Changing the Concept of Type 2 Diabetes: Beta Cell Workload Hypothesis Revisited

Chronic consumption of imbalance diets high in sucrose or fat induces abdominal obesity with different pattern of metabolic disturbances and lost in Langerhans cells population

AIM

Obesity is a worldwide health issue, associated with development of type 2 Diabetes Mellitus. The aim of this study is to analyze the effect of consumption of two hypercaloric diets on metabolic disturbance and beta cells damage.

MAIN METHODS

Male Wistar rats were subjected to twelve months consumption of three diets: a Control balanced diet (CTD, carbohydrates 58 %, proteins 29 %, lipids 13 %) and two hypercaloric diets, high in sucrose (HSD, carbohydrates 68 %, proteins 22 %, lipids 10 %) or high in fat (HFD, carbohydrates 31 %, proteins 14 %, lipids 55 %). Serum levels of glucose, triglycerides and free fatty acids were measured after zoometric parameters determination. Antioxidant enzymes activity and oxidative stress-marker were measured in pancreas tissue among histological analysis of Langerhans islets.

KEY FINDINGS

Although diets were hypercaloric, the amount of food consumed by rats decreased, resulting in an equal caloric consumption. The HSD induced hypertriglyceridemia and hyperglycemia with higher levels in free fatty acids (FFA, lipotoxicity); whereas HFD did not increased neither the triglycerides nor FFA, nevertheless the loss of islets' cell was larger. Both diets induced obesity with hyperglycemia and significant reduction in Langerhans islets size.

SIGNIFICANCE

Our results demonstrate that consumption of HSD induces more significant metabolic disturbances that HFD, although both generated pancreas damage; as well hypercaloric diet consumption is not indispensable to becoming obese; the chronic consumption of unbalanced diets (rich in carbohydrates or lipids) may lead to abdominal obesity with metabolic and functional disturbances, although the total amount of calories are similar.

Favorable Effect of Pemafibrate on Insulin Resistance and β-Cell Function in Subjects with Type 2 Diabetes and Hypertriglyceridemia: A Subanalysis of the PARM-T2D Study

Pemafibrate, a novel selective peroxisome proliferator-activated receptor modulator, has beneficial effects on lipid metabolism. However, its effects on glucose metabolism in individuals with type 2 diabetes (T2DM) remain to be fully clarified. This was a subanalysis of the PARM-T2D study, a multicenter prospective observational study on the use of pemafibrate versus conventional therapy for 52 weeks in subjects with T2DM complicated with hypertriglyceridemia. The subanalysis included participants who did not change their treatment for diabetes and did not receive insulin or insulin secretagogues during the study period. Changes in glucose metabolism markers, including homeostatic model assessment (HOMA2) scores and disposition index, were assessed. A total of 279 participants (141 in the pemafibrate group; 138 in the control group) met the criteria for the subanalysis. There were no significant changes in HbA1c during the 52-week study period in both groups. However, the pemafibrate group showed significant improvements versus the control group for insulin resistance assessed by HOMA2-R (-0.15 versus 0.08; estimated treatment difference -0.23 (95% confidence interval -0.44, -0.02); p = 0.03) and maintenance of β-cell function assessed by disposition index (0.015 versus -0.023; estimated treatment difference 0.037 (95% confidence interval 0.005, 0.069); p = 0.02). Correlation analyses showed that improvements in HOMA2-R and disposition index were significantly associated with improvements in lipid abnormalities and γ-glutamyl transpeptidase. In conclusion, pemafibrate reduced insulin resistance and maintained β-cell function in subjects with T2DM and hypertriglyceridemia, presumably by improving lipid profiles and lipid-related hepatocyte stress.

Will GLP-1 Analogues and SGLT-2 Inhibitors Become New Game Changers for Diabetic Retinopathy?

