Obstructive sleep apnea syndrome (OSAS) has been associated with cardiovascular complications and insulin resistance has been implicated in the pathogenesis and progression of atherosclerosis. We investigated whether insulin resistance is associated with OSAS independent of obesity. A total of 183 male patients with OSAS and 52 healthy controls were assessed ...

Context: It is clinically relevant and of physiological interest to investigate whether GH-induced insulin resistance depends on the timing of GH exposure relative to when insulin sensitivity is assessed. Hypothesis: GH-induced insulin resistance is rapidly reversible. Design and Participants: Eight male GH-deficient patients underwent a 6-h euglycemic-hyperinsulinemic glucose clamp thrice ...

Eur J Clin Invest 2011 ABSTRACT: Background  Hyperlipidaemia, hyperglycaemia and hyperinsulinaemia, hallmarks of the postprandial state, have been also associated with increased oxidative stress and lipoprotein oxidation contributing to vascular injury and atherosclerosis. However, the specific links among metabolic disorders, postprandial state, insulin resistance and oxidative stress are still to ...

Context: The co-occurrence of insulin resistance (IR) and hypertension is a heritable condition leading to cardiovascular complications. Caveolin-1 (CAV1), a gene previously associated with metabolic dysfunction in animal and cellular models, may be a marker for these conditions in humans. Objective: The objective of the study was to examine the ...

Obesity is a highly prevalent health problem in Western countries that leads to many important diseases such as type 2 diabetes and metabolic syndrome being now considered an inflammatory chronic disease. Adipocytes are no longer considered passive cells storing fat since they are major producers of inflammatory cytokines during obesity. ...

Cellular resistance to insulin caused by reduced glucose transport and metabolism is a primary defect leading to the development of metabolic disease. While the etiology of insulin resistance is multifactorial, reduced insulin action is associated with impaired activity of the glucose transporter GLUT4 in insulin-sensitive tissues. Yet, the role of ...

PTP1B is a negative regulator of insulin signaling pathway. This study investigated the effects of compound CCF06240, a PTP1B inhibitor, on insulin sensitivity and lipid metabolic abnormalities in vivo and in vitro, respectively. The insulin resistant IRM mouse model was induced by HFD. The responses to insulin were determined by ...

Type 1 diabetes (T1D) results from the interaction of genetic and environmental factors. Previous studies indicate an association between detection of Enterovirus (EV) genome in blood and the clinical onset of T1D. Insulin resistance can also represent a risk factor for progression to clinically overt T1D. This study aimed at ...

The aim of this study was to evaluate the relationship between vitiligo and insulin resistance (IR). A total of 96 subjects were included in the study; 57 patients with vitiligo and 39 subjects in an age and a body mass index-matched control group. In fasting blood samples, insulin, C-peptide, glucose, ...

Quantification of skin changes due to acanthosis nigricans (AN), a disorder common among insulin-resistant diabetic and obese individuals, was investigated using two optical techniques: diffuse reflectance spectroscopy (DRS) and colorimetry. Measurements were obtained from AN lesions on the neck and two control sites of eight AN patients. A principal component/discriminant ...

AIM: The aims of this study were to determine the prevalence of hypertension in type 1 diabetes patients and to analyze its relationship with insulin resistance and other associated factors. DESIGN AND METHODS: A cross-sectional study on 291 patients with type 1 immune-mediated diabetes managed at two outpatient endocrinology clinics ...

Context: Roux-en-Y gastric bypass (RYGB) has been shown to induce rapid and durable reversal of type 2 diabetes. Objective: The aim of the study was to investigate a possible mechanism for the remission of type 2 diabetes after RYGB. Design: A cross-sectional, nonrandomized, controlled study was conducted. Surgery patients were ...

Context: Polycystic ovary syndrome (PCOS) affects 5-8% of fertile women and is often accompanied by insulin resistance, leading to increased risk of developing type 2 diabetes. Skeletal muscle from insulin-resistant PCOS subjects display reduced expression of nuclear encoded genes involved in mitochondrial oxidative metabolism. Objective: We aimed to investigate whether ...

