Recent advances and structure-activity relationship studies of DPP-4 inhibitors as anti-diabetic agents

Diabetes mellitus (DM) is one of the largest public health problems worldwide and in the last decades various therapeutic targets have been investigated. For the treatment of type-2 DM (T2DM), dipeptidyl peptidase-4 (DPP-4) is one of the well reported target and has established safety in terms of cardiovascular complexicity. Preclinical and clinical studies using DPP-4 inhibitors have demonstrated its safety and effectiveness and have lesser risk of associated hypoglycaemic effect making it suitable for elderly patients. FDA has approved a number of structurally diverse DPP-4 inhibitors for clinical use. The present manuscript aims to focus on the well reported hybrid and non-hybrid analogues and their structural activity relationship (SAR) studies. It aims to provide structural insights for this class of compounds pertaining to favourable applicability of selective DPP-4 inhibitors in the treatment of T2DM.

Comparison of SGLT2 inhibitors vs. DPP4 inhibitors for patients with metabolic dysfunction associated fatty liver disease and diabetes mellitus

PURPOSE

This study aimed to examine the potential benefit of sodium-glucose cotransporter 2 (SGLT2) inhibitors for patients with metabolic dysfunction-associated fatty liver disease (MAFLD) and diabetes mellitus (DM) using a real-world database.

METHODS

We analyzed individuals with MAFLD and DM newly initiated on SGLT2 or dipeptidyl peptidase 4 (DPP4) inhibitors from a large-scale administrative claims database. The primary outcome was the change in the fatty liver index (FLI) assessed using a linear mixed-effects model from the initiation of SGLT2 or DPP4 inhibitors. A propensity score-matching algorithm was used to compare the change in FLI among SGLT2 and DPP4 inhibitors.

RESULTS

After propensity score matching, 6547 well-balanced pairs of SGLT2 and 6547 DPP4 inhibitor users were created. SGLT2 inhibitor use was associated with a greater decline in FLI than DPP4 inhibitor use (difference at 1-year measurement, - 3.8 [95% CI - 4.7 to - 3.0]). The advantage of SGLT2 inhibitor use over DPP4 inhibitor use for improvement in FLI was consistent across subgroups. The relationship between SGLT2 inhibitors and amelioration of FLI was comparable between individual SGLT2 inhibitors.

CONCLUSIONS

Our analysis using large-scale real-world data demonstrated the potential advantage of SGLT2 inhibitors over DPP4 inhibitors in patients with MAFLD and DM.

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.

Synthesis and Anti-Diabetic Activity of an 8-Purine Derivative as a Novel DPP-4 Inhibitor in Obese Diabetic Zücker Rats

Type 2 diabetes mellitus (T2DM) is one of the world's principal metabolic diseases characterized by chronic hyperglycemia. The gut incretin hormones, glucagon-like peptide 1 (GLP-1) and gastric inhibitory polypeptide (GIP), which has been proposed as a new treatment for T2DM, are extensively metabolized by Dipeptidyl peptidase 4 (DPP-4). Inhibitors of DPP-4 block the degradation of GLP-1 and GIP and may increase their natural circulating levels, favoring glycemic control in T2DM. A novel and potent selective inhibitor of DPP-4 with an 8-purine derived structure (1) has been developed and tested in vitro and in vivo in Zücker obese diabetic fatty (ZDF) rats, an experimental model of the metabolic syndrome and T2DM to assess the inhibitory activity using vildagliptin as reference standard. ZDF rats were subdivided into three groups (n = 7/group), control (C-ZDF), and those treated with compound 1 (Compound1-ZDF) and with vildagliptin (V-ZDF), both at 10 mg/kg/d rat body weight, in their drinking water for 12 weeks, and a group of lean littermates (ZL) was used. ZDF rats developed DM (fasting hyperglycemia, 425 ± 14.8 mg/dL; chronic hyperglycemia, HbA1c 8.5 ± 0.4%), compared to ZL rats. Compound 1 and vildagliptin reduced sustained HbAl1c (14% and 10.6%, P < 0.05, respectively) and fasting hyperglycemia values (24% and 19%, P < 0.05, respectively) compared to C-ZDF group (P < 0.001). Compound 1 and vildagliptin have shown a potent activity with an IC50 value of 4.92 and 3.21 µM, respectively. These data demonstrate that oral compound 1 administration improves diabetes in ZDF rats by the inhibitory effect on DPP-4, and the potential to be a novel, efficient and tolerable approach for treating diabetes of obesity-related T2DM, in ZDF rats.

Network-based drug repositioning of linagliptin as a potential agent for uterine fibroids targeting transforming growth factor-beta mediated fibrosis

Uterine fibroid is the most common non-cancerous tumor with no satisfactory options for long-term pharmacological treatment. Fibroblast activation protein-α (FAP) is one of the critical enzymes that enhances the fibrosis in uterine fibroids. Through STITCH database mining, we found that dipeptidyl peptidase-4 inhibitors (DPP4i) have the potential to inhibit the activity of FAP. Both DPP4 and FAP belong to the dipeptidyl peptidase family and share a similar catalytic domain. Hence, ligands which have a binding affinity with DPP4 could also bind with FAP. Among the DPP4i, linagliptin exhibited the highest binding affinity (Dock score = -8.562 kcal/mol) with FAP. Our study uncovered that the differences in the S2 extensive-subsite residues between DPP4 and FAP could serve as a basis for designing selective inhibitors specifically targeting FAP. Furthermore, in a dynamic environment, linagliptin was able to destabilize the dimerization interface of FAP, resulting in potential inhibition of its biological activity. True to the in-silico results, linagliptin reduced the fibrotic process in estrogen and progesterone-induced fibrosis in rat uterus. Furthermore, linagliptin reduced the gene expression of transforming growth factor-β (TGF-β), a critical factor in collagen secretion and fibrotic process. Masson trichrome staining confirmed that the anti-fibrotic effects of linagliptin were due to its ability to reduce collagen deposition in rat uterus. Altogether, our research proposes that linagliptin has the potential to be repurposed for the treatment of uterine fibroids.

