The Role of SGLT2 Inhibitor on the Treatment of Diabetic Retinopathy

Neuroprotective Effects of Sodium-Glucose Cotransporter-2 (SGLT2) Inhibitors (Gliflozins) on Diabetes-Induced Neurodegeneration and Neurotoxicity: A Graphical Review

Diabetes is a chronic endocrine disorder that negatively affects various body systems, including the nervous system. Diabetes can cause or exacerbate various neurological disorders, and diabetes-induced neurodegeneration can involve several mechanisms such as mitochondrial dysfunction, activation of oxidative stress, neuronal inflammation, and cell death. In recent years, the management of diabetes-induced neurodegeneration has relied on several types of drugs, including sodium-glucose cotransporter-2 (SGLT2) inhibitors, also called gliflozins. In addition to exerting powerful effects in reducing blood glucose, gliflozins have strong anti-neuro-inflammatory characteristics that function by inhibiting oxidative stress and cell death in the nervous system in diabetic subjects. This review presents the molecular pathways involved in diabetes-induced neurodegeneration and evaluates the clinical and laboratory studies investigating the neuroprotective effects of gliflozins against diabetes-induced neurodegeneration, with discussion about the contributing roles of diverse molecular pathways, such as mitochondrial dysfunction, oxidative stress, neuro-inflammation, and cell death. Several databases-including Web of Science, Scopus, PubMed, Google Scholar, and various publishers, such as Springer, Wiley, and Elsevier-were searched for keywords regarding the neuroprotective effects of gliflozins against diabetes-triggered neurodegenerative events. Additionally, anti-neuro-inflammatory, anti-oxidative stress, and anti-cell death keywords were applied to evaluate potential neuronal protection mechanisms of gliflozins in diabetes subjects. The search period considered valid peer-reviewed studies published from January 2000 to July 2023. The current body of literature suggests that gliflozins can exert neuroprotective effects against diabetes-induced neurodegenerative events and neuronal dysfunction, and these effects are mediated via activation of mitochondrial function and prevention of cell death processes, oxidative stress, and inflammation in neurons affected by diabetes. Gliflozins can confer neuroprotective properties in diabetes-triggered neurodegeneration, and these effects are mediated by inhibiting oxidative stress, inflammation, and cell death.

The lower incidence of endometrial cancer after sodium-glucose cotransporter 2 inhibitors administration in type 2 diabetes mellitus population: a nationwide cohort study

The Sodium-glucose co-transporter 2 (SGLT2) inhibitor is an anti-glycemic agent that frequently used in type 2 diabetes mellitus (T2DM) with antioxidant effects. Endometrial cancer (EC) is a common gynecological malignancy that correlates with oxidative stress. The aim in the present study is to survey the potential association between the SGLT2 inhibitor administration and the incidence of EC by the application of the National Health Insurance Research Database (NHIRD) of Taiwan. A retrospective cohort study was directed and the T2DM participants were divided into the SGLT2 inhibitors users and non-SGLT2 inhibitors users. After matching, a total of 163,668 and 327,336 participants were included into the SGLT2 inhibitors and control groups, respectively. The primary outcome is regarded as the development of EC according to the diagnostic, image, and procedure codes. Cox proportional hazard regression was employed to generate the adjusted hazard ratio (aHR) and 95% confidence interval (CI) of EC between the two groups. There were 422 and 876 EC events observed in the SGLT2 inhibitors and control groups, respectively. The SGLT2 inhibitors group demonstrated a significantly lower incidence of EC formation compared to the control groups (aHR: 0.87, 95% CI: 0.76-0.99). In the subgroup analysis, the correlation between SGLT2 inhibitor administration and lower rate of EC existed in the T2DM individuals with aged under 60. Moreover, the association between SGLT2 inhibitor administration and lower EC incidence only presented in the T2DM population with SGLT2 inhibitor administration under one year (aHR: 0.58, 95% CI: 0.45-0.73). In conclusion, the administration of SGLT2 inhibitors correlates to lower incidence of EC in T2DM population.

