Worsening of diabetic retinopathy with rapid improvement in systemic glucose control: A review

Diabetes in French Guiana, adapting national standards of therapeutic education and care to the amazonian challenge

French Guiana is a territory located more than 7000 km from France. It is also the largest French territory, with almost 84000 km² and 90% of it is covered by forest. Some municipalities are isolated due to the scarcity of transportation and the poor road infrastructure. The population is extremely diverse ethnically and culturally, and includes more than thirty ethnic groups. Immigration is high because it is one of the richest countries in the area bordering northern Brazil, Suriname, Guyana, and as a result of socio-economic crises in some other countries such as Haiti, and it has permeable natural borders. Diabetes and obesity, are emerging issues, with double the prevalence of Mainland France, whereas infectious diseases, such as HIV, take second place. Therapeutic and educational management are challenging because they require the adaptation of tools and treatments to the mul-ticulturalism and precariousness often encountered in these populations. The French and European recommendations are unsuited to the needs of the territory and must take into account the epidemiological, sociological and cultural parameters of these populations in order to provide appropriate and graded management of diabetes in the French Amazon.

The Safety of Pharmacological and Surgical Treatment of Diabetes in Patients with Diabetic Retinopathy-A Review

BACKGROUND

Diabetes mellitus (DM) is a non-infectious pandemic of the modern world; it is estimated that in 2045 it will affect 10% of the world's population. As the prevalence of diabetes increases, the problem of its complications, including diabetic retinopathy (DR), grows. DR is a highly specific neurovascular complication of diabetes that occurs in more than one third of DM patients and accounts for 80% of complete vision loss cases in the diabetic population. We are currently witnessing many groundbreaking studies on new pharmacological and surgical methods of treating diabetes.

AIM

The aim of the study is to assess the safety of pharmacological and surgical treatment of DM in patients with DR.

MATERIAL AND METHODS

An analysis of the data on diabetes treatment methods currently available in the world literature and their impact on the occurrence and progression of DR.

RESULTS

A rapid decrease in glycaemia leads to an increased occurrence and progression of DR. Its greatest risk accompanies insulin therapy and sulfonylurea therapy. The lowest risk of DR occurs with the use of SGLT2 inhibitors; the use of DPP-4 inhibitors and GLP-1 analogues is also safe. Patients undergoing pancreatic islet transplants or bariatric surgeries require intensive monitoring of the state of the eye, both in the perioperative and postoperative period.

CONCLUSIONS

It is of utmost importance to individualize therapy in diabetic patients, in order to gradually achieve treatment goals with the use of safe methods and minimize the risk of development and progression of DR.

Long-acting GLP-1RAs: An overview of efficacy, safety, and their role in type 2 diabetes management

Over recent decades, an improved understanding of the pathophysiology of type 2 diabetes mellitus (T2DM) and glucose regulation has led to innovative research and new treatment paradigms. The discovery of the gut peptide glucagon-like peptide-1 (GLP-1) and its role in glucose regulation paved the way for the class of GLP-1 receptor agonist compounds, or GLP-1RAs. The long-acting GLP-1RAs (dulaglutide, exenatide extended-release, liraglutide, semaglutide [injectable and oral]) are classified as such based on a minimum 24-hour duration of clinically relevant effects after administration. In phase 3 clinical trial programs of long-acting GLP-1RAs, A1C typically was reduced in the range of 1% to 1.5%, with reductions close to 2% in some studies. GLP-1RAs when used alone (without sulfonylureas or insulin) have a low risk of hypoglycemia because, like endogenous GLP-1, their insulinotropic effects are glucose-dependent. In addition to local actions in the gastrointestinal (GI) tract, GLP-1RAs stimulate receptors in the central nervous system to increase satiety, resulting in weight loss. All long-acting GLP-1RAs have, at minimum, been shown to be safe and not increase cardiovascular (CV) risk and most (liraglutide, semaglutide injectable, dulaglutide, albiglutide) have been shown in CV outcomes trials (CVOTs) to significantly reduce the risk of major cardiac adverse events. The class has good tolerability overall, with generally transient GI adverse events being most common. The weekly injectable agents offer scheduling convenience and may promote treatment adherence. One long-acting GLP-1RA is available as an oral daily tablet, which may be preferable for some patients and providers.