Glucose regulation by newly synthesized boronic acid functionalized molecules as dipeptidyl peptidase IV inhibitor: a potential compound for therapeutic intervention in hyperglycaemia

Management of type 2 diabetes mellitus (T2DM) using dipeptidyl peptidase IV (DPP IV) inhibitors is gaining precedence as this enzyme plays an indispensable role in cleaving and inactivating peptides, such as glucagon-like peptide-1 (GLP-1), incretin hormones, and glucose-dependent insulinotropic polypeptide (GIP). There are several DPP IV inhibitors used to treat T2DM, but limited by side effects such as disturbed GIT, flu-like symptoms, etc. Thus, there is an urgent need for the development of novel and better DPP IV inhibitors for the management of the same. In the present study, we investigated the effect of new boronic acid-based thiazole compounds as DPP IV inhibitors. We used substituted anilines that were progressively modified through a multi-step synthesis and then chemically characterised. These molecules have good binding affinity and molecular interactions at the active site of the DPP IV enzyme. Two boronic acid-based molecules, i.e. PC06R58 and PC06R108, were used for the assessment of their in-vitro enzymatic activities. Both molecules (PC06108 and PC06R58) exhibited potent uncompetitive DPP IV enzyme inhibition at two different concentrations of 90.9 and 15.6 nM, respectively, compared to sitagliptin having an IC50 of 17.3 nM. Furthermore, the oral glucose tolerance test suggested significantly reduced blood glucose levels at 20 mg/kg of the body weight upon administration of PC06R58 and PC06R108 molecules in rats after glucose ingestion (2 g/kg of the body weight). The compounds showed satisfactory DPP IV inhibition. Furthermore, DPP IV inhibitory activity and acceptable pre-ADME/Tox profile indicate it is a lead compound in this novel class of DPP IV inhibitors.Communicated by Ramaswamy H. Sarma.

Outcomes of Various Classes of Oral Antidiabetic Drugs on Nonalcoholic Fatty Liver Disease

Importance

Several oral antidiabetic drug (OAD) classes can potentially improve patient outcomes in nonalcoholic fatty liver disease (NAFLD) to varying degrees, but clinical data on which class is favored are lacking.

Objective

To investigate which OAD is associated with the best patient outcomes in NAFLD and type 2 diabetes (T2D).

Design, Setting, and Participants

This retrospective nonrandomized interventional cohort study used the National Health Information Database, which provided population-level data for Korea. This study involved patients with T2D and concomitant NAFLD.

Exposures

Receiving either sodium-glucose cotransporter 2 (SGLT2) inhibitors, thiazolidinediones, dipeptidyl peptidase-4 (DPP-4) inhibitors, or sulfonylureas, each combined with metformin for 80% or more of 90 consecutive days.

Main Outcomes and Measures

The main outcomes were NAFLD regression assessed by the fatty liver index and composite liver-related outcome (defined as liver-related hospitalization, liver-related mortality, liver transplant, and hepatocellular carcinoma) using the Fine-Gray model regarding competing risks.

Results

In total, 80 178 patients (mean [SD] age, 58.5 [11.9] years; 43 007 [53.6%] male) were followed up for 219 941 person-years, with 4102 patients experiencing NAFLD regression. When compared with sulfonylureas, SGLT2 inhibitors (adjusted subdistribution hazard ratio [ASHR], 1.99 [95% CI, 1.75-2.27]), thiazolidinediones (ASHR, 1.70 [95% CI, 1.41-2.05]), and DPP-4 inhibitors (ASHR, 1.45 [95% CI, 1.31-1.59]) were associated with NAFLD regression. SGLT2 inhibitors were associated with a higher likelihood of NAFLD regression when compared with thiazolidinediones (ASHR, 1.40 [95% CI, 1.12-1.75]) and DPP-4 inhibitors (ASHR, 1.45 [95% CI, 1.30-1.62]). Only SGLT2 inhibitors (ASHR, 0.37 [95% CI, 0.17-0.82]), not thiazolidinediones or DPP-4 inhibitors, were significantly associated with lower incidence rates of adverse liver-related outcomes when compared with sulfonylureas.

Conclusions and Relevance

The results of this cohort study suggest that physicians may lean towards prescribing SGLT2 inhibitors as the preferred OAD for individuals with NAFLD and T2D, considering their potential benefits in NAFLD regression and lower incidences of adverse liver-related outcomes. This observational study should prompt future research to determine whether prescribing practices might merit reexamination.

Real-World Effectiveness of Once-Weekly Glucagon-Like Peptide-1 Receptor Agonists (OW GLP-1RAs) in Comparison with Dipeptidyl Peptidase-4 Inhibitors (DPP-4is) for Glycemic Control and Weight Outcomes in Type 2 Diabetes Mellitus (RELATE)

BACKGROUND

The efficacy of once-weekly (OW) glucagon-like peptide-1 receptor agonists (GLP-1RAs) has been established in several trials in people with type 2 diabetes mellitus (T2DM); however, real-world evidence on their effectiveness is limited. This study evaluated the effectiveness of OW GLP-1RA regarding glycemic and weight outcomes, and relative to DPP-4i in a comparator analysis.

