Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011860 (type 2 diabetes)
 57,723 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Increased plasma plasminogen activator inhibitor-1 (PAI-1) has been implicated in the development of vascular disease. In type 2 diabetes mellitus high PAI-1 levels are associated with increased plasma concentrations of free fatty acids (FFA) and triacylglycerol indicating an association or a causal relationship. To answer that question, the effect of FFA/triacylglycerol on plasma PAI-1 was examined. Ten healthy male volunteers were studied for 6 h during infusion of triacylglycerol [1.5 ml/min]/heparin [0.2 IU/(kg.min)] (LIP; n=10), saline only (SAL; n=10), and saline/heparin (HEP; n=5). Plasma insulin concentrations were kept constant at approximately 35 pmol/l by intravenous somatostatin-insulin infusions and there was no significant change in plasma glucose levels during any of the study protocols. LIP increased plasma triacylglycerol and FFA approximately 3- (p < 0.001) and approximately 8- (p < 0.000001) fold, respectively, within 90 min. Baseline plasma PAI-1 measured by a bio-immunoassay was similar in HEP (11.4 +/- 2.8 ng/ml), SAL (16.6 +/- 3.6 ng/ml), and LIP studies (15.2 +/- 3.4 ng/ml). Since studies were initiated in the morning, PAI-1 decreased (p < 0.025) over time following its normal diurnal variation to 6.4 +/- 2.0 ng/ml and 4.0 +/- 2.4 ng/ml at 360 min in SAL and HEP, respectively. During LIP, however, PAI-1 increased to approximately 2.6 fold higher levels than during SAL at 360 min (16.4 +/- 4.0 ng/ml, p < 0.01). While tissue plasminogen activator (tPA) and adipsin, an adipocyte derived protease, were unaffected by LIP, changes in soluble vascular cell adhesion molecule-1 (sVCAM-1) were significantly correlated (p = 0.02) with those seen for PAI-1. This suggests that hyperlipidemia independent of insulin and plasma glucose levels stimulates vascular tissue and in turn might induce an increase in plasma PAI-1. PAI-1 then could contribute to the development of atherothrombotic vascular disease.
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PMID:Increased plasma levels of plasminogen activator inhibitor-1 and soluble vascular cell adhesion molecule after triacylglycerol infusion in man. 1295 10

Type 2 diabetes is characterised by insulin resistance in association with clustering of atherothrombotic risk factors (dysglycaemia, hyperinsulinaemia, hypertension, raised triglyceride, low HDL cholesterol and increased levels of plasminogen activator inhibitor-1 (PAI-1) and clotting factor VII). There is a 3-5 fold increase in risk of myocardial infarction rising to 10-20 fold in the presence of microalbuminuria and overall around 70-75% of subjects with type 2 diabetes die of cardiovascular disease. However, classical risk factors which associate with insulin resistance do not account for all the increased burden of vascular disease in diabetic subjects. Metformin is a biguanide compound which is antihyperglycaemic, reduces insulin resistance and has cardioprotective effects on lipids, thrombosis and blood flow. Metformin has a weight neutral/weight lowering effect and reduces hypertriglyceridaemia, elevated levels of PAI-1, factor VII and C-reactive protein. In addition recent studies indicate that metformin has direct effects on fibrin structure/function and stabilises platelets, two important components of arterial thrombus. The United Kingdom Prospective Diabetes Study (UKPDS) reported that metformin was associated with a 32% reduction in any diabetes related endpoint (p<0.002), a 39% reduction in myocardial infarction (p<0.01) and a non-significant 29% fall in microvascular complications. The figures for macrovascular complications compare favourably for those described for other cardioprotective agents such as ACE inhibitors and statins. These findings confirm metformin as first line therapy in the management of obese insulin resistant type 2 diabetes and in the prevention of the vascular complications of this common condition.
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PMID:Beneficial effects of metformin on haemostasis and vascular function in man. 1450