Diabetic Retinopathy: New Treatment Approaches Targeting Redox and Immune Mechanisms

Diabetic retinopathy (DR) represents a severe complication of diabetes mellitus, characterized by irreversible visual impairment resulting from microvascular abnormalities. Since the global prevalence of diabetes continues to escalate, DR has emerged as a prominent area of research interest. The development and progression of DR encompass a complex interplay of pathological and physiological mechanisms, such as high glucose-induced oxidative stress, immune responses, vascular endothelial dysfunction, as well as damage to retinal neurons. Recent years have unveiled the involvement of genomic and epigenetic factors in the formation of DR mechanisms. At present, extensive research explores the potential of biomarkers such as cytokines, molecular and cell therapies, antioxidant interventions, and gene therapy for DR treatment. Notably, certain drugs, such as anti-VEGF agents, antioxidants, inhibitors of inflammatory responses, and protein kinase C (PKC)-β inhibitors, have demonstrated promising outcomes in clinical trials. Within this context, this review article aims to introduce the recent molecular research on DR and highlight the current progress in the field, with a particular focus on the emerging and experimental treatment strategies targeting the immune and redox signaling pathways.

Dapagliflozin ameliorated retinal vascular permeability in diabetic retinopathy rats by suppressing inflammatory factors

BACKGROUND

Diabetic retinopathy is a common microvascular complication of diabetes and one of the major causes of blindness in the working-age population. Emerging evidence has elucidated that inflammation drives the key mechanism of diabetes-mediated retinal disturbance. As a new therapeutic drug targeting diabetes, whether dapagliflozin could improve vascular permeability from the perspective of anti-inflammatory effect need to be further explored.

METHODS

Type 2 diabetic retinopathy rat model was established and confirmed by fundus fluorescein angiography (FFA). ELISA detected level of plasma inflammatory factors and C-peptide. HE staining, immunohistochemistry and western blot detected histopathology changes of retina, expression of retinal inflammatory factors and tight junction proteins.

RESULTS

Dapagliflozin exhibited hypoglycemic effect comparable to insulin, but did not affect body weight. By inhibiting expression of inflammatory factors (NLRP3, Caspase-1, IL-18, NF-κB) in diabetic retina and plasma, dapagliflozin reduced damage of retinal tight junction proteins and improved retinal vascular permeability. The anti-inflammatory effect of dapagliflozin was superior to insulin.

CONCLUSIONS

Dapagliflozin improved retinal vascular permeability by reducing diabetic retinal and plasma inflammatory factors. The anti-inflammatory mechanism of dapagliflozin is independent of hypoglycemic effect and superior to insulin.

The use of sodium-glucose cotransporter 2 inhibitors and the incidence of uveitis in type 2 diabetes: a population-based cohort study

Introduction

To survey the potential correlation between the application of sodium-glucose cotransporter 2 (SGLT2) inhibitors and the incidence of uveitis in individuals with type 2 diabetes mellitus (T2DM).

Material and methods

A retrospective cohort study using the National Health Insurance Research Database (NHIRD) was conducted. The T2DM patients using SGLT2 inhibitors and those taking other anti-diabetic medications were assigned to the SGLT2 group and the control group, respectively, with a 1 : 2 ratio via the propensity score-matching (PSM) method. The major outcome in this study is the development of uveitis according to the diagnostic codes. The Cox proportional hazard regression was adopted to yield the adjusted hazard ratio (aHR) with 95% confidence interval (CI) between the groups.

Results

There were 147 and 371 new uveitis episodes in the SGLT2 and control groups after the follow-up period up to 5 years. The incidence of uveitis in the SGLT2 group (aHR = 0.736, 95% CI: 0.602-0.899, p = 0.0007) was significantly lower than that in the control group after adjusting for the effect of all the confounders. In the subgroup analyses, the SGLT2 inhibitors showed a higher correlation with low uveitis incidence in T2DM patients aged under 50 than T2DM individuals aged over 50 years (p = 0.0012), while the effect of SGLT2 inhibitors on the incidence of anterior and posterior uveitis development was similar (p = 0.7993).

Conclusions

The use of SGLT2 inhibitors could be an independent protective factor for uveitis development in T2DM population.

Association of sodium-glucose cotransporter 2 inhibitors with the incidence of corneal diseases in type 2 diabetes mellitus