METHODS

This observational cohort study evaluated glycated hemoglobin (HbA1c) and weight outcomes in people with T2DM with two or more prescription claims for the same OW GLP-1RA using a pre-post study design (including for a semaglutide OW T2DM subgroup, hereafter referred to as semaglutide). Comparator analysis for the same outcome was performed for OW GLP-1RAs versus DPP-4i and semaglutide subgroup versus DPP-4i. A linked patient population from the IQVIA PharMetrics® Plus database and the Ambulatory Electronic Medical Records (AEMR) database was analyzed using data from January 2017 to April 2022. HbA1c and weight were assessed at baseline and at the end of the 12-month post-index period. Inverse probability of treatment weighting (IPTW) was used to adjust for imbalances in baseline patient characteristics in the comparator analysis.

RESULTS

In the pre-post analysis, a greater numerical reduction in HbA1c and weight was observed for the semaglutide subgroup (N = 354) relative to the OW GLP-1RA cohort (N = 921). In the semaglutide subgroup, 52.5% and 34.2% of patients achieved HbA1c of < 7.0% and ≥ 5% weight loss, respectively. For the comparator analysis, the OW GLP-1RAs (N = 651) were significantly more effective (p < 0.001) in reducing HbA1c (- 1.5% vs. -  1.0%) and weight (- 3.2 kg vs. -  1.0 kg) than the DPP-4is (N = 431). Similarly, the semaglutide cohort (N = 251) also displayed more effectiveness (p < 0.001) in reducing HbA1c (- 1.7% vs. -  0.9%) and weight (- 4.1 kg vs. -  1.3 kg) than the respective DPP-4i cohort (N = 417). Patients initiating OW GLP-1RAs, including the semaglutide cohort, were at least twice as likely to achieve HbA1c and weight outcomes as well as composite outcomes compared with those initiating DPP-4is.

CONCLUSION

The study reinforces that OW GLP-1RAs are more effective in glycemic control and weight reduction compared with DPP-4is in people with T2DM in the real-world setting. These findings align with the recommendation in the current guidelines for utilizing glucose-lowering treatment regimens that support weight-management goals in people with T2DM.

Sodium-Glucose Cotransporter 2 Inhibitors Should Be Avoided for the Inpatient Management of Hyperglycemia

OBJECTIVE

Hyperglycemia in patients with type 2 diabetes mellitus is frequently encountered in the hospital setting. The recent guidelines for the management of inpatient hyperglycemia have included the use of dipeptidyl peptidase 4 inhibitors as an alternative to standard insulin therapy in select patients. This raises the question of the inpatient use of sodium-glucose cotransporter 2 inhibitors (SGLT2i), which have gained increasing popularity in the outpatient setting because of beneficial cardiovascular and renal outcomes. This article describes the risks associated with the use of SGLT2i for the management of inpatient hyperglycemia.

METHODS

A literature review was performed using PubMed and Google Scholar for studies assessing the inpatient use of SGLT2i. Search terms included "SGLT2 inhibitors," "euglycemic DKA," "inpatient hyperglycemia," "DPP4 inhibitors," "hypovolemia," and "urinary tract infections." Studies not written in English were excluded. Forty-eight articles were included.

RESULTS

Review of the literature showed significant safety concerns with the use of SGLT2i for the inpatient management of hyperglycemia. Hospitalized patients treated with SGLT2i were at increased risk of diabetic ketoacidosis, euglycemic diabetic ketoacidosis, hypovolemia, and urinary tract infections. When compared head-to-head, SGLT2i were not more effective for inpatient glycemic control than dipeptidyl peptidase 4 inhibitors and did not reduce insulin requirements when used in combination with insulin. Although SGLT2i can be considered for the treatment of congestive heart failure, they should be started close to or at the time of discharge.

CONCLUSION

Although SGLT2i are a preferred pharmacotherapy class for the outpatient management of type 2 diabetes mellitus, there are considerable safety concerns when using them in a hospital setting, and avoidance is recommended.

The association between sodium glucose cotransporter-2 inhibitors vs dipeptidyl peptidase-4 inhibitors and renal outcomes in people discharged from hospital with type 2 diabetes: A population-based cohort study

BACKGROUND

We investigated the association between post-hospital discharge use of sodium glucose cotransporter-2 inhibitors (SGLT-2is) compared to dipeptidyl peptidase-4 inhibitors (DPP-4is) and the incidence of hospitalization for acute renal failure (ARF) and chronic kidney disease (CKD) in people with type 2 diabetes.

METHODS

We conducted a retrospective cohort study using linked hospital and prescription data. Our cohort included people aged ≥30 years with type 2 diabetes discharged from a hospital in Victoria, Australia, from December 2013 to June 2018. We compared new users of SGLT-2is with new users of DPP-4is following discharge. People were followed from first dispensing of a SGLT-2i or DPP-4i to a subsequent hospital admission for ARF or CKD. We used competing risk models with inverse probability of treatment weighting (IPTW) to estimate subhazard ratios.

