Semaglutide, reduction in glycated haemoglobin and the risk of diabetic retinopathy

Semaglutide, central retinal thickness and continuous glucose monitoring in persons with type 2 diabetes: A post-hoc analysis from a randomised trial

AIMS

Glycemic control is important for preventing diabetic retinopathy (DR), but rapid improvements could deteriorate the disease. In some, but not all studies, semaglutide is speculated to worsen DR, but the mechanism is unknown. Central retinal thickness (CRT) is an early marker of DR. Therefore, the objective was to investigate whether increased Time in Range (TIR (3.9-10.0 mmol/L)), was associated with reduced CRT in persons treated with semaglutide.

METHODS

Forty participants with type 2 diabetes were included in this post-hoc analysis of a 32-week randomised, placebo-controlled, partly open-label trial investigating the separate and combined effects of semaglutide and empagliflozin on target organ damage in 120 participants with type 2 diabetes. Individuals were randomised into four groups: i) semaglutide, ii) empagliflozin, iii) the combination or iv) placebo, n = 30 for each group). In the present study, 10 participants from each of the 4 arms participated. TIR was assessed using Continuous Glucose Measurement for 7-8 days and CRT was assessed using ocular coherence tomography.

RESULTS

In the 10 individuals treated with semaglutide, CRT increased ~1 % (3.76 μm, 95%CI [-0.32; 7.85], p = 0.065) compared to placebo. This was attenuated with adjustment for TIR (p = 0.21). Independently of the four interventions, increased TIR remained associated with increased CRT (0.07 μm, 95%CI[0.03; 0.12]μm, p = 0.002).

CONCLUSION

Semaglutide treatment did not impact CRT beyond what could be explained by changes in glycaemia. Across all interventions, increased TIR was associated with increases in CRT, thus supporting the link between rapid improved glycemia and DR.

Hypoxia-inducible factors link poor glycemic controlto diabetic retinopathy

Hypoglycemic episodes exacerbate diabetic eye disease, which is targetable by dual-HIF inhibition (Guo et al., this issue).

Association between various dosage forms of semaglutide and ocular adverse events in a real-world setting

BACKGROUND

This study systematically compares the risk of long-term ocular adverse events between subcutaneous and oral semaglutide preparations to assess pathway-specific safety differences.

METHODS

In this study, the Report odds ratio (ROR) technique was employed to detect signals of adverse drug reactions (ADRs) associated with the use of semaglutide. Analysis was conducted on data extracted from the FDA Adverse Event Reporting System (FAERS) database, covering the period from 2004(Q1) through 2024(Q3). This investigation encompasses a descriptive analysis focused on the administration of semaglutide through various routes, encompassing a broad range of demographics including gender (male and female), age groups, along with other demographic data and the timing of disease onset. Following this, the study employs the ROR methodology to assess the differential adverse event signals across distinct semaglutide formulations.

RESULTS

We categorized the eye as the System Organ Class (SOC) and obtained 1733 ADE reports related to it from the FAERS database. Of these, 1541 reports were associated with injectables, while tablets were linked to 192 ADE reports. In both dosage forms, most cases occurred within the first month of administration, although the median time to onset (TTO) differed, with injectables identified at 7.00 [IQR 0.00-56.00] days and tablets at only 3.50 [IQR 0.00-35.00] days. It is worth noting that 5.41% of patients administered subcutaneous injections and 2.17% of those receiving oral medications reported ADEs following one year of treatment with semaglutide. Furthermore, female patients exhibited a higher susceptibility to ocular adverse reactions compared to their male counterparts. Regarding the primary preferred terms (PTs), blurred vision constitutes 34.33% of the total ADEs associated with tablet formulations. This incidence is marginally higher than that observed with injectable formulations. This investigation further discerned ocular ADEs signals associated with specific formulations: subcutaneous injections have a higher frequency of reports concerning retinal complications, such as diabetic retinopathy, ischemic optic neuropathy, retinal detachment, retinal tear, and retinal hemorrhage.

CONCLUSION

The results of this study identified a significant difference between subcutaneous and oral semaglutide in ocular ADE risk, providing some evidence for dosage form selection and risk monitoring for clinical use.

Increased vision impairment reports linked to semaglutide: analysis of FDA adverse event data

BACKGROUND

Semaglutide, a GLP-1 receptor agonist widely prescribed for type 2 diabetes and obesity, has recently raised concerns about its ocular safety. This study aimed to investigate the association between semaglutide use and vision impairment using data from the FDA Adverse Event Reporting System (FAERS).

METHODS

We conducted an analysis of FAERS data, comparing reports of vision impairment associated with semaglutide to those associated with other antidiabetic and weight loss medications. The main outcome measure was the reporting odds ratio (rOR) for vision impairment linked to semaglutide use compared to other medications.

RESULTS

Semaglutide showed significantly higher reporting of vision impairment compared to other GLP-1 receptor agonists (rOR 1.95, 95% CI 1.75-2.17, p < 0.0001), DPP-4 inhibitors (rOR 2.46, 95% CI 2.12-2.86, p < 0.0001), SGLT2 inhibitors (rOR 3.89, 95% CI 3.35-4.51, p < 0.0001), and metformin (rOR 2.23, 95% CI 1.90-2.62, p < 0.0001). Similar findings were observed when compared to phentermine (rOR 1.57, 95% CI 1.07-2.31, p = 0.026) and orlistat (rOR 3.77, 95% CI 2.96-4.81, p < 0.0001). Topiramate was the sole exception, showing higher vision impairment reporting than semaglutide (rOR 0.30, 95% CI 0.20-0.45, p < 0.0001).

CONCLUSIONS

These findings suggest a potentially elevated risk of vision impairment with semaglutide use compared to other diabetes and weight loss medications, warranting further investigation and vigilant post-marketing surveillance. Future studies should assess the clinical impact of this potential increased risk on an absolute scale to better inform treatment decisions.

Real-world evidence on the utilization, clinical and comparative effectiveness, and adverse effects of newer GLP-1RA-based weight-loss therapies

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have emerged as key agents for weight management, based on their marked efficacy as observed in randomized controlled trials. While still limited, real-world studies on GLP-1RA use in populations with obesity are increasingly available. This narrative review discusses contemporary real-world evidence demonstrating the utilization, clinical and comparative effectiveness, and adverse effects of the currently approved GLP-1RA-based weight-loss therapies, that is, liraglutide, semaglutide and tirzepatide. The observed weight reduction in clinical practice overall tends to be lower than in randomized controlled trials; however, outcomes approach those seen in trials when focusing on highly adherent patients. Real-world studies demonstrate high discontinuation rates of GLP-1RAs (20%-50%) within the first year, and the use of much lower doses than those evaluated in clinical trials. Evidence from observational studies within type 2 diabetes or obesity populations suggests frequent gastrointestinal disturbances in GLP-1RA users, as also observed in trials, but no clear increase in risks of severe events like pancreatitis or pancreatic cancer, thyroid disorders, or depression and self-harm. Further evidence is needed to understand possible real-world associations of GLP-1RAs with eye disease and other rare outcomes. We provide 10 areas of particular importance for further research on GLP-1RA within the real-world space, including improved understanding of the exact drivers of early discontinuation and suboptimal dosing, studies of the effects of stopping GLP-1RA treatment, and investigations of clinical and cost-effectiveness for hard clinical outcomes in real-world settings, including not only cardio-reno-metabolic outcomes but also obesity-induced diseases like neuropsychiatric disease, cancer, musculoskeletal disease, and infections. PLAIN LANGUAGE SUMMARY: Recent advancements in weight-loss medications have sparked a lot of interest. The so-called GLP-1 receptor agonist medications (GLP-1RAs) have gained a lot of attention, because they have shown to be very effective, leading to significant weight loss in patients participating in clinical trials. GLP-1RAs, like liraglutide, semaglutide, and tirzepatide, help manage weight by mimicking hormones that control blood sugar and appetite. However, how these medications perform in real life can be different from the controlled settings of clinical trials, in which patients are carefully selected and their treatment plans closely followed. This literature review looks at how these medications are used and their effectiveness and safety in real-world settings. In real-life practice, GLP-1RAs are often less effective than in clinical trial conditions. This is usually because patients don't follow their medication plans as strictly as in trials. Real-world data shows that many patients use lower doses and do not stick to their treatment as strictly as participants in a controlled trial might, leading to less weight loss. However, those who do follow their plans closely can achieve results similar to those in trials. A major issue with GLP-1RAs is that many patients stop using them within the first year due to side effects or high costs of the medications, especially if not covered by insurance. Common side effects include nausea and digestive problems, which are the main reasons patients stop taking these treatments. These side effects are often manageable and decrease over time, and this reviews found no strong real-world evidence that GLP-1RAs cause severe side effects in many users. Despite these challenges, when GLP-1RAs are used effectively and consistently, they show substantial benefits in weight loss, most so the newest medications semaglutide and tirzepatide. These medications are also likely to help manage and prevent weight-related health conditions like type 2 diabetes and cardiovascular disease, but evidence for these beneficial outcomes is still scarce in real-world settings. The review emphasizes the need for more research to understand why many patients stop using these medications and how to improve dosing. It also calls for studies on the long-term effects of these therapies on various health outcomes, including mental health, cardiometabolic health, cancer, and rare conditions like eye diseases. Overall, while GLP-1RAs are a valuable tool for weight management, their real-world use requires careful consideration of individual patient factors, such as the ability to stick to treatment plans, manage side effects, and afford the medications. Further research will help make these treatments more effective for a wider range of people that need them.