Sodium-glucose cotransporter 2 (SGLT2) inhibitors revealed the protective function on various systemic diseases. This study aimed to determine whether the usage of SGLT2 inhibitors associates with incidences of superficial keratopathy and infectious keratitis in type 2 diabetes mellitus (T2DM) patients. A retrospective cohort study with the usage of National Health Insurance Research Database of Taiwan was conducted. The T2DM patients were divided into the SGLT2 inhibitors and control groups according to the usage of SGLT2 inhibitors or not. The major outcomes were defined as the occurrence of superficial keratopathy and infectious keratitis. There were 766 and 1037 episodes of superficial keratopathy in the SGLT2 inhibitors and control groups and SGLT2 inhibitors group showed a significantly lower incidence of superficial keratopathy than the control group (aHR: 0.721, 95% CI: 0.656-0.791, P < 0.0001). Also, there were 166 and 251 infectious keratitis events in the SGLT2 inhibitors and control groups and patients in the SGLT2 inhibitors group revealed a significantly lower infectious keratitis incidence than those in the control group (aHR: 0.654, 95% CI: 0.537-0.796, P < 0.0001). In addition, the patients that received SGLT2 inhibitors demonstrated lower cumulative incidences of both superficial keratopathy and infectious keratitis compared to the non-SGLT2 inhibitors users (both P < 0.0001). In conclusion, the usage of SGLT2 inhibitors correlates to lower incidence of superficial keratopathy and infectious keratitis in T2DM individuals, which is more significant in patients with persistent SGLT2 inhibitors application.

Ocular and Plasma Pharmacokinetics of Enavogliflozin Ophthalmic Solution in Preclinical Species

An enavogliflozin ophthalmic solution (DWRX2008) is being developed to treat diabetic retinopathy and macular edema. This study evaluated the ocular distribution and plasma pharmacokinetics (PKs) of enavogliflozin in animal species. A sample of [14C] enavogliflozin was ocularly administered to two rabbits per time point at single doses of 600 μg/eye to evaluate ocular PK, which was evaluated using autoradiography until 48 h post-dose. Plasma concentrations after ocular administration in six rabbits, three rats, and three beagle dogs with single doses of 400 μg, 25 μg, and 100 μg, respectively, were investigated for 24 h. The retinal concentration of [14C] enavogliflozin reached Cmax at 2.0 h with an elimination half-life of 32.5 h, which remained above the IC50 value of sodium-dependent glucose transporter 2 until 24 h post-dose. In the plasma of rabbits, the fastest Tmax of 0.5 h and a 3.6 h half-life were observed among animal species. The relative bioavailability in rabbits after ocular administration was 3.4 compared to oral administration. Ocular administration of enavogliflozin could be a potential therapeutic route for diabetic retinal complications, based on relative bioavailability and effective delivery to the posterior ocular segment. DWRX2008 would be applicable to humans with favorable PK profiles and minimal systemic adverse effect.

Associations of antidiabetic drugs with diabetic retinopathy in people with type 2 diabetes: an umbrella review and meta-analysis

Background

Diabetic retinopathy (DR) is the most frequent complication of type 2 diabetes and remains the leading cause of preventable blindness. Current clinical decisions regarding the administration of antidiabetic drugs do not sufficiently incorporate the risk of DR due to the inconclusive evidence from preceding meta-analyses. This umbrella review aimed to systematically evaluate the effects of antidiabetic drugs on DR in people with type 2 diabetes.

Methods

A systematic literature search was undertaken in Medline, Embase, and the Cochrane Library (from inception till 17th May 2022) without language restrictions to identify systematic reviews and meta-analyses of randomized controlled trials or longitudinal studies that examined the association between antidiabetic drugs and DR in people with type 2 diabetes. Two authors independently extracted data and assessed the quality of included studies using the AMSTAR-2 (A MeaSurement Tool to Assess Systematic Reviews) checklist, and evidence assessment was performed using the GRADE (Grading of recommendations, Assessment, Development and Evaluation). Random-effects models were applied to calculate relative risk (RR) or odds ratios (OR) with 95% confidence intervals (CI). This study was registered with PROSPERO (CRD42022332052).

Results

With trial evidence from 11 systematic reviews and meta-analyses, we found that the use of glucagon-like peptide-1 receptor agonists (GLP-1 RA), sodium-glucose cotransporter-2 inhibitors (SGLT-2i), or dipeptidyl peptidase-4 inhibitors (DPP-4i) was not statistically associated with the risk of DR, compared to either placebo (RR: GLP-1 RA, 0.98, 0.89-1.08; SGLT-2i, 1.00, 95% CI 0.79-1.27; DPP-4i, 1.17, 0.99-1.39) or other antidiabetic drugs. Compared to other antidiabetic drugs, meglitinides (0.34, 0.01-8.25), SGLT-2i (0.73, 0.10-5.16), thiazolidinediones (0.92, 0.67-1.26), metformin (1.15, 0.81-1.63), sulphonylureas (1.24, 0.93-1.65), and acarbose (4.21, 0.44-40.43) were not statistically associated with the risk of DR. With evidence from longitudinal studies only, insulin was found to have a higher risk of DR than other antidiabetic drugs (OR: 2.47, 95% CI: 2.04-2.99).