RESULTS

In total, 9620 people initiated SGLT-2is and 9962 initiated DPP-4is. The incidence rate of ARF was 12.3 per 1000 person-years (median years of follow-up [interquartile range [IQR] 1.4 [0.7-2.2]) among SGLT-2i initiators and 18.9 per 1000 person-years (median years of follow-up [IQR] 1.7 [0.8-2.6]) among DPP-4i initiators (adjusted subhazard ratio with IPTW 0.78; 95% confidence interval [CI] 0.70-0.86). The incidence rate of CKD was 6.0 per 1000 person-years (median years of follow-up [IQR] 1.4 [0.7-2.2]) among SGLT-2i initiators and 8.9 per 1000 person-years (median years of follow-up [IQR] 1.7 [0.8-2.6]) among DPP-4i initiators (adjusted subhazard ratio with IPTW 0.83; 95% CI 0.73-0.94).

CONCLUSIONS

Real-world data support using SGLT-2is over DPP-4is for preventing acute and chronic renal events in people with type 2 diabetes.

A comprehensive review of small-molecule drugs for the treatment of type 2 diabetes mellitus: Synthetic approaches and clinical applications

Type 2 diabetes mellitus (T2DM) is a long-term metabolic disorder characterized by the body's resistance to insulin and inadequate production of insulin. Small molecule drugs to treat T2DM mainly control blood sugar levels by improving insulin sensitivity, increasing insulin secretion, or reducing liver glycogen production. With the deepening of research on the pathogenesis of diabetes, many drugs with new targets and mechanisms of action have been discovered. The targets of the drugs for T2DM are mainly dipeptidyl peptidase IV inhibitors (DPP4), sodium/glucose cotransporter 2 inhibitors (SGLT2), sulfonylurea receptor modulators (SUR), peroxisome proliferator-activated receptor γ agonists (PPARγ), etc. We are of the opinion that acquiring a comprehensive comprehension of the synthetic procedures employed in drug molecule production will serve as a source of inventive and pragmatic inspiration for the advancement of novel, more potent, and feasible synthetic methodologies. This review aims to outline the clinical applications and synthetic routes of some representative drugs to treat T2DM, which will drive the discovery of new, more effective T2DM drugs.

DPP-4 inhibition by linagliptin ameliorates age-related mild cognitive impairment by regulating microglia polarization in mice

Extensive preclinical evidence demonstrates a causative link between insulin signaling dysfunction and the pathogenesis of Alzheimer's disease (AD), and diabetic drugs may represent a promising approach to fighting AD. However, it remains to be determined which antidiabetic drugs are more effective in preventing cognitive impairment. Thus, the present study investigated the effect of dipeptidyl peptidase-4 (DPP-4) inhibitor linagliptin on cognitive impairment in middle-aged mice by comparing it with the effect of metformin. We found that DPP-4 activity increased in the hippocampus of middle-aged mice, and DPP-4 was mainly expressed by microglia rather than astrocytes and oligodendrocytes. DPP-4 directly regulated M1/M2 microglia polarization following LPS or IL-4 stimulation, while DPP-4 inhibitor, linagliptin, suppressed M1-polarized activation and induced M2-polarized activation. Both linagliptin and metformin enhanced cognitive ability, increased hippocampal synaptic plasticity and neurogenesis, and decreased age-related oxidative stress and inflammation by regulating microglia polarization in the hippocampus of middle-aged mice. The combination of linagliptin and metformin showed a maximum protective effect compared to the individual drugs alone. Loss of macrophage inflammatory protein-1α (MIP-1α), a DPP-4 substrate, abrogated the cognitive protection and anti-inflammation effects of linagliptin. Therefore, the current investigation exhibits a potential utility for DPP-4 inhibition in attenuating microglia-mediated inflammation and preventing mild cognitive impairment (MCI) in middle-aged mice, and the effect was partly mediated by MIP-1α.

Healthcare resource utilization and healthcare costs in patients with type 2 diabetes mellitus initiating sodium-glucose cotransporter 2 inhibitors vs dipeptidyl peptidase-4 inhibitors in Japan: A real-world administrative database analysis

AIMS/INTRODUCTION

Healthcare resource utilization (HCRU) and healthcare costs are important factors to consider when selecting appropriate treatment for type 2 diabetes mellitus. We compared the HCRU and healthcare costs of sodium-glucose cotransporter 2 inhibitors (SGLT2i) vs dipeptidyl peptidase-4 inhibitors (DPP4i) in patients with type 2 diabetes mellitus in Japan.

MATERIALS AND METHODS

This was a Japanese retrospective cohort study conducted using the JMDC Claims Database (January 1, 2015-December 31, 2021). Patients newly treated with an SGLT2i (31,872 patients) or a DPP4i (73,279 patients) were matched 1:1, using propensity score, after excluding patients without continuous SGLT2i or DPP4i prescriptions after the index date. HCRU and healthcare costs were compared between the treatment groups in the full cohort and subcohorts/subgroups of different baseline characteristics, including body mass index (BMI).

RESULTS

After matching, patient characteristics were well balanced (17,767 patients each). Patients receiving an SGLT2i vs those receiving a DPP4i had significantly lower numbers of hospitalizations per person per month (PPPM) and outpatient visits PPPM, and had shorter lengths of stay per hospitalization. Healthcare costs, including all-cause overall healthcare costs PPPM and all-cause hospitalization costs PPPM, were generally lower in patients receiving an SGLT2i than those receiving a DPP4i. Similar results were observed among patients with a higher BMI but not among patients with a lower BMI.

CONCLUSIONS

SGLT2i were associated with lower HCRU and healthcare costs than DPP4i, suggesting economic benefits with SGLT2i vs DPP4i in type 2 diabetes mellitus management.

Impact of treatment with GLP-1RAs on suicide attempts in adults persons with type 2 diabetes: A retrospective comparative effectiveness study based on a global TriNetX health research database

OBJECTIVE

To assess the association between glucagon-like peptide-1 receptor agonists (GLP-1RA) treatment and the risk of suicide attempts in people with type 2 diabetes (T2D), with a focus on subgroups with and without a history of depression or suicide attempts.

