Pathophysiology Of Type 2 Diabetes Mellitus Research Articles

Assessment of telomerase activity in leukocytes of type 2 diabetes mellitus patients having or not foot ulcer: Possible correlation with other clinical parameters.

Telomerase is the enzyme that maintains telomere length by adding telomeric repeats after each cell division. Numerous metabolic factors such as obesity, insulin resistance or physical inactivity have been associated with shortened telomeres. In the present study, we assessed telomerase activity in diabetic patients having or not foot ulcer. A total of 90 adult patients with type 2 diabetes mellitus (T2DM) were studied. Patients were allocated into two groups according to the absence or presence of active foot ulcers as follows: Νon-ulcer group (N=58) and ulcer group (N=32). Our data revealed that the patients with diabetic ulcers had significantly greater waist circumference and neuropathy disability score, while exhibiting lower telomerase activity, indicating the possible existence of a common clinical profile among ulcer-bearing diabetic patients. Validation of our findings by extending the study in larger patient groups may contribute to the understanding of T2DM pathophysiology and its main clinical implications.

The Diabetes Gene and Wnt Pathway Effector TCF7L2 Regulates Adipocyte Development and Function.

The gene encoding for transcription factor 7-like 2 (TCF7L2) is the strongest type 2 diabetes mellitus (T2DM) candidate gene discovered to date. The TCF7L2 protein is a key transcriptional effector of the Wnt/β-catenin signaling pathway, which is an important developmental pathway that negatively regulates adipogenesis. However, the precise role that TCF7L2 plays in the development and function of adipocytes remains largely unknown. Using a combination of in vitro approaches, we first show that TCF7L2 protein is increased during adipogenesis in 3T3-L1 cells and primary adipocyte stem cells and that TCF7L2 expression is required for the regulation of Wnt signaling during adipogenesis. Inactivation of TCF7L2 protein by removing the high-mobility group (HMG)-box DNA binding domain in mature adipocytes in vivo leads to whole-body glucose intolerance and hepatic insulin resistance. This phenotype is associated with increased subcutaneous adipose tissue mass, adipocyte hypertrophy, and inflammation. Finally, we demonstrate that TCF7L2 mRNA expression is downregulated in humans with impaired glucose tolerance and adipocyte insulin resistance, highlighting the translational potential of these findings. In summary, our data indicate that TCF7L2 has key roles in adipose tissue development and function that may reveal, at least in part, how TCF7L2 contributes to the pathophysiology of T2DM.

The Hot and Potential Targets of Type 2 Diabetes Mellitus Treatment in Recent Decade

Type 2 diabetes mellitus (T2DM) has been a great burden to the world and it is urgent to develop new treatment strategies. Recently, many targets are currently available to aid in the drug discovery of this disease as our understanding of the pathophysiology of T2DM develops. This article is intended to provide a broad ranging overview of 14 prominent molecule targets being pursued for the treatment of diabetes in recent decade, with regard to their therapeutic rationale, small molecule modulators and application prospects. These targets are roughly divided into three general areas that correlate with insulin secretion, act on the insulin sensitivity, and have an effect on the complications, and these three kinds of targets are all helpful for the treatment of T2DM. Considering the fact that the lack of insulin become the main problem with the progress of T2DM, these targets based on insulin secretion would be more promising. Most of these new and potential targets mentioned in article lack clinical data and may or may not come to fruition for the treatment of diabetes in the future. Hence, further studies will illuminate the potential for each drug targets, although it is clear that this will take a lot of time.

The relationship between of ACE I/D and the MTHFR C677T polymorphisms in the pathophysiology of type 2 diabetes mellitus in a population of Brazilian obese patients.

