mice ; Mice, Inbred NOD ; fas Receptor ; physiology

BACKGROUND: Insulin assays are affected by varying degrees of interference from anti-insulin antibodies (IAs) and by cross-reactivity with recombinant insulin analogues. We evaluated the usefulness of the E170 insulin assay by assessing IA effects and cross-reactivity with 2 analogues. METHODS: Sera were obtained from 59 type 2 diabetes patients receiving continuous subcutaneous insulin infusion and 18 healthy controls. Insulin levels were determined using an E170 analyzer. To investigate the effects of IAs, we performed IA radioimmunoassays, and analyzed the differences between directly measured insulin (direct insulin) and polyethylene glycol (PEG)-treated insulins (free, IA-unbound; total, IA-bound and unbound insulin). We performed in-vitro cross-reactivity tests with insulin aspart and insulin glulisine. RESULTS: In IA-positive patients, E170 free insulin levels measured using the E170 analyzer were significantly lower than the direct insulin levels. The mean value of the direct/free insulin ratio and IA-bound insulin, which were calculated as the difference between total and free insulin, increased significantly as endogenous IA levels increased. The E170 insulin assay showed low cross-reactivities with both analogues (< 0.7%). CONCLUSIONS: IAs interfered with E170 insulin assay, and the extent of interference correlated with the IA levels, which may be attributable to the increase in IA-bound insulin, and not to an error in the assay. The E170 insulin assay may measure only endogenous insulin since cross-reactivity is low. Our results suggest that the measurement of free insulin after PEG pre-treatment could be useful for beta cell function assessment in diabetic patients undergoing insulin therapy.
Adult ; Aged ; Aged, 80 and over ; Cross Reactions ; Diabetes Mellitus, Type 2/blood/immunology ; Female ; Humans ; Infusions, Subcutaneous ; Insulin/analogs & derivatives/*blood/chemistry/immunology ; Insulin Antibodies/*blood ; Male ; Middle Aged ; Polyethylene Glycols/chemistry ; Radioimmunoassay/instrumentation/*methods ; Recombinant Proteins/analysis/immunology/metabolism

OBJECTIVE: To determine the correlation of serum soluble CD14 (sCD14) level with the injury of vascular endothelial cells and chronic low grade inflammation in newly diagnosed Type 2 diabetes (T2DM). METHODS: ELISA was used to examine serum sCD14 and serum soluble E-selectin (sE-selectin) level, while immunoturbidimetric assay was used to detect serum high sensitivity C reactive protein (hsCRP). RESULTS: The levels of serum sCD14, sE-selectin, and hsCRP in newly diagnosed T2DM group were higher than those in the euglycemic group [sCD14: (300.7+/-136.6) ng/mL vs. (273.3+/-86.0) ng/mL); sE-selectin: (21.3+/-7.7) ng/mL vs. (32.9+/-11.4) ng/mL; hsCRP: (1.45+/-1.21) mg/L vs. (2.37+/-1.45)mg/L], and there was a significant difference in the latter two parameters between the 2 groups(P<0.01). In the patients with newly diagnosed T2DM, after matching blood pressure, blood sugar, and blood lipid, the levels of serum sCD14, sE-selectin, and hsCRP in the obese group were higher than those in the non-obese group. There was no significant difference in the former 2 parameters between the 2 groups. The serum sE-selectin was correlated with fasting blood sugar (r=0.369, P<0.001), 2-hour postprandial blood sugar (r=0.421, P<0.001), glycosylated hemoglobin (r=0.291, P=0.005), sCD14(r=0.312, P=0.002), and homeostasis model assessment-insulin resistance(r=0.247, P=0.018) in the newly diagnosed T2DM group. Stepwise regression ana-lysis showed that the serum sCD14 was one of the chief influencing factors on serum sE-selectin. CONCLUSION Serum sCD14 levels tend to increase in newly diagnosed T2DM patients, especially in the obese diabetic patients, which is one of the chief influencing factors to induce the injury of vascular endothelial cells. The innate immunity mediated by Toll-like receptor 4 may take part in the injury of vascular endothelial cells in newly diagnosed T2DM patients.
Aged ; C-Reactive Protein ; metabolism ; Diabetes Mellitus, Type 2 ; blood ; immunology ; E-Selectin ; blood ; Female ; Humans ; Lipopolysaccharide Receptors ; analysis ; blood ; Male ; Middle Aged ; Regression Analysis ; Solubility ; Toll-Like Receptor 4 ; immunology

AIMTo observe the stability of BCG-induced insulin resistance model.

