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

Type 2 diabetes is characterised by both impaired insulin secretion and insulin resistance but their relative contribution to the development of hyperglycaemia may differ due to heterogeneity of the disease. Under most circumstances, insulin resistance is the earliest detectable defect in pre-diabetic individuals but it is not known whether this is the primary defect or secondary to other abnormalities such as abdominal obesity with excessive free fatty acid turnover and increased lipid deposits in muscle. Initially, enhanced insulin secretion can compensate for the insulin resistance but early phase insulin secretion is impaired. In the transition from normal to impaired and diabetic glucose tolerance, insulin sensitivity deteriorates about 40% whereas insulin secretion deteriorates 3-4 fold. In addition to insulin resistance, the metabolic syndrome includes hypertension, dyslipidaemia, obesity and microalbuminuria. In patients with manifest diabetes, chronic hyperglycaemia can result in further deterioration of insulin sensitivity and secretion (glucotoxicity), which is aggravated by elevated free fatty acids (lipotoxicity). Abdominal obesity and insulin resistance are strongly correlated and studies have aimed at understanding the genetic basis. Candidate genes for the metabolic syndrome include those for the beta 3-adrenergic receptor, lipoprotein lipase, hormone sensitive lipase, peroxisome proliferator-activated receptor-gamma, insulin receptor substrate-1 and glycogen synthase. Therefore, type 2 diabetes is multigenic and appears to represent a collision between thrifty genes and an affluent society. Successful management will require treatments targeted at defects of both insulin secretion and insulin resistance.
 ...
PMID:Pathogenesis of type 2 diabetes: the relative contribution of insulin resistance and impaired insulin secretion. 1196 29

Tumor necrosis factor-alpha (TNF-alpha) is a contributing cause of the insulin resistance seen in obesity and obesity-linked type 2 diabetes, but the mechanism(s) by which TNF-alpha induces insulin resistance is not understood. By using 3T3-L1 adipocytes and oligonucleotide microarrays, we identified 142 known genes reproducibly upregulated by at least threefold after 4 h and/or 24 h of TNF-alpha treatment, and 78 known genes downregulated by at least twofold after 24 h of TNF-alpha incubation. TNF-alpha-induced genes include transcription factors implicated in preadipocyte gene expression or NF-kappaB activation, cytokines and cytokine-induced proteins, growth factors, enzymes, and signaling molecules. Importantly, a number of adipocyte-abundant genes, including GLUT4, hormone sensitive lipase, long-chain fatty acyl-CoA synthase, adipocyte complement-related protein of 30 kDa, and transcription factors CCAAT/enhancer binding protein-alpha, receptor retinoid X receptor-alpha, and peroxisome profilerator-activated receptor gamma were significantly downregulated by TNF-alpha treatment. Correspondingly, 24-h exposure of 3T3-L1 adipocytes to TNF-alpha resulted in reduced protein levels of GLUT4 and several insulin signaling proteins, including the insulin receptor, insulin receptor substrate 1 (IRS-1), and protein kinase B (AKT). Nuclear factor-kappaB (NF-kappaB) was activated within 15 min of TNF-alpha addition. 3T3-L1 adipocytes expressing IkappaBalpha-DN, a nondegradable NF-kappaB inhibitor, exhibited normal morphology, global gene expression, and insulin responses. However, absence of NF-kappaB activation abolished suppression of >98% of the genes normally suppressed by TNF-alpha and induction of 60-70% of the genes normally induced by TNF-alpha. Moreover, extensive cell death occurred in IkappaBalpha-DN-expressing adipocytes after 2 h of TNF-alpha treatment. Thus the changes in adipocyte gene expression induced by TNF-alpha could lead to insulin resistance. Further, NF-kappaB is an obligatory mediator of most of these TNF-alpha responses.
 ...
PMID:Tumor necrosis factor-alpha suppresses adipocyte-specific genes and activates expression of preadipocyte genes in 3T3-L1 adipocytes: nuclear factor-kappaB activation by TNF-alpha is obligatory. 1197 27

(1) Treatments for obesity are disappointing, and none has yet shown an effect on morbidity or mortality. Non drug treatments have not been assessed adequately. Long-term maintenance of weight loss requires long-term patient management. (2) Orlistat, a gastrointestinal lipase inhibitor, is licensed in Europe for the treatment of obesity, in combination with a low-calorie diet. (3) The risk-benefit ratio of orlistat could not be estimated from the initial assessment file in 1999. There were fears over a possible increase in the risk of breast cancer. (4) Few new efficacy data have been obtained since. Medium-term trials (12-24 months) show that orlistat (120 mg three times a day), combined with dietary intervention, has a minor supplementary effect on weight loss (-3.5 kg on average). (5) A meta-analysis of three of the four available comparative trials lasting two years failed to conclude that orlistat prevents the onset of type 2 diabetes. Likewise, there is no firm evidence that orlistat lowers cardiovascular morbidity or mortality. (6) Orlistat frequently has gastrointestinal adverse effects, and case reports of hypertension have been published. Orlistat probably interacts with a number of other drugs. (7) Follow-up of nearly 8,000 women for only a few years showed no increase in the incidence of breast cancer on orlistat. (8) In practice, dietary intervention and risk factor management remain the cornerstones in the management of obesity. Orlistat is only a minor, optional and temporary aid, although it appears so far to have no serious adverse effects.
 ...
PMID:Orlistat: a second look. At best, a minor adjunct to dietary measures. 1198 67