Objectives This study aimed to evaluate the frequencies of the angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) and methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphisms in obese patients with and without type 2 diabetes mellitus (T2DM). Subjects and methods These polymorphisms were analyzed by polymerase chain reaction in 125 patients with obesity, 47 (T2DM) and 78 (Control Group). Results No significant difference was found on comparing the T2DM and Control Groups in respect to the genotypic frequencies of the polymorphisms - (II: 13.3% vs. 12.0%; ID: 37.8% vs. 37.3; DD: 48.9% vs. 50.7%; CC: 36.2% vs. 39.0%; CT: 46.8% vs. 49.3%; TT: 17.0% vs. 11.7%), and alleles (I: 32.2% vs. 30.7%; D: 67.8% vs. 69.3%; C: 59.6% vs. 63.6%; T: 40.4% vs. 36.4%) and their synergisms in the pathophysiology of T2DM. On analyzing the T2DM Group, there were no significant differences in the presence of complications. In this population of Brazilian obese patients, no correlation was found between the ACE and MTHFR polymorphisms in the development of T2DM. Conclusion Analyzing only the group with diabetes, there was also no relationship between these polymorphisms and comorbidities.

Comparison of Goto-Kakizaki rats and high fat diet-induced obese rats: Are they reliable models to study Type 2 Diabetes mellitus?

Type 2 Diabetes mellitus (T2DM) is an evident growing disease that affects different cultures throughout the world. T2DM occurs under the influence of three main factors: the genetic background, environmental and behavioral components. Obesity is strongly associated to the development of T2DM in the occident, while in the orient most of the diabetic patients are considered lean. Genetics may be a key factor in the development of T2DM in societies where obesity is not a recurrent public health problem. Herein, two different models of rats were used to understand their differences and reliability as experimental models to study the pathophysiology of T2DM, in two different approaches: the genetic (GK rats) and the environmental (HFD-induced obese rats) influences. GK rats were resistant to weight gain even though food/energy consumption (relative to body weight) was higher in this group. HFD, on the other hand, induced obesity in Wistar rats. White adipose tissue (WAT) expansion in this group was accompanied by immune cells infiltration, inflammation and insulin resistance. GK rats also presented WAT inflammation and insulin resistance; however, no immune cells infiltration was observed in the WAT of this group. Liver of HFD group presented fat accumulation without differences in inflammatory cytokines content, while liver of GK rats didn’t present fat accumulation, but showed an increase of IL-6 and IL-10 content and glycogen. Also, GK rats showed increased plasma GOT and GPT. Soleus muscle of HFD presented normal insulin signaling, contrary to GK rats, which presented higher content of basal phosphorylation of GSK-3β. Our results demonstrated that HFD developed a mild insulin resistance in Wistar rats, but was not sufficient to develop T2DM. In contrast, GK rats presented all the typical hallmarks of T2DM, such as insulin resistance, defective insulin production, fasting hyperglycemia/hyperinsulinemia and lipid plasma alteration. Thus, on the given time point of this study, we may conclude that only GK rats shown to be a reliable model to study T2DM.

Differential adipokine DNA methylation and gene expression in subcutaneous adipose tissue from adult offspring of women with diabetes in pregnancy

BackgroundOffspring of women with diabetes in pregnancy are at increased risk of type 2 diabetes mellitus (T2DM), potentially mediated by epigenetic mechanisms. The adipokines leptin, adiponectin, and resistin (genes: LEP, ADIPOQ, RETN) play key roles in the pathophysiology of T2DM. We hypothesized that offspring exposed to maternal diabetes exhibit alterations in epigenetic regulation of subcutaneous adipose tissue (SAT) adipokine transcription.We studied adipokine plasma levels, SAT gene expression, and DNA methylation of LEP, ADIPOQ, and RETN in adult offspring of women with gestational diabetes (O-GDM, N = 82) or type 1 diabetes (O-T1DM, N = 67) in pregnancy, compared to offspring of women from the background population (O-BP, N = 57).ResultsCompared to O-BP, we found elevated plasma leptin and resistin levels in O-T1DM, decreased gene expression of all adipokines in O-GDM, decreased RETN expression in O-T1DM, and increased LEP and ADIPOQ methylation in O-GDM. In multivariate regression analysis, O-GDM remained associated with increased ADIPOQ methylation and decreased ADIPOQ and RETN gene expression and O-T1DM remained associated with decreased RETN expression after adjustment for potential confounders and mediators.ConclusionsIn conclusion, offspring of women with diabetes in pregnancy exhibit increased ADIPOQ DNA methylation and decreased ADIPOQ and RETN gene expression in SAT. However, altered methylation and expression levels were not reflected in plasma protein levels, and the functional implications of these findings remain uncertain.

