Insufficient glucocorticoid receptor signaling and flattened salivary cortisol profile are associated with metabolic and inflammatory indices in type 2 diabetes.

PURPOSE: Impaired negative feedback and hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis characterizes type 2 diabetes mellitus (T2DM). The glucocorticoid receptor (GR) is a key mediator of HPA axis negative feedback; however, its role in linking hypercortisolemia and T2DM-associated hyperglycemia, hyperlipidemia and inflammation is not yet known. METHODS: In peripheral mononuclear cells (PBMC) from 31 T2DM patients and 24 healthy controls, we measured various GR-signaling parameters such as phosphorylated GR (pGR-S211), GRα/GRß gene expression and GC-sensitivity [using the basal and dexamethasone (DEX)-induced leucine zipper (GILZ) and FK506 binding-protein (FKBP5) mRNA levels as well as the basal interleukin (IL)-1ß protein levels]. Diurnal salivary cortisol curve parameters such as the cortisol awaking response (CAR) and area under the curve (AUCtotal and AUCi) as well as inflammatory and metabolic indices were also determined. RESULTS: T2DM patients exhibited diminished pGR-S211 protein content, increased GRß, decreased basal GILZ and FKBP5 mRNA levels and increased IL-1ß levels. Flattened DEX-induced GILZ and FKBP5 response curves and a flattened salivary cortisol profile characterized T2DM patients. Significant associations of GR measures and saliva cortisol curve parameters with biochemical and clinical characteristics were found. CONCLUSION: Our novel data implicate an insufficient GR signaling in PBMCs in T2DM patients and HPA axis dysfunction. The significant associations of GR-signaling parameters with inflammatory and metabolic indices implicate that GR may be the critical link between HPA axis dysfunction, hypercortisolemia and diabetes-associated metabolic disturbances. Our findings provide significant insights into the contribution of GR-mediated mechanisms in T2DM aetiopathology and therapy.

Effects of 6 vs 3 eucaloric meal patterns on glycaemic control and satiety in people with impaired glucose tolerance or overt type 2 diabetes: A randomized trial.

BACKGROUND/OBJECTIVES: The study aimed to compare the effects of two eucaloric meal patterns (3 vs 6 meals/day) on glycaemic control and satiety in subjects with impaired glucose tolerance and plasma glucose (PG) levels 140-199mg/dL at 120min (IGT-A) or PG levels 140-199mg/dL at 120min and >200mg/dL at 30/60/90min post-oral glucose load on 75-g OGTT (IGT-B), or overt treatment-naïve type 2 diabetes (T2D). SUBJECTS/METHODS: In this randomized crossover study, subjects with IGT-A (n=15, BMI: 32.4±5.2kg/m2), IGT-B (n=20, BMI: 32.5±5kg/m2) or T2D (n=12, BMI: 32.2±5.2kg/m2) followed a weight-maintenance diet (45% carbohydrates, 20% proteins, 35% fats) in 3 or 6 meals/day (each intervention lasting 12 weeks). Anthropometrics, diet compliance and subjective appetite were assessed every 2 weeks. OGTT and measurements of HbA1c and plasma lipids were performed at the beginning and end of each intervention period. RESULTS: Body weight and physical activity levels remained stable throughout the study. In T2D, HbA1c and PG at 120min post-OGTT decreased with 6 vs 3 meals (P<0.001 vs P=0.02, respectively). The 6-meal intervention also improved post-OGTT hyperinsulinaemia in IGT-A subjects and hyperglycaemia in IGT-B subjects. In all three groups, subjective hunger and desire to eat were reduced with 6 vs 3 meals/day (P<0.05). There were no differences in HOMA-IR or plasma lipids between interventions. CONCLUSION: Although weight loss remains the key strategy in hyperglycaemia management, dietary measures such as more frequent and smaller meals may be helpful for those not sufficiently motivated to adhere to calorie-restricted diets. Our study shows that 6 vs 3 meals a day can increase glycaemic control in obese patients with early-stage T2D, and may perhaps improve and/or stabilize postprandial glucose regulation in prediabetes subjects.

P673Improvement of arterial stiffness and myocardial deformation in patients with poorly controlled diabetes mellitus type 2 after optimization of antidiabetic medication.