Optimizing Therapeutic Outcomes With Oral Semaglutide: A Patient-Centered Approach

In September 2019, the U.S. Food and Drug Administration approved oral semaglutide as the first orally administered glucagon-like peptide 1 (GLP-1) receptor agonist for treating people with type 2 diabetes. Although injectable GLP-1 receptor agonists are well-established treatment options for people with type 2 diabetes, clinical experience with an oral formulation in this class is limited. This article provides practical guidance for diabetes care and education specialists on how to effectively counsel patients initiating therapy with oral semaglutide on appropriate administration of the treatment and its possible effects on glycemic control, body weight, and quality of life. Strategies for mitigating potential side effects typical of the GLP-1 receptor agonist class, namely nausea, vomiting, and diarrhea, are also provided. Involving patients in treatment decisions and educating them about available and prescribed medications are key strategies for encouraging treatment adherence and ensuring optimal therapeutic outcomes.

The Impact of Glycemic Control on Retinal Photoreceptor Layers and Retinal Pigment Epithelium in Patients With Type 2 Diabetes Without Diabetic Retinopathy: A Follow-Up Study

AIMS

To establish the sequential changes by glycemic control in the mean thickness, volume and reflectance of the macular photoreceptor layers (MPRLs) and retinal pigment epithelium in patients with type 2 diabetes without diabetic retinopathy.

METHODS

Thirty-one poorly controlled (HbA1c > 8.0%) patients with type 2 diabetes without diabetic retinopathy undergoing glycemic control and 39 control subjects with normal HbA1c levels (< 5.9%) underwent periodical full medical, neurological and ophthalmological examinations over 2 years. Glycemic variability was evaluated by standard deviation and coefficient of variation of monthly measured HbA1c levels and casual plasma glucose. 3D swept source-optical coherence tomography (OCT) and OCT-Explorer-generated enface thickness, volume and reflectance images for 9 subfields defined by Early Treatment Diabetic Retinopathy Study of 4 MPRLs {outer nuclear layer, ellipsoid zone, photoreceptor outer segment (PROS) and interdigitation zone} and retinal pigment epithelium were acquired every 3 months.

RESULTS

Glycemic control sequentially restored the thickness and volume at 6, 4 and 5 subfields of outer nuclear layer, ellipsoid zone and PROS, respectively. The thickness and volume of outer nuclear layer were restored related to the decrease in HbA1c and casual plasma glucose levels, but not related to glycemic variability and neurological tests. The reflectance of MPRLs and retinal pigment epithelium in patients was marginally weaker than controls, and further decreased at 6 or 15 months during glycemic control. The reduction at 6 months coincided with high HbA1c levels.

CONCLUSION

Glycemic control sequentially restored the some MPRL thickness, especially of outer nuclear layer. In contrast, high glucose during glycemic control decreased reflectance and may lead to the development of diabetic retinopathy induced by glycemic control. The repeated OCT examinations can clarify the benefit and hazard of glycemic control to the diabetic retinopathy.

HbA1c Change and Diabetic Retinopathy During GLP-1 Receptor Agonist Cardiovascular Outcome Trials: A Meta-analysis and Meta-regression

BACKGROUND

Long-term glycemic control reduces retinopathy risk, but transient worsening can occur with glucose control intensification. Glucagon-like peptide 1 receptor agonists (GLP-1RA) lower glucose, but the long-term impact on retinopathy is unknown. GLP-1RA cardiovascular outcome trials (CVOTs) provide long-term follow-up, allowing examination of retinopathy outcomes.

PURPOSE

To examine the associations between retinopathy, HbA_1c, systolic blood pressure (SBP), and weight in GLP-1RA CVOTs.

DATA SOURCES

Systematic review identified six placebo-controlled GLP-1RA CVOTs reporting prespecified retinopathy outcomes.

STUDY SELECTION

Published trial reports were used as the primary data sources.

DATA EXTRACTION

HbA_1c, SBP, and weight data throughout follow-up by treatment group were extracted.

DATA SYNTHESIS

Random-effects model meta-analysis showed no association between GLP-1RA treatment and retinopathy (odds ratio [OR] 1.10; 95% CI 0.93, 1.30), with high heterogeneity between studies (I ² = 52.2%; Q statistic P = 0.063). Univariate meta-regression showed an association between retinopathy and average HbA_1c reduction during the overall follow-up (slope = 0.77, P = 0.007), but no relationship for SBP or weight. Sensitivity analyses for HbA_1c showed a relationship at 3 months (P = 0.006) and 1 year (P = 0.002). A 0.1% (1.09 mmol/mol) increase in HbA_1c reduction was associated with 6%, 14%, or 8% increased Ln(OR) for retinopathy at the 3-month, 1-year, and overall follow-up, respectively.