Conclusion

Our results indicate that antidiabetic drugs are generally safe to prescribe regarding the risk of DR among people with type 2 diabetes. Further robust and large-scale trials investigating the effects of insulin, meglitinides, and acarbose on DR are warranted.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=332052, identifier CRD42022332052.

Sodium Glucose Transporter-2 Inhibitors (SGLT2Is)-TLRs Axis Modulates Diabetes

Diabetes affects millions of people worldwide and is mainly associated with impaired insulin function. To date, various oral anti-diabetic drugs have been developed, of which, the sodium glucose transporter-2 inhibitors (SGLT2Is) are of the most recent classes that have been introduced. They differ from other classes in terms of their novel mechanism of actions and unique beneficial effects rather than just lowering glucose levels. SGLT2Is can protect body against cardiovascular events and kidney diseases even in non-diabetic individuals. SGLT2Is participate in immune cell activation, oxidative stress reduction, and inflammation mediation, thereby, moderating diabetic complications. In addition, toll like receptors (TLRs) are the intermediators of the immune system and inflammatory process, thus it's believed to play crucial roles in diabetic complications, particularly the ones that are related to inflammatory reactions. SGLT2Is are also effective against diabetic complications via their anti-inflammatory and oxidative properties. Given the anti-inflammatory properties of TLRs and SGLT2Is, this review investigates how SGLT2Is can affect the TLR pathway, and whether this could be favorable toward diabetes.

Evaluation of the effect of sodium-glucose cotransporter-2 inhibitor treatment on choroidal vascular parameters in patients with type 2 diabetes mellitus

BACKGROUND

To evaluate the effect of sodium-glucose cotransporter-2 inhibitor treatment on choroidal vascular parameters in patients with type 2 diabetes mellitus (T2DM).

METHODS

Twenty eyes of 20 patients with T2DM without diabetic retinopathy and 20 eyes of 20 age- and sex-matched patients as the control group were included in the study. The patients were evaluated using enhanced depth imaging optic coherence tomography before treatment and at the third month of treatment. The choroidal images were binarized into luminal areas (LAs) and stromal areas (SAs). The choroidal vascularity index (CVI) was defined as the ratio of the LA to the total circumscribed choroid area (TCA).

RESULTS

The mean age of the patients was 56.65±8.41 years. The patients' mean disease duration was 6.65±5.72 years, the mean HbA1c level was 8.89±1.62%, and the mean body mass index was 33.13±4.84 kg/m2. The subfoveal TCA, subfoveal LA, subfoveal SA, total TCA, total LA, and total SA values ​​of the patient group were found to be significantly lower than those of the control group (p = 0.006, p = 0.003, p = 0.028, p = 0.001, p = 0.001, and p = 0.006, respectively). There was a significant increase in the subfoveal TCA, subfoveal LA, subfoveal SA, subfoveal CVI, total TCA, total LA, and total SA values ​​after empagliflozin treatment compared to before empagliflozin treatment (p = 0.005, p = 0.003, p = 0.021, p = 0.032, p < 0.001, p < 0.001, and p = 0.001 respectively).

CONCLUSIONS

Empagliflozin provides an improvement in diabetic choroidal changes through its effect on choroidal vascularity parameters.

Utilization of sodium-glucose cotransporter 2 inhibitors on dry eye disease severity in patients with type 2 diabetes mellitus

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have protective effects against various systemic diseases and neoplasms. This retrospective cohort study evaluated the severity of dry eye disease (DED) in patients with type 2 diabetes mellitus (T2DM) who were treated with SGLT2 inhibitors. Data were obtained from the National Health Insurance Research Database of Taiwan. Patients with T2DM who were treated with SGLT2 inhibitors were assigned to the SGLT2 group. Each patient in the SGLT2 group was matched to two individuals with T2DM who had not used SGLT2 inhibitors, constituting the control group. The primary outcomes were the development of DED and severe DED. A diagnosis of severe DED was indicated by the usage of cyclosporine. Cox proportional hazard regression was applied to yield adjusted hazard ratios (aHR) and 95% confidence intervals (CIs). In the SGLT2 group, 1864 new DED events and 147 severe DED events were recorded. Conversely, 4367 new DED events and 392 severe DED events were recorded in the control group. The incidence (aHR: 0.858, 95% CI: 0.811-0.908, p = 0.0010) and severity (aHR: 0.652, 95% CI: 0.481-0.777, p = 0.0006) of DED were significantly lower in the SGLT2 group than the control group after adjusting for multiple covariates. In subgroup analyses, the incidence and severity of DED were significantly lower in patients younger than 60 years old who were treated with SGLT2 inhibitors than in their older counterparts (p = 0.0008 and 0.0011, respectively). In conclusion, utilization of SGLT2 inhibitors in the T2DM population could reduce both the incidence and severity of DED.

