SGLT2 Inhibitors in the Management of Type 1 Diabetes (T1D): An Update on Current Evidence and Recommendations

Metabolic interventions as adjunctive therapies to insulin in type 1 diabetes: Current clinical landscape and perspectives

Type 1 diabetes (T1D) is classically characterized as an autoimmune disease wherein the immune system erroneously attacks insulin-producing pancreatic β-cells, causing insulin insufficiency and severe metabolic dysregulation. However, intensive investigation and numerous clinical trials with immunotherapies have been largely unable to significantly alter the course of disease. Currently, there is no effective way to prevent or cure T1D, and insulin remains the cornerstone of T1D treatment. In recent years, a growing body of research suggests that β-cells actively contribute to the immune response and to disease development. Factors including glucotoxicity, lipotoxicity, inflammation, endoplasmic reticulum (ER) and oxidative stress can induce β-cell apoptosis and senescence, further promoting insulitis. Recent studies highlight the importance of targeting metabolic control for T1D management and treatment. Metabolic interventions, through their direct and indirect impacts on β-cells, have shown promise in preserving β-cell function. These interventions can reduce glucose toxicity, alleviate oxidative stress and inflammation, enhance insulin sensitivity, and indirectly mitigate the autoimmune responses. By preserving β-cell function, individuals with T1D attain better glycaemic control, reduced complication risks and exhibit improved overall metabolic health. Here, we provide an overview of insights from clinical studies, systematic reviews and meta-analyses that collectively demonstrate that adjunctive metabolic interventions can enhance glycaemic control, reduce insulin requirements and mitigate adverse effects associated with insulin monotherapy. They also show potential for halting disease progression, preserving residual β-cell function and improving long-term outcomes for newly diagnosed individuals. Future research should focus on optimizing these treatment strategies and establishing their long-term efficacy and safety.

Metabolic health in people living with type 1 diabetes in Belgium: a repeated cross-sectional study

AIMS/HYPOTHESIS

Metabolic abnormalities such as central obesity, insulin resistance, dyslipidaemia and hypertension, often referred to as 'the metabolic syndrome' (or 'combined metabolic abnormalities'), are increasingly being identified in people living with type 1 diabetes, accelerating the risk for CVD. As a result, in recent years, treatment in people living with type 1 diabetes has shifted to improving overall metabolic health rather than glucose control alone. In Belgium, diabetes care for people living with type 1 diabetes is centrally organised. The Initiative for Quality Improvement and Epidemiology in Diabetes, imposed by the Belgian health insurance system, has systematically collected data from patients on intensive insulin therapy treated in all 101 diabetes clinics in Belgium since 2001. The aim of this real-world study is to describe the evolution of treatment and metabolic health, including the prevalence of obesity and combined metabolic abnormalities, in people living with type 1 diabetes over the past 20 years, and to compare the treatment and prevalence of complications between those with and without combined metabolic abnormalities.

METHODS

We analysed data on adults (≥16 years old) living with type 1 diabetes, who were diagnosed at age ≤45 years and who had a diabetes duration ≥1 year, collected between 2001 and 2022. The evolution of HbA1c, BMI, LDL-cholesterol, systolic BP, lipid-lowering therapy and antihypertensive therapy over time was analysed. The prevalence of individual and multiple metabolic abnormalities according to various definitions of the metabolic syndrome/combined metabolic abnormalities was analysed, and the association between combined metabolic abnormalities and metabolic health indicators, complications and treatment was investigated in the 2022 data.