Early Combination Therapy with Oral Glucose-Lowering Agents in Type 2 Diabetes.

Despite the considerable burden of disease associated with type 2 diabetes mellitus (T2DM), most patients are not at, or are unable to achieve, recommended glycemic targets. This is partly because of the relentless progressive nature of the disease, but it may also be attributable to the current diabetes treatment paradigm. The recommended stepwise approach may lead to frequent early treatment failure with prolonged periods of elevated glucose as a consequence of clinical inertia and delays in achieving optimal glycemic control. Thus, it is most appropriate to consider the current treatment paradigm for T2DM in the context of a more aggressive initial therapy with early combination therapy. Current guidelines advise that initial combination therapy should be used for patients presenting with elevated glycated hemoglobin (HbA1c). However, several studies and recent meta-analyses suggest a potential benefit from initial combination therapy on glycemic outcomes in diabetes compared with metformin monotherapy across a wide range of baseline HbA1c levels. Indeed, combination therapy can increase the number of patients achieving glycemic goals, and the newer glucose-lowering agents may reduce the risk of hypoglycemia and body weight gain. Moreover, our improving understanding of the complex pathophysiology of T2DM and the availability of treatments tackling specific mechanisms contributing to hyperglycemia should lead to more pathophysiologically sound combination therapy. We discuss the rationale behind and evidence for early combination therapy as well as what is needed in the future to better understand its potential.

Clinical Review of Antidiabetic Drugs: Implications for Type 2 Diabetes Mellitus Management.

Type 2 diabetes mellitus (T2DM) is a global pandemic, as evident from the global cartographic picture of diabetes by the International Diabetes Federation (http://www.diabetesatlas.org/). Diabetes mellitus is a chronic, progressive, incompletely understood metabolic condition chiefly characterized by hyperglycemia. Impaired insulin secretion, resistance to tissue actions of insulin, or a combination of both are thought to be the commonest reasons contributing to the pathophysiology of T2DM, a spectrum of disease originally arising from tissue insulin resistance and gradually progressing to a state characterized by complete loss of secretory activity of the beta cells of the pancreas. T2DM is a major contributor to the very large rise in the rate of non-communicable diseases affecting developed as well as developing nations. In this mini review, we endeavor to outline the current management principles, including the spectrum of medications that are currently used for pharmacologic management, for lowering the elevated blood glucose in T2DM.

Type 2 Diabetes Mellitus: Beyond the Beta Cell

Type 2 diabetes mellitus (T2DM) currently affects >8% of the world population. It is the leading cause of blindness, end-stage kidney disease, and neuropathy, and doubles the risk of developing cardiovascular disease. Until recently, the treatment of diabetes had broadly emphasised the management of hyperglycaemia as the key diagnostic criterion for T2DM. The pathophysiology of T2DM however is now understood to be rooted in the associated metabolic syndrome including intra-abdominal fat deposition, lipid abnormalities, high blood pressure, hypercoagulability, and macrovascular complications occurring in parallel with glucose dysregulation. Accordingly, closer attention to the medical management of these conditions is at the forefront of diabetologists’ treatment rationale in an attempt to prevent and mitigate both micro and macrovascular complications, especially in light of the recent positive data from cardiovascular outcome trials with both sodium-glucose co-transporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists. This symposium included a discussion of the evolution of treatment for T2DM and presented the rationale for the use of novel agents and combination therapies for patients according to their individual disease progression. Several newer drug classes were highlighted, including GLP-1 receptor agonists, dipeptidyl-peptidase-4 inhibitors (DPP-4 inhibitors), and SGLT2 inhibitors. Finally, an overview of the exciting new fields of prevention and treatment for T2DM were discussed; including stem cell proliferation into pancreatic beta cells, the reprogramming of white adipose tissue into brown fat, mimicking physiological effects of bariatric surgery pharmacologically, and other approaches to make the treatment more targeted and personalised.