BACKGROUND: Arterial stiffness is associated with increased risk for cardiovascular disease. The purpose of this study is to investigate the arterial stiffness and myocardial deformation in patients with poorly controlled diabetes mellitus type 2 before and after glycemic control by optimal medication. METHODS: In 50 patients with uncontrolled type 2 diabetes(age:52±10years)and 25 controls of similar age and sex and no atherosclerotic risk factors we measured at baseline and 6 months after glycemic control a) carotid-femoral pulse wave velocity(PWVc m/sec-Complior SP ALAM),central systolic blood pressure(cSBP -mmHg),augmentation index(AI%), of the aortic pulse wave(ArteriographTensioMed) b)S',E'(m/sec)andE'/A'of mitral annulus by Tissue Doppler c)LV longitudinal strain(GLS-%),systolic(LongSr-l/sec)and diastolic(LongSrE-l/sec)strain rate, twisting(Tw-deg),peak twisting(Tw)and untwisting(unTw-deg/sec)velocity using speckle tracking echocardiography.The degree of LV untwisting was calculated as the percentage difference between peak twisting and untwisting at MVO(%dp PeakTw-UntwMVO)and between peak twisting and untwisting at peak and end of the mitral inflow E wave d)perfusion boundary region(PBR- micrometers)of the sublingual arterial microvessels(ranged from 5-25 micrometers)using Sideview,Darkfield imaging(Microscan,Glycocheck).Increased PBR is considered an accurate index of reduced endothelial glucocalyx thickness because of a deeper RBC penetration in the glucocalyx e) Flow mediated dilatation(FMD) of the brachial artery and percentage difference of FMD (FMD%). RESULTS: Compared to controls,diabetics had higher PWVa(10.3±2.2 vs. 8.1±1.9), AI(27.9±15 vs. 19.4±14.7), PWVc(11.8±3.2 vs. 8.8±1.3),cSBP(136±20 vs. 119±18),PBR (2.1±0.2 vs 1.89±0.1)and lower GLS(-15±3 vs. -18±3),LongSr(-0.78±0.1 vs. -0.96±0.2),LongSrE(0.77±0.29 vs. 1.2±0.3),S',E' and E/A(p<0.05 for all comparisons). Baseline FMD was related with Untw at peak E%(r=0,65, p<0.05). Six months after the modification of antidiabetic medication all patients achieved glycaemic control and there was a reduction of PWVc(12.3±2.9 vs. 11.3±3.2,p<0.05) in parallel with a increase of Untw velocity (-73±27 vs. -98±43,p<0.05),Untw MVO%(20±9 vs. 30±2),Untw peak E% (40±14 vs. 50±16)and FMD%(7.8±3 vs. 13.6±11,p<0.01).Reduced PWVc was related with reduced SBP(r=0.62),cSBP(r=0.55)and increased LongsrE(r=-0.50), Untw at end E(r=-0.56)respectively(p<0.05 for all associations). CONCLUSION: Glycaemic control after optimizing medical treatment improves arterial stiffness, LV myocardial strain, twisting and untwisting velocity in diabetics.

Homocysteine, cortisol, diabetes mellitus, and psychopathology.

OBJECTIVE: This study investigates the association of homocysteine and cortisol with psychological factors in type 2 diabetic patients. METHOD: Homocysteine, cortisol, and psychological variables were analyzed from 131 diabetic patients. Psychological factors were assessed with the Eysenck Personality Questionnaire (EPQ), Hostility and Direction of Hostility Questionnaire (HDHQ), the Symptom Checklist 90-R (SCL 90-R), the Zung Self-Rating Depression Scale (ZDRS), and the Maudsley O-C Inventory Questionnaire (MOCI). Blood samples were taken by measuring homocysteine and cortisol in both subgroups during the initial phase of the study (T0). One year later (T1), the uncontrolled diabetic patients were reevaluated with the use of the same psychometric instruments and with an identical blood analysis. RESULTS: The relation of psychoticism and homocysteine is positive among controlled diabetic patients (P value = 0.006 < 0.05) and negative among uncontrolled ones (P value = 0.137). Higher values of cortisol correspond to lower scores on extraversion subscale (r(p) = -0.223, P value = 0.010). Controlled diabetic patients showed a statistically significant negative relationship between homocysteine and the act-out hostility subscale (r(sp) = -0.247, P = 0.023). There is a statistically significant relationship between homocysteine and somatization (r(sp) = -0.220, P = 0.043). CONCLUSIONS: These findings support the notion that homocysteine and cortisol are related to trait and state psychological factors in patients with diabetes mellitus type 2.

The role of acetic acid on glucose uptake and blood flow rates in the skeletal muscle in humans with impaired glucose tolerance.