Risk of ophthalmic adverse drug reactions in patients prescribed glucagon-like peptide 1 receptor agonists: a pharmacovigilance study based on the FDA adverse event reporting system database

OBJECTIVE

To investigate the association between glucagon-like peptide 1 receptor agonists (GLP-1 RAs) and ophthalmic adverse drug reactions (OADRs) using data from the FDA Adverse Event Reporting System (FAERS).

METHODS

This retrospective pharmacovigilance study analyzed post-marketing FAERS data from 2018 to 2023 to identify GLP-1 RA-related OADRs. This study employed the Weibull model for time-to-onset (TTO) analysis, Bayesian Information Component analysis for disproportionality comparing GLP-1 RAs with other drugs, and the Ω shrinkage method for co-medication analysis.

RESULTS

FAERS reported 5003 OADRs associated with GLP-1 RAs, including retinopathy and visual impairment. Disproportionality analysis identified significant signals for semaglutide, liraglutide, and exenatide, suggesting potential associations with OADRs. Co-medication analysis indicated that OADRs primarily resulted from GLP-1 RA use. TTO analysis categorized most OADRs as early failures, emphasizing the need for early monitoring.

CONCLUSION

This study emphasizes the importance of ophthalmic surveillance in patients using GLP-1 RAs, particularly semaglutide, dulaglutide, and exenatide. Enhanced monitoring and patient education are essential for timely detection and management of potential OADRs. Regulatory agencies should consider updating drug labels to include comprehensive warnings about OADRs associated with GLP-1 RA therapies.

Anterior ischemic optic neuropathy in patients treated with semaglutide: report of four cases with a possible association

BACKGROUND

Semaglutide, a glucagon-like peptide-1 receptor agonist, is increasingly used worldwide for its cardiometabolic benefits. However, it has recently been associated with nonarteritic anterior ischemic optic neuropathy (NAION). This report presents four clinical cases and explores a possible association.

CASE PRESENTATION

Four male patients were diagnosed with NAION during semaglutide treatment, with treatment durations of less than one year in three cases. All presented with significant optic disc edema and intraretinal fluid on optical coherence tomography, along with crowded optic disc and small Bruch's membrane opening diameters (< 1.4 mm in three cases). One patient exhibited optic disc drusen. Visual field defects corresponded with ganglion cell layer atrophy on optical coherence tomography. Systemic risk factors varied; two patients had only obesity.

CONCLUSIONS

Our observation suggests that individuals with small Bruch's membrane opening diameter may be at risk of developing NAION during semaglutide treatment.

What is the evidence regarding the safety of new obesity pharmacotherapies

The use of gut-hormone receptors agonists as new therapeutic options for obesity and some of its related comorbidities, such as type 2 diabetes, has resulted in an unprecedented efficacy in the medical management of people living with obesity (PLWO). Appraisal of the safety of these drugs is of utmost importance considering the large number of PLWO, and the potentially long exposure to these pharmacotherapies. In this narrative review we summarize the evidence on the safety of liraglutide, semaglutide, and tirzepatide as derived from randomized clinical trials conducted in adults living with obesity. Additionally, the safety of these drugs is put into perspective with that of other drugs currently approved for the treatment of PLWO. Overall, the available data support a favorable efficacy versus safety balance for gut-hormone hormone receptor analogues in the treatment of these subjects. Nonetheless, it should be acknowledged that in the context of a chronic disease that has reached epidemic proportions, data from randomized clinical trials aimed primarily at proving the efficacy of these drugs may have been insufficient to unveil all the safety issues. Thus, continuous surveillance on the adverse effects of liraglutide, semaglutide, and tirzepatide is required as we use these drugs in a broader population than that represented in currently available clinical trials.

Ophthalmic Complications Associated With the Antidiabetic Drugs Semaglutide and Tirzepatide

Importance

Nearly 2% of the US population received a prescription for semaglutide in 2023. There has been a recent concern that this drug and other similar medications may be associated with ophthalmic complications.

Objective

To report ophthalmic complications associated with the use of semaglutide or tirzepatide.

Design, Setting, and Participants

This was a retrospective case series. All patients were initially seen in a community setting. Patients experiencing an ophthalmic complication in association with the use of semaglutide or tirzepatide were included in this analysis.

Exposures

Patients described were using either semaglutide or tirzepatide.

Main Outcomes and Measures

Visual acuity and visual field defects.

Results

A total of 9 patients (mean [SD] age, 57.4 [11.6] years; age range, 37-77 years; 5 female [56%]; 4 male [44%]) were included in this study. Seven patients with nonarteritic ischemic anterior optic neuropathy, 1 patient with bilateral papillitis, and 1 patient with paracentral acute middle maculopathy were reported. Atypical features included sequential ischemic optic neuropathy, bilateral disc swelling at presentation, and progressive vision loss.

Conclusions and Relevance

In this case series study, it was not possible to determine if there is a causal link between these drugs and the ophthalmic complications reported. In some cases, it is hypothesized that rapid correction of hyperglycemia induced by these drugs, rather than a toxic effect of the drugs, could be associated with the ophthalmic complications reported.

Progression of Diabetic Retinopathy After Initiation of Automated Insulin Delivery System in Adults With Type 1 Diabetes

BACKGROUND

To evaluate the progression of diabetic retinopathy (DR) after the initiation of automated insulin delivery (AID) systems in adults with type 1 diabetes (T1D).

METHODS

In this longitudinal study with 152 adults, retinal exams and clinical variables were collected before and after AID initiation up to 2.7 years. The DR worsening was defined as an increase in Early Treatment of Diabetic Retinopathy Study (ETDRS) scores or qualitative retinal exam.

RESULTS

A total of 152 adults with mean age of 42 years (57% female), 26 years of T1D duration, and mean baseline HbA1c of 7.6% (60 mmol/mol) were included in this analysis. Of 152 adults with T1D, 42 (28%) adults had DR worsening after AID initiation. After adjusting for age, diabetes duration, and sex, baseline HbA1c (odds ratio [OR] = 2.1 [1.34-3.04]) and low-density lipoprotein cholesterol (LDL-C) >100 mg/dL with HbA1c >8% (OR = 3.33 [1.12-9.91]) were associated with two- and three-fold increased risk for DR worsening, respectively. The decline of HbA1c with AID initiation between DR worsening and no-DR worsening groups was not significant (-0.38 ± 1.2% vs -0.47 ± 0.9%; P = .6).

CONCLUSIONS

Higher baseline HbA1c with LDL-C >100 mg/dL may be associated with DR worsening after initiation of AID systems in T1D. Those with elevated HbA1c should get periodic ophthalmic examination after AID initiation to detect progression of DR. Prompt diagnosis may result in timely treatment.

Early combination therapy with SGLT2i and GLP-1 RA or dual GIP/GLP-1 RA in type 2 diabetes

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) and glucagon-Like peptide-1 receptor agonists (GLP-1 RA) are recommended in people with type 2 diabetes (T2D) for glycaemic control and for people with high cardiovascular risk. However, current guidelines do not specifically address the role of initial early combination therapy with SGLT2i and GLP-1 RA or dual gastric inhibitory polypeptide (GIP)/GLP-1 RA, but rather sequential initiation with either in T2D. This review synthesizes the available evidence on the use of SGLT2i and GLP-1-based therapies for T2D and provides a rationale for their combination. The combination of SGLT2i with GLP-1-based therapies addresses complementary pathophysiological mechanisms and enhances efficacy in achieving target haemoglobin A1C (HbA1c) levels. SGLT2i and GLP-1 RA also have been shown to prevent complications of T2D. While both classes reduce adverse cardiorenal events, SGLT2i has a predominant effect on prevention of kidney dysfunction and heart failure, whereas GLP-1 RA has a more marked effect on the risk of atherosclerotic cardiovascular disease. Both drug classes have favourable safety profiles. Finally, weight loss with combination therapy may have disease-modifying effects that may reverse T2D progression. We propose that the combination of SGLT2i with GLP-1 RA or dual GIP/GLP-1 RA should be considered for most patients with T2D who do not have contraindications.

