Pharmacologic adjunctive to insulin therapies in type 1 diabetes: The journey has just begun

Gamma-aminobutyric acid for delaying type 1 diabetes mellitus: an update

The current gold-standard management of hyperglycemia in individuals with type 1 diabetes mellitus (T1DM) is insulin therapy. However, this therapy is associated with a high incidence of complications, and delaying the onset of this disease produces a substantially positive impact on quality of life for individuals with a predisposition to T1DM, especially children. This review aimed to assess the use of gamma-aminobutyric acid (GABA) to delay the onset of T1DM in children. GABA produces protective and proliferative effects in 2 ways, β cell and immune cell modulation. Various in vitro and in vivo studies have shown that GABA induces proliferation of β cells, increases insulin levels, inhibits β-cell apoptosis, and suppresses T helper 1 cell activity against islet antigens. Oral GABA is safe as no serious adverse effects were reported in any of the studies included in this review. These findings demonstrate promising results for the use of GABA treatment to delay T1DM, specifically in genetically predisposed children, through immunoregulatory effects and the ability to induce β-cell proliferation.

Drawing lines in the sand: The growing threat of obesity in type 1 diabetes

In this editorial, we comment on the article by Zeng et al published in the recent issue of the World Journal of Diabetes in 2024. We focus on the epidemiological, pathophysiological, and clinical interplay between obesity and type 1 diabetes mellitus (T1DM). Overweight and obesity represent a growing threat for modern societies and people with T1DM could not be an exception to this rule. Chronic exogenous insulin administration, genetic and epigenetic factors, and psy-chosocial and behavioral parameters, along with the modern way of life that incorporates unhealthy eating patterns and physical inactivity, set the stage for the increasing obesity rates in T1DM. As our knowledge of the underlying mechanisms that lead to the development of obesity and hyperglycemia expands, it becomes clear that there are overlap zones in the pathophysiology of the two main types of diabetes. Stereotypes regarding strict dividing lines between "autoimmune" and "metabolic" phenotypes increase the risk of trapping physicians into ineffective therapeutic approaches, instead of individualized diabetes care. In this context, the use of adjuncts to insulin therapy that have the potential to alleviate cardiorenal risk and decrease body weight can reduce the burden of obesity in patients with T1DM.

Efficacy of teplizumab for treatment of type 1 diabetes: A meta-analysis of randomized controlled trials

BACKGROUND

The management of Type 1 Diabetes Mellitus (T1DM) is a significant clinical challenge. This study evaluated the efficacy of teplizumab, an immunomodulatory drug, in patients with T1DM, using a systematic review and meta-analysis approach.

METHODS

We systematically searched multiple databases including Medline, Scopus, and others up to 10 January 2024, without language or regional restrictions. We included randomized controlled trials (RCTs) comparing teplizumab with placebo in T1DM patients.

RESULTS

Our analysis incorporated 8 RCTs, predominantly involving participants aged 7-35 years, diagnosed with T1DM and treated with 14-day courses of teplizumab. The primary outcomes included insulin use, C-peptide levels, and HbA1c levels. We observed a significant reduction in insulin use in the teplizumab group standardised mean difference of -0.50 (95% Confidence Interval [CI]: -0.76 to -0.23, p < 0.001; I2 = 49%). C-peptide levels were consistently higher in the teplizumab group, indicating improved endogenous insulin production. However, no significant change was noted in HbA1c levels between the groups. Quality assessment indicated a low risk of bias in most studies.

CONCLUSIONS

Teplizumab has a significant impact on reducing insulin dependence and enhancing endogenous insulin production in T1DM patients. However, its effect on long-term glycaemic control, as indicated by HbA1c levels, remains inconclusive.

Effect of kolaviron on islet dynamics in diabetic rats

Kolaviron, a biflavonoid isolated from the edible seeds of Garcinia kola, lowers blood glucose in experimental models of diabetes; however, the underlying mechanisms are not yet fully elucidated. The objective of the current study was to assess the effects of kolaviron on islet dynamics in streptozotocin-induced diabetic rats. Using double immunolabeling of glucagon and insulin, we identified insulin-producing β- and glucagon-producing α-cells in the islets of diabetic and control rats and determined the fractional β-cell area, α-cell area and islet number. STZ challenged rats presented with islet hypoplasia and reduced β-cell area concomitant with an increase in α-cell area. Kolaviron restored some islet architecture in diabetic rats through the increased β-cell area. Overall, kolaviron-treated diabetic rats presented a significant (p < 0.05) increase in the number of large and very large islets compared to diabetic control but no difference in islet number and α-cell area. The β-cell replenishment potential of kolaviron and its overall positive effects on glycemic control suggest that it may be a viable target for diabetes treatment.

