SGLT2 inhibitors in type 1 diabetes: knocked down, but up again?

Interindividual Heterogeneity of SGLT2 Expression and Function in Human Pancreatic Islets

Studies implicating sodium-glucose cotransporter 2 (SGLT2) inhibitors in glucagon secretion by pancreatic α-cells reported controversial results. We hypothesized that interindividual heterogeneity in SGLT2 expression and regulation may affect glucagon secretion by human α-cells in response to SGLT2 inhibitors. An unbiased RNA-sequencing analysis of 207 donors revealed an unprecedented level of heterogeneity of SLC5A2 expression. To determine heterogeneity of SGLT2 expression at the protein level, the anti-SGLT2 antibody was first rigorously evaluated for specificity, followed by Western blot and immunofluorescence analysis on islets from 10 and 12 donors, respectively. The results revealed a high interdonor variability of SGLT2 protein expression. Quantitative analysis of 665 human islets showed a significant SGLT2 protein colocalization with glucagon but not with insulin or somatostatin. Moreover, glucagon secretion by islets from 31 donors at low glucose (1 mmol/L) was also heterogeneous and correlated with dapagliflozin-induced glucagon secretion at 6 mmol/L glucose. Intriguingly, islets from three donors did not secrete glucagon in response to either 1 mmol/L glucose or dapagliflozin, indicating a functional impairment of the islets of these donors to glucose sensing and SGLT2 inhibition. Collectively, these data suggest that heterogeneous expression of SGLT2 protein and variability in glucagon secretory responses contribute to interindividual differences in response to SGLT2 inhibitors.

Systematic literature review and network meta-analysis of sodium-glucose co-transporter inhibitors vs metformin as add-on to insulin in type 1 diabetes

AIMS

To identify and synthesize phase 3 and phase 4 randomized controlled trials (RCTs) of sodium-glucose co-transporter (SGLT) inhibitors and metformin as adjuncts to insulin in type 1 diabetes (T1DM) using network meta-analysis (NMA).

MATERIALS AND METHODS

A systematic literature review (SLR) identified relevant RCTs of ≥12 Weeks duration. MEDLINE, Embase, the Cochrane Library and grey literature were searched through October 2018. NMAs indirectly compared SGLT inhibitors and metformin for change from baseline in HbA1c, weight, total daily insulin dose and systolic blood pressure at Week 24 to 26 and Week 52. Safety outcomes were also explored.

RESULTS

Nine trials (N = 6780) were included in the SLR. NMAs indicated that all therapies performed better than placebo for the efficacy outcomes at both time points. Compared with metformin at Week 24 to 26, the SGLT inhibitors dapagliflozin (5 mg), sotagliflozin (200 mg) and empagliflozin (10 mg) had larger reductions in HbA1c (mean difference [MD] = -0.24, 95% credible interval [CrI], -0.41 to -0.07, MD = -0.23, 95% CrI, -0.39 to -0.08 and MD = -0.35, 95% CrI, -0.51 to -0.19, respectively) and in weight, which were sustained in sensitivity analyses. There were few differences observed in the results of safety outcomes, such as risk of diabetic ketoacidosis (DKA), which should be interpreted cautiously because of wide CrIs.

CONCLUSIONS

Adjunctive use of SGLT inhibitors in T1DM can improve glycaemic control compared with metformin while enabling weight loss, with consistent efficacy across the class. However, these results are based on indirect evidence so confirmation in a head-to-head study would be valuable.

Exploring Patient Preferences for Adjunct-to-Insulin Therapy in Type 1 Diabetes

OBJECTIVE

While sodium-glucose cotransporter inhibitor (SGLTi) therapy has been evaluated in type 1 diabetes (T1D) trials, patient reactions to benefits and risks are unknown. Using established methodology, we evaluated patient preferences for different adjunct-to-insulin therapy options in T1D.

RESEARCH DESIGN AND METHODS

An online survey, completed by 701 respondents with T1D (231 U.S., 242 Canada, and 228 Germany), used conjoint analysis to present six hypothetical, masked, pairwise drug profile choices composed of different benefit-risk attributes and effect ranges. Data used in analyses were derived from actual phase 3 trials of a low-dose SGLTi (comparable to oral empagliflozin 2.5 mg q.d.), a high-dose SGLTi (comparable to oral sotagliflozin 400 mg q.d.), and an available adjunct-to-insulin therapy (comparable to subcutaneous pramlintide 60 μg t.i.d.).

RESULTS

Conjoint analysis identified diabetic ketoacidosis risk as most important to patients (23% relative score; z test, P < 0.05); ranked second were HbA_1c reduction (14%), risk of severe hypoglycemia (13%), oral versus injectable treatment (12%), and risk of genital infection (12%). Next was risk of nausea (11%), followed by weight reduction (8%) and the risk of diarrhea (7%). A low-dose SGLTi drug profile was identified by conjoint analysis as the top patient preference (83% of participants; z test, P < 0.05) versus high-dose SGLTi (8%) or pramlintide (9%). Separate from conjoint analysis, when respondents were asked to choose their preferred adjunct-to-insulin therapy (masked to drug name/dose), 69%, 17%, 6%, and 9% of respondents chose low-dose SGLTi, high-dose SGLTi, pramlintide, and insulin therapy alone, respectively.