Twenty-Year Trends in Prevalence and Incidence of Diabetic Retinal Disease

PURPOSE

To determine how the rates of diabetic retinal disease (DRD) and its vision-threatening components (VTDR), diabetic macular edema (DME), and proliferative diabetic retinopathy (PDR) among patients with diabetes mellitus (DM) have changed over the past 20 years.

DESIGN

Retrospective cohort study.

PARTICIPANTS

All DM patients insured by commercial and Medicare Advantage insurance plans in a claims database from 2000 through 2022 and at least 1 full calendar year of data. Cohorts were created using International Classification of Diseases codes to determine the yearly prevalence and incidence of DRD, VTDR, DME, and PDR.

METHODS

Logistic and Poisson regression models created prevalence and incidence estimates, respectively.

MAIN OUTCOME MEASURES

DRD, DME, and PDR prevalence and incidence.

RESULTS

The prevalence of DRD initially decreased from 2001 (13.6%) to 2007 (10.9%), but then increased every year through 2021 (20.8%; P < 0.001, adjusted test for trend [aTT]). Incidence of DRD varied considerably, ranging from 16.9 cases per 1000 patient-years in 2013 to its highest of 32.2 cases per 1000 patient-years in 2021 (P < 0.001, aTT). The prevalence of VTDR and DME trended similarly, with increases from 2007 (VTDR, 5.2%; DME, 3.2%) through 2016 (VTDR, 7.5%; DME, 5.4%), followed by decreases each year through 2021 (VTDR, 6.9%; DME, 4.9%; P < 0.001, aTT). The VTDR and DME incidence rates peaked in 2009 (VTDR, 12.4 cases per 1000 patient-years; DME, 8.6 cases per 1000 patient-years) and decreased through 2022 (VTDR, 6.1 cases per 1000 patient-years; DME, 5.0 cases per 1000 patient-years; P < 0.001, aTT, for both VTDR and DME). Prevalence of PDR varied between 3.2% and 4.0% throughout the 20-year observation period (P < 0.001, aTT). Incidence of PDR decreased over time to 2.6 cases per 1000 patient-years in 2022 (P < 0.001, aTT).

CONCLUSIONS

DRD prevalence (through 2007) and incidence (through 2014) initially decreased, but the rate of each has doubled since. Despite increases in DRD, incidence rates of VTDR, DME, and PDR have improved dramatically over the past 20 years.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Consensus Report on Glucagon-Like Peptide-1 Receptor Agonists as Adjunctive Treatment for Individuals With Type 1 Diabetes Using an Automated Insulin Delivery System

With increasing prevalence of obesity and cardiovascular diseases, there is a growing interest in the use of glucagon-like peptide-1 receptor agonists (GLP-1RAs) as an adjunct therapy in type 1 diabetes (T1D). The GLP-1RAs are currently not approved by the US Food and Drug Administration for the treatment of T1D in the absence of randomized controlled trials documenting efficacy and safety of these agents in this population. The Diabetes Technology Society convened a series of three consensus meetings of clinicians and researchers with expertise in diabetes technology, GLP-1RA therapy, and T1D management. The project was aimed at synthesizing current literature and providing conclusions on the use of GLP-1RA therapy as an adjunct to automated insulin delivery (AID) systems in adults with T1D. The expert panel members met virtually three times on January 17, 2024, and April 24, 2024, and August 14, 2024, to discuss topics ranging from physiology and outcomes of GLP-1RAs in T1D to limitations of current sensors, algorithms, and insulin for AID systems. The panelists also identified research gaps and future directions for research. The panelists voted to in favor of 31 recommendations. This report presents the consensus opinions of the participants that, in adults with T1D using AID systems, GLP-1RAs have the potential to (1) provide effective adjunct therapy and (2) improve glycemic and metabolic outcomes without increasing the risk of severe hypoglycemia or diabetic ketoacidosis.

Glucagon-like Peptide-1 Receptor Agonists in the Management of Diabetic Retinopathy

Glucagon-like peptide-1 (GLP-1) receptor agonists are a family of drugs, most well known by the third-generation once-weekly subcutaneous semaglutide, that act on the incretin pathway of metabolic, hormonal signaling to modulate pancreatic insulin release, gastric emptying, energy intake, and subjective feelings of satiety. This class of drugs' efficacy and safety in the treatment of type 2 diabetes and obesity have been demonstrated across multiple large randomized controlled trials. These data have propelled GLP-1 receptor agonists to ubiquity in diabetic management and weight loss therapy, leading them to be frequently encountered in ophthalmic practice. The effect of GLP-1 receptor agonists like semaglutide on diabetic retinopathy (DR) is at this point unclear; some studies indicate a worsening of DR with the initiation of GLP-1 agonists, especially semaglutide. Overall, the macrovascular reduction of cardiovascular and stroke risks from GLP-1 receptor agonists should be prioritized over the potential microvascular progression of DR, as long as the patient is regularly followed by ophthalmology.

Cost-Effectiveness of Semaglutide in Patients With Obesity and Cardiovascular Disease

BACKGROUND

Randomized clinical trials have shown that semaglutide is associated with a clinically relevant reduction in body weight and a lower risk of adverse cardiovascular events in those who are overweight or obese with a history of cardiovascular disease but no diabetes. The objective of this study was to assess the cost-effectiveness of semaglutide for this indication.

METHODS

A decision analytic Markov model was used to compare the lifetime benefits and costs of semaglutide 2.4-mg subcutaneous weekly vs standard care in a hypothetical cohort of patients who were overweight or obese with preexisting cardiovascular disease (and no diabetes) from the health care payer perspective. Our model included ischemic stroke, heart failure hospitalization and/or urgent visit or myocardial infarction, and death over monthly transition cycles. Model outcomes included costs (2023 CAD$), quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios.

RESULTS

Base case analysis showed that the incremental cost-effectiveness ratio for semaglutide compared with standard care was $72,962 per QALY gained with a 14% likelihood of cost-effectiveness adopting a $50,000 per QALY gained willingness to pay threshold. Factors with the greatest influence on cost-effectiveness were medication efficacy on mortality and medication cost. When the price of semaglutide was reduced by 50%, it was economically attractive at $37,190 per QALY gained with an 80% likelihood of cost-effectiveness at a $50,000 per QALY threshold.

CONCLUSIONS

Semaglutide might be a cost-effective option for the publicly funded health care system contingent on initial pricing. Considering the candidate population-patients who are overweight or obese with preexisting cardiovascular disease-policymakers should consider the budget effect of funding semaglutide and weigh it against other ways scarce health care dollars might be used.

Once-weekly semaglutide doubles the five-year risk of nonarteritic anterior ischemic optic neuropathy in a Danish cohort of 424,152 persons with type 2 diabetes

BACKGROUND

Nonarteritic anterior ischemic optic neuropathy (NAION) is an untreatable condition often causing severe and irreversible visual loss in the affected eye. As it has recently been implied that the use of semaglutide associates with NAION, the aim of the present study was to evaluate this risk prospectively in all persons with type 2 diabetes (T2D) in Denmark.

METHODS

In a five-year longitudinal cohort study, we identified all persons with T2D in Denmark (n = 424,152) between 2018 and 2024. Patients were stratified according to exposure (n = 106,454) or non-exposure (n = 317,698) to once-weekly semaglutide, and incidence rates and hazard ratios (HR) of NAION were estimated in a multivariable Cox proportional hazard regression model.

RESULTS

At baseline, median age and hemoglobin A1c were 65 years and 50 mmol/mol, and 54·5% were male. During 1,915,120 person-years of observation, 218 persons developed NAION. Semaglutide exposure was associated with a higher incidence rate (0·228 vs. 0·093 per 1000 person-years, p < 0·001) and independently predicted a higher risk of upcoming NAION (HR 2·19, 95% confidence interval 1·54 - 3·12), even when multiple other factors were taken into account. Overall, 67 persons exposed to semaglutide developed NAION with a median time from first prescription to event of 22·2 months (interquartile range 10·2-37·8 months).

CONCLUSIONS

During five years of observation of all persons with T2D in Denmark, use of once-weekly semaglutide independently more than doubled the risk of NAION. Given the irreversible nature of NAION, it is important to acknowledge this risk, and upcoming studies should aim to identify high-risk subgroups.

Incretin-based therapy: a new horizon in diabetes management

Diabetes mellitus, a metabolic syndrome characterized by hyperglycemia and insulin dysfunction, often leads to serious complications such as neuropathy, nephropathy, retinopathy, and cardiovascular disease. Incretins, gut peptide hormones released post-nutrient intake, have shown promising therapeutic effects on these complications due to their wide-ranging biological impacts on various body systems. This review focuses on the role of incretin-based therapies, particularly Glucagon-like peptide-1 (GLP-1) agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors, in managing diabetes and its complications. We also discuss the potential of novel agents like semaglutide, a recently approved oral compound, and dual/triple agonists targeting GLP-1/GIP, GLP-1/glucagon, and GLP-1/GIP/glucagon receptors, which are currently under investigation. The review aims to provide a comprehensive understanding of the beneficial impacts of natural incretins and the therapeutic potential of incretin-based therapies in diabetes management.

Total retinal thickness is an important factor in evaluating diabetic retinal neurodegeneration

OBJECTIVE

Macular retinal nerve fibre layer (mRNFL) and ganglion cell-inner plexiform layer thickness (GC-IPL) measurements are important markers of diabetic retinal neurodegeneration (DRN). In this cross-sectional study, we aimed to quantify the contribution of total retinal thickness (TRT) and other factors in the variation of mRNFL and GC-IPL thickness among participants with diabetes.

METHODS AND ANALYSIS

We used macular-centred spectral domain-optical coherence tomography scans from participants with diabetes in the UK Biobank. Two multiple linear regression models (prior to and after adjusting for TRT) were used to determine factors associated with mRNFL and GC-IPL thicknesses. A p value of less than 0.05 was considered statistically significant.

RESULTS

A total of 3832 eyes from 3832 participants with diabetes were analysed. Factors that explained the greatest variation in thickness were TRT (20.9% for mRNFL and 57.2% for GC-IPL), followed by spherical equivalent (8.0% for mRNFL only), gender (2.2% for mRNFL only) and age (1.4% for GC-IPL only). Other factors significantly associated with mRNFL and/or GC-IPL thickness explained less than 1% of the variation in their thicknesses. Self-reported ancestral background was not significantly associated with mRNFL thickness after accounting for TRT.

CONCLUSIONS

Although many factors were significantly associated with mRNFL and GC-IPL thickness in participants with diabetes, they accounted for a fraction of the variation in the thickness of both layers. TRT explained most of the variation in these measurements, hence accounting for TRT is needed when using these metrics to evaluate DRN.

The Effect of Glucagon-Like Peptide-1 Receptor Agonists on Diabetic Retinopathy at a Tertiary Care Center

Objective

The potential association between diabetic retinopathy (DR) worsening and glucagon-like peptide-1 receptor agonists (GLP-1RA) has affected therapeutic management of diabetic patients but remains controversial. This study compared rates of DR development or progression in patients on GLP-1RA to those on SGLT-2 inhibitors (SGLT-2I).

Design

Retrospective cohort study.

Subjects

Nine hundred eighty-one patients with diabetes mellitus taking GLP-1RA or SGLT-2I, the latter serving as controls, between 2012 and 2023.

Methods

Patients were one-to-one greedy matched by propensity scores on race/ethnicity, age, smoking status, baseline body mass index and hemoglobin A1c %, type of diabetes mellitus, baseline DR status and history of DR procedures, duration of drug use, whether they had taken both drug types, and change in hemoglobin A1c % after 1 year on the drug.

Main Outcome Measures

The primary outcome was clinical DR development or progression (termed "worsening") detected by International Classification of Diseases (ICD), 10th edition codes, confirmed by manual review, on GLP-1RA compared with SGLT-2I after propensity score matching. Secondary outcomes included DR worsening indicated by need for procedures due to complications, and time-to-first DR worsening event.

Results

The study included 692 GLP-1RA users and 289 SGLT-2I users. The mean follow-up periods for GLP-1RA versus SGLT-2I use were 1.54 (standard deviation [SD] 1.82) years and 1.38 (SD 1.56) years, respectively. The rates of clinical worsening were 2.3% and 2.8%, respectively. After propensity score matching, an association was not identified between GLP1-RA and DR worsening neither clinically by ICD-10 codes (odds ratio [OR] = 0.33, 95% confidence interval [CI]: 0.11-1.03) nor by indication for procedures (OR = 0.50, 95% CI 0.13-2.00). Time-to-first DR worsening did not differ between the groups in Kaplan-Meier analysis. The most common type of clinical worsening event for both drug types was vitreous hemorrhage (43.7% and 50% of worsening events in GLP-1RA and SGLT-2I users, respectively). The most common DR procedure indicated was anti-VEGF injections (34% and 35% of GLP-1RA and SGLT-2I events, respectively).

Conclusions

Diabetic retinopathy worsening, either clinically or by procedures, was not associated with GLP-1RA compared with SGLT-2I, both before and after propensity score matching on all analyses, including time-to-first worsening event.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Preoperative hemoglobin A1c is associated with postoperative bleeding after vitrectomy for vitreous hemorrhage in patients with diabetic retinopathy

We previously reported that a high HbA1c level 3 months before vitrectomy for vitreous hemorrhage or a large preoperative decrease in the HbA1c level over 3 months tended to increase the risk of rebleeding in diabetic retinopathy patients evaluated between 2010 and 2014. Here, we aimed to confirm these results with an extended study period and an increased number of operated eyes. This study included 121 diabetic patients who were admitted to Osaka University Hospital between 2010 and 2019 and who underwent vitrectomy for vitreous hemorrhage. Binomial logistic regression analysis was performed with the presence of postoperative bleeding as the outcome. The present study showed that the duration of the operation was associated with rebleeding (odds ratio = 1.02, p = 0.0016). A high HbA1c level just before vitrectomy tended to be associated with the bleeding (odds ratio = 1.27, p = 0.05), while preoperative HbA1c changes were not associated with rebleeding. The results of this study suggest that a high preoperative HbA1c level just before vitrectomy, not a decrease in HbA1c levels, in addition to the duration of the operation may increase the risk of postoperative bleeding after vitrectomy in diabetic retinopathy patients.

Neuropathy of diabetes following initiation of a low-carbohydrate diet: Case report

Introduction

This case study portrays an unusual case of treatment-induced neuropathy of diabetes (TIND) in a patient with uncontrolled type 2 diabetes (T2D) who achieved rapid improvement in glucose control primarily with dietary intervention. Initial presentation was 50-year-old white male with a long-standing history of obesity and a family history of T2D with a screening glucose level >500mg/dL by glucometer, HbA1c of 14.9%, and initial weight 213 lbs.

Methods

The initial intervention included a low-carbohydrate diet, metformin, and a continuous glucose monitor (CGM). Semaglutide was added after seven days.

Results

His glycemia was within the target range within three weeks. Four weeks after initiation of therapy, he developed TIND symptoms consisting of burning, tightness, and numbness of bilateral feet along with 10/10 pain. At three months, his HbA1c dropped to 6.9% and his weight to 195 lbs. Treatment of his TIND reduced his pain from 10/10 to 2/10.

Conclusion

Whereas TIND is commonly associated with the use of insulin or sulfonylureas, this study adds evidence to the paucity of literature regarding TIND precipitated by dietary intervention.

Modern Management of Cardiometabolic Continuum: From Overweight/Obesity to Prediabetes/Type 2 Diabetes Mellitus. Recommendations from the Eastern and Southern Europe Diabetes and Obesity Expert Group

The increasing global incidence of obesity and type 2 diabetes mellitus (T2D) underscores the urgency of addressing these interconnected health challenges. Obesity enhances genetic and environmental influences on T2D, being not only a primary risk factor but also exacerbating its severity. The complex mechanisms linking obesity and T2D involve adiposity-driven changes in β-cell function, adipose tissue functioning, and multi-organ insulin resistance (IR). Early detection and tailored treatment of T2D and obesity are crucial to mitigate future complications. Moreover, personalized and early intensified therapy considering the presence of comorbidities can delay disease progression and diminish the risk of cardiorenal complications. Employing combination therapies and embracing a disease-modifying strategy are paramount. Clinical trials provide evidence confirming the efficacy and safety of glucagon-like peptide 1 receptor agonists (GLP-1 RAs). Their use is associated with substantial and durable body weight reduction, exceeding 15%, and improved glucose control which further translate into T2D prevention, possible disease remission, and improvement of cardiometabolic risk factors and associated complications. Therefore, on the basis of clinical experience and current evidence, the Eastern and Southern Europe Diabetes and Obesity Expert Group recommends a personalized, polymodal approach (comprising GLP-1 RAs) tailored to individual patient's disease phenotype to optimize diabetes and obesity therapy. We also expect that the increasing availability of dual GLP-1/glucose-dependent insulinotropic polypeptide (GIP) agonists will significantly contribute to the modern management of the cardiometabolic continuum.

Glucagon-like peptide-1 receptor agonists and risk of sight-threatening retinopathy in Taiwanese population: A propensity based cohort study

AIMS

To compare the risk of vision-threatening retinopathy between glucagon-like peptide-1 receptor agonists (GLP-1 RA) use and no use in patients with type 2 diabetes.

METHODS

Using propensity score matching, we identified 27,506 pairs of GLP-1 RA users and non-users, 3904 pairs of GLP-1 RA and dipeptidyl peptidase-4 inhibitors (DPP-4i) users, 10,985 pairs of GLP-1 RA and sodium-glucose cotransporter-2 inhibitors (SGLT2i) users, 2542 pairs of GLP-1 RA and sulfonylurea, respectively, from Taiwan's National Health Insurance Research Database from January 1, 2009 to December 31, 2018. We used Cox proportional hazards models to compare the risk of vision-threatening retinopathy between GLP-1 RA use and other matched groups.

RESULTS

In the matched cohorts, the time-varying exposure analysis showed that GLP-1 RA use was not associated with an increased risk of vision-threatening retinopathy compared to GLP-1 RA non-use (aHR 0.96, 95 % CI 0.89-1.03). New-user and active-comparator analyses showed that GLP-1 RA was associated with a significantly lower risk of vision-threatening retinopathy than DPP-4i (aHR 0.8, 95 % CI 0.66-0.97) but had no significant association with this risk compared to SGLT2i (aHR 1.09, 95 % CI 0.96-1.24) or sulfonylureas (aHR 0.79, 95 % CI 0.49-1.06).

CONCLUSIONS

This nationwide cohort study showed that GLP-1 RA use was not associated with an increased risk of vision-threatening retinopathy compared to non- GLP-1 RA use, and GLP-1 RA could significantly lower the risk of vision-threatening retinopathy than DPP-4i.

Role of Systemic Factors in Improving the Prognosis of Diabetic Retinal Disease and Predicting Response to Diabetic Retinopathy Treatment

Topic

To review clinical evidence on systemic factors that might be relevant to update diabetic retinal disease (DRD) staging systems, including prediction of DRD onset, progression, and response to treatment.

Clinical relevance

Systemic factors may improve new staging systems for DRD to better assess risk of disease worsening and predict response to therapy.

Methods

The Systemic Health Working Group of the Mary Tyler Moore Vision Initiative reviewed systemic factors individually and in multivariate models for prediction of DRD onset or progression (i.e., prognosis) or response to treatments (prediction).

Results

There was consistent evidence for associations of longer diabetes duration, higher glycosylated hemoglobin (HbA1c), and male sex with DRD onset and progression. There is strong trial evidence for the effect of reducing HbA1c and reducing DRD progression. There is strong evidence that higher blood pressure (BP) is a risk factor for DRD incidence and for progression. Pregnancy has been consistently reported to be associated with worsening of DRD but recent studies reflecting modern care standards are lacking. In studies examining multivariate prognostic models of DRD onset, HbA1c and diabetes duration were consistently retained as significant predictors of DRD onset. There was evidence of associations of BP and sex with DRD onset. In multivariate prognostic models examining DRD progression, retinal measures were consistently found to be a significant predictor of DRD with little evidence of any useful marginal increment in prognostic information with the inclusion of systemic risk factor data apart from retinal image data in multivariate models. For predicting the impact of treatment, although there are small studies that quantify prognostic information based on imaging data alone or systemic factors alone, there are currently no large studies that quantify marginal prognostic information within a multivariate model, including both imaging and systemic factors.

Conclusion

With standard imaging techniques and ways of processing images rapidly evolving, an international network of centers is needed to routinely capture systemic health factors simultaneously to retinal images so that gains in prediction increment may be precisely quantified to determine the usefulness of various health factors in the prognosis of DRD and prediction of response to treatment.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Unlocking the Potential: Semaglutide's Impact on Alzheimer's and Parkinson's Disease in Animal Models

Semaglutide (SEM), a glucagon-like peptide-1 receptor agonist, has garnered increasing interest for its potential therapeutic effects in neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD). This review provides a comprehensive description of SEM's mechanism of action and its effects in preclinical studies of these debilitating conditions. In animal models of AD, SEM has proved beneficial effects on multiple pathological hallmarks of the disease. SEM administration has been associated with reductions in amyloid-beta plaque deposition and mitigation of neuroinflammation. Moreover, SEM treatment has been shown to ameliorate behavioral deficits related to anxiety and social interaction. SEM-treated animals exhibit improvements in spatial learning and memory retention tasks, as evidenced by enhanced performance in maze navigation tests and novel object recognition assays. Similarly, in animal models of PD, SEM has demonstrated promising neuroprotective effects through various mechanisms. These include modulation of neuroinflammation, enhancement of mitochondrial function, and promotion of neurogenesis. Additionally, SEM has been shown to improve motor function and ameliorate dopaminergic neuronal loss, offering the potential for disease-modifying treatment strategies. Overall, the accumulating evidence from preclinical studies suggests that SEM holds promise as a novel therapeutic approach for AD and PD. Further research is warranted to elucidate the underlying mechanisms of SEM's neuroprotective effects and to translate these findings into clinical applications for the treatment of these devastating neurodegenerative disorders.

Semaglutide and obesity: beyond the nutritional and lifestyle intervention?

Semaglutide is the second marketed glucagon-like peptide 1 receptor agonist that can be used safely and efficiently in non-diabetic people with excess weight, providing a new milestone in the pharmacological treatment of obesity. This narrative review aims to describe the clinical actions of this new drug in weight management in non-diabetic patients along with possible side-effects and dropout reasons. To accomplish this, the PubMed database was searched to retrieve the most relevant clinical studies published to date on this topic, using the following keywords "semaglutide and obesity". Currently, semaglutide is on the market in two formulations, the once-weekly subcutaneous (s.c.) semaglutide and once-daily oral semaglutide. Data in the literature on the anti-obesity action of semaglutide are available for both routes of administration of the drug, with a prevalence of studies using the s.c. one. However, given its dosage, oral semaglutide may provide greater attractiveness and better treatment adherence, but further research is needed in this field.

Treatment adherence and the contemporary approach to treating type 2 diabetes mellitus

The rising burden of type 2 diabetes mellitus (T2D) poses a significant healthcare challenge on a global scale. The economic impact is also substantial and continually increasing. In Serbia, even though the prevalence is officially around 12 percent, nearly 40 percent of the adult population is estimated to be living with undiagnosed diabetes and more than half the population is obese or overweight. This review comprehensively addresses the present approach to treating T2D, emphasizing the critical role of treatment adherence. We review the various components of T2D treatment, underlining the significance of lifestyle modifications. The pros and cons of medications used in treatment are discussed and factors influencing adherence are analysed. A healthy lifestyle remains the foundation of the treatment, and if not sufficient, early pharmacotherapy is initiated. Medications have been developed to lower blood sugar levels with cardiorenal protection, however, due to their still high cost, metformin remains the drug of first choice for most patients. Adherence to the treatment regimen is often poor. Factors associated with this are diverse and often multiple in a particular patient. Poor adherence is associated with poor glycaemic control, increased risk of disease complications, higher cardiovascular risk, increased mortality, hospitalizations, and healthcare costs. In addition to reducing the complexity of drug therapy and better informing the patient, improved education and motivation could lead to greater adherence. Enhanced communication between the patient and the physician and reduced treatment costs could also have a positive impact. The review concludes that addressing factors affecting adherence can significantly improve T2D outcomes and reduce costs. Further research is needed to identify region-specific risk factors for poor adherence.

Glycaemic control and macrovascular and microvascular outcomes in type 2 diabetes: Systematic review and meta-analysis of cardiovascular outcome trials of novel glucose-lowering agents

AIM

Using a systematic review and meta-analysis of placebo-controlled cardiovascular outcome trials (CVOTs) of newer glucose-lowering agents [sodium-glucose cotransporter-2 inhibitors (SGLT-2is), glucagon-like peptide-1 receptor agonists (GLP-1RAs), and dipeptidyl peptidase-4 inhibitors (DPP-4is)] in type 2 diabetes (T2D), we aimed to determine the macrovascular and microvascular outcomes of these agents and clarify the relationships between glycated haemoglobin (HbA1c) reduction and risk of these outcomes.

MATERIALS AND METHODS

Randomized controlled trials were identified from MEDLINE, Embase and the Cochrane Library until September 2023. Study-specific hazard ratios with 95% confidence intervals (CIs) were pooled, and meta-regression was used to assess the relationships between outcomes and between trial arm HbA1c reductions.

RESULTS

Twenty unique CVOTs (six SGLT-2is, nine GLP-1RAs, five DPP-4is), based on 169 513 participants with T2D, were eligible. Comparing SGLT-2is, GLP-1RAs and DPP-4is with placebo, the hazard ratios (95% CIs) for 3-point major adverse cardiovascular events were 0.88 (0.82-0.94), 0.85 (0.79-0.92) and 1.00 (0.94-1.06), respectively. SGLT-2is and GLP-1RAs consistently reduced the risk of several macrovascular and microvascular complications, particularly kidney events. DPP-4is showed no macrovascular benefits. There was potential evidence of an inverse linear relationship between HbA1c reduction and 3-point major adverse cardiovascular event risk (estimated risk per 1% reduction in HbA1c: 0.84, 95% CI 0.67-1.06; p = .14; R2 = 14.2%), which was driven by the component of non-fatal stroke (R2 = 100.0%; p = .094). There were non-significant inverse linear relationships between HbA1c reduction and the risk of several vascular outcomes.

CONCLUSIONS

SGLT-2is and GLP-1RAs showed consistent risk reductions in macrovascular and microvascular outcomes. The vascular benefits of SGLT-2is and GLP-1RAs in patients with T2D extend beyond mere glycaemic control.

Cost consequence analysis of adding semaglutide to treatment regimen for patients with Type II diabetes in Saudi Arabia

Introduction

Semaglutide, a Glucagon-like Peptide-1 Receptor Agonist (GLP-1 RA), is often prescribed for managing type 2 diabetes, particularly in cases unresponsive to other hypoglycemic agents. Despite its popularity, the real-world efficacy and cost-effectiveness of Semaglutide relative to other treatments remain understudied.

Objective

This study aimed to examine the direct medical cost and consequences of adding Semaglutide to the treatment regimen for patients with type 2 diabetes in Saudi Arabia.

Methods

We conducted a single-center, retrospective review of Electronic Medical Records (EMRs) for adults with type 2 diabetes. Patients who had been on Semaglutide for at least three months were matched with those receiving alternative hypoglycemic therapies. Exclusions were made for patients with cancer, incomplete EMRs, or lacking prescription data. Investigated outcomes included changes in HbA1C levels and weight, and the direct costs comprised medications, clinic visits, and emergency care. Baseline adjustments were made through inverse probability treatment weighting, and uncertainty was assessed via bootstrapping with 10,000 replications.

Results

Out of 350 patients meeting the criteria, 116 were on Semaglutide. Predominantly females (62%), the cohort had an average age of 60 and a disease duration of 22 years. The difference in HbA1C (%) reductions between Semaglutide and non-Semaglutide users over 3,6, and 12 months were 0.154 (95% CI: -0.452-0.483), -0.031(95% CI: -0.754-0.239), -0.16(95% CI: -1.425-0.840), respectively. Semaglutide users did experience modest weight reductions ranging from 0.42 kg to 1.16 kg. The annual additional direct medical cost for Semaglutide was USD 4,086.82 (95% CI: $3,710.85 - $4,294.99).

Conclusion

Although Semaglutide induced modest weight reductions, it did not offer significant advantages in lowering HbA1C levels compared to other hypoglycemic treatments. These findings suggest the need for further research involving larger and more diverse cohorts to corroborate these findings.

The preclinical discovery and clinical evaluation of tirzepatide for the treatment of type 2 diabetes

INTRODUCTION

Despite numerous antidiabetic medications available for the treatment of type 2 diabetes, a substantial percentage of patients fail to achieve optimal glycemic control. Furthermore, the escalating obesity pandemic underscores the urgent need for effective relevant pharmacotherapies. Tirzepatide, a novel dual GIP and GLP-1 receptor agonist, offers a promising therapeutic option.

AREAS COVERED

This review describes the discovery and clinical development of tirzepatide. Based on data from pivotal in vivo and in vitro studies, the authors present the pharmacodynamic profile of tirzepatide. Furthermore, they summarize data from the clinical trial programs that assessed the efficacy and safety of tirzepatide for the treatment of type 2 diabetes or obesity in a broad spectrum of patients, and discuss its therapeutic potential.

EXPERT OPINION

Tirzepatide effectively reduces glucose levels and body weight in patients with type 2 diabetes and/or obesity, with a generally safe profile. Based on data from phase 3 clinical trials, several agencies have approved its use for the treatment of type 2 diabetes and obesity. Clinicians should be aware of possible adverse events, mainly mild-to-moderate gastrointestinal side effects. Overall, tirzepatide represents a promising treatment option for the treatment of type 2 diabetes.

Weight loss, bariatric surgery, and novel antidiabetic drugs effects on diabetic retinopathy: a review

PURPOSE OF REVIEW

Diabetic retinopathy (DR) is a leading cause of visual impairment, and the increasing prevalence of diabetes and obesity will impact rates of visual impairment moving forward. Our review aims to synthesize the current body of evidence regarding the impact of lifestyle interventions, such as weight loss, bariatric surgery, and novel antidiabetic drugs, on DR.

RECENT FINDINGS

Literature review revealed insufficient evidence regarding the impact of weight loss on DR. Preoperative DR patients undergoing bariatric surgery were found to have similar short-term chances of improvement or worsening DR. Progression of DR with glucagon-like peptide 1 receptor agonists treatments appears unrelated to specific drugs and was also observed with traditional antidiabetic medications.

SUMMARY

Rapidly correcting HbA1c levels (≥2%) can paradoxically lead to early worsening DR. Patients considering weight loss, bariatric surgery, and novel antidiabetic drugs should be aware of the potential for DR progression, but they should not be discouraged, as achieving glycemic control is essential for reducing long-term morbidity and mortality from other diabetes-related complications. It is advisable to conduct a baseline retinal examination before treatment and continue monitoring during therapy. Further research is needed to understand the long-term effects of these treatments on DR.

GLP-1 agonists: A review for emergency clinicians

INTRODUCTION

Glucagon-like peptide 1 (GLP-1) based therapies, including GLP-1 agonists, are currently in use for treatment of diabetes and obesity. However, several complications may occur with their use.

OBJECTIVE

This narrative review provides a focused evaluation of GLP-1 agonist therapy and associated complications for emergency clinicians.

DISCUSSION

GLP-1 agonists potentiate insulin release and reduce gastric emptying and food intake. These agents have demonstrated significant improvements in glucose control in diabetics and weight loss in obese patients. The two most common agents include subcutaneous semaglutide (Ozempic, approved for type 2 diabetes, and Wegovy, approved for weight loss) and liraglutide (Saxenda, approved for weight loss, and Victoza, approved for type 2 diabetes), though an oral formulation of semaglutide is available (Rybelsus). While these drugs are associated with improved long-term outcomes, there are a variety of associated adverse events. The most common include gastrointestinal (GI) adverse events such as nausea, vomiting, diarrhea, and abdominal pain. Pancreatitis and biliary disease may also occur. Hypersensitivity including injection site reactions have been associated with use, with reports of anaphylaxis and other rashes. Renal adverse events are most commonly associated with severe GI losses. Hypoglycemia may occur when these agents are used with sulfonylureas or insulin. There is also an increased risk of diabetic retinopathy. Due to the current shortage and expense of these medications, many patients have attempted to obtain these medications from non-licensed and unregulated agents, which may be associated with increased risk of serious complications.

CONCLUSIONS

An understanding of the indications for GLP-1 agonist use and associated adverse events can assist emergency clinicians.

Practical guide: Glucagon-like peptide-1 and dual glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonists in diabetes mellitus

In 2005, exenatide became the first approved glucagon-like peptide-1 receptor agonist (GLP-1 RA) for type 2 diabetes mellitus (T2DM). Since then, numerous GLP-1 RAs have been approved, including tirzepatide, a novel dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 RA, which was approved in 2022. This class of drugs is considered safe with no hypoglycemia risk, making it a common second-line choice after metformin for treating T2DM. Various considerations can make selecting and switching between different GLP-1 RAs challenging. Our study aims to provide a comprehensive guide for the usage of GLP-1 RAs and dual GIP and GLP-1 RAs for the management of T2DM.

Effects of newer-generation anti-diabetics on diabetic retinopathy: a critical review

Diabetic retinopathy (DR) is the leading etiology of blindness in the working population of the USA. Its long-term management relies on effective glycemic control. Seven anti-diabetic classes have been introduced for patients with type 2 diabetes (T2D) in the past two decades, with different glucose-lowering and cardiovascular benefits. Yet, their effects specifically on DR have not been studied in detail. A systematic review of the literature was conducted to investigate this topic, focusing on the available clinical data for T2D. Published studies were evaluated based on their level of statistical evidence, as long as they incorporated at least one endpoint or adverse event pertaining to retinal health. Fifty nine articles met our inclusion criteria and were grouped per anti-diabetic class as follows: alpha-glucosidase inhibitors (1), peroxisome proliferator-activated receptor gamma (PPAR-γ) agonists (8), amylin analogs (1), glucagon-like peptide-1 (GLP-1) receptor agonists (28), dipeptidyl peptidase 4 (DPP-4) inhibitors (9), and sodium glucose co-transporter-2 (SGLT-2) inhibitors (9), plus one retrospective study and two meta-analyses evaluating more than one of the aforementioned anti-diabetic categories. We also reviewed publicly-announced results of trials for the recently-introduced class of twincretins. The available data indicates that most drugs in the newer anti-diabetic classes are neutral to DR progression; however, there are subclasses differences in specific drugs and T2D populations. In particular, there is evidence suggesting there may be worse diabetic macular edema with PPAR-gamma agonists, potential slight DR worsening with semaglutide (GLP-1 receptor agonist), and potential slight increase in the incidence of retinal vein occlusion in elderly and patients with advanced kidney disease receiving SGLT-2 inhibitors. All these warrant further investigation. Longer follow-up and systematic assessment of at least one DR-related endpoint are highly recommended for all future trials in the T2D field, to ultimately address this topic.

Glucagon-Like Peptide-1 Receptor Agonist and Risk of Diabetic Retinopathy in Patients with Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis of Randomized Placebo-Controlled Trials

BACKGROUND

Glucagon-like peptide 1 receptor agonists (GLP-1RAs) exhibit glucose-lowering, weight-reducing, and blood pressure-lowering effects. Nevertheless, a debate exists concerning the association between GLP-1RA treatment and the risk of diabetic retinopathy (DR) in patients diagnosed with type 2 diabetes mellitus (T2DM).

OBJECTIVE

To ascertain the risk of DR in patients with T2DM undergoing GLP-1RA treatment, we conducted a meta-analysis utilizing data derived from randomized placebo-controlled studies (RCTs).

METHODS

A comprehensive literature search was conducted using PubMed, Cochrane Library, Web of Science, and EMBASE. We focused on RCTs involving the use of GLP-1RAs in patients with T2DM. Utilizing R software, we compared the risk of DR among T2DM patients undergoing GLP-1RA treatment. The Cochrane risk of bias method was employed to assess the research quality.

RESULTS

The meta-analysis incorporated data from 20 RCTs, encompassing a total of 24,832 T2DM patients. Across all included trials, randomization to GLP-1 RA treatment did not demonstrate an increased risk of DR (odds ratio = 1.17; 95% CI 0.98-1.39). Furthermore, no significant heterogeneity or publication bias was detected in the analysis.

CONCLUSION

The results of this systematic review and meta-analysis indicate that the administration of GLP-1 RA is not associated with an increased risk of DR. PROSPERO REGISTRATION IDENTIFIER: CRD42023413199.

Design and rationale for the SIB trial: a randomized parallel comparison of semaglutide versus placebo on intestinal barrier function in type 2 diabetes mellitus

Objective

To describe the rationale and design of the SIB trial, an interventional clinical trial testing the hypothesis that subcutaneous (s.c.) once-weekly semaglutide can improve intestinal permeability and reduce systemic inflammation in participants with type 2 diabetes (T2D) and obesity.

Methods

SIB (NCT04979130) is an investigator-initiated, single-center randomized, double-blinded, placebo-controlled clinical study being conducted at the University of Colorado Anschutz Medical Campus. The primary objective of this novel trial is to test the hypothesis that subcutaneous (s.c.) once-weekly semaglutide could improve intestinal permeability and reduce systemic inflammation in participants with T2D and obesity. Eligible participants had a diagnosis of type 2 diabetes, elevated body mass index, and evidence of systemic inflammation. Participants were randomized 1:1 to s.c. semaglutide or placebo. Participants were assessed for intestinal permeability and markers of inflammation at baseline, mid-study, and at the end of the study. Efficacy assessments were based on the analysis of the following: lactulose:mannitol ratio test, serum lipopolysaccharide-binding protein (LBP), fecal calprotectin, inflammatory biomarkers (IL-6, TNF, IL-1, IL-8, hs-CRP), and HbA1c. All participants who enrolled in the trial provided written informed consent after having received written and oral information on the trial. The risks of semaglutide use were minimized by administration according to FDA-labeled use and close monitoring for adverse events.

Discussion

SIB is the first study to examine the effects of GLP-1 receptor agonists on intestinal permeability in humans and will provide important data on their impact on systemic inflammation and intestinal permeability in the setting of T2D and obesity.

Incretins and microvascular complications of diabetes: neuropathy, nephropathy, retinopathy and microangiopathy

Glucagon-like peptide-1 receptor agonists (GLP-1RAs, incretin mimetics) and dipeptidyl peptidase-4 inhibitors (DPP-4is, incretin enhancers) are glucose-lowering therapies with proven cardiovascular safety, but their effect on microvascular disease is not fully understood. Both therapies increase GLP-1 receptor agonism, which is associated with attenuation of numerous pathological processes that may lead to microvascular benefits, including decreased reactive oxygen species (ROS) production, decreased inflammation and improved vascular function. DPP-4is also increase stromal cell-derived factor-1 (SDF-1), which is associated with neovascularisation and tissue repair. Rodent studies demonstrate several benefits of these agents in the prevention or reversal of nephropathy, retinopathy and neuropathy, but evidence from human populations is less clear. For nephropathy risk in human clinical trials, meta-analyses demonstrate that GLP-1RAs reduce the risk of a composite renal outcome (doubling of serum creatinine, eGFR reduction of 30%, end-stage renal disease or renal death), whereas the benefits of DPP-4is appear to be limited to reductions in the risk of albuminuria. The relationship between GLP-1RAs and retinopathy is less clear. Many large trials and meta-analyses show no effect, but an observed increase in the risk of retinopathy complications with semaglutide therapy (a GLP-1RA) in the SUSTAIN-6 trial warrants caution, particularly in individuals with baseline retinopathy. Similarly, DPP-4is are associated with increased retinopathy risk in both trials and meta-analysis. The association between GLP-1RAs and peripheral neuropathy is unclear due to little trial evidence. For DPP-4is, one trial and several observational studies show a reduced risk of peripheral neuropathy, with others reporting no effect. Evidence in other less-established microvascular outcomes, such as microvascular angina, cerebral small vessel disease, skeletal muscle microvascular disease and autonomic neuropathies (e.g. cardiac autonomic neuropathy, gastroparesis, erectile dysfunction), is sparse. In conclusion, GLP-1RAs are protective against nephropathy, whereas DPP-4is are protective against albuminuria and potentially peripheral neuropathy. Caution is advised with DPP-4is and semaglutide, particularly for patients with background retinopathy, due to increased risk of retinopathy. Well-designed trials powered for microvascular outcomes are needed to clarify associations of incretin therapies and microvascular diseases.

Exendin-4 promotes retinal ganglion cell survival and function by inhibiting calcium channels in experimental diabetes

Progressive damage of retinal ganglion cells (RGCs) is observed in early diabetic retinopathy. Intracellular Ca2+ overload mediated by Ca2+ influx through voltage-gated Ca2+ channels (VGCCs) is involved in neurodegeneration, whereas glucagon-like peptide-1 (GLP-1) provides neuroprotection. However, whether GLP-1 plays a neuroprotective role in diabetic retinas by modulating VGCCs remains unknown. We found that eye drops of exendin-4, a long-acting GLP-1 receptor (GLP-1R) agonist, prevented the increase of L-type Ca2+ current (ILCa) densities of RGCs induced by 4-week hyperglycemia and promoted RGC survival by suppressing L-type VGCC (L-VGCC) activity in streptozotocin-induced diabetic rats. Moreover, exendin-4-induced suppression of ILCa in RGCs may be mediated by a GLP-1R/Gs/cAMP-PKA/ryanodine/Ca2+/calmodulin/calcineurin/PP1 signaling pathway. Furthermore, exendin-4 functionally improved the light-evoked spiking ability of diabetic RGCs. These results suggest that GLP-1R activation enhances cAMP to PP1 signaling and that PP1 inactivates L-VGCCs by dephosphorylating them, thereby reducing Ca2+ influx, which could protect RGCs against excitotoxic Ca2+ overload.

Impact of Intensive Glycemic Treatment on Diabetes Complications-A Systematic Review

Diabetes complications can be related to the long duration of the disease or chronic hyperglycemia. The follow-up of diabetic patients is based on the control of chronic hyperglycemia, although this correction, if obtained rapidly in people living with severe chronic hyperglycemia, can paradoxically interfere with the disease or even induce complications. We reviewed the literature describing the impact of the rapid and intense treatment of hyperglycemia on diabetic complications. The literature review showed that worsening complications occurred significantly in diabetic microangiopathy with the onset of specific neuropathy induced by the correction of diabetes. The results for macroangiopathy were somewhat mixed with the intensive and rapid correction of chronic hyperglycemia having a neutral impact on stroke and myocardial infarction but a significant increase in cardiovascular mortality. The management of diabetes has now entered a new era with new therapeutic molecules, such as gliflozin for patients living with type 2 diabetes, or hybrid insulin delivery systems for patients with insulin-treated diabetes. Our manuscript provides evidence in support of these personalized and progressive algorithms for the control of chronic hyperglycemia.

Relationship between Helicobacter pylori and glycated hemoglobin: a cohort study

Background

Helicobacter pylori (H. pylori) has increasingly been shown to be related to extragastric diseases. Glycated hemoglobin A1c (HbA1c), an indicator of glycemic control, is closely linked to the event of diabetes. The purpose of this research was to analyze the association between H. pylori and HbA1c through a cohort study.

Methods

The population who underwent multiple physical checkups in the physical examination center of Taizhou Hospital was included. All of them underwent urea breath test, serological examination and physical parameter measurement. Multiple regression was used for analyzing the influencing factors of HbA1c. In addition, the result of HbA1c on H. pylori infection was studied by restricted cubic spline (RCS) analysis. The triglyceride glucose (TyG) index represents the level of insulin resistance (IR) in the population. The population was classified on the basis of primary and last H. pylori infection, therefore, the variations of HbA1c and TyG index among totally different teams were investigated.

Results

Multiple regression demonstrated that H. pylori was an influential factor in HbA1c. RCS analysis showed a nonlinear relationship between HbA1c and H. pylori infection. When HbA1c>5.7%, the chance of H. pylori infection was considerably enlarged. Additionally, long-term H. pylori infection increased HbA1c levels, while HbA1c levels decreased after H. pylori eradication. Similarly, long-term H. pylori infection also increased the TyG index.

Conclusion

Prediabetes increases the danger of H. pylori infection, long-term H. pylori infection increases HbA1c and IR levels, and wipeout of H. pylori could have a positive impact for glycemic control in the population.

Semaglutide-eye-catching results

Semaglutide is a glucagon-like peptide-1 receptor agonist used either orally every day or subcutaneously once a week for the treatment of type 2 diabetes mellitus and, more recently, at higher doses, for the treatment of obesity. Both diseases are reaching epidemic proportions and often coexist, posing patients with a high risk for cardiovascular disease and death. Therefore, an agent such as semaglutide, which offers clinically significant weight loss and cardiovascular benefits, is essential and will be increasingly used in high-risk patients. However, during the SUSTAIN clinical trial program (Semaglutide Unabated Sustainability in treat-ment of type 2 diabetes), a safety issue concerning the progression and worsening of diabetic retinopathy emerged. The existing explanation so far mainly supports the role of the magnitude and speed of HbA1c reduction, a phenomenon also associated with insulin treatment and bariatric surgery. Whether and to which extent the effect is direct is still a matter of debate and an intriguing topic to investigate for suitable preventative and rehabilitative purposes. In this minireview, we will summarize the available data and suggest guidelines for a comprehensive semaglutide clinical utilization until new evidence becomes available.

Effects of semaglutide and empagliflozin on oxygenation, vascular autoregulation, and central thickness of the retina in people with type 2 diabetes: A prespecified secondary analysis of a randomised clinical trial

AIMS

Semaglutide and empagliflozin have shown cardiovascular protection. In SUSTAIN-6, semaglutide was associated with an increased risk of diabetic retinopathy. We investigated whether changes in retinal oxygenation, retinal vascular autoregulation, and central retinal thickness are altered by semaglutide, empagliflozin or the combination.

METHODS

This study was a prespecified, secondary outcome from a randomised, 32 weeks partly placebo-controlled, partly open-label, clinical trial on the effects of semaglutide and empagliflozin on arterial stiffness and kidney oxygenation. A total of 120 participants with type 2 diabetes, established or high risk of cardiovascular disease and age ≥50 years were randomised into four parallel groups (semaglutide, empagliflozin, the combination or tablet placebo, n = 30 for each group). We primarily hypothesized that semaglutide would increase venular oxygenation.

RESULTS

We found no changes in retinal arteriolar, venular or venular-arteriolar oxygenation nor in retinal vessel diameter regardless of treatment group. Semaglutide increased central retinal thickness compared to placebo with ~1 % (3.8 μm 95 % CI [0.9;6.7], p = 0.009) with no changes in the empagliflozin or combination group.

CONCLUSION

Neither semaglutide, empagliflozin nor the combination alters markers of retinal function. The effect of semaglutide on central retinal thickness was small, but the clinical significance is uncertain.

Time to Reach Glycaemic and Body Weight Loss Thresholds with Tirzepatide in Patients with Type 2 Diabetes: A Pre-planned Exploratory Analysis of SURPASS-2 and SURPASS-3

INTRODUCTION

Tirzepatide, a once-weekly glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 receptor agonist, provides clinically meaningful improvements in glycaemic control and body weight loss in people with type 2 diabetes. The early efficacy profile of tirzepatide after treatment initiation is of interest. In this exploratory pre-planned analysis, we evaluated the time to achieve glycaemic control and body weight loss thresholds with tirzepatide.

METHODS

In two randomised studies, we compared time to achieve HbA1c (< 7.0% and ≤ 6.5%) and weight loss (≥ 5%, SURPASS-2 only) thresholds among people treated with tirzepatide (5, 10, and 15 mg), semaglutide 1 mg in SURPASS-2, and titrated insulin degludec in SURPASS-3. Longitudinal logistic regression models were used to explore the proportion of participants achieving HbA1c and body weight loss thresholds at 4, 12, and 24 weeks. The time to achieve these thresholds was analysed and compared between groups using the Cox proportional-hazards model.

RESULTS

Overall, greater proportions of participants achieved the HbA1c and body weight loss thresholds at 4, 12, and 24 weeks with tirzepatide compared with semaglutide 1 mg and insulin degludec. The median time to achieve HbA1c < 7.0% (8.1 weeks with each tirzepatide dose, 12.0 weeks with semaglutide 1 mg, and 12.1 weeks with insulin degludec) and ≤ 6.5% (12.1, 15.7, and 24.1 weeks, respectively) was faster with tirzepatide than semaglutide 1 mg and insulin degludec. In SURPASS-2, the median time to first achieve a body weight loss of ≥ 5% was faster with tirzepatide 5 mg (16.0 weeks) and 10 and 15 mg (12.4 weeks) than with semaglutide 1 mg (24.0 weeks).

CONCLUSION

Analyses of data from SURPASS-2 and -3 revealed that tirzepatide treatment enabled more people with type 2 diabetes to achieve glycaemic thresholds and these were achieved faster than with semaglutide 1 mg or insulin degludec. Tirzepatide-treated participants also achieved a body weight loss of ≥ 5% significantly faster with tirzepatide than with semaglutide 1 mg.

TRIAL REGISTRATION NUMBERS

NCT03987919; NCT03882970.