Insulin treatment to type 1 male diabetic rats protects fertility by avoiding testicular apoptosis and cell cycle arrest

BACKGROUND

Uncontrolled type 1 diabetes mellitus (T1D) impairs reproductive potential of males. Insulin treatment restores metabolic parameters but it is unclear how it protects male reproductive health. Herein, we hypothesized that insulin treatment to T1D rats protects testicular physiology by mediating mechanisms associated with apoptosis and cell cycle.

METHODS

Mature male Wistar rats (n = 24) were divided into 3 groups: control, T1D-induced (received 40 mg kg-1 streptozotocin) and insulin-treated T1D (Ins T1D; received 40 mg kg-1 streptozotocin and then treated 0.9 IU/100 gr of insulin for 56 days) (N = 8/group). Expression levels of intrinsic apoptosis pathways regulators (Bcl-2, Bax, Caspase-3 and p53) and core regulators of cell cycle machinery (Cyclin D1, Cdk-4 and p21) were determined in testicular tissue by immunohistochemistry (IHC) and RT-PCR techniques. The percentage of testicular apoptotic cells was evaluated by TUNEL staining.

RESULTS

Our data shows that insulin treatment to T1D rats restored (P < 0.05) T1D-induced increased of caspase-3 and p53 expression in testis. Moreover, the testis of T1D rats treated with insulin exhibited increased expression of Cyclin D1 and cdk-4, and a reduced expression of p21 when compared with the expression in testis of T1D rats. Finally, insulin treatment could fairly control T1D-induced apoptosis. Accordingly, treatment of T1D rats with insulin led to a remarkable reduction (p < 0.05) in the percentage of apoptotic cells in the testis.

CONCLUSIONS

Insulin treatment is able to restore the network expression of apoptosis and proliferation-related genes caused by T1D in the testis and via this mechanism, preserve the fertility of males.

The SimpliciT1 Study: A Randomized, Double-Blind, Placebo-Controlled Phase 1b/2 Adaptive Study of TTP399, a Hepatoselective Glucokinase Activator, for Adjunctive Treatment of Type 1 Diabetes

OBJECTIVE

Despite advances in exogenous insulin therapy, many patients with type 1 diabetes do not achieve acceptable glycemic control and remain at risk for ketosis and insulin-induced hypoglycemia. We conducted a randomized controlled trial to determine whether TTP399, a novel hepatoselective glucokinase activator, improved glycemic control in people with type 1 diabetes without increasing hypoglycemia or ketosis.

RESEARCH DESIGN AND METHODS

SimpliciT1 was a phase 1b/2 adaptive study. Phase 2 activities were conducted in two parts. Part 1 randomly assigned 20 participants using continuous glucose monitors and continuous subcutaneous insulin infusion (CSII). Part 2 randomly assigned 85 participants receiving multiple daily injections of insulin or CSII. In both parts 1 and 2, participants were randomly assigned to 800 mg TTP399 or matched placebo (fully blinded) and treated for 12 weeks. The primary end point was change in HbA_1c from baseline to week 12.

RESULTS

The difference in change in HbA_1c from baseline to week 12 between TTP399 and placebo was -0.7% (95% CI -1.3, -0.07) in part 1 and -0.21% (95% CI -0.39, -0.04) in part 2. Despite a greater decrease in HbA_1c with TTP399, the frequency of severe or symptomatic hypoglycemia decreased by 40% relative to placebo in part 2. In both parts 1 and 2, plasma β-hydroxybutyrate and urinary ketones were lower during treatment with TTP399 than placebo.

CONCLUSIONS

TTP399 lowers HbA_1c and reduces hypoglycemia without increasing the risk of ketosis and should be further evaluated as an adjunctive therapy for the treatment of type 1 diabetes.