LIMITATIONS

CVOTs were not powered to assess retinopathy outcomes and differed in retinopathy-related criteria and methodology. The median follow-up of 3.4 years is short compared with the onset of retinopathy.

CONCLUSIONS

HbA_1c reduction was significantly associated with increased retinopathy risk in meta-regression for GLP-1RA CVOTs. The magnitude of HbA_1c reduction was correlated with retinopathy risk in people with diabetes and additional cardiovascular risk factors, but the long-term impact of improved glycemic control on retinopathy was unmeasured in these studies. Retinopathy status should be assessed when intensifying glucose-lowering therapy.

Obesity and GLP-1

Obesity is an important public health issue that has been on the rise over the last decades. It calls for effective prevention and treatment. Bariatric surgery is the most effective medical therapy for weight loss in morbid obesity, but we are in need for less aggressive treatments. Glucagon-like-peptide-1 receptor agonists are a group of incretin-based drugs that have proven to be productive for obesity treatment. Through activation of the GLP-1 receptor they not only have an important role stimulating insulin secretion after meals, but with their extrapancreatic actions, both peripheral and central, they also help reduce body weight by promoting satiety and delaying gastric emptying. Liraglutide in a dose of 3 mg is currently the only drug of this group that is approved by the FDA to treat obesity, with weight losses up to 8.5 kg in relatively short periods of time. Here we review the data so far collected of GLP-1 use for obesity with and without diabetes, including the recent data of oral semaglutide.

Early worsening of diabetic retinopathy after simultaneous pancreas and kidney transplantation-Myth or reality?

Early worsening of diabetic retinopathy due to sudden glucose normalization is a feared complication of pancreas transplantation; however, its rate or severity has not been studied prospectively. We followed up 43 pancreas and kidney recipients for a composite endpoint comprising new need for laser therapy, newly diagnosed proliferation, macular edema, visual acuity worsening, and blindness over 12 months. Although 37% of patients met this primary endpoint, its severity was rather low. Mean central retinal thickness and proportion of patients with subclinical macular edema increased significantly, with spontaneous resolution in half of them. Visual acuity did not change. There was no significant difference in the absolute glycated hemoglobin (HbA1c) drop, age, and diabetes duration between the patients who met and those who did not meet the primary endpoint, but a higher proportion of patients with worsening had a recent history of laser treatment. Retinopathy remained stable in 62.8% of patients. In 26%, the visual acuity significantly improved. Although retinopathy worsening was documented in more than one-third of patients, its evolution was not related to the magnitude of metabolic change; rather, it corresponded to the expected natural course of retinopathy. Nonetheless, comprehensive ophthalmologic care should be a substantial component of the recipient management.

Tau reduction in aged mice does not impact Microangiopathy

Microangiopathy, including proliferation of small diameter capillaries, increasing vessel tortuosity, and increased capillary blockage by leukocytes, was previously observed in the aged rTg4510 mouse model. Similar gene expression changes related to angiogenesis were observed in both rTg4510 and Alzheimer's disease (AD). It is uncertain if tau is directly responsible for these vascular changes by interacting directly with microvessels, and/or if it contributes indirectly via neurodegeneration and concurrent neuronal loss and inflammation. To better understand the nature of tau-related microangiopathy in human AD and in tau mice, we isolated capillaries and observed that bioactive soluble tau protein could be readily detected in association with vasculature. To examine whether this soluble tau is directly responsible for the microangiopathic changes, we made use of the tetracycline-repressible gene expression cassette in the rTg4510 mouse model and measured vascular pathology following tau reduction. These data suggest that reduction of tau is insufficient to alter established microvascular complications including morphological alterations, enhanced expression of inflammatory genes involved in leukocyte adherence, and blood brain barrier compromise. These data imply that 1) soluble bioactive tau surprisingly accumulates at the blood brain barrier in human brain and in mouse models, and 2) the morphological and molecular phenotype of microvascular disturbance does not resolve with reduction of whole brain soluble tau. Additional consideration of vascular-directed therapies and strategies that target tau in the vascular space may be required to restore normal function in neurodegenerative disease.

Semaglutide injection for the treatment of adults with type 2 diabetes

INTRODUCTION

Current estimates suggest that approximately 10% of the global adult population have type 2 diabetes. In recent years there has been a significant increase in the therapeutic options available for its treatment. This article examines the use of injectable semaglutide in the treatment of type 2 diabetes.