CONCLUSIONS

Low-dose SGLTi profile was the favored adjunct-to-insulin therapy by persons with T1D.

Empagliflozin as Adjunctive to Insulin Therapy in Type 1 Diabetes: The EASE Trials

OBJECTIVE

To evaluate the safety and efficacy of empagliflozin 10- and 25-mg doses plus a unique lower dose (2.5 mg) as adjunct to intensified insulin in patients with type 1 diabetes (T1D).

RESEARCH DESIGN AND METHODS

The EASE (Empagliflozin as Adjunctive to inSulin thErapy) program (N = 1,707) included two double-blind, placebo-controlled phase 3 trials: EASE-2 with empagliflozin 10 mg (n = 243), 25 mg (n = 244), and placebo (n = 243), 52-week treatment; and EASE-3 with empagliflozin 2.5 mg (n = 241), 10 mg (n = 248), 25 mg (n = 245), and placebo (n = 241), 26-week treatment. Together they evaluated empagliflozin 10 mg and 25 mg, doses currently approved in treatment of type 2 diabetes, and additionally 2.5 mg on 26-week change in glycated hemoglobin (primary end point) and weight, glucose time-in-range (>70 to ≤180 mg/dL), insulin dose, blood pressure, and hypoglycemia.

RESULTS

The observed largest mean placebo-subtracted glycated hemoglobin reductions were -0.28% (95% CI -0.42, -0.15) for 2.5 mg, -0.54% (-0.65, -0.42) for 10 mg, and -0.53% (-0.65, -0.42) for 25 mg (all P < 0.0001). Empagliflozin 2.5/10/25 mg doses, respectively, reduced mean weight by -1.8/-3.0/-3.4 kg (all P < 0.0001); increased glucose time-in-range by +1.0/+2.9/+3.1 h/day (P < 0.0001 for 10 and 25 mg); lowered total daily insulin dose by -6.4/-13.3/-12.7% (all P < 0.0001); and decreased systolic blood pressure by -2.1/-3.9/-3.7 mmHg (all P < 0.05). Genital infections occurred more frequently on empagliflozin. Adjudicated diabetic ketoacidosis occurred more with empagliflozin 10 mg (4.3%) and 25 mg (3.3%) but was comparable between empagliflozin 2.5 mg (0.8%) and placebo (1.2%). Severe hypoglycemia was rare and frequency was similar between empagliflozin and placebo.

CONCLUSIONS

Empagliflozin improved glycemic control and weight in T1D without increasing hypoglycemia. Ketoacidosis rate was comparable between empagliflozin 2.5 mg and placebo but increased with 10 mg and 25 mg. Ketone monitoring for early ketoacidosis detection and intervention and lower empagliflozin doses may help to reduce this risk.

2020 vision - An overview of prospects for diabetes management and prevention in the next decade

After a century of medical progress, people nowadays live longer with diabetes than ever before. However, current preventative approaches, compounded in part by increased life-expectancy, are failing to reduce the prevalence of diabetes. Cardiovascular sequelae account for many of the four million deaths annually attributable to diabetes. Evidence indicates that certain glucose-lowering medications can improve vascular outcomes in some people with type 2 diabetes, which, together with better understanding of using multiple therapies concurrently, offers opportunities for beneficial personalization of medication regimens. However, further well-designed long-term studies are needed to evaluate cardiovascular benefits and safety of new and older medications, particularly in users typical of everyday diabetes care. Although there are numerous other promising advances in pharmacotherapies and biotechnology, these will probably be unaffordable for most people with diabetes globally. Therefore, effective national public health approaches will be essential to reducing the incidence of diabetes and its associated burdens; these may entail politically controversial measures to change unhealthy lifestyle behaviours. Stakeholders could learn from past failures and emulate successes in other health-care initiatives. Without early action at all levels, we face a future in which approaching one-quarter of humans will have diabetes, with more than half afflicted during their lifetime.

Recent Updates on Type 1 Diabetes Mellitus Management for Clinicians

Type 1 diabetes mellitus (T1DM) is a chronic autoimmune condition that requires life-long administration of insulin. Optimal management of T1DM entails a good knowledge and understanding of this condition both by the physician and the patient. Recent introduction of novel insulin preparations, technological advances in insulin delivery and glucose monitoring, such as continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring and improved understanding of the detrimental effects of hypoglycaemia and hyperglycaemia offer new opportunities and perspectives in T1DM management. Evidence from clinical trials suggests an important role of structured patient education. Our efforts should be aimed at improved metabolic control with concomitant reduction of hypoglycaemia. Despite recent advances, these goals are not easy to achieve and can put significant pressure on people with T1DM. The approach of physicians should therefore be maximally supportive. In this review, we provide an overview of the recent advances in T1DM management focusing on novel insulin preparations, ways of insulin administration and glucose monitoring and the role of metformin or sodium-glucose co-transporter 2 inhibitors in T1DM management. We then discuss our current understanding of the effects of hypoglycaemia on human body and strategies aimed at mitigating the risks associated with hypoglycaemia.