RESULTS

The final dataset consisted of 26,791 registrations of adults living with type 1 diabetes collected between 2001 and 2022. Although glycaemic and lipid control generally improved over time, the prevalence of obesity strongly increased (12.1% in 2001 vs 21.7% in 2022, p<0.0001), as did the presence of combined metabolic abnormalities (WHO criteria: 26.9% in 2001 vs 42.9% in 2022 in women, p<0.0001; 30.4% in 2001 vs 52.1% in 2022 in men, p<0.0001; WHO criteria without albuminuria: 22.3% in 2001 vs 40.6% in 2022 in women, p<0.0001; 25.1% in 2001 vs 49.2% in 2022 in men, p<0.0001; NCEP-ATPIII criteria: 39.9% in 2005 vs 57.2% in 2022 in women, p<0.0001; 40.8% in 2005 vs 60.9% in 2022 in men, p<0.0001; IDF criteria: 43.9% in 2005 vs 59.3% in 2022 in women, p<0.001; 33.7% in 2005 vs 50.0% in 2022 in men, p<0.0001). People with combined metabolic abnormalities had higher glucose levels compared to those without combined metabolic abnormalities (HbA1c >58 mmol in men: 48.9% vs 36.9%; HbA1c >58 mmol in women: 53.3% vs 41.1%, p<0.0001). People with combined metabolic abnormalities were more often treated with adjunct therapies such as metformin, sodium-glucose transport protein 2 inhibitors and glucagon-like peptide-1 receptor agonists. In both men and women, the presence of combined metabolic abnormalities was strongly related to the presence of eye complications, peripheral neuropathy, chronic kidney disease and CVD, corrected for age, diabetes duration and HbA1c.

CONCLUSIONS/INTERPRETATION

Overweight, obesity and combined metabolic abnormalities are increasingly being identified in people living with type 1 diabetes, further accelerating the risk of microvascular and macrovascular complications. Early identification of the presence of combined metabolic abnormalities should enable therapeutic interventions to be modified towards multifactorial approaches, with attention to education on avoidance of overweight (e.g. dietary counselling) in addition to strict glycaemic control and intensification of use of antihypertensive agents and statins. Use of adjunct therapies in this population as a tool should be explored more thoroughly to reduce risk of complications.

Continuous ketone monitoring: Exciting implications for clinical practice

Diabetic ketoacidosis (DKA) is a life-threatening complication usually affecting people with type 1 diabetes (T1D) and, less commonly, people with type 2 diabetes. Early identification of ketosis is a cornerstone in DKA prevention and management. Current methods for ketone measurement by people with diabetes include capillary blood or urine testing. These approaches have limitations, including the need to carry testing strips that have a limited shelf life and a requirement for the user to initiate a test. Recent studies have shown the feasibility of continuous ketone monitoring (CKM) via interstitial fluid with a sensor inserted subcutaneously employing an enzymatic electrochemical reaction. Ketone readings can be updated every 5 minutes. In the future, one would expect that commercialized devices will incorporate alarms linked with standardized thresholds and trend arrows. Ideally, to minimize the burden on users, CKM functionality should be integrated with other devices used to implement glucose management, including continuous glucose monitors and insulin pumps. We suggest CKM provision to all at risk of DKA and recommend that the devices should be worn continuously. Those who may particularly benefit are individuals who have T1D, are pregnant, on medications such as sodium-glucose linked transporter (SGLT) inhibitors that increase DKA, people with recurrent DKA, those with T1D undertaking high intensity exercise, are socially or geographically isolated, or those on low carbohydrate diets. The provision of ketone profiles will provide important clinical insights that have previously been unavailable to people living with diabetes and their healthcare professionals.

Handling the sugar rush: the role of the renal proximal tubule

Blood glucose homeostasis is critical to ensure the proper functioning of the human body. Through the processes of filtration, reabsorption, secretion, and metabolism, much of this task falls to the kidneys. With a rise in glucose and other added sugars, there is an increased burden on this organ, mainly the proximal tubule, which is responsible for all glucose reabsorption. In this review, we focus on the current physiological and cell biological functions of the renal proximal tubule as it works to reabsorb and metabolize glucose and fructose. We also highlight the physiological adaptations that occur within the proximal tubule as sugar levels rise under pathophysiological conditions including diabetes. This includes the detrimental impacts of an excess glucose load that leads to glucotoxicity. Finally, we explore some of the emerging therapeutics that modulate renal glucose handling and the systemic protection that can be realized by targeting the reabsorptive properties of the kidney.