Aspirin is a kind of anti-inflammatory drug and may be used to reverse hyperglycemia, hyperinsulinemia, and dyslipidemia by improving insulin resistance. We hypothesized that aspirin improves insulin resistance in type 2 diabetes by inhibiting hepatic nuclear factor kappa-β (NF-κB) activation and serum tumor necrosis factor-α (TNF-α). Adult male Wistar rats ...

Retinol binding protein 4 (RBP4) has been postulated to provide a new link between obesity and insulin resistance. We aimed to assess the relationship between serum RBP4 and insulin resistance by investigating serum RBP4 levels in children and adolescents according to degree of obesity and pubertal stage. A total of ...

Bile acids (BA) participate in the maintenance of metabolic homeostasis acting through different signaling pathways. The nuclear BA receptor farnesoid X receptor (FXR) regulates pathways in BA, lipid, glucose, and energy metabolism, which become dysregulated in obesity. However, the role of FXR in obesity and associated complications, such as dyslipidemia ...

Neutral lipids are stored in so-called lipid droplets, which are formed as small primordial droplets at microsomal membranes and increase in size by a fusion process. The fusion is catalyzed by the SNARE proteins SNAP23, syntaxin-5 and VAMP4. SNAP23 is involved in the insulin dependent translocation of GLUT4 to the ...

The primary player that induces insulin resistance has not been established. Here, we studied whether or not fat can cause insulin resistance in the presence of insulin deficiency. Our results showed that high fat diet (HFD) induced insulin resistance in C57BL/6 (B6) mice. The HFD-induced insulin resistance was largely prevented ...

Angiopoietin-like (Angptl)2, a member of the Angptl protein family, is predominantly secreted from adipose tissue and the heart. Here, we demonstrate that the expression of Angptl2 in epididymal adipose tissue of C57BL/6J mice shows pulsatility and circadian rhythmicity and that the rhythmicity was disrupted in high-fat-fed and leptin receptor-deficient diabetic ...

C57BL/6J and 129S6/Sv (B6 and 129) mice differ dramatically in their susceptibility to developing diabetes in response to diet- or genetically induced insulin resistance. A major locus contributing to this difference has been mapped to a region on mouse chromosome 14 that contains the gene encoding PKCδ. Here, we found ...

Under pathophysiological conditions such as obesity, excessive oxidation of nutrients may induce mitochondrial stress, leading to mitochondrial unfolded protein response (UPR(mt)) and initiation of a retrograde stress signaling pathway. Defects in the UPR(mt) and the retrograde signaling pathways may disrupt the integrity and homeostasis of the mitochondria, resulting in endoplasmic ...

Mitochondria and endoplasmic reticulum (ER) are two important metabolic organelles for the maintenance of cellular homeostasis and their functional defects are suspected to participate to the aetiology of type 2 diabetes (T2D). Particularly, excessive lipid intake and/or ectopic lipid accumulation in tissues (referred as lipotoxicity) are involved in alterations of ...

A placebo controlled prospective safety study of quick release bromocriptine in patients with type 2 diabetes has shown a 40% reduction in cardiovascular events. Possible explanations for this decrease are that through reestablishing diurnal variation a decrease in insulin resistance and its associated risk factors occurs. In addition, a decrease ...

The objectives of this study were to test the hypothesis that diabetes and impaired glucose tolerance (IGT), diabetes control and diabetes duration, and metabolic biomarkers in adults with normal glucose tolerance (NGT) are inversely associated with spirometry-measured lung function. We conducted a cross-sectional observational cohort study that included nonsmoking African ...

Visceral obesity has been defined as an important element of the metabolic syndrome and contributes to the development of insulin resistance and cardiovascular disease. Increasing endogenous levels of epoxyeicosatrienoic acids (EETs) are known for their analgesic, antihypertensive, and antiinflammatory effects. The availability of EETs is limited primarily by the soluble ...