METHODS

This retrospective cohort study utilized TriNetX, a federated network of real-world data. Using the Global Collaborative Network data, we collected electronic medical records from 113 health care organizations with 135 million patient records with 8 million with T2D, 83% from the United States. The four cohorts were identified based on age, medication, diagnosis, and presence of depression or suicide attempts. Analytic methods included measures of association and number of Instances, with propensity score matching employed to mitigate potential confounders. The primary outcome was the incidence of suicide attempts among people with T2D with GLP-1RA treatment in comparison with dipeptidyl peptidase-4 inhibitor (DPP-4i) treatment.

RESULTS

People with T2D treated with GLP-1RA consistently exhibited a lower risk of suicide attempts compared to those treated with DPP-4i. This was particularly significant in people with a history of depression or suicide attempts. The risk and odds ratios were significantly lower in the GLP-1RA-treated cohorts than in DPP-4i across all analyses.

CONCLUSION

As compared with DPP-4i, our analysis shows a protective effect associated with GLP-1RA treatment on the risk of suicide attempts among people with T2D. However, further research, particularly prospective and randomized studies, is necessary to confirm these observations and understand the underlying mechanisms.

DPP-4 inhibitor sitagliptin treatment results in altered myocardial metabolic proteome and oxidative phosphorylation in a swine model of chronic myocardial ischemia

Small animal models have shown improved cardiac function with DPP-4 inhibition, but many human studies have shown worse outcomes or no benefit. We seek to bridge the gap by studying the DPP-4 inhibitor sitagliptin in a swine model of chronic myocardial ischemia using proteomic analysis. Thirteen Yorkshire swine underwent the placement of an ameroid constrictor on the left coronary circumflex artery to model chronic myocardial ischemia. Two weeks post-op, swine received either sitagliptin 100 mg daily (SIT, n = 5) or no drug (CON, n = 8). After 5 weeks of treatment, swine underwent functional measurements and tissue harvest. In the SIT group compared to CON, there was a trend towards decreased cardiac index (p = 0.06). The non-ischemic and ischemic myocardium had 396 and 166 significantly decreased proteins, respectively, in the SIT group compared to CON (all p < 0.01). This included proteins involved in fatty acid oxidation (FAO), myocardial contraction, and oxidative phosphorylation (OXPHOS). Sitagliptin treatment resulted in a trend towards decreased cardiac index and decreased expression of proteins involved in OXPHOS, FAO, and myocardial contraction in both ischemic and non-ischemic swine myocardium. These metabolic and functional changes may provide some mechanistic evidence for outcomes seen in clinical studies.

Association between sodium-glucose cotransporter-2 inhibitors and arrhythmic outcomes in patients with diabetes and pre-existing atrial fibrillation

AIMS

Prior studies suggest that sodium-glucose cotransporter-2 inhibitors (SGLT2is) may decrease the incidence of atrial fibrillation (AF). However, it is unknown whether SGLT2i can attenuate the disease course of AF among patients with pre-existing AF and Type II diabetes mellitus (DM). In this study, our objective was to examine the association between SGLT2i prescription and arrhythmic outcomes among patients with DM and pre-existing AF.

METHODS AND RESULTS

We conducted a population-based cohort study of adults with DM and AF between 2014 and 2019. Using a prevalent new-user design, individuals prescribed SGLT2i were matched 1:1 to those prescribed dipeptidyl peptidase-4 inhibitors (DPP4is) based on time-conditional propensity scores. The primary endpoint was a composite of AF-related healthcare utilization (i.e. hospitalization, emergency department visits, electrical cardioversion, or catheter ablation). Secondary outcome measures included all-cause mortality, heart failure (HF) hospitalization, and ischaemic stroke or transient ischaemic attack (TIA). Cox proportional hazard models were used to examine the association of SGLT2i with the study endpoint. Among 2242 patients with DM and AF followed for an average of 3.0 years, the primary endpoint occurred in 8.7% (n = 97) of patients in the SGLT2i group vs. 10.0% (n = 112) of patients in the DPP4i group [adjusted hazard ratio 0.73 (95% confidence interval 0.55-0.96; P = 0.03)]. Sodium-glucose cotransporter-2 inhibitors were associated with significant reductions in all-cause mortality and HF hospitalization, but there was no difference in the risk of ischaemic stroke/TIA.

CONCLUSION

Among patients with DM and pre-existing AF, SGLT2is are associated with decreased AF-related health resource utilization and improved arrhythmic outcomes compared with DPP4is.

Burden of Illness of Type 2 Diabetes Mellitus in the Kingdom of Saudi Arabia: A Five-Year Longitudinal Study

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is associated with huge clinical and economic burden in the Kingdom of Saudi Arabia (KSA) which can be curtailed by efficacious treatment. In order to achieve this, current treatment pathways for T2DM and associated costs need to be assessed.

METHODS

A longitudinal cohort review was conducted to collect country-specific and patient-specific clinical data, over a minimum observation period of 5 years in the KSA. Patient demographics, clinical characteristics and treatment patterns were recorded. The IQVIA Core Diabetes Model (CDM) version 9.5 Plus was used to assess the burden of illness, which included long-term projections of clinical (life expectancy [LE], quality-adjusted life-years [QALYs], event rates of diabetes-related complications) and direct medical cost (per-patient annual or lifelong [50 years]) outcomes of the most commonly used first-line (1st-line) regimens for T2DM from a payer perspective in the KSA.