Carbonyl stress is one of the important mechanisms of tissue damage in vascular complications of diabetes. In the present study, we observed that the plasminogen activator inhibitor-1 (PAI-1) levels in serum and its gene expression in adipose tissue were up-regulated in aged OLETF rats, model animals of obese type 2 diabetes. To study the mechanism of PAI-1 up-regulation, we examined the effect of advanced glycation end products (AGEs) and the product of lipid peroxidation (4-hydroxy-2-nonenal (HNE)), both of which are endogenously generated under carbonyl stress. Stimulation of primary white adipocytes by either AGE or HNE resulted in the elevation of PAI-1 in culture medium and at mRNA levels. The up-regulation of PAI-1 was also observed by incubating the cells in high glucose medium (30 mm, 48 h). The stimulatory effects by AGE or high glucose were inhibited by antioxidant, pyrrolidine dithiocarbamate, and reactive oxygen scavenger, probucol, suggesting a pivotal role of oxidative stress in white adipocytes. We also found that the effect by HNE was inhibited by antioxidant, N-acetylcysteine and that a specific inhibitor of glutathione biosynthesis, l-buthionine-S,R-sulfoximine, augmented the effect of subthreshold effect of HNE. Bioimaging of reactive oxygen species (ROS) by a fluorescent indicator, 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate, revealed ROS production in white adipocytes treated with AGE or HNE. These results suggest that cellular carbonyl stress induced by AGEs or HNE may stimulate PAI-1 synthesis in and release from adipose tissues through ROS formation.
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PMID:Cellular carbonyl stress enhances the expression of plasminogen activator inhibitor-1 in rat white adipocytes via reactive oxygen species-dependent pathway. 1461 81

The prevalence of overweight and obesity continues to increase rapidly in the United States, with more than half of all adults currently overweight or obese. In general, people become obese because of a combination of inherited genes and a lifestyle consisting of low levels of physical activity and consumption of excess calories. Obesity, especially the central or visceral type, is a predisposing factor for the development of type 2 diabetes mellitus, hypertension, and cardiovascular disease (CVD). Obesity and type 2 diabetes are associated with insulin resistance. The relation among obesity, insulin resistance, and CVD appears to develop at a relatively young age. Central obesity is linked with hyperinsulinemia, insulin resistance, dyslipidemia, and proinflammatory and prothrombotic clinical states. Adipose tissue synthesizes and secretes biologically active molecules that may affect CVD risk factors. These chemical messengers include adiponectin, resistin, leptin, plasminogen activator inhibitor-1, tumor necrosis factor-alpha, and interleukin-6. In overweight and obese individuals, weight loss may improve insulin sensitivity, leading to reduction in risk factors for CVD and, consequently, the potential for cardiovascular events. Agents that improve insulin sensitivity, such as the thiazolidinediones, have been shown to reduce visceral obesity. Decreases in visceral adipose tissue contribute to improvements in insulin sensitivity and blood pressure, and weight loss reduces serum levels of triglycerides and low-density lipoprotein cholesterol while increasing serum levels of high-density lipoprotein cholesterol. Reduction of risk factors suggests that the development of cardiovascular disease will be reduced by the improvement of insulin sensitivity and weight loss.
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PMID:Obesity as a cardiovascular risk factor. 1467 64

Insulin resistance is a key metabolic defect in type 2 diabetes that is exacerbated by obesity, especially if the excess adiposity is located intra-abdominally/centrally. Insulin resistance underpins many metabolic abnormalities-collectively known as the insulin resistance syndrome-that accelerate the development of cardiovascular disease. Thiazolidinedione anti-diabetic agents improve glycaemic control by activating the nuclear receptor peroxisome proliferator activated receptor-gamma (PPARgamma). This receptor is highly expressed in adipose tissues. In insulin resistant fat depots, thiazolidinediones increase pre-adipocyte differentiation and oppose the actions of pro-inflammatory cytokines such as tumour necrosis factor-alpha. The metabolic consequences are enhanced insulin signalling, resulting in increased glucose uptake and lipid storage coupled with reduced release of free fatty acids (FFA) into the circulation. Metabolic effects of PPARgamma activation are depot specific-in people with type 2 diabetes central fat mass is reduced and subcutaneous depots are increased. Thiazolidinediones increase insulin sensitivity in liver and skeletal muscle as well as in fat, but they do not express high levels of PPARgamma, suggesting that improvement in insulin action is indirect. Reduced FFA availability from adipose tissues to liver and skeletal muscle is a pivotal component of the insulin-sensitising mechanism in these latter two tissues. Adipocytes secrete multiple proteins that may both regulate insulin signalling and impact on abnormalities of the insulin resistance syndrome--this may explain the link between central obesity and cardiovascular disease. Of these proteins, low plasma adiponectin is associated with insulin resistance and atherosclerosis--thiazolidinediones increase adipocyte adiponectin production. Like FFA, adiponectin is probably an important signalling molecule regulating insulin sensitivity in muscle and liver. Adipocyte production of plasminogen activator inhibitor-1 (PAI-1), an inhibitor of fibrinolysis, and angiotensin II secretion are partially corrected by PPARgamma activation. The favourable modification of adipocyte-derived cardiovascular risk factors by thiazolidinediones suggests that these agents may reduce cardiovascular disease as well as provide durable glycaemic control in type 2 diabetes.
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PMID:Central role of the adipocyte in the insulin-sensitising and cardiovascular risk modifying actions of the thiazolidinediones. 1473 74