BACKGROUND: Glycemic effects of the Women's Health Initiative (WHI) low-fat dietary intervention are unknown. OBJECTIVE: Our objective was to analyze the effects of the WHI low-fat dietary intervention on serum glucose and insulin and insulin resistance up to 6 y after random assignment. DESIGN: Postmenopausal WHI Dietary Modification trial intervention ...

BACKGROUND: Prolactin improves glucose homeostasis by increasing β-cell mass in certain conditions such as pregnancy whereas hyperprolactinemia due to a pituitary gland adenoma tumor exacerbates insulin resistance. However, previous studies have not evaluated how prolactin modulates β-cell function and insulin sensitivity at different dosages. Here, we determined that chronic intraperitoneal ...

We recently showed that patients with mitochondrial diabetes are insulin resistant in skeletal muscle before the decline in insulin secretion is observed. In this study, we further evaluate whether insulin resistance is associated with increased ectopic fat accumulation and altered adipose and hepatic tissue insulin sensitivity. We studied 15 nonobese ...

The aim of this work was to study if the failure of the compensatory mechanisms in response to insulin resistance aggravates or its onset attenuates vascular damage. Thus, we analyzed the differential vascular damage induced by insulin resistance in obese brown adipose tissue insulin receptor knockout (BATIRKO) mice. BATIRKO mice ...

Two common variants (rs1387153, rs10830963) in MTNR1B have been reported to have independent effects on fasting blood glucose (FBG) levels with increased risk to type 2 diabetes (T2D) in recent genome-wide association studies (GWAS). In this investigation, we report the association of these two variants, and an additional variant (rs1374645) ...

Case: A 33-year-old male presented to the emergency department with complaints of polydipsia, polyuria, nausea, headaches, blurry vision and malaise. Lab work revealed a serum glucose level of 1166 mg/dl (64.8 mmol/L). The patient admitted to completing a cycle of androgenic anabolic steroids (AASs) for bodybuilding. His regimen consisted of ...

ABSTRACT: BACKGROUND: Obesity leads to an increase in inflammation and insulin resistance. This study determined antioxidant activity of flaxseed and its role in inflammation and insulin resistance in obese glucose intolerant people. METHODS: Using a randomized crossover design, nine obese glucose intolerant people consumed 40 g ground flaxseed or 40 ...

Mitochondrial dysfunction is associated with insulin resistance and type 2 diabetes. It has thus been suggested that primary and/or genetic abnormalities in mitochondrial function may lead to accumulation of toxic lipid species in muscle and elsewhere, impairing insulin action on glucose metabolism. Alternatively, however, defects in insulin signaling may be ...

Subjects with impaired fasting glucose (IFG) are at increased risk for type 2 diabetes. We recently demonstrated that IFG subjects have increased hepatic insulin resistance with normal insulin sensitivity in skeletal muscle. In this study, we quantitated the insulin secretion rate from deconvolution analysis of the plasma C-peptide concentration during ...

Insulin resistance is getting important in the course of type 1 diabetes mellitus. Visceral fat depot is associated with insulin resistance and assessment of epicardial fat thickness is a way of measuring visceral fat. The aim of the study was to measure epicardial adipose tissue (EAT) thickness and to determine ...

Objective:  Waveform analysis has been used to assess vascular resistance and predict cardiovascular events. We aimed to identify microvascular abnormalities in patients with impaired glucose tolerance (IGT) using ocular waveform analysis. The effects of pioglitazone were also assessed. Methods:  Forty patients with IGT and twenty-four controls were studied. Doppler velocity ...

BACKGROUND: According to the classification of polycystic ovary syndrome (PCOS) published by the Androgen Excess Society (AES), 10 different phenotypes of the condition are possible. The question remains of whether using these phenotypes might enable us to identify women with impaired insulin resistance or an impaired lipid profile among patients ...