RESULTS

Data were collected from a subpopulation of 638 patients from 15 participating centres. There was an equal gender representation with a majority of the patients belonging to Arabian/Saudi ethnicity (71.0%). Biguanides (81.5%), sulfonylureas (51.6%), dipeptidyl peptidase 4 (DPP4) inhibitors (26.2%) and fast-acting insulins (17.2%) were the most prescribed 1st-line agents. The most frequently used 1st-line regimens resulted in an estimated LE of 25-28 years, QALYs of 18-21 years and lifelong total cost of illness of 201,377-437,371 Saudi Arabian riyal (53,700-116,632 US dollars).

CONCLUSION

Our study addresses gaps in the current research by providing a complete landscape of baseline demographic, clinical characteristics and treatment patterns from a heterogeneous group of patients with T2DM in the KSA. Additionally, the burden of illness analysis using CDM showed substantially higher cost of T2DM care from a payer perspective in the KSA.

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.

Microbial gatekeepers: unraveling the role of the gut microbiota enzyme DPP4 in diabetes management

Wang et al. identified dipeptidyl peptidase 4 (DPP4) as a gut microbe-derived enzyme that impacts on host glucose metabolism. They further introduced a novel therapeutic, daurisoline-d4 (Dau-d4), a selective microbial DPP4 (mDPP4) inhibitor that shows promise in improving glucose tolerance, highlighting the potential of therapies that target both host enzymes and gut microbial enzymes.

Safety of GLP-1 Receptor Agonists and Other Second-Line Antidiabetics in Early Pregnancy

Importance

Increasing use of second-line noninsulin antidiabetic medication (ADM) in pregnant individuals with type 2 diabetes (T2D) may result in fetal exposure, but their teratogenic risk is unknown.

Objective

To evaluate periconceptional use of second-line noninsulin ADMs and whether it is associated with increased risk of major congenital malformations (MCMs) in the infant.

Design, Setting, and Participants

This observational population-based cohort study used data from 4 Nordic countries (2009-2020), the US MarketScan Database (2012-2021), and the Israeli Maccabi Health Services database (2009-2020). Pregnant women with T2D were identified and their live-born infants were followed until up to 1 year after birth.

Exposure

Periconceptional exposure was defined as 1 or more prescription fill of sulfonylureas, dipeptidyl peptidase 4 (DPP-4) inhibitors, glucagon-like peptide 1 (GLP-1) receptor agonists, and sodium-glucose cotransporter 2 (SGLT2) inhibitors, or insulin (active comparator) from 90 days before pregnancy to end of first trimester.

Main Outcomes and Measures

Relative risks (RRs) and 95% CIs for MCMs were estimated using log-binomial regression models, adjusting for key confounders in each cohort and meta-analyzed.

Results

Periconceptional exposure to second-line noninsulin ADMs differed between countries (32, 295, and 73 per 100 000 pregnancies in the Nordics, US, and Israel, respectively), and increased over the study period, especially in the US. The standardized prevalence of MCMs was 3.7% in all infants (n = 3 514 865), 5.3% in the infants born to women with T2D (n = 51 826), and among infants exposed to sulfonylureas was 9.7% (n = 1362); DPP-4 inhibitors, 6.1% (n = 687); GLP-1 receptor agonists, 8.3% (n = 938); SGLT2 inhibitors, 7.0% (n = 335); and insulin, 7.8% (n = 5078). Compared with insulin, adjusted RRs for MCMs were 1.18 (95% CI, 0.94-1.48), 0.83 (95% CI, 0.64-1.06), 0.95 (95% CI, 0.72-1.26), and 0.98 (95% CI, 0.65-1.46) for infants exposed to sulfonylureas, DPP-4 inhibitors, GLP-1 receptor agonists, and SGLT2 inhibitors, respectively.

Conclusions and Relevance

Use of second-line noninsulin ADMs is rapidly increasing for treatment of T2D and other indications, resulting in an increasing number of exposed pregnancies. Although some estimates were imprecise, results did not indicate a large increased risk of MCMs above the risk conferred by maternal T2D requiring second-line treatment. Although reassuring, confirmation from other studies is needed, and continuous monitoring will provide more precise estimates as data accumulate.

The impact of sodium-glucose co-transporter-2 inhibitors on dementia and cardiovascular events in diabetic patients with atrial fibrillation

AIMS

The effectiveness of sodium-glucose co-transporter-2 inhibitors (SGLT2i) on incident dementia in patients with diabetes and atrial fibrillation (AF) remains unknown. This study aimed to investigate the association between SGLT2i and the risk of incident dementia in diabetic patients with AF, and to explore the interactions with oral anticoagulants or dipeptidyl peptidase-4 inhibitors (DPP4i).

MATERIALS AND METHODS

We conducted a cohort study using Taiwan's National Health Insurance Research Database. Patients with diabetes and AFwithout a prior history of established cardiovascular diseases, were identified. Using propensity score matching, 810 patients receiving SGLT2i were matched with 1620 patients not receiving SGLT2i. The primary outcome was incident dementia, and secondary outcomes included composite cardiovascular events and mortality.

RESULTS

After up to 5 years of follow-up, SGLT2i use was associated with a significantly lower risk of incident dementia (hazard: 0.71, 95% confidence interval: 0.51-0.98), particularly vascular dementia (HR: 0.44, 95% CI: 0.24-0.82). SGLT2i was related to reduced risks of AF-related hospitalisation (HR: 0.72, 95% CI: 0.56-0.93), stroke (HR: 0.75, 95% CI: 0.60-0.94), and all-cause death (HR: 0.33, 95% CI: 0.24-0.44). The protective effects were consistent irrespective of the concurrent use of non-vitamin K antagonist oral anticoagulants (NOACs) or DPP4i.