Systemic Reduction of Glut1 Normalizes Retinal Dysfunction, Inflammation, and Oxidative Stress in the Retina of Spontaneous Type 2 Diabetic Mice

Defects in the light-evoked responses of the retina occur early in the sequalae of diabetic retinopathy (DR). These defects, identified through the electroretinogram (ERG), represent dysfunction of retinal neurons and the retinal pigment epithelium and are commonly identifiable at the timing of, or almost immediately following, diabetes diagnosis. Recently, systemic reduction of the facilitated glucose transporter type 1, Glut1, in type 1 diabetic mice was shown to reduce retinal sorbitol accumulation, mitigate ERG defects, and prevent retinal oxidative stress and inflammation. Herein, the study investigated whether systemic reduction of Glut1 also diminished hallmarks of DR in type 2 diabetic mice. Transgenic nondiabetic Leprdb/+ and spontaneously diabetic Leprdb/db mice that expressed wild-type (Glut1+/+) or systemically reduced levels of Glut1 (Glut1+/-) were aged and subjected to standard strobe flash electroretinography and c-wave analysis before evaluation of inflammatory cytokines and oxidative stress molecules. Although Leprdb/dbGlut1+/- mice still displayed overt obesity and diabetes, no scotopic, photopic, or c-wave ERG defects were present through 16 weeks of age, and expression of inflammatory cytokines and oxidative stress molecules was also normalized. These findings suggest that systemic reduction of Glut1 is sufficient to prevent functional retinal pathophysiology in type 2 diabetes. Targeted, moderate reductions of Glut1 or inhibition of Glut1 activity in the retina of diabetic patients should be considered as a novel therapeutic strategy to prevent development and progression of DR.

Prevalence and severity of diabetic retinopathy at first presentation to vitreoretinal services in Bhutan: a 3-year national study

PURPOSE

To determine the prevalence and severity of diabetic retinopathy (DR) at first presentation among diabetic patients attending national vitreoretinal (VR) services in Bhutan STUDY DESIGN: Retrospective cross-sectional study METHODS: We included all diabetic patients in Bhutan who presented for retinal evaluation for the first time over a 3-year period (2013-2016). Data including demography, clinical details, diagnostic tests, and clinical staging of DR were analyzed.

RESULTS

A total of 843 diabetic patients, aged 57.2 ± 12.0 (range 18-86) years, were enrolled. The majority were male (452, 53.6%; cumulative frequency [cf] 391, 46.4%; P = .14) and from urban settings (570, 67.6%; cf 273; 32.4%) and did not have modern schooling (555, 65.8%). Hypertension was the most common systemic comorbidity (501, 59.4%). The prevalence of DR was 42.7%, with mild nonproliferative DR (NPDR) being the most common type (187, 51.9%), followed by moderate NPDR (88, 24.4%) and proliferative DR (45, 12.5%). In addition, 120 patients had clinically significant macular edema (CSME), with a prevalence of 14.2%. Best-corrected visual acuity (BCVA) of 6/60 or worse occurred in 231 eyes (13.7%), and 41 patients (4.86%) had BCVA of 6/60 or worse bilaterally due to DR/CSME. A logistic regression model indicated that the major determinant of DR was the duration of diabetes, the odds rising by 1.27× with each year of disease (P < .0001).

CONCLUSION

The prevalence of DR, including CSME, was high. Although a national DR screening program is established in Bhutan, there is a need to accelerate health education, community screening, and referral systems to reduce the prevalence of DR and CSME.

Global trends and performances in diabetic retinopathy studies: A bibliometric analysis

Objective

The objective of this study is to conduct a comprehensive bibliometric analysis to identify and evaluate global trends in diabetic retinopathy (DR) research and visualize the focus and frontiers of this field.