Glucometabolic Efficacy of the Empagliflozin/Metformin Combination in People with Type 1 Diabetes and Increased Cardiovascular Risk: A Sub-Analysis of a Pilot Randomized Controlled Trial

Background/Objectives: People with type 1 diabetes have an unmet need for cardiovascular protection due to the lack of new recommended antidiabetic therapies with cardiovascular benefits. We examined whether the addition of an empagliflozin/metformin combination, and each drug alone, can complement insulin to improve glucometabolic parameters in overweight people with type 1 diabetes at high cardiovascular risk. Methods: This pilot, single-center double-blind randomized controlled trial included 40 people with type 1 diabetes. In addition to insulin, they received empagliflozin (25 mg daily), metformin (2000 mg daily), an empagliflozin/metformin combination, or a placebo. The intervention period was 12 weeks. Glycemic parameters, insulin requirements, and blood and urine samples were analyzed. Indices for liver fibrosis were calculated. Due to potential safety concerns, participants regularly measured blood ketone values. Results: The empagliflozin/metformin combination decreased HbA1c (-0.6%, p < 0.05) and weight (-6.1 kg, p < 0.05). Empagliflozin decreased the urinary albumin-to-creatinine ratio (-31.4 ± 4.9%, p = 0.002). The empagliflozin/metformin combination and empagliflozin decreased the estimated daily proteinuria (-34.6 ± 5.0%, p = 0.006 and -35.9 ± 6.2%, p = 0.03, respectively), the calculated FIB-4 (up to -17.8 ± 5.2%, p = 0.04 and -10.7 ± 3.7%, p = 0.02, respectively), and other liver fibrosis indices and uric acid values. No significant side effects occurred during the study. Conclusions: The empagliflozin/metformin combination improved glycemic control, reduced weight and insulin requirements, and produced several additional beneficial metabolic effects in overweight people with type 1 diabetes with increased cardiovascular risk.

Sodium-Glucose Cotransporter 2 (SGLT2) Inhibitors: Guardians against Mitochondrial Dysfunction and Endoplasmic Reticulum Stress in Heart Diseases

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are an innovative class of antidiabetic drugs that provide cardiovascular benefits to both diabetic and nondiabetic patients, surpassing those of other antidiabetic drugs. Although the roles of mitochondria and endoplasmic reticulum (ER) in cardiovascular research are increasingly recognized as promising therapeutic targets, the exact molecular mechanisms by which SGLT2 inhibitors influence mitochondrial and ER homeostasis in the heart remain incompletely elucidated. This review comprehensively summarizes and discusses the impacts of SGLT2 inhibitors on mitochondrial dysfunction and ER stress in heart diseases including heart failure, ischemic heart disease/myocardial infarction, and arrhythmia from preclinical and clinical studies. Based on the existing evidence, the effects of SGLT2 inhibitors may potentially involve the restoration of mitochondrial biogenesis and alleviation of ER stress. Such consequences are achieved by enhancing adenosine triphosphate (ATP) production, preserving mitochondrial membrane potential, improving the activity of electron transport chain complexes, maintaining mitochondrial dynamics, mitigating oxidative stress and apoptosis, influencing cellular calcium and sodium handling, and targeting the unfolded protein response (UPR) through three signaling pathways including inositol requiring enzyme 1α (IRE1α), protein kinase R like endoplasmic reticulum kinase (PERK), and activating transcription factor 6 (ATF6). Therefore, SGLT2 inhibitors have emerged as a promising target for treating heart diseases due to their potential to improve mitochondrial functions and ER stress.