METHODSThe glucose tolerance, serum glucose, FFA, insulin, triglycerides, cholesterol, TNF-alpha and ALT level were measured. The change of GDR was measured by euglycemic clamp in model rats after given i.v. BCG 2, 4 and 8 weeks.

RESULTSAfter 2, 4 and 8 weeks, the GIR and glucose tolerance of the animals deceased significantly. After 2, 4 and 8 weeks, BCG infusion resulted in a pronounced reduction in glucose tolerance and insulin-stimulated glucose disposal rate [GDR = GDR: (29 +/- 6) vs (13 +/- 7) mg.kg-1.min-1 2 weeks; (29 +/- 6) vs (11 +/- 7) mg.kg-1.min-1 4 weeks and (23 +/- 3) vs (16 +/- 3) mg.kg-1.min-1 8 weeks, respectively, P < 0.01]. BCG infusion resulted in a pronounced increase in the weights of the liver [(6.2 +/- 0.9) vs (8.2 +/- 1.3) g, P < 0.05] and spleens [(0.51 +/- 0.11) vs (1.4 +/- 0.4) g, P < 0.01]. The histo-pathological results showed that BCG infusion resulted severe inflammation in the livers and spleens and the ratio of beta/alpha in pancreas increased. The serum levels of triglyceride, FFA and glucose were unchanged, but the level of serum TNF-alpha [543 +/- 60) vs (759 +/- 137) pg.mL-1, P < 0.05] and insulin [(31 +/- 5) vs (36 +/- 5) mu.L-1, P > 0.05] increased.

CONCLUSIONThis novel model of immune insulin resistance is completely and constantly established.

Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus ; metabolism ; Glucose Clamp Technique ; Glucose Tolerance Test ; Injections, Intravenous ; Insulin ; blood ; Insulin Resistance ; immunology ; Male ; Mycobacterium bovis ; Random Allocation ; Rats ; Rats, Wistar ; Spleen ; pathology ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo investigate the difference between serum true insulin (TI) and immunoreactive insulin (IRI) in evaluating islet beta-cell function and insulin resistance.

METHODSThe arginine stimulation test was performed in 141 individuals, including 35 with normal glucose tolerance (NGT) and 106 with type 2 diabetes (T2DM). Plasma glucose (PG), TI, IRI and proinsulin (PI) levels were measured; the incremental value of TI/PG, (TI+PI)/PG and IRI/PG (delta TI/PG, delta(TI+PI)/PG and deltaIRI/PG) and the area under curve of TI/PG, (TI+PI)/PG and IRI/PG (AUC [TI/PG], AUC[(TI+PI)/PG] and AUC [IRI/PG]) after arginine stimulation were calculated to evaluate beta-cell function.

RESULTThere were positive correlations of delta TI/PG with delta (TI+PI)/PG and delta IRI/PG in both NGT and T2DM patients (r=0.68 - 0.99, P<0.01). The similar correlations of AUC [TI/PG] with AUC [(TI+PI)/PG] and AUC [IRI/PG] were also shown (r=0.62 - 0.99, P<0.01). delta TI/PG was correlated with AUC [TI/PG] in two groups (NGT r=0.96, T2DM r=0.82, P<0.01). HOMA-IRTI, HOMA-IR(TI+PI) and HOMA-IRIRI in T2DM were higher than those in NGT (P<0.01). After arginine stimulation T2DM subjects mainly presented insulin resistance and decreased insulin secretion.

CONCLUSIONThe determination of TI may be more accurate than IRI in evaluating beta-cell function and insulin resistance.

Adult ; Aged ; Arginine ; pharmacology ; Blood Glucose ; metabolism ; Diabetes Mellitus, Type 2 ; blood ; Female ; Glucose Tolerance Test ; Humans ; Insulin ; blood ; immunology ; Insulin Resistance ; Insulin-Secreting Cells ; physiology ; Male ; Middle Aged ; Proinsulin ; blood