Diabetic retinopathy (DR) is the most frequent microvascular complication of diabetes mellitus (DM), estimated to affect approximately one-third of the diabetic population, and the most common cause of preventable vision loss. The available treatment options focus on the late stages of this complication, while in the early stages there is no dedicated treatment besides optimizing blood pressure, lipid and glycemic control; DR is still lacking effective preventive methods. glucagon-like peptide 1 receptor agonists (GLP-1 Ras) and sodium-glucose cotransporter 2 (SGLT-2) inhibitors have a proven effect in reducing risk factors of DR and numerous experimental and animal studies have strongly established its retinoprotective potential. Both drug groups have the evident potential to become a new therapeutic option for the prevention and treatment of diabetic retinopathy and there is an urgent need for further comprehensive clinical trials to verify whether these findings are translatable to humans.

The dual role of empagliflozin: Cardio renal protection in T2DM patients

Empagliflozin (Jardiance®) is an insulin independent antihyperglycemic agent used in treatment of T2D.The drug is a sodium glucose cotransporter-2 (SGLT2) inhibitor approved in USA and Europe and other countries of the world. As empagliflozin demonstrates cardioprotective and Reno protective properties its prime target are patients having CVD and CKD complicated by T2D.

This review sheds light on mechanism of action of the drug and with the help of clinical outcomes establishes the use of empagliflozin in T2D patients.

Although empagliflozin is a well-tolerated and easy to administer drug, it has some side effects and contraindications which are discussed in the article to help the reader weigh its beneficial effects against its adverse effect and understand its use in clinical medicine.

Metabolic changes in female rats exposed to intrauterine Hyperglycemia and post-weaning consumption of high-fat diet

We evaluated the influence of the hyperglycemic intrauterine environment and post-weaning consumption of a high-fat diet on the glycemia, insulin, lipid and immunological profile of rat offspring in adulthood. Female rats received citrate buffer (Control - C) or Streptozotocin (a beta cell-cytotoxic drug to induce diabetes - D) on post-natal day 5. In adulthood, these rats were mated to obtain female offspring, who were fed a standard diet (SD) or high-fat diet (HFD) from weaning to adulthood (n = 10 rats/group). OC/SD and OC/HFD represent female offspring of control mothers and received SD or HFD, respectively; OD/SD and OD/HFD represent female offspring of diabetic mothers and received SD or HFD, respectively. At adulthood, the Oral Glucose Tolerance Test (OGTT) was performed and, next, the rats were anesthetized and euthanized. Pancreas was collected and analyzed, and adipose tissue was weighted. Blood samples were collected to determine biochemical and immunological profiles. The food intake was lower in HFD-fed rats and visceral fat weight was increased in the OD/HFD group. OC/HFD, OD/SD, and OD/HFD groups presented glucose intolerance and lower insulin secretion during OGTT. An impaired pancreatic beta-cell function was shown in the adult offspring of diabetic rats, regardless of diet. Interleukin (IL)-6 and IL-10 concentrations were lower in the OD/HFD group and associated to a low-grade inflammatory condition. The fetal programming was responsible for impaired beta cell function in experimental animals. The association of maternal diabetes and post-weaning high-fat diet is responsible for greater glucose intolerance, impaired insulin secretion and immunological change.

Revisiting Regulators of Human β-cell Mass to Achieve β-cell-centric Approach Toward Type 2 Diabetes

Type 2 diabetes (T2DM) is characterized by insulin resistance and β-cell dysfunction. Because patients with T2DM have inadequate β-cell mass (BCM) and β-cell dysfunction worsens glycemic control and makes treatment difficult, therapeutic strategies to preserve and restore BCM are needed. In rodent models, obesity increases BCM about 3-fold, but the increase in BCM in humans is limited. Besides, obesity-induced changes in BCM may show racial differences between East Asians and Caucasians. Recently, the developmental origins of health and disease hypothesis, which states that the risk of developing noncommunicable diseases including T2DM is influenced by the fetal environment, has been proposed. It is known in rodents that animals with low birthweight have reduced BCM through epigenetic modifications, making them more susceptible to diabetes in the future. Similarly, in humans, we revealed that individuals born with low birthweight have lower BCM in adulthood. Because β-cell replication is more frequently observed in the 5 years after birth, and β cells are found to be more plastic in that period, a history of childhood obesity increases BCM. BCM in patients with T2DM is reduced by 20% to 65% compared with that in individuals without T2DM. However, since BCM starts to decrease from the stage of borderline diabetes, early intervention is essential for β-cell protection. In this review, we summarize the current knowledge on regulatory factors of human BCM in health and diabetes and propose the β-cell–centric concept of diabetes to enhance a more pathophysiology-based treatment approach for T2DM.