Cardiomyocytes use glucose as well as fatty acids for ATP production. These substrates are transported into the cell by glucose transporter 4 (GLUT4) and the fatty acid transporter CD36. Besides being located at the sarcolemma, GLUT4 and CD36 are stored in intracellular compartments. Raised plasma insulin concentrations and increased cardiac ...

AIMS/HYPOTHESIS: Hepatic steatosis is strongly associated with hepatic and whole-body insulin resistance. It has proved difficult to determine whether hepatic steatosis itself is a direct cause of insulin resistance. In patients with familial hypobetalipoproteinaemia (FHBL), hepatic steatosis is a direct consequence of impaired hepatic VLDL excretion, independently of metabolic derangements. ...

Intestinal lipid dysregulation is a common feature of insulin resistant states. The present study investigated alterations in gene expression of key proteins involved in the active absorption of dietary fat and cholesterol in response to development of insulin resistance. Studies were conducted in two diet-induced animal models of insulin resistance: ...

Aims. The study aims to determine the effect of long-chain saturated and polyunsaturated (PUFA) fatty acids, specifically palmitic acid (PA; 16:0), docosahexaenoic acid (DHA; 22:6n-3) and linoleic acid (LA; 18:2n-6), and their interactions with factors from adipose tissue, on insulin sensitivity and lipid metabolism in skeletal muscle. Methods. L6 myotubes ...

No data is so far available on the relation between glucose values and insulin resistance and mortality, both at short- and long-term, in patients with acute heart failure syndromes (AHF). We prospectively assessed in 100 consecutive non-diabetic AHF patients whether acute glucose metabolism, as indicated by fasting glycemia and insulin ...

Accumulation of β-amyloid (Aβ) peptide in the brain is a major hallmark of Alzheimer's disease. An optimal brain insulin level promotes Aβ clearance, which may play protective roles against Alzheimer's disease. In this study we examined the role of dietary conditions leading to insulin resistance on amyloidosis in fructose-drinking rats. ...

Context: Endocrine effects of gastric bypass (GBP) surgery for obesity on glucose homeostasis are not fully understood. Main Objective: The main objective of the study was to assess the changes in plasma glucose, insulin, glucagon-like peptide-1 (GLP-1), leptin, somatostatin, glucose-dependent insulinotropic peptide, enteroglucagon, and glucagon early after GBP. Method: Twelve ...

To determine whether waist circumference (WC) is a better predictor of insulin resistance (IR) than body mass index (BMI) in U.S. adolescents aged 12-18 years. Using data from the National Health and Nutrition Examination Survey 1999-2002, we evaluated an ethnically diverse sample of 1,571 adolescents with regard to BMI, WC, ...

BACKGROUND: The metabolic syndrome is an obesity-associated disease manifested as severe insulin resistance, hyperlipidemia, hepatic steatosis, and diabetes. Previously we proposed that a nonapeptide, FIAWLVKGRamide, GLP-1(28-36)amide, derived from the gluco-incretin hormone, glucagon-like peptide-1 (GLP-1), might have insulin-like actions. Recently, we reported that the nonapeptide appears to enter hepatocytes, target to ...

Endothelin-1 (ET-1) modulates several vascular functions and plays an important role in the pathogenesis of insulin resistance. However, its role in the pathogenesis of impaired angiogenesis observed under insulin resistance conditions is not known. In the present study, we addressed this issue by analyzing the effect of ET-1 in human ...

Insulin resistance is among the most prevalent endocrine derangements in the world, and it is closely associated with major diseases of global reach including diabetes mellitus, atherosclerosis, nonalcoholic fatty liver disease, and ovulatory dysfunction. It is most commonly found in those with obesity but may also occur in an unusually ...

The use of atypical antipsychotics in the clinical management of schizophrenia and schizoaffective disorders has been associated with the development of insulin resistance. The present study evaluates the possible individual ameliorating effect of single daily oral treatments with 20 mg/kg/day of metformin and 0.1 mg/kg of glibenclamide in two groups ...

See article in J. Gastroenterol. Hepatol. 2011; 26: 875-883.