Pharmacological Intervention in Type 2 Diabetes Mellitus - A Pathophysiologically Reasoned Approach?

In recent years, numerous pharmacological approaches for the treatment of type 2 diabetes mellitus (T2DM) have become available. While all of them have proven blood glucose-lowering effects, identifying the most beneficial drug or drug combination for the treatment of an individual patient has become an increasing challenge. Several guidelines attempt to provide decision criteria based on clinical characteristics and comorbidities in patients with T2DM, however, these guidelines still leave a broad range of capabilities for pharmacological treatment escalation. Pathophysiological Approach: Addressing the pathophysiology of T2DM might be a valuable approach for the selection and combination of different drugs that can provide the most comprehensive effects in the treatment of T2DM. Besides decreasing insulin sensitivity, a progressing imbalance in alpha and beta cell function of the Langerhans islet is a fundamental component in the complex pathophysiology of the disease. Considering the effect of different pharmacological interventions on the pathophysiological components in T2DM might be an effective tool guiding to most beneficial treatments, and may lead to a more tailored pharmacological intervention in patients with T2DM. .

Altered Intranetwork and Internetwork Functional Connectivity in Type 2 Diabetes Mellitus With and Without Cognitive Impairment.

Type 2 diabetes mellitus (T2DM) is associated with cognitive impairment. We investigated whether alterations of intranetwork and internetwork functional connectivity with T2DM progression exist, by using resting-state functional MRI. MRI data were analysed from 19 T2DM patients with normal cognition (DMCN) and 19 T2DM patients with cognitive impairment (DMCI), 19 healthy controls (HC). Functional connectivity among 36 previously well-defined brain regions which consisted of 5 resting-state network (RSN) systems [default mode network (DMN), dorsal attention network (DAN), control network (CON), salience network (SAL) and sensorimotor network (SMN)] was investigated at 3 levels (integrity, network and connectivity). Impaired intranetwork and internetwork connectivity were found in T2DM, especially in DMCI, on the basis of the three levels of analysis. The bilateral posterior cerebellum, the right insula, the DMN and the CON were mainly involved in these changes. The functional connectivity strength of specific brain architectures in T2DM was found to be associated with haemoglobin A1c (HbA1c), cognitive score and illness duration. These network alterations in intergroup differences, which were associated with brain functional impairment due to T2DM, indicate that network organizations might be potential biomarkers for predicting the clinical progression, evaluating the cognitive impairment, and further understanding the pathophysiology of T2DM.

Type 2 Diabetes Mellitus and Alzheimer's Disease: Bridging the Pathophysiology and Management.

Although type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) are two independent diseases, evidences from epidemiological, pathophysiological and animal studies have indicated a close pathophysiological relationship between these diseases. Due to the pathophysiological similarity of T2DM and AD, which includes insulin resistance and deficiency, protein aggregation, oxidative stress, inflammation, autophagocytosis and advanced glycation end products; AD is often referred to as "type 3 diabetes". In addition to the targeted regimens usually used for treating T2DM and AD individually, currently, anti-diabetic drugs are successfully used to reduce the cognitive decline in AD patients. Therefore, if a common pathophysiology of T2DM and AD could be clearly determined, both diseases could be managed more efficiently, possibly by shared pharmacotherapy in addition to understanding the broader spectrum of preventive strategies. The aim of this review is to discuss the pathophysiological bridge between T2DM and AD to lay the foundation for the future treatment strategies in the management of both diseases.