CONCLUSIONS

In diabetic patients with AF, SGLT2i was associated with reduced risks of incident dementia, AF-related hospitalisation, stroke, and all-cause death. The protective effects were independent of either concurrent use of NOACs or DPP4i.

Pharmacotherapeutic advances for chronic myelogenous leukemia: beyond tyrosine kinase inhibitors

INTRODUCTION

Despite the notable success of tyrosine kinase inhibitors (TKIs) in treating chronic myeloid leukemia (CML), a subset of patients experiences resistance, or relapse after discontinuation. This challenge is attributed to the Ph+ leukemia stem cells (LSCs) pool not fully involved in the inhibition process due to the current therapeutic approach.

AREAS COVERED

Current pharmacological advancements in CML therapy focus on targeting LSCs, intervening in self-renewal pathways, and exploiting biological vulnerabilities. Beyond BCR::ABL1 inhibition, innovative approaches include immunotherapy, epigenetic modulation, and interference with microenvironmental mechanisms.

EXPERT OPINION

Diverse therapeutic strategies beyond TKIs are under investigation. Immunotherapy with interferon-α (IFN-α) shows some biological effects, although further research is needed for optimal application in enhancing discontinuation rates. Other compounds were able to mobilize Ph+ LSCs from the bone marrow niche (DPP-IV inhibitor vildagliptin or PAI-1 inhibitor TM5614) increasing the LSC clearance or target the CD26, a Ph+ specific surface receptor. It is noteworthy that the majority of these alternative strategies still incorporate TKIs. In conclusion, novel therapeutic perspectives are emerging for CML, holding the potential for substantial advancements in disease treatment.

Effects of SGLT2 Inhibitors and DPP-4 Inhibitors on Advanced Glycation End Products

Clinical trials have revealed that sodium glucose cotransporter 2 (SGLT2) inhibitors suppress the onset of heart failure and cardiovascular death in diabetic patients. On the other hand, few reports have been published concerning such effects of dipeptidyl peptidase-4 (DPP-4) inhibitors. We undertook the present study to evaluate the effects of SGLT2 inhibitors and DPP-4 inhibitors on the advanced glycation end products (AGEs), well known as a risk factor for the development of cardiovascular disorders.Type 2 diabetes mellitus were divided into two groups and treated with either SGLT2 inhibitors or DPP-4 inhibitors for 3 months. Before and after the 3-month treatment period with each drug, the AGEs and diabetes-related parameters were measured. Methylglyoxal-derived hydroimidazolone-1 (MG-H1) was measured as one of the AGEs.In the SGLT2 inhibitor group, both the blood HbA1c and MG-H1 levels decreased significantly after the 3-month treatment period. In the DPP-4 inhibitor group, only the blood HbA1c level decreased significantly, with no significant change of the blood MG-H1 level.SGLT2 inhibitor reduced both the blood levels of HbA1c and AGEs (MG-H1). Considering that the blood levels of AGEs are associated with the risk of heart failure and cardiovascular disorders, the results of the present study suggest that the effect of SGLT2 inhibitors in suppressing cardiovascular death might be mediated by the reduction in the blood levels of AGEs induced by this class of drugs. DPP-4 inhibitors showed no significant effects on the blood levels of AGEs.

Effects of Dipeptidyl Peptidase-4 Inhibitor and Angiotensin-Converting Enzyme Inhibitor on Experimental Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease in the United States and worldwide. Proteinuria is a major marker of the severity of injury. Dipeptidyl peptidase-4 inhibitor (DPP-4I) increases incretin-related insulin production and is, therefore, used to treat diabetes. We investigated whether DPP4I could have direct effect on kidney independent of its hypoglycemic activity. We, therefore, tested the effects of DPP4I with or without angiotensin-converting enzyme inhibitor (ACEI) on the progression of diabetic nephropathy and albuminuria in a murine model of DKD. eNOS-/-db/db mice were randomized to the following groups at age 10 weeks and treated until sacrifice: baseline (sacrificed at week 10), untreated control, ACEI, DPP4I, and combination of DPP4I and ACEI (Combo, sacrificed at week 18). Systemic parameters and urine albumin-creatinine ratio were assessed at baseline, weeks 14, and 18. Kidney morphology, glomerular filtration rate (GFR), WT-1, a marker for differentiated podocytes, podoplanin, a marker of foot process integrity, glomerular collagen IV, and alpha-smooth muscle actin were assessed at the end of the study. All mice had hyperglycemia and proteinuria at study entry at week 10. Untreated control mice had increased albuminuria, progression of glomerular injury, and reduced GFR at week 18 compared with baseline. DPP4I alone reduced blood glucose and kidney DPP-4 activity but failed to protect against kidney injury compared with untreated control. ACEI alone and combination groups showed significantly reduced albuminuria and glomerular injury, and maintained GFR and WT-1+ cells. Only the combination group had significantly less glomerular collagen IV deposition and more podoplanin preservation than the untreated control. DPP-4I alone does not decrease the progression of kidney injury in the eNOS-/-db/db mouse model, suggesting that targeting only hyperglycemia is not an optimal treatment strategy for DKD. Combined DPP-4I with ACEI added more benefit to reducing the glomerular matrix.