Applications of SGLT2 inhibitors beyond glycaemic control

Sodium-glucose cotransporter 2 (SGLT2) inhibitors were initially developed for their glucose-lowering effects and have shown a modest glycaemic benefit in people with type 2 diabetes mellitus (T2DM). In the past decade, a series of large, robust clinical trials of these therapies have demonstrated striking beneficial effects for various care goals, transforming the chronic disease therapeutic landscape. Cardiovascular safety studies in people with T2DM demonstrated that SGLT2 inhibitors reduce cardiovascular death and hospitalization for heart failure. Subsequent trials in participants with heart failure with reduced or preserved left ventricular ejection fraction demonstrated that SGLT2 inhibitors have beneficial effects on heart failure outcomes. In dedicated kidney outcome studies, SGLT2 inhibitors reduced the incidence of kidney failure among participants with or without diabetes. Post hoc analyses have suggested a range of other benefits of these drugs in conditions as diverse as metabolic dysfunction-associated steatotic liver disease, kidney stone prevention and anaemia. SGLT2 inhibitors have a generally favourable adverse effect profile, although patient selection and medication counselling remain important. Concerted efforts are needed to better integrate these agents into routine care and support long-term medication adherence to close the gap between clinical trial outcomes and those achieved in the real world.

A Review of Sotagliflozin: The First Dual SGLT-1/2 Inhibitor

Sotagliflozin (trade name INFEPA) is a novel dual sodium-glucose cotransporter-1 and -2 (SGLT-1/2) inhibitor that was developed by Lexicon Pharmaceuticals. It has emerged as a promising therapy for managing heart failure and other cardiovascular complications associated with type 2 diabetes mellitus (T2DM). Its dual inhibition of SGLT-1 and SGLT-2 receptors uniquely decreases glucose absorption in the intestine in addition to decreasing renal glucose reabsorption, leading to improved glycemic control and cardio-reno protection. Clinical trials have demonstrated its efficacy in reducing cardiovascular death, heart failure hospitalizations, and urgent visits, particularly in T2DM patients with chronic kidney disease (CKD). The drug was approved in 2023 by the Food and Drug Administration for reducing cardiovascular death and heart failure in T2DM patients with CKD and those with heart failure, irrespective of diabetic status or ejection fraction. However, despite its considerable therapeutic potential, sotagliflozin does pose notable adverse effects, including diabetic ketoacidosis, genital infections, and diarrhea. As a result, it has faced regulatory challenges in certain regions, notably the United States. The Food and Drug Administration has so far withheld approval for sotagliflozin in the treatment of type 1 diabetes due to concerns about its safety profile, specifically the risk of diabetic ketoacidosis, although Lexicon Pharmaceuticals plans to submit another new drug application for this use in 2024. Further investigation and clinical trials are warranted to fully elucidate sotagliflozin's impact on diabetes and CKD.

SGLT2 inhibitors in diabetic and non-diabetic kidney transplant recipients: current knowledge and expectations

The beneficial effect of sodium-glucose cotransporter-2 inhibitors (SGLT2i) have been shown recently in numerous randomized controlled trials (RCT) and systematic reviews. According to KDIGO guidelines, SGLT2i currently represent a first choice for diabetic patients with chronic kidney disease (CKD). In addition, a recent meta-analysis of 13 large led by the 'SGLT2 inhibitor Meta-Analysis Cardio-Renal Trialists' Consortium' (SMART-C) provided solid evidence of SGLT2i beneficial effects in CKD or in patients with heart failure, with and without diabetes. Collectively, the patients treated with SGLT2i had a decreased risk of CKD progression, acute kidney injury (AKI), end-stage kidney disease (ESKD) or death from heart failure. Whether these cardio-renal benefits should be extrapolated to kidney transplant recipients (KTR) needs to be assessed in further studies. In this article, we report recent data accumulated so far in the literature, looking at the efficacy and safety of SGLT2i in diabetic and non-diabetic KTR. We found encouraging data regarding the use of SGLT2i in KTR with diabetes. These agents appeared to be safe, and they reduced body weight and blood pressure in this group of patients. Potential effects on kidney graft function and survival are yet to be investigated.