BACKGROUND/OBJECTIVES: Previous studies support the glucose-lowering effect of vinegar. However, the effect of vinegar on muscle glucose metabolism and endothelial function has not been studied in humans. This open, randomized, crossover, placebo-controlled study aims to investigate the effects of vinegar on muscle glucose metabolism, endothelial function and circulating lipid levels in subjects with impaired glucose tolerance (IGT) using the arteriovenous difference technique. SUBJECTS/METHODS: Eight subjects with IGT (4 males, age 46±10 years, body mass index 30±5) were randomised to consume 0.50 mmol vinegar (6% acetic acid) or placebo before a mixed meal. Plasma samples were taken for 300 min from the radial artery and the forearm vein for measurements of glucose, insulin, triglycerides, non-esterified fatty acids (NEFAs) and glycerol. Muscle blood flow was measured with strain gauge plethysmography. Glucose flux was calculated as the arteriovenous difference of glucose multiplied by the blood flow rates. RESULTS: Vinegar compared with placebo: (1) decreased arterial plasma insulin (Poverall<0.001; P75 min=0.014, ß=-42), (2) increased forearm blood flow (Poverall<0.001; P240 min=0.011, ß=1.53; P300 min=0.023, ß=1.37), (3) increased muscle glucose uptake (Poverall<0.001; P60 min=0.029, ß=2.78) and (4) decreased arterial plasma triglycerides (Poverall=0.005; P240 min<0.001, ß=-344; P300 min<0.001, ß=-373), without changing NEFA and glycerol. CONCLUSIONS: In individuals with IGT, vinegar ingestion before a mixed meal results in an enhancement of muscle blood flow, an improvement of glucose uptake by the forearm muscle and a reduction of postprandial hyperinsulinaemia and hypertriglyceridaemia. From this point of view, vinegar may be considered beneficial for improving insulin resistance and metabolic abnormalities in the atherogenic prediabetic state.

Skeletal muscle insulin resistance in morbid obesity: the role of interleukin-6 and leptin.

BACKGROUND: Although insulin resistance in obesity is established, the link between excess body fat and skeletal muscle insulin resistance is obscure. The aim of this study was to investigate whether cytokines secreted from the subcutaneous adipose tissue are related to the sensitivity of glucose metabolism to insulin in skeletal muscle. METHODS: A meal was given to 14 obese and 10 non-obese women. Plasma samples were taken for 360 min from a forearm vein and from the radial artery for glucose and insulin measurements. Interleukin-6, leptin, TNFα, resistin and adiponectin were measured preprandially from the radial artery and from the superficial epigastric vein. Forearm blood flow was measured with plethysmography. RESULTS: (1) In obese vs non-obese: (a) Glucose uptake by skeletal muscle was decreased (AUC (0-360)369 ± 55 vs. 877 ± 146 µmol/100 g tissue, p=0.001) (b) arterial interleukin-6 (2.5 ± 0.5 vs. 1 ± 0.1 pg/ml, p=0.013) and subcutaneous venous interleukin-6 (5 ± 0.5 vs. 3.4 ± 0.5 pg/ml, p=0.027) were increased (c) arterial leptin (63 ± 7 vs. 5 ± 0.6 ng/ml, p<0.0001) and subcutaneous venous leptin 80 ± 8 vs. 6.5 ± 0.7 ng/ml, p<0.0001) were increased. (2) Arterial interleukin-6 (p=0.002) and subcutaneous venous interleukin-6 (p=0.014) were negatively associated with forearm glucose uptake in obese. (3) No association was found between leptin and forearm glucose uptake, after correcting with fat mass. CONCLUSIONS: In morbid obesity: (1) Subcutaneous adipose tissue releases interleukin-6 which could then mediate insulin resistance in skeletal muscle. (2) Although there is increased secretion of leptin by the subcutaneous adipose tissue, leptin levels are not correlated to the sensitivity of glucose metabolism to insulin in muscle.

Effect of hyperthyroidism on clearance and secretion of glucagon in man.