Obesity is a chronic disease so that results of obesity treatment should only be evaluated on a long-term basis. The present paper aims at analyzing the long-term (1 year or more) results of three anti-obesity approaches, i.e. lifestyle modifications, pharmacological treatments and surgical procedures. Dietary interventions include diets with moderate calorie restriction and very-low energy diets (VLED). Even if an initial greater weight loss is observed with VLED, no study has conclusively shown that the long-term approaches including VLED are better than non-VLED programmes. Physical activity is not the most efficient method of initial weight loss, but it appears to be more crucial for maintaining weight loss once it has occurred. In general, long-term results of lifestyle modifications are disappointing because of poor compliance. Several 1-2 year large-scale randomized placebo-controlled clinical trials with orlistat, an intestinal lipase inhibitor, and sibutramine, a central appetite regulator, have demonstrated that both drugs significantly, although modestly on average, increase weight reduction, almost double the number of responders (weight loss >=5 or 10% of initial body weight) and improve weight maintenance up to 2 years. Surgical procedures provide a much greater weight reduction than medical interventions in patients with morbid obesity, particularly after a follow-up of several years. Weight loss is greater with gastric bypass, inducing some malbsorption, than with gastroplasty, a pure gastric restriction technique. Associated risk factors such as markers of insulin resistance syndrome and type 2 diabetes are remarkably reduced, but no prospective study of morbidity or mortality is available yet. In all cases, the management of obesity requires a multidisciplinary approach to improve the success rate.
 ...
PMID:Results of obesity treatment. 1199 82

The prevalence of Type 2 diabetes mellitus (DM-2) is increasing throughout the world and poses a major public health concern. With the majority of patients DM-2 are overweight or obese and weight loss is generally recommended, both as a first-line therapy and as an adjunct to pharmacological therapies. However, it is generally acknowledged that weight loss, a difficult goal for many overweight and obese individuals, is especially difficult for those with DM-2 and there is interest in whether pharmacological adjuncts may be useful for this purpose. Orlistat is an intestinal lipase inhibitor previously approved for the treatment of obesity. During the past several years, clinical trials have been completed concerning the use of orlistat in the treatment of overweight or obese patients with DM-2. The purpose of this review is to examine the results of these clinical trials. Data on > 2500 orlistat-treated patients with DM-2 are reviewed and summarised. Orlistat therapy led to greater weight loss and improved metabolic control in overweight and obese patients with DM-2.
 ...
PMID:Orlistat in the treatment of Type 2 diabetes mellitus. 1199 37

In patients with familial combined hyperlipidemia (FCHL) and type 2 diabetes (DM2) organ-specific differences in insulin resistance may exist. In FCHL and DM2 in vivo insulin mediated muscle glucose uptake and inhibition of lipolysis were studied by euglycemic hyperinsulinemic clamp. Insulin mediated glucose uptake was impaired to the same extent in both FCHL and DM2. Only FCHL subjects showed no reduction in plasma glycerol concentrations during insulin infusion and incomplete suppression of plasma free fatty acid (FFA) concentrations combined. This finding indicated that insulin-induced suppression of lipolysis, or glycerol/FFA utilization, or both, were impaired in FCHL, in contrast to DM2 or control subjects. To analyze these possibilities in more detail, control, FCHL, and DM2 adipocytes were studied in vitro. In contrast to adipocytes from DM2 or control subjects, no reduction in medium FFA concentration was detected with FCHL adipocytes after incubation with insulin. This finding indicated impaired intracellular FFA utilization, most likely impaired FFA re-esterification. Genetic linkage analysis in 18 Dutch families with FCHL revealed no evidence for involvement of LIPE, the hormone sensitive lipase gene, indicating that genetic variation in adipocyte lipolysis by LIPE is not the key defect in FCHL. In conclusion, FCHL as well as DM2 subjects exhibited in vivo insulin resistance to glucose disposal, which occurs mainly in muscle. FCHL subjects showed insulin resistant adipose tissue lipid metabolism, in contrast to DM2 and controls. The different pattern of organ-specific insulin resistance in FCHL versus DM2 advances our understanding of differences and similarities in phenotypes between these disorders.
 ...
PMID:Evidence of insulin resistant lipid metabolism in adipose tissue in familial combined hyperlipidemia, but not type 2 diabetes mellitus. 1220 6