AREAS COVERED

We will describe the global problem posed by type 2 diabetes followed by consideration of the glucagon-like peptide 1 receptor agonist class of glucose lowering therapies. The focus is then shifted to semaglutide and a description of the large phase 3 pre-approval trial programme known as SUSTAIN. There is consideration of glucose control, the primary end-point of the phase 3 programme, as well as secondary end-points such as weight and blood pressure. There follows a précis of the cardiovascular outcomes trial for subcutaneous semaglutide (SUSTAIN 6) and the post-approval publications. As well as the SUSTAIN trial programme we used PubMed to identify relevant publications.

EXPERT OPINION

This section discusses the position of semaglutide and the risks and benefits versus other once weekly GLP-1RAs and finally the development of an oral version of semaglutide, which has recently been approved in the United States.

Adjuvant Therapies in Diabetic Retinopathy as an Early Approach to Delay Its Progression: The Importance of Oxidative Stress and Inflammation

Diabetes mellitus (DM) is a progressive disease induced by a sustained state of chronic hyperglycemia that can lead to several complications targeting highly metabolic cells. Diabetic retinopathy (DR) is a multifactorial microvascular complication of DM, with high prevalence, which can ultimately lead to visual impairment. The genesis of DR involves a complex variety of pathways such as oxidative stress, inflammation, apoptosis, neurodegeneration, angiogenesis, lipid peroxidation, and endoplasmic reticulum (ER) stress, each possessing potential therapeutic biomarkers. A specific treatment has yet to be developed for early stages of DR since no management is given other than glycemic control until the proliferative stage develops, offering a poor visual prognosis to the patient. In this narrative review article, we evaluate different dietary regimens, such as the Mediterranean diet, Dietary Pattern to Stop Hypertension (DASH) and their functional foods, and low-calorie diets (LCDs). Nutraceuticals have also been assessed in DR on account of their antioxidant, anti-inflammatory, and antiangiogenic properties, which may have an important impact on the physiopathology of DR. These nutraceuticals have shown to lower reactive oxygen species (ROS), important inflammatory factors, cytokines, and endothelial damage biomarkers either as monotherapies or combined therapies or concomitantly with established diabetes management or nonconventional adjuvant drugs like topical nonsteroidal anti-inflammatory drugs (NSAIDs).

Comparative Effectiveness of Long-Acting GLP-1 Receptor Agonists in Type 2 Diabetes: A Short Review on the Emerging Data

Glucagon-like peptide-1 (GLP-1) receptor agonists have been available as glucose-lowering therapies for people with type 2 diabetes since 2006, when twice-daily exenatide was licenced. Since then, advances in peptide chemistry and delivery have allowed for once-daily and more recently once-weekly (QW) delivery of peptides in this class and there are currently three QW "long-acting" GLP-1 receptor agonists available in clinical practice. This short review describes the therapeutic landscape that is occupied by the modern type 2 diabetes glucose-lowering therapies with a particular focus on long-acting GLP-1 receptor agonists. The efficacy and side-effect profiles of the available QW GLP-1 receptor agonists are discussed, focusing on head-to-head clinical trial comparisons. There is also an appraisal of the cardiovascular outcome trials, for which there has been an assessment of each of the QW GLP-1 receptor agonists, leading to clinical conclusions regarding their comparative effectiveness.

Oxidative Stress as the Main Target in Diabetic Retinopathy Pathophysiology

Diabetic retinopathy (DR) is one of the most common complications of diabetes mellitus (DM) causing vision impairment even at young ages. There are numerous mechanisms involved in its development such as inflammation and cellular degeneration leading to endothelial and neural damage. These mechanisms are interlinked thus worsening the diabetic retinopathy outcome. In this review, we propose oxidative stress as the focus point of this complication onset.

Worsening of diabetic retinopathy with rapid improvement in systemic glucose control: A review

Worsening of diabetic retinopathy (DR) is associated with the initiation of effective treatment of glycaemia in some patients with diabetes. It has been associated with risk factors such as poor blood-glucose control and hypertension, and it manifests prior to the long-term benefits of optimizing glycaemic control. The majority of evidence supports an association of large and rapid reductions in blood-glucose levels with early worsening of DR. Despite a general awareness of early worsening within the diabetes community, mechanisms to explain the phenomenon remain speculative. We provide an overview of early worsening of DR and its pathophysiology based on current data. We describe the phenomenon in various settings, including in patients receiving insulin- or non-insulin-based treatments, in those undergoing bariatric surgery, and in pregnant women. We discuss various mechanisms and theories that have been suggested to explain this paradoxical phenomenon, and we summarize the implications of these in clinical practice.