We have investigated the effect of atorvastatin on the endothelial function of patients with diabetes and subjects at risk for type 2 diabetes in a 12-wk, prospective, randomized, placebo-controlled, double-blind clinical trial. The flow- mediated dilation (FMD; endothelium dependent) and nitroglycerin-induced dilation (endothelium independent) in the brachial artery and the vascular reactivity at the forearm skin were measured. FMD improved in the atorvastatin-treated, at-risk subjects [median (25-75 percentile), 7.2% (2.9-9.6%) at exit visit vs. 6.6% (2.9-9.5%) at baseline; P < 0.05]. A similar improvement of FMD was found in atorvastatin-treated diabetic patients [median (25-75 percentile), 5.6 (3.9-7.9) at exit visit vs. 4.2 (3.2-7.2) at baseline; P = 0.07]. No changes were observed in nitroglycerin-induced dilation and the microcirculation reactivity measurements in either group. In the at-risk group, there was a decrease in the C-reactive protein [median (25-75 percentile), 0.12 mg/dl (0.07-0.27 mg/dl) at exit visit vs. 0.24 mg/dl (0.07-0.35 mg/dl) at baseline; P < 0.05] and TNF alpha [median (25-75 percentile), 2.6 pg/ml (1.8-4.1 pg/ml) at exit visit vs. 4.4 pg/ml (3.6-6.0 pg/ml) at baseline; P < 0.05] in the atorvastatin-treated patients, whereas in the diabetes group, a decrease in endothelin-1 (mean +/- SD, 0.97 +/- 0.29 pg/ml at exit visit vs. 1.19 +/- 0.42 pg/ml at baseline; P < 0.05) and plasminogen activator inhibitor-1 [median (25-75 percentile), 18 ng/ml (9-24 ng/ml) at exit visit vs. 27 ng/ml (7-41 ng/ml) at baseline; P < 0.05] were observed. We conclude that atorvastatin improves endothelial function and decreases levels of markers of endothelial activation and inflammation.
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PMID:The effects of atorvastatin on endothelial function in diabetic patients and subjects at risk for type 2 diabetes. 1476 90

JCR:LA-cp/cp obese rats and their lean controls were evaluated as a type 2 diabetic wound healing model and the healing quality was characterized. This model of insulin resistance has been used extensively to study atherosclerosis but has not previously been used to study wound healing. Six circular excisional wounds were made on the dorsum of each rat and followed to day 21. Tracings of the wounds were made and used to assess the rate of wound closure. Planimetry showed a significantly diminished contraction of wounds in obese rats, but no significant difference in reepithelialization was observed. Collagen content was determined from the hydroxyproline content in wounded and unwounded skin. There were significantly lower levels of hydroxyproline in the wounds of obese compared to lean animals at day 21. Histology showed adipose tissue in place of dermal tissue in the JCR:LA-cp/cp rat in both unwounded tissue and in the wound at day 21. Active transforming growth factor-beta 1 (TGF-beta 1) was measured in the serum using the plasminogen activator inhibitor-1/luciferase assay and serum total TGF-beta was measured using an enzyme-linked immunosorbent assay. Active TGF-beta was significantly higher in the serum of obese animals compared with lean animals, while total TGF-beta 1 was not significantly different between the groups. Both active and total TGF-beta was measured in tissue sections using the plasminogen activator inhibitor-1/luciferase assay. There was no significant difference in active TGF-beta between genotypes, while obese rats had significantly higher levels of total TGF-beta at day 21. These results indicate a deficiency in wound healing in obese animals characterized by decreased wound contraction, decreased collagen production, and changes in histology. The JCR:LA-cp rat develops insulin resistance, atherosclerosis and early type 2 diabetes and may be a good model for impairment of wound healing in humans with metabolic syndrome.
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PMID:The JCR:LA-cp rat: a novel model for impaired wound healing. 1497 69