Hormone-sensitive lipase (HSL) is an intracellular neutral lipase that is capable of hydrolyzing triacylglycerols, diacylglycerols, monoacylglycerols, and cholesteryl esters, as well as other lipid and water soluble substrates. HSL activity is regulated post-translationally by phosphorylation and also by pretranslational mechanisms. The enzyme is highly expressed in adipose tissue and steroidogenic tissues, with lower amounts expressed in cardiac and skeletal muscle, macrophages, and islets. Studies of the structure of HSL have identified several amino acids and regions of the molecule that are critical for enzymatic activity and regulation of HSL. This has led to important insights into its function, including the interaction of HSL with other intracellular proteins, such as adipocyte lipid binding protein. Accumulating evidence has defined important functions for HSL in normal physiology, affecting adipocyte lipolysis, steroidogenesis, spermatogenesis, and perhaps insulin secretion and insulin action; however, direct links between abnormal expression or genetic variations of HSL and human disorders, such as obesity, insulin resistance, type 2 diabetes, and hyperlipidemia, await further clarification. The published reports examining the regulation, and function of HSL in normal physiology and disease are reviewed in this paper.
 ...
PMID:Hormone-sensitive lipase: control of intracellular tri-(di-)acylglycerol and cholesteryl ester hydrolysis. 1236 42

Obesity is a major chronic health problem in adults. It is a complex, multifactorial disorder characterised by excess accumulation of adipose tissue. It is associated with a number of complications including cardiovascular disease, hypertension, type 2 diabetes, dyslipidaemia and cancer. A weight loss in the order of 5-10% is associated with clinically meaningful reductions with respect to all comorbidities. Diet and exercise has been the cornerstone of weight management therapy, but this approach has limitations, especially for weight maintenance. Previous drugs used in obesity had serious side effects including valvular heart disease. However, recent drugs like orlistat and sibutramine have been rigorously tested and proven safe. Orlistat, a lipase inhibitor, inhibits absorption of dietary fat by approximately 30%. Taken with a hypocaloric diet, it produces and maintains clinically meaningful weight loss. Sibutramine is a centrally-acting agent which enhances satiety and thermogenesis by inhibiting serotonin and noradrenaline re-uptake. It is appropriate for patients who are unable to lose weight by lifestyle modification.
 ...
PMID:Pharmacological management of obesity. 1247 68

This study evaluated the postprandial (PP) response to an oral fat load in 28 male patients with type 2 diabetes (mean HbA1c of 5.1%), all receiving metformin and performing physical exercise, compared with healthy subjects. The effects of micronized fenofibrate (200 mg once daily) on triglycerides (TG) and retinyl palmitate (RP) responses, lipoprotein mass concentrations, post-heparin lipase activities and coagulation factors were investigated after a 16-week double-blind, placebo-controlled period. Higher and delayed TG response after the oral fat load (P<0.001) corresponding to increases in both intestinally and endogenous TG-rich lipoproteins and lower lipoprotein lipase (LPL) activity 30 and 60 min post-heparin injection (P<0.05) were observed in the patients as compared with controls. Fasting PAI-1 activity, 6 h PP Factor VII and PAI-1 activities were higher in patients (P=0.036, P=0.032 and P=0.017, respectively). After fenofibrate treatment, TG and RP responses and peak LPL activity were no more significantly different from controls at baseline. Compared with placebo, fasting TG-rich lipoproteins and HDL(3) mass concentrations were significantly lower and higher, respectively; PP chylomicrons and very low density lipoprotein (VLDL) mass concentrations were lower; fasting and PP fibrinogen levels were significantly reduced after fenofibrate treatment. Diabetes control was unchanged throughout the study. Fenofibrate normalized the abnormal PP response and improved the fasting lipoprotein abnormalities in patients with type 2 diabetes and optimal glucose control.
 ...
PMID:Micronized fenofibrate normalizes the enhanced lipidemic response to a fat load in patients with type 2 diabetes and optimal glucose control. 1248 62

Type 2 diabetes is the most common metabolic disease. The cost of diabetes to the individual and to society, and the pandemic prevalence makes disease prevention of extreme importance. Persons with impaired glucose tolerance, modest elevations in blood glucose that remain below levels diagnostic for diabetes, are at increased risk of progression to overt diabetes. New studies evaluate the role of lifestyle interventions including diet and exercise, and the potential role of multiple classes of pharmaceutical agents including the insulin sensitizers, biguanides and thiazolidendiones, and carbohydrase and lipase inhibitors in disease prevention of such high-risk individuals. Many of these strategies appear to be effective to delay, and perhaps prevent, the development of type 2 diabetes and thus should be considered for broader clinical application. Awareness of the extent of the problem and the potential benefits of prevention needs to be raised in both physicians and in the at high risk population.
 ...
PMID:Prevention of type 2 diabetes: are we ready? 1271 98


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>