Challenges Involved in Incorporating Personalised Treatment Plan as Routine Care of Patients with Diabetes

Diabetes is a heterogenous disorder, and patients with this disorder vary considerably in their clinical presentation, response to therapy and risk of complications. Expanding knowledge about the pathophysiology of various forms of diabetes has raised the possibility that diagnostic and therapeutic modalities can be tailored to the individual patient in a personalized manner. The recent publication of a Consensus Statement on precision diabetes care underlines the major strides made in this field in the recent past. However, while personalized diabetes care has the potential to significantly improve outcomes in patients with diabetes in a safe and cost-effective manner, its wider application presents several challenges, especially in resource-strained settings. These challenges pertain equally to precision diagnostics, precision therapeutics and precision monitoring. This article discusses some of the important challenges that care providers are likely to face in applying the personalized approach in caring for their patients with diabetes, in the context of diagnosis and management of type 1 diabetes, type 2 diabetes and monogenic forms of diabetes. Suggestions are also presented for overcoming some of these challenges.

Beta-Cell Mass in Obesity and Type 2 Diabetes, and Its Relation to Pancreas Fat: A Mini-Review

Type 2 diabetes (T2DM) is characterized by insulin resistance and beta-cell dysfunction. Although insulin resistance is assumed to be a main pathophysiological feature of the development of T2DM, recent studies have revealed that a deficit of functional beta-cell mass is an essential factor for the pathophysiology of T2DM. Pancreatic fat contents increase with obesity and are suggested to cause beta-cell dysfunction. Since the beta-cell dysfunction induced by obesity or progressive decline with disease duration results in a worsening glycemic control, and treatment failure, preserving beta-cell mass is an important treatment strategy for T2DM. In this mini-review, we summarize the current knowledge on beta-cell mass, beta-cell function, and pancreas fat in obesity and T2DM, and we discuss treatment strategies for T2DM in relation to beta-cell preservation.

[Early intensification of glucose-lowering therapy: VERIFY lessons and real clinical practice on the example of the Moscow region diabetes register data]

BACKGROUND

The prevalence of T2DM is steadily increasing not only among the elderly, but also at a young age. T2DM is preceded by a long period of significant metabolic changes with the development of insulin resistance and в-cell dysfunction. To reduce the prevalence of complications, treatment is needed which affects several pathophysiological mechanisms underlying the disease. Monotherapy with metformin at the onset of T2DM is often insufficient. The VERIFY study demonstrated the advantage of early administration of a combination of vildagliptin and metformin in relation to the glycemic durability compared to the sequential intensification of metformin with vildagliptin in patients with type 2 diabetes.

AIMS

To assess the current situation in terms of the incidence of T2DM complications and the structure of the prescribing glucose lowering drugs based on the data from the Diabetes Register (DR) of the Moscow Region. To demonstrate the advantages of early combination therapy in patients with newly diagnosed T2DM using clinical cases.

MATERIALS AND METHODS

The data from the DR of the Moscow region, which is part of the National Diabetes Register of the Russian Federation, were used for the analysis. The data of 6,096 patients with T2DM who died in 2019 were evaluated for building the structure of the causes of death of patients with T2DM. The pattern of glucose-lowering therapy was analyzed based on data of 226,327 patients with T2DM (for 2020), as well as separately of 14,379 patients with newly diagnosed T2DM in 2019. Clinical cases are described based on the data of two patients with T2DM, available in the DR database and outpatient records.