Methods

Diabetic retinopathy-related publications from the establishment of the Web of Science (WOS) through 1 November 2022 were retrieved for qualitative and quantitative analyses. This study analyzed annual publication counts, prolific countries, institutions, journals, and the top 10 most cited literature. The findings were presented through descriptive statistics. VOSviewer 1.6.17 was used to exhibit keywords with high frequency and national cooperation networks, while CiteSpace 5.5.R2 displayed the timeline and burst keywords for each term.

Results

A total of 10,709 references were analyzed, and the number of publications continuously increased over the investigated period. America had the highest h-index and citation frequency, contributing to the most influence. China was the most prolific country, producing 3,168 articles. The University of London had the highest productivity. The top three productive journals were from America, and Investigative Ophthalmology Visual Science had the highest number of publications. The article from Gulshan et al. (2016; co-citation counts, 2,897) served as the representative and symbolic reference. The main research topics in this area were incidence, pathogenesis, treatment, and artificial intelligence (AI). Deep learning, models, biomarkers, and optical coherence tomography angiography (OCTA) of DR were frontier hotspots.

Conclusion

Bibliometric analysis in this study provided valuable insights into global trends in DR research frontiers. Four key study directions and three research frontiers were extracted from the extensive DR-related literature. As the incidence of DR continues to increase, DR prevention and treatment have become a pressing public health concern and a significant area of research interest. In addition, the development of AI technologies and telemedicine has emerged as promising research frontiers for balancing the number of doctors and patients.

Mouse Models with SGLT2 Mutations: Toward Understanding the Role of SGLT2 beyond Glucose Reabsorption

The sodium–glucose cotransporter 2 (SGLT2) mainly carries out glucose reabsorption in the kidney. Familial renal glycosuria, which is a mutation of SGLT2, is known to excrete glucose in the urine, but blood glucose levels are almost normal. Therefore, SGLT2 inhibitors are attracting attention as a new therapeutic drug for diabetes, which is increasing worldwide. In fact, SGLT2 inhibitors not only suppress hyperglycemia but also reduce renal, heart, and cardiovascular diseases. However, whether long-term SGLT2 inhibition is completely harmless requires further investigation. In this context, mice with mutations in SGLT2 have been generated and detailed studies are being conducted, e.g., the SGLT2−/− mouse, Sweet Pee mouse, Jimbee mouse, and SAMP10-ΔSglt2 mouse. Biological changes associated with SGLT2 mutations have been reported in these model mice, suggesting that SGLT2 is not only responsible for sugar reabsorption but is also related to other functions, such as bone metabolism, longevity, and cognitive functions. In this review, we present the characteristics of these mutant mice. Moreover, because the relationship between diabetes and Alzheimer’s disease has been discussed, we examined the relationship between changes in glucose homeostasis and the amyloid precursor protein in SGLT2 mutant mice.

The association between the use of sodium glucose cotransporter 2 inhibitor and the risk of diabetic retinopathy and other eye disorders: a systematic review and meta-analysis

OBJECTIVE

To assess the association between the use of sodium-glucose cotransporter 2 inhibitor (SGLT2i) and the incidence of diabetic retinopathy (DR).

RESEARCH DESIGN AND METHODS

Pubmed, Medline, Embase, the Cochrane Central Register of Controlled Trials and Clinicaltrial.gov were searched from inception to October 2021. Randomized controlled trials (RCTs) with reports of incidence of DR and other eye disorders between SGLT2i users and non-SGLT2i users with type 2 diabetes mellitus were included.

RESULTS

In general, the incidences of DR were comparable between SGLT2i users and non-SGLT2i users (OR=0.80, 95%CI 0.61 to 1.06, P=0.12). However, compared with non-SGLT2i users, the incidence of DR was significantly reduced in SGLT2i users with diabetes duration less than 10 years (OR=0.32, 95%CI 0.13 to 0.76, P=0.01). Weight reduction in SGLT2i users was associated with the decreased risk of retinal detachment. Moreover, longer study duration was associated with lower incidence of cataract and retinal vasculopathy in SGLT2i users.

CONCLUSIONS

In general, the use of SGLT2i was not associated with the incidence of DR. However, a reduced risk of DR was observed in SGLT2i users with diabetes duration less than 10 years. An early initiation of SGLT2i might be more likely to provide with ocular benefits.