OBJECTIVE: Glucagon has been proposed to contribute to the increased glucose production found in hyperthyroidism. However, fasting plasma glucagon levels are not increased in hyperthyroidism suggesting that the activity of the α-cell is normal. Nevertheless, an increase in the clearance rate of glucagon may mask increased glucagon secretion. This study was designed to examine the effects of hyperthyroidism on the kinetics of glucagon. DESIGN AND METHODS: A primed-continuous infusion of glucagon was administered to 9 euthyroid and 9 hyperthyroid subjects at 3 sequential rates (1,200, 3,000 and 6,000 pg/kg/min, each given for 2 h). Arterialized blood was drawn at 15-30 min intervals for determination of glucagon. RESULTS: Fasting plasma glucagon levels were comparable in euthyroids (195±8 pg/ml) and hyperthyroids (231±16 pg/ml). During infusions (1,200, 3,000 and 6,000 pg/kg/min), plasma glucagon increased to 387±19, 624±44 and 977±51 pg/ml in euthyroids and to 348±23, 597±42 and 938±56 pg/ml in hyperthyroids respectively. At these infusion rates, metabolic clearance of glucagon (ml/kg/min) was 6.6±0.5, 7.4±0.6 and 7.9±0.5 in euthyroids and 12.6±2, 8.9±1 and 8.8±0.6 in hyperthyroids, respectively. Metabolic clearance of glucagon differed between hyperthyroids and euthyroids at 1 200 pg/kg/min infusion rate (p=0.001). The basal delivery rate of glucagon (ng/kg/min) was 1.3±0.1 in euthyroids and 2.9±0.6 in hyperthyroids (p=0.0005). CONCLUSIONS: In hyperthyroidism, the secretion and metabolic clearance rates of glucagon are increased. These effects may explain the changes in plasma glucagon levels observed in hyperthyroidism and support the important role of glucagon in increasing endogenous glucose production in this condition.

Rates of lipid fluxes in adipose tissue in vivo after a mixed meal in morbid obesity.

OBJECTIVE: Although insulin resistance in obesity is established, information on insulin action on lipid fluxes, in morbid obesity, is limited. This study was undertaken in morbidly obese women to investigate insulin action on triacylglycerol fluxes and lipolysis across adipose tissue. SUBJECTS AND DESIGN: A meal was given to 26 obese (age 35+/-1 years, body mass index 46+/-1 kg m(-2)) and 11 non-obese women (age 38+/-2 years, body mass index 24+/-1 kg m(-2)). Plasma samples for glucose, insulin, triglycerides and non-esterified fatty acids (NEFAs) were taken for 360 min from a vein draining the abdominal subcutaneous adipose tissue and from the radial artery. Adipose tissue blood flow was measured with (133)Xe. RESULTS: In obese vs non-obese: (1) Arterial glucose was similar, but insulin was increased (P=0.0001). (2) Adipose tissue blood flow was decreased (P=0.0001). (3) Arterial triglycerides (P=0.0001) and NEFAs (P=0.01) were increased. (4) Lipoprotein lipase was decreased (P=0.0009), although the arteriovenous triglyceride differences were similar. (5) Veno-arterial NEFA differences across the adipose tissue were similar. (6) NEFA fluxes and hormone-sensitive lipase-derived glycerol output from 100 g adipose tissue were not different. (7) Total adipose tissue NEFA release was increased (P=0.02). CONCLUSIONS: In morbid obesity: (a) hypertriglycerinemia could be attributed to a defect in the postprandial dynamic adjustment of triglyceride clearance across the adipose tissue, partly caused by blunted BF; and (b) postprandially, there is an impairment of adipose tissue to buffer NEFA excess, despite hyperinsulinemia.

Studies of insulin resistance in patients with clinical and subclinical hypothyroidism.

OBJECTIVE: Although clinical hypothyroidism (HO) is associated with insulin resistance, there is no information on insulin action in subclinical hypothyroidism (SHO). DESIGN AND METHODS: To investigate this, we assessed the sensitivity of glucose metabolism to insulin both in vivo (by an oral glucose tolerance test) and in vitro (by measuring insulin-stimulated rates of glucose transport in isolated monocytes with flow cytometry) in 21 euthyroid subjects (EU), 12 patients with HO, and 13 patients with SHO. RESULTS: All three groups had comparable plasma glucose levels, with the HO and SHO having higher plasma insulin than the EU (P<0.05). Homeostasis model assessment index was increased in HO (1.97+/-0.22) and SHO (1.99+/-0.13) versus EU (1.27+/-0.16, P<0.05), while Matsuda index was decreased in HO (3.89+/-0.36) and SHO (4.26+/-0.48) versus EU (7.76+/-0.87, P<0.001), suggesting insulin resistance in both fasting and post-glucose state. At 100 microU/ml insulin: i) GLUT4 levels on the monocyte plasma membrane were decreased in both HO (215+/-19 mean fluorescence intensity, MFI) and SHO (218+/-24 MFI) versus EU (270+/-25 MFI, P=0.03 and 0.04 respectively), and ii) glucose transport rates in monocytes from HO (481+/-30 MFI) and SHO (462+/-19 MFI) were decreased versus EU (571+/-15 MFI, P=0.04 and 0.004 respectively). CONCLUSIONS: In patients with HO and SHO: i) insulin resistance was comparable; ii) insulin-stimulated rates of glucose transport in isolated monocytes were decreased due to impaired translocation of GLUT4 glucose transporters on the plasma membrane; iii) these findings could justify the increased risk for insulin resistance-associated disorders, such as cardiovascular disease, observed in patients with HO or SHO.