RESULTS

In patients with young onset T2DM (<40 years), the prevalence of severe complications is higher than in the general population of patients with T2DM: blindness is in 5.9 times, end-stage chronic renal failure in 2.9 times, lower limb amputations in 6.4 times more. When prescribing glucose lowering drugs, monotherapy is prevalent, mostly metformin. In double combination, metformin is used in 96.22% of cases. In the structure of glucose lowering drugs, with newly diagnosed T2DM, combination therapy is used less frequently than in patients with T2DM in general. Of the drugs of the IDP-4 group, vildagliptin is most often prescribed - 46.25% (including of a fixed combination with metformin - 12.22%). Clinical cases reflect a rapid clinical outcome: a decrease in HbA1c to the target in 6 months, the absence of hypoglycemia or other side effects, and positive weight dynamics.

CONCLUSIONS

A fairly large propotion of patients with T2DM are on monotherapy with glucouse lowering drugs. Early prescription of the combination of metformin plus vildagliptin provides a longer maintenance of glycemic control without increasing the risk of hypoglycemia and weight gain for patients with newly diagnosed T2DM.

An emerging new concept for the management of type 2 diabetes with a paradigm shift from the glucose-centric to beta cell-centric concept of diabetes - an Asian perspective

INTRODUCTION

Recent advances in anti-diabetic medications and glucose monitoring have led to a paradigm shift in diabetes care. Newer anti-diabetic medications such as DPP-4 inhibitors, GLP-1 receptor agonists (GLP-1RAs), and SGLT2 inhibitors have enabled optimal glycemic control to be achieved without increasing the risk of hypoglycemia and weight gain. Treatment with GLP-1RAs and SGLT2 inhibitors has been demonstrated to improve cardiorenal outcomes, positioning these agents as the mainstay of treatment for patients with type 2 diabetes (T2DM). The development of these newer agents has also prompted a paradigm shift in the concept of T2DM, highlighting the importance of beta cell dysfunction in the pathophysiology of T2DM.

AREAS COVERED

Recent advances in pharmacotherapy for diabetes are summarized with a focus on the role of incretin-based drugs and SGLT2 inhibitors. The importance of a paradigm shift from a glucose-centric to a beta cell-centric concept of T2DM is also discussed, given from an Asian perspective.

EXPERT OPINION

Management of T2DM including lifestyle modification as well as pharmacotherapy should be focused on reducing beta cell workload, to preserve functional beta cell mass. A paradigm shift from a glucose-centric to a beta cell-centric concept of T2DM enhances the implementation of person-centered diabetes care.

SGLT2 Inhibitors: the Star in the Treatment of Type 2 Diabetes?

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a novel class of oral hypoglycemic agents which increase urinary glucose excretion by suppressing glucose reabsorption at the proximal tubule in the kidney. SGLT2 inhibitors lower glycated hemoglobin (HbA1c) by 0.6-0.8% (6-8 mmol/mol) without increasing the risk of hypoglycemia and induce weight loss and improve various metabolic parameters including blood pressure, lipid profile and hyperuricemia. Recent cardiovascular (CV) outcome trials have shown the improvement of CV and renal outcomes by treatment with the SGLT2 inhibitors, empagliflozin, canagliflozin, and dapagliflozin. The mechanisms by which SGLT2 inhibitors improve CV outcome appear not to be glucose-lowering or anti-atherosclerotic effects, but rather hemodynamic effects through osmotic diuresis and natriuresis. Generally, SGLT2 inhibitors are well-tolerated, but their adverse effects include genitourinary tract infection and dehydration. Euglycemic diabetic ketoacidosis is a rare but severe adverse event for which patients under SGLT2 inhibitor treatment should be carefully monitored. The possibility of an increase in risk of lower-extremity amputation and bone fracture has also been reported with canagliflozin. Clinical trials and real-world data have suggested that SGLT2 inhibitors improve CV and renal outcomes and mortality in patients with type 2 diabetes (T2DM), especially in those with prior CV events, heart failure, or chronic kidney disease. Results of recent trials including individuals without diabetes may change the positioning of this drug as ″a drug for cardiorenal protection″. This review summarizes the potential of SGLT2 inhibitors and discusses their role in the treatment of T2DM.