We have evaluated the possible association of polycystic ovary syndrome (PCOS) with 15 genomic variants previously described to influence insulin resistance, obesity, and/or type 2 diabetes mellitus. Seventy-two PCOS patients and 42 healthy controls were genotyped for 15 variants in the genes encoding for paraoxonase (three variants), plasma cell differentiation antigen glycoprotein, human sorbin and SH3 domain containing 1, plasminogen activator inhibitor-1, peroxisome proliferator-activated receptor-gamma2, protein tyrosine phosphatase 1B (two variants), adiponectin (two variants), IGF1, IGF2, IGF1 receptor, and IGF2 receptor. Compared with controls, PCOS patients were more frequently homozygous for the -108T variant in paraoxonase (36.6% vs. 9.5%; P = 0.002) and homozygous for G alleles of the ApaI variant in IGF2 (62.9% vs. 38.1%; P = 0.018). Paraoxonase is a serum antioxidant enzyme and, because -108T alleles result in decreased paraoxonase expression, this increase in oxidative stress might result in insulin resistance. G alleles of the ApaI variant in IGF2 may increase IGF2 expression, and IGF2 stimulates adrenal and ovarian androgen secretion. In conclusion, the paraoxonase -108 C-->T variant and the ApaI polymorphism in the IGF2 gene are associated with PCOS and might contribute to increased oxidative stress, insulin resistance, and hyperandrogenism in this prevalent disorder.
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PMID:Association of the polycystic ovary syndrome with genomic variants related to insulin resistance, type 2 diabetes mellitus, and obesity. 1518 Oct 35

Insulin resistance in patients with type 2 diabetes is associated with an increased risk of cardiovascular events. While this can be partly explained by an impairment of direct insulin action on the endothelial cell, an independent contribution can be assigned also to the secretory dysfunction of the beta-cell. If the demand for insulin triggered by insulin resistance is arriving at a certain threshold, an insufficiency of the cleavage capacity of beta-cell carboxypeptidase H leads to an increased secretion of intact proinsulin in addition to the desired insulin molecule. Proinsulin, however, has been demonstrated to be an independent cardiovascular risk factor by stimulating plasminogen activator inhibitor-1 secretion and blocking fibrinolysis. A recently introduced intact proinsulin assay is able to distinguish between intact proinsulin and its specific and non-specific cleavage products. This assay allows for a pathophysiological staging of type 2 diabetes based on beta-cell secretion. It could be confirmed by a large epidemiological study (IRIS-2, 4,265 patients) that intact proinsulin is a highly specific marker for insulin resistance. It could also be shown in other studies that successful resistance treatment with insulin or glitazones led to a decrease in elevated proinsulin levels and, thus, to a decrease of cardiovascular risk, while the levels remained high during sulfonylurea therapy. Therefore, patients with increased fasting intact proinsulin values should be treated with a therapy focusing on insulin resistance. Assessment of beta-cell function by determination of intact proinsulin may facilitate the selection of the most promising therapy and may also serve to monitor treatment success in the further course of the disease.
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PMID:Role of intact proinsulin in diagnosis and treatment of type 2 diabetes mellitus. 1519 46

Recent progress in adipocyte-biology shows that adipocytes are not merely fat-storing cells but that they secrete a variety of hormones, cytekines, growth factors and other bioactive substabces, conceptualized as adipocytokines. These include plasminogen activator inhibitor 1(PAI-1), tumor necrosis factor(TNF-alpha), leptin and adiponectin. Dysregulated productions of these adipocytekines participate in the pathogenesis of obesity-associated metabolic syndrome such as insulin resistance, type 2 diabetes, hyperlipidemia, and vascular diseases. Increased productions of PAI-1 and TNF-alpha from accumulated fat contribute to the formation of thrombosis and insulin resistance in obesity, respectively. Lack of leptin causes metabolic syndrome. Adiponectin exerts insulin-sensitizing and anti-atherogenic effects, hence decrease of plasma adiponectin is causative for insulin resistance and atherosclerosis in obesity.
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PMID:[Adipocytokines and metabolic syndrome--molecular mechanism and clinical implication]. 1520 45


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