Although peroxisome proliferator receptor (PPAR)-alpha and PPAR-gamma agonist have been developed as chemical tools to uncover biological roles for the PPARs such as lipid and carbohydrate metabolism, PPAR-delta has not been fully investigated. In this study, we examined the effects of the PPAR-delta agonist GW0742 on fatty liver changes and inflammatory markers. We investigated the effects of PPAR-delta agonist GW0742 on fatty liver changes in OLETF rats. Intrahepatic triglyceride contents and expression of inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) and monocyte chemo-attractant protein-1 (MCP-1) and also, PPAR-gamma coactivator (PGC)-1alpha gene were evaluated in liver tissues of OLETF rats and HepG2 cells after GW0742 treatment. The level of TNF-alpha and MCP-1 was also examined in supernatant of Raw264. 7 cell culture. To address the effects of GW0742 on insulin signaling, we performed in vitro study with AML12 mouse hepatocytes. Rats treated with GW0742 (10 mg/kg/day) from 26 to 36 weeks showed improvement in fatty infiltration of the liver. In liver tissues, mRNA expressions of TNF-alpha, MCP-1, and PGC-1alpha were significantly decreased in diabetic rats treated with GW0742 compared to diabetic control rats. We also observed that GW0742 had inhibitory effects on palmitic acid-induced fatty accumulation and inflammatory markers in HepG2 and Raw264.7 cells. The expression level of Akt and IRS-1 was significantly increased by treatment with GW0742. The PPAR-delta agonist may attenuate hepatic fat accumulation through anti-inflammatory mechanism, reducing hepatic PGC-1alpha gene expression, and improvement of insulin signaling.
Animals ; Anti-Inflammatory Agents/*pharmacology/therapeutic use ; Blood Glucose ; Cytokines/genetics/metabolism ; Diabetes Mellitus/blood/immunology/metabolism ; Fatty Liver/blood/*drug therapy/immunology ; Glucose Tolerance Test ; Hep G2 Cells ; Humans ; Insulin Resistance ; Liver/metabolism ; Male ; PPAR delta/*agonists/metabolism ; Rats ; Rats, Long-Evans ; Thiazoles/*pharmacology/therapeutic use ; Triglycerides/metabolism

BACKGROUNDAs two novel adipocytokines, chemerin and apelin play a key role in the pathological process of insulin resistance (IR), glucose metabolism and obesity, researchers have found that the levels of chemerin and apelin changed significantly in type 2 diabetic patients with obesity, however, the underlying mechanism involved remains unclear. The aim of this study was to investigate whether chemerin and apelin play an important role in the pathophysiologic proceeding of diabetes.

METHODSThis study enrolled 81 newly diagnosed obese type 2 diabetes mellitus (T2DM) patients (T2DM group, n = 81). All the patients were randomly assigned to DM1 group treated with metformin (n = 41) and DM2 group treated with pioglitazone (n = 40). After hypoglycemic agents treatment, patients under better blood glucose control were chosen to be given antioxidant treatment. Another 79 subjects without T2DM were recruited as normal control group (NC group), including 40 subjects (NC1 group) with normal body mass index (BMI) and 39 obese subjects (NC2 group). Levels of chemerin, apelin, BMI, tumor necrosis factor-α (TNF-α), homeostasis model assessment of IR (HOMA-IR) and 8-isoprotaglandim F2α (8-iso-PGF2α) were examined at baseline and post-treatment. The relationship between chemerin, apelin and BMI, TNF-α, HOMA-IR, 8-iso-PGF2α was analyzed.

RESULTSThe baseline levels of chemerin, apelin, TNF-α, HOMA-IR and 8-iso-PGF2α in T2DM group were significantly higher than normal control group (P < 0.001). All indices mentioned above were significantly decreased after treatment (P < 0.05). In T2DM patients treated with pioglitazone, indices mentioned above except for HOMA-IR, were decreased significantly compared with patients treated with metformin (P < 0.05). After antioxidant treatment using lipoic acid, levels of chemerin, apelin, TNF-α and 8-iso-PGF2α were further significantly decreased (P < 0.05). Correlation analysis showed that the levels of chemerin and apelin correlated positively with BMI, TNF-α, HOMA-IR and 8-iso-PGF2α before and after treatment with hypoglycemic agents (P < 0.01). The levels of chemerin and apelin also had positive correlation with TNF-α and 8-iso-PGF2α after antioxidant treatment (P < 0.05).

CONCLUSIONSThe levels of chemerin and apelin in obese T2DM patients are closely related to IR. The increased levels may be a result of compensatory response to IR, and also may be the causative factor of IR. The levels of chemerin and apelin correlate closely with oxidative stress and inflammation. The two adipokines may be inflammatory factors playing important roles in the initiation and development of obese T2DM. Chemerin and apelin are related to the pathophysiology of IR, oxidative stress and inflammation.

Apelin ; Blood Glucose ; metabolism ; Body Mass Index ; Chemokines ; metabolism ; Diabetes Mellitus, Type 2 ; drug therapy ; immunology ; metabolism ; Dinoprost ; analogs & derivatives ; metabolism ; Humans ; Hypoglycemic Agents ; therapeutic use ; Inflammation ; metabolism ; Intercellular Signaling Peptides and Proteins ; metabolism ; Metformin ; therapeutic use ; Thiazolidinediones ; therapeutic use ; Tumor Necrosis Factor-alpha ; metabolism