Metabolic Control of Type 2 Diabetes by Targeting the GLUT4 Glucose Transporter: Intervention Approaches

Type 2 diabetes mellitus (T2DM), the most common form of diabetes, is characterized by insulin resistance in the hepatic and peripheral tissues. Glucose transporter 4 (GLUT4) plays a major role in the pathophysiology of T2DM. Its defective expression or translocation to the peripheral cell plasma membrane in T2DM patients hinders the entrance of glucose into the cell for energy production. In addition to suitable drugs, an appropriate diet and/or exercise can be implemented to target the increase in GLUT4 expression, GLUT4 concentrations and GLUT4 translocation to the cell surface when managing the glucose metabolism of T2DM patients. In this review, we discussed successful intervention strategies that were individually administered or coupled with diet and/or exercise and affected the expression and translocation of GLUT4 in T2DM while reducing the excess glucose load from the blood. Additionally, some potentially good synthetic and natural compounds, which can activate the insulin-independent GLUT4 signaling pathways for the efficient management of T2DM, are highlighted as possible targets or emerging alternative sources for future anti-diabetic drug development.

English

While Type 2 diabetes mellitus (T2DM) continues to be a disease of the elderly and the middle aged, currently there has been an upsurge in the incidence of T2DM in the adolescents and the young. Family history, maternal gestational diabetes, low birth weight have contributory role to play in the pathophysiology of T2DM. The pathophysiology underlying the development of alterations in glucose metabolism ranging from abnormal fasting glucose (AFG) to impaired glucose intolerance (IGT) is multifactorial. The early onset of diabetes in childhood or adolescence heralds a long disease interval with resultant escalation of the probability of development of co-morbidities and the entire range of macro- and microvascular complications.

Pancreas Transplantation for Type 2 Diabetes Mellitus: Who and Why?

In the past, type 2 diabetes mellitus (T2DM) was a contraindication for simultaneous pancreas-kidney transplantation (SPKT) even though it was generally accepted to be an effective treatment option for selected patients with type 1 DM (T1DM) and advanced chronic kidney disease. However, because there may be tremendous overlap in the clinical presentations of T1DM versus T2DM, the presence of detectable C-peptide is no longer considered reliable in determining DM “type.” Experiences with SPKT in uremic patients with detectable pretransplant C-peptide levels with a type 2 diabetes phenotype (older age of onset of DM and older age at transplant, shorter duration of insulin-requiring DM, higher body weight/BMI, higher proportion of African-Americans) have demonstrated outcomes equivalent to those with T1DM although clearly a more robust selection bias exists for patients with presumed T2DM. The success of SPKT in this setting provides evidence that the pathophysiology of T2DM is heterogeneous and not related exclusively to insulin resistance. The purpose of this review is to summarize evidence that appropriately selected uremic patients with T2DM may benefit from SPKT, with a focus on recipient selection in order to optimize outcomes.

Continual evolution of type 2 diabetes: an update on pathophysiology and emerging treatment options.

Diabetes is a complex and progressive disease that has a major societal and economic impact. The most common form of diabetes, type 2 diabetes mellitus (T2DM), is a multifactorial disease, the pathophysiology of which involves not only the pancreas but also the liver, skeletal muscle, adipose tissue, gastrointestinal tract, brain, and kidney. Novel therapies with mechanisms of action that are different from most existing drugs are emerging. One such class consists of compounds that inhibit renal sodium-glucose cotransporter 2, which is responsible for the bulk of glucose reabsorption by the kidneys. This new class of compounds improves glycemic control independently of insulin and promotes weight reduction, providing an additional tool to treat patients with T2DM. This review discusses the underlying pathophysiology of T2DM, clinical guidelines, and available and emerging treatment options, with particular emphasis on sodium-glucose cotransporter 2 inhibitors.

Dipeptidyl Peptidase 4: A New Link between Diabetes Mellitus and Atherosclerosis?