Glucose transporter expression on the plasma membrane of resting and activated white blood cells.

BACKGROUND: In white blood cells (WBC), the increase in glucose utilization is a prominent feature during immune response and this depends on the function of specific glucose transporter (GLUT) isoforms. The objective was to examine the effects of activation by Phorbol 12-myristate 13-acetate (PMA) or lipopolysaccharide (LPS) and insulin on the expression of GLUT isoforms in all subpopulations of WBC. MATERIALS AND METHODS: Blood was withdrawn from 27 healthy subjects. The expression of GLUT1, GLUT3 and GLUT4 on the plasma membrane of resting and activated monocytes, T- and B-lymphocytes and polymorphonuclear cells (PMNs) was determined in the absence and presence of physiological concentrations of insulin, by flow cytometry. RESULTS: GLUT1 did not respond to insulin in either resting or PMA/LPS activated state. In the resting state, monocytes and B-lymphocytes increased the abundance of GLUT3 and GLUT4 on their plasma membrane in response to insulin; in contrast, T-lymphocytes and PMNs were unresponsive to insulin. In the activated state, monocytes, B- and T- lymphocytes increased the expression of all three GLUT isoforms on their plasma membrane, whilst PMNs increased only GLUT1 and GLUT3; in all WBC, insulin augmented the expression of GLUT4 and GLUT3 isoforms in addition to the stimulation provided by the PMA or LPS treatment alone. CONCLUSION: Activation of WBC leads to increased expression of GLUT1, GLUT3 and GLUT4 isoforms on their plasma membrane; this process was further augmented by insulin. During infection, these mechanisms may help to redistribute glucose as a potential source of energy away from peripheral tissues and direct it towards cells that mediate the immune response and are therefore crucial to survival.

Dermatomyositis associated with breast cancer.

An increased risk of underlying malignancy has been found in patients with dermatomyositis (DM). The risk is increased even in patients with DM aged 45 or younger and remains high for many years after diagnosis. Breast carcinoma does not represent the most common solid tumor associated with this autoimmune disorder. In the present report, two new cases of DM associated with breast cancer are described, together with an extensive literature review.

Restoration of early insulin secretion after a meal in type 2 diabetes: effects on lipid and glucose metabolism.

BACKGROUND: In type 2 diabetes (T2D) insulin secretion after a meal is delayed; this may have an impact on the development of hyperglycaemia and hyperlipidaemia. DESIGN: To investigate this, a meal was given to 15 T2D (age 52 +/- 2 years, BMI 25 +/- 0.8 kg m(-2)) on three different occasions: (1) without treatment, (2) after 120 mg of nateglinide before the meal (acute treatment), and (3) after 3 months of nateglinide (120 mg t.i.d., chronic treatment). Fifteen healthy subjects (CON, age 48 +/- 2 years, BMI 24 +/- 0.5 kg m(-2)) were also studied. Blood was withdrawn for 360 min from veins draining the anterior abdominal subcutaneous adipose tissue (AD) and from an arterialized hand vein. Blood flow (BF) in AD was measured with (133)Xe. Lipoprotein lipase activity (LPL) was calculated as the triacylglycerol (TAG) flux across AD, and hormone-sensitive lipase (HSL) as the glycerol flux minus LPL. RESULTS: (1) In T2D the increase in prandial insulin secretion was delayed; postprandial nonesterified fatty acid (NEFA) and TAG levels in blood were increased, while BF, LPL and TAG clearance were blunted vs. CON. (2) Acute or chronic nateglinide treatment induced a prompt increase in prandial insulin secretion, resulting in a decrease in blood glucose and NEFA levels owing to suppression of HSL, while BF, LPL and TAG clearance remained suppressed. CONCLUSIONS: In T2D, restoration of early phase insulin secretion improved postprandial hyperglycaemia and suppressed endogenous lipolysis, resulting in suppression of NEFA levels. These results suggest that in nonobese T2D, metabolic defects may result, to a large extent, from the delay in prandial insulin secretion.