SGLT2i Improves Glycemic Control in Patients With Congenital Severe Insulin Resistance

Insulin-resistant diabetes in Rabson-Mendenhall syndrome (RMS) is relatively unresponsive to first-line antidiabetic treatments, including metformin and insulin. We report 2 patients with RMS treated with 2 different sodium-glucose cotransporter inhibitors 2: empagliflozin in an 11-year-old boy and dapagliflozin in a 12-year-old girl. In the first patient, we began empagliflozin at 2.5 mg/day and increased the dose to 10 mg/day over 3 months. During treatment with empagliflozin, the amount of time during which the patient maintained serum glucose in the 70 to 180 mg/dL target range increased by 2 hours per day. Hemoglobin A1C dropped from >14% to 11.9%, urinary calcium increased almost twofold, and β-hydroxybutyrate remained <2.5 mmol/L. Because glycemic control did not further improve with dose escalation, we reverted to the 2.5 mg/day dose. We initiated dapagliflozin in a second patient at 5 mg/day and witnessed a reduction of hemoglobin A1C from 8.5% to 6.2% after 6 months and a mild increase in urinary excretion of phosphorus but not calcium. Insulin levels fell by >50%. In 2 patients with RMS, empagliflozin and dapagliflozin were well tolerated and improved glycemic control without significantly increasing ketonemia. Renal calcium excretion should be carefully monitored.

Beyond the Glycaemic Control of Dapagliflozin: Microangiopathy and Non-classical Complications

Dapagliflozin is a selective sodium-glucose cotransporter 2 inhibitor (SGLT2i) indicated for the treatment of type 2 diabetes mellitus (T2DM), heart failure (HF) with reduced ejection fraction (EF) and chronic kidney disease (CKD). In monotherapy or as an additive therapy, dapagliflozin aids glycaemic control, is associated with reductions in blood pressure and weight, and promotes a favourable lipid profile. In this review, we address the impact of dapagliflozin on cardiovascular risk factors and common microangiopathic complications such as kidney disease and retinopathy in patients with T2DM. Furthermore, we evaluate its potential beneficial effects on other less frequent complications of diabetes, such as macular oedema, cognitive impairment, non-alcoholic fatty liver disease and respiratory disorders during sleep. Moreover, the underuse of SGLT2i in clinical practice is discussed. Our goal is to help translate this evidence into clinical practice.

Association between Sodium Glucose Co-transporter 2 Inhibitors and Incident Glaucoma in Patients with Type 2 Diabetes: A Multi-institutional Cohort Study in Taiwan

PURPOSE

Type 2 diabetes (T2D) is an important risk factor for glaucoma, and sodium-glucose co-transporter 2 (SGLT2) inhibitors have been shown to protect the optic nerves. We therefore aimed to evaluate the association between SGLT2 inhibitors and incident glaucoma.

METHODS

This retrospective cohort study analyzed the largest multi-institutional electronic medical records database in Taiwan, containing data of over a million individuals. We included T2D patients newly prescribed SGLT2 inhibitors or glucagon-like peptide-1 receptor agonists (GLP-1 RAs) from 2016 to 2018. Our primary outcome was incident glaucoma diagnosis between initiation of SGLT2 inhibitors or GLP-1 RAs, and 31st March 2021. After applying inverse probability of treatment weighting (IPTW) to increase homogeneity between the two treatment groups, we estimated hazard ratios (HR) with 95% confidence intervals (CI) for the risk of glaucoma, based on Cox proportional hazards regression models.

RESULTS

We included 9,927 and 1,065 T2D patients who had been newly prescribed SGLT2 inhibitors or GLP-1 RAs, respectively. Lower risk of incident glaucoma was observed in patients receiving SGLT2 inhibitors (7.9 events per 1,000 person-years), compared to those receiving GLP-1 RAs (10.0 events per 1,000 person-years), with an HR of 0.81 (95% CI: 0.69-0.95). Multiple sensitivity analyses and a negative control outcome analysis confirmed the robustness of our main findings.

CONCLUSION

This study suggests that T2D patients newly prescribed SGLT2 inhibitors have a reduced risk of incident glaucoma, compared to those prescribed GLP-1 RAs, in clinical practice. Future prospective studies are suggested to confirm this association.