Type 2 diabetes mellitus (T2DM) has become one of the most prevalent noncommunicable diseases in the past years. It is undoubtedly associated with atherosclerosis and increased risk for cardiovascular diseases. Incretins, which are intestinal peptides secreted during digestion, are able to increase insulin secretion and its impaired function and/or secretion is involved in the pathophysiology of T2DM. Dipeptidyl peptidase 4 (DPP4) is an ubiquitous enzyme that regulates incretins and consequently is related to the pathophysiology of T2DM. DPP4 is mainly secreted by endothelial cells and acts as a regulatory protease for cytokines, chemokines, and neuropeptides involved in inflammation, immunity, and vascular function. In T2DM, the activity of DPP4 seems to be increased and there are a growing number of in vitro and in vivo studies suggesting that this enzyme could be a new link between T2DM and atherosclerosis. Gliptins are a new class of pharmaceutical agents that acts by inhibiting DPP4. Thus, it is expected that gliptin represents a new pharmacological approach not only for reducing glycemic levels in T2DM, but also for the prevention and treatment of atherosclerotic cardiovascular disease in diabetic subjects. We aimed to review the evidences that reinforce the associations between DPP4, atherosclerosis, and T2DM.

Modulation of Adipocytokines Production and Serum NEFA Level by Metformin, Glimepiride, and Sitagliptin in HFD/STZ Diabetic Rats.

Type 2 diabetes mellitus (T2DM) is a group of metabolic disorders characterized by hyperglycemia owing to insulin resistance and/or insulin deficiency. Current theories of T2DM pathophysiology include a decline in β-cells function, a defect in insulin signaling pathways, and a dysregulation of secretory function of adipocytes. This study aimed to investigate the effect of different antidiabetic drugs on serum levels of certain adipocytokines and nonesterified fatty acids (NEFA) in high-fat diet (HFD)/streptozotocin- (STZ-) induced diabetic rats. All treatments significantly decreased serum NEFA level. Metformin and sitagliptin increased serum adiponectin level, whereas they decreased serum leptin level. Glimepiride showed significant decline in serum levels of both adiponectin and leptin. All treatments remarkably ameliorated insulin resistance, suggested by an improvement of glycemic control, a significant reduction in homeostasis model assessment of insulin resistance (HOMA-IR), and a correction in lipid profile. Modulation of adipocytokines production (i.e., increased serum adiponectin and decreased serum leptin) may also underlie the improvement of insulin resistance and could be a possible mechanism for the beneficial cardiovascular effects of metformin and sitagliptin.

Effects of Sitagliptin on Insulin and Glucagon Levels in Type 2 Diabetes Mellitus.

Effects of Sitagliptin on Insulin and Glucagon Levels in Type 2 Diabetes Mellitus.

Importance of sulfur-containing metabolites in discriminating fecal extracts between normal and type-2 diabetic mice.

A metabolic disorder such as Type-2 Diabetes mellitus (T2DM) is a complex disease induced by genetic, environmental, and nutritional factors. The db/db mouse model, bearing a nonfunctional leptin receptor, is widely used to investigate the pathophysiology of T2DM. Fecal extracts of db/db and wild-type littermates were studied to unravel a broad spectrum of new and relevant metabolites related to T2DM as proxies of the interplay of gut microbiome and murine metabolomes. The nontargeted metabolomics approach consists of an integrated analytical concept of high-resolution mass spectrometry FT-ICR-MS, followed by UPLC-TOF-MS/MS experiments. We demonstrate that a metabolic disorder such as T2DM affects the gastrointestinal tract environment, thereby influencing different metabolic pathways and their respective metabolites in diabetic mice. Fatty acids, bile acids concerning cholic and deoxycholic acid, and steroid metabolism were highly discriminative comparing fecal meta-metabolomes of wt and db/db mice. Furthermore, sulfur-(S)-containing metabolites including N-acyl taurines were altered in diabetic mice, enabling us to focus on S-containing metabolites, especially the sulfate and taurine conjugates of bile and fatty acids. Different sulfate containing bile acids including sulfocholic acid, oxocholic acid sulfate, taurocholic acid sulfate, and cyprinol sulfate were significantly altered in diabetic mice. Moreover, we identified 12 new sulfate and taurine conjugates of hydroxylated fatty acids with significant importance in T2DM metabolism in db/db mice.