Clinical characteristics and healthcare utilisation associated with undiagnosed cognitive impairment in elderly patients with diabetes in a primary care setting: a population-based cohort study

OBJECTIVES

The objective of this study is to report the prevalence, clinical characteristics and healthcare utilisation of patients with type 2 diabetes (T2DM) and previously undiagnosed cognitive impairment who were identified as having a low Montreal Cognitive Assessment (MoCA) score.

DESIGN

A population-based cohort study comparing clinical characteristics, medications, outpatient and inpatient care of patients with a MoCA score <19 to MoCA >26 using descriptive statistics, linear regression and multivariate logistic regression.

SETTING

Electronic medical records of a large health maintenance organisation in Israel.

PARTICIPANTS

350 patients, age >65 with T2DM who participated in a cognitive function screening initiative using MoCA, and had a follow-up visit during the 12 months after screening.

RESULTS

130 (37.1%) had a MoCA score >26 and 68 (19.4%) <19. Patients with MoCA<19 had more diabetes-related complications, poorer glycaemic and lipid control, fewer visits to their main primary care physician (PCP; 3.9±3.2 vs 7.3±4.2 visits/year p=0.008), shorter duration of PCP visits (8.3±4.5 vs 4.0±3.5 min, p=0.007), fewer nutritionist and endocrinologist visits, and lower participation in diabetes or smoking cessation workshops. They were less likely to be treated with glucagon-like peptide-1 (GLP-1) agonists, dipeptidyl peptidase-4 inhibitor (DPP-4), or sodium-glucose transport protein 2 (SGLT-2) inhibitors and more likely to receive insulin or sulfonylurea. Moreover, they had more emergency room visits (ER; 15 (11.5%) vs 16 (23.5%), p=0.019), hospitalisations (8 (6.2%) vs 22 (32.4%), p=0.001), and longer hospital stays (4.3±3.2 vs 14.5±9.8, p=0.001). Using statistical models, MoCA<19 was identified as a risk factor for fewer and shorter PCP visits and more ER visits and hospitalisations.

CONCLUSIONS

This study highlights the high prevalence of undiagnosed severe cognitive impairment in elderly patients with T2DM and its association with poor outpatient care. Appropriate interventions are needed to improve outcomes and prevent hospitalisation in this high-risk population.

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

Background

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

Methods

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

Results

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

Conclusion

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

Systematic review registration

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

An Insight into the Development of Potential Antidiabetic Agents along with their Therapeutic Targets

Diabetes is a metabolic disorder that has been reported to increase the mortality rate worldwide. About 40 million people across the globe suffer from diabetes, with people living in developing countries being affected the most due to this deadly disease. Although the therapeutic management of hyperglycaemia can treat diabetes, metabolic disorders associated with this disease are a greater challenge in its treatment. Hence, potential strategies to treat hyperglycaemia and its side effects are needed. In this review, we have summarized several therapeutic targets, like dipeptidyl peptidase-4 (DPP-4), glucagon receptor antagonists, glycogen phosphorylase or fructose-1,6- biphosphatase inhibitors, SGLT inhibitors, 11beta-HSD-1 inhibitors, glucocorticoids receptor antagonists, glucose-6-phosphatase and glycogen phosphorylase inhibitors. These targets can help in designing and developing novel antidiabetic agents.

Usage of vildagliptin among patients with type 2 diabetes mellitus attending a public primary healthcare clinics in Kuala Selangor District, Selangor

INTRODUCTION

Studies showed that vildagliptin can lower HbA1c levels by 0.8%-1%. However, there is limited data looking at vildagliptin use among suburban populations. The efficacy of vildagliptin use may differ among different populations, especially those with low socio-economic status. Thus, this study aimed to assess the HbA1c reduction after vildagliptin initiation, treatment patterns and the reason for its initiation among patients with type 2 diabetes mellitus attending outpatient clinics in Kuala Selangor District, Selangor.

MATERIALS AND METHODS

This is a cross-sectional, retrospective study design. All patients who received vildagliptin in the Pharmacy Integrated Health System (PHIS) registry database from 2016 to 2021 were included as study samples. The exclusion criteria were being less than 18 years old and having type 1 diabetes mellitus. Patients' medical records were retrieved after sampling, and data were collected. One medical record was missing, thus SPSS analysis were performed on 144 vildagliptin users.

RESULTS

In total, 84 females (58.3%) and 60 males (41.7%) with a mean age of 62.1 (±10.1) years were analysed in this study. Mean HbA1c pre-therapy was 8.5 ± 2.1%; while posttherapy 6 months demonstrated a mean HbA1c of 7.9 ± 1.8%. Use of vildagliptin alone or as an adjunct was associated with a mean reduction of 0.6% in HbA1c (p = 0.01). Factors influencing this HbA1c reduction were advancing age, specifically individuals aged 62 years and older (p = 0.02), patients who are already receiving insulin therapy (p=0.00) and those who express a willingness to commence insulin treatment during the counselling session prior to initiating the treatment plan (p = 0.00). Reasons for vildagliptin initiation documented by prescribers were non-insulin acceptance (n = 59, 40.97%), frequent hypoglycaemia (n = 6, 4.1%) and non-compliance with medications (n = 23, 15.9%). There was no association between demographic, medical background and reason for starting vildagliptin variables and HbA1c reduction (p < 0.001).

CONCLUSION

This study showed that initiating vildagliptin alone or as an adjunct therapy significantly reduced HbA1c and is beneficial for uncontrolled diabetes patients. While advancing age, concurrent administration of insulin and the patients' willingness to accept insulin treatment prior to the commencement of therapy were the factors that influenced HbA1c reduction among patients receiving vildagliptin therapy, we recommend primary care