The Relationship Between the Blood-Brain-Barrier and the Central Effects of Glucagon-Like Peptide-1 Receptor Agonists and Sodium-Glucose Cotransporter-2 Inhibitors

Diabetes and obesity are growing problems worldwide and are associated with a range of acute and chronic complications, including acute myocardial infarction (AMI) and stroke. Novel anti-diabetic medications designed to treat T2DM, such as glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT-2is), exert beneficial effects on metabolism and the cardiovascular system. However, the underlying mechanisms are poorly understood. GLP-1RAs induce anorexic effects by inhibiting the central regulation of food intake to reduce body weight. Central/peripheral administration of GLP-1RAs inhibits food intake, accompanied by an increase in c-Fos expression in neurons within the paraventricular nucleus (PVN), amygdala, the nucleus of the solitary tract (NTS), area postrema (AP), lateral parabrachial nucleus (LPB) and arcuate nucleus (ARC), induced by the activation of GLP-1 receptors in the central nervous system (CNS). Therefore, GLP-1RAs need to pass through the blood-brain barrier to exert their pharmacological effects. In addition, studies revealed that SGLT-2is could reduce the risk of chronic heart failure in people with type 2 diabetes. SGLT-2 is extensively expressed throughout the CNS, and c-Fos expression was also observed within 2 hours of administration of SGLT-2is in mice. Recent clinical studies reported that SGLT-2is improved hypertension and atrial fibrillation by modulating the "overstimulated" renin-angiotensin-aldosterone system (RAAS) and suppressing the sympathetic nervous system (SNS) by directly/indirectly acting on the rostral ventrolateral medulla. Despite extensive research into the central mechanism of GLP-1RAs and SGLT-2is, the penetration of the blood-brain barrier (BBB) remains controversial. This review discusses the interaction between GLP-1RAs and SGLT-2is and the BBB to induce pharmacological effects via the CNS.

Screening for diabetic retinopathy with fluorescein angiography in patients with type 1 diabetes from adolescence to adult life. A retrospective study of the past 30 years of clinical practice in a tertiary Belgian centre

Background

The aim of the present study was to describe the prevalence and progression of DR diagnosed by fluorescein angiography (FA) in patients with type 1 diabetes (T1D) during a 30‐year follow‐up, and the relationship with glycated haemoglobin (HbA1c).

Materials and methods

We included 4325 FA reports representing 851 patients with T1D with a mean age at diagnosis of 10.4 years (range: 0.0–49.9) and followed between 1986 and 2015. Clinical characteristics of the population were collected from patients’ files. The HbA1c level was measured within a maximum period of ±1 year from the date of FA. Descriptive statistics were realized to study prevalence and progression of DR.

Results

At diagnosis of incipient abnormalities, mean age was 22.8 years (range 13.7–46.9) and mean diabetes duration was 13 years (range: 4.3–29.6). Lesions requiring treatment were observed in 5.9% of the patients at a mean age of 32.4 years (range: 30.4–34.3) and a mean diabetes duration of 23.8 years (range: 19.4–28.1). On average, it took 12.9 years (range: 12.2–13.5) to progress from an incipient abnormality to a lesion requiring treatment. Mean HbA1c ± SD was 7.8 ± 1.5% over a period of 30 years.

Conclusions

While it could have been expected to observe a higher prevalence of DR, our study described by far the lowest results of prevalence comparing to similar studies, probably due to a good average HbA1c over 30 years.

Diabetic Retinopathy in the Aging Population: A Perspective of Pathogenesis and Treatment

The elderly population in the United States is projected to almost double by the year 2050. In addition, the numbers of diabetics are rising, along with its most common complication, diabetic retinopathy (DR). To effectively treat DR within the elderly population, it is essential first to consider the retinal changes that occur due to aging, such as decreased blood flow, retinal thinning, and microglial changes, and understand that these changes can render the retina more vulnerable to oxidative and ischemic damage. Given these considerations, as well as the pathogenesis of DR, specific pathways could play a heightened role in DR progression in elderly patients, such as the polyol pathway and the vascular endothelial growth factor (VEGF) axis. Current ocular treatments include intravitreal corticosteroids, intravitreal anti-VEGF agents, laser photocoagulation and surgical interventions, in addition to better control of underlying diabetes with an expanding range of systemic treatments. While using therapeutics, it is also essential to consider how pharmacokinetics and pharmacodynamics change with aging; oral drug absorption can decrease, and ocular drug metabolism might affect the dosing and delivery methods. Also, elderly patients may more likely be nonadherent to their medication regimen or appointments than younger patients, and undertreatment with anti-VEGF drugs often leads to suboptimal outcomes. With a rising number of elderly DR patients, understanding how aging affects disease progression, pharmacological metabolism, and adherence are crucial to ensuring that this population receives adequate care.