Fibrosis in Chronic Kidney Disease: Pathophysiology and Therapeutic Targets

Chronic kidney disease (CKD) is a slowly progressive condition characterized by decreased kidney function, tubular injury, oxidative stress, and inflammation. CKD is a leading global health burden that is asymptomatic in early stages but can ultimately cause kidney failure. Its etiology is complex and involves dysregulated signaling pathways that lead to fibrosis. Transforming growth factor (TGF)-β is a central mediator in promoting transdifferentiation of polarized renal tubular epithelial cells into mesenchymal cells, resulting in irreversible kidney injury. While current therapies are limited, the search for more effective diagnostic and treatment modalities is intensive. Although biopsy with histology is the most accurate method of diagnosis and staging, imaging techniques such as diffusion-weighted magnetic resonance imaging and shear wave elastography ultrasound are less invasive ways to stage fibrosis. Current therapies such as renin-angiotensin blockers, mineralocorticoid receptor antagonists, and sodium/glucose cotransporter 2 inhibitors aim to delay progression. Newer antifibrotic agents that suppress the downstream inflammatory mediators involved in the fibrotic process are in clinical trials, and potential therapeutic targets that interfere with TGF-β signaling are being explored. Small interfering RNAs and stem cell-based therapeutics are also being evaluated. Further research and clinical studies are necessary in order to avoid dialysis and kidney transplantation.

Risks and Benefits of SGLT-2 Inhibitors for Type 1 Diabetes Patients Using Automated Insulin Delivery Systems-A Literature Review

The primary treatment for autoimmune Diabetes Mellitus (Type 1 Diabetes Mellitus-T1DM) is insulin therapy. Unfortunately, a multitude of clinical cases has demonstrated that the use of insulin as a sole therapeutic intervention fails to address all issues comprehensively. Therefore, non-insulin adjunct treatment has been investigated and shown successful results in clinical trials. Various hypoglycemia-inducing drugs such as Metformin, glucagon-like peptide 1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 (DPP-4) inhibitors, amylin analogs, and Sodium-Glucose Cotransporters 2 (SGLT-2) inhibitors, developed good outcomes in patients with T1DM. Currently, SGLT-2 inhibitors have remarkably improved the treatment of patients with diabetes by preventing cardiovascular events, heart failure hospitalization, and progression of renal disease. However, their pharmacological potential has not been explored enough. Thus, the substantial interest in SGLT-2 inhibitors (SGLT-2is) underlines the present review. It begins with an overview of carrier-mediated cellular glucose uptake, evidencing the insulin-independent transport system contribution to glucose homeostasis and the essential roles of Sodium-Glucose Cotransporters 1 and 2. Then, the pharmacological properties of SGLT-2is are detailed, leading to potential applications in treating T1DM patients with automated insulin delivery (AID) systems. Results from several studies demonstrated improvements in glycemic control, an increase in Time in Range (TIR), a decrease in glycemic variability, reduced daily insulin requirements without increasing hyperglycemic events, and benefits in weight management. However, these advantages are counterbalanced by increased risks, particularly concerning Diabetic Ketoacidosis (DKA). Several clinical trials reported a higher incidence of DKA when patients with T1DM received SGLT-2 inhibitors such as Sotagliflozin and Empagliflozin. On the other hand, patients with T1DM and a body mass index (BMI) of ≥27 kg/m2 treated with Dapagliflozin showed similar reduction in hyperglycemia and body weight and insignificantly increased DKA incidence compared to the overall trial population. Additional multicenter and randomized studies are required to establish safer and more effective long-term strategies based on patient selection, education, and continuous ketone body monitoring for optimal integration of SGLT-2 inhibitors into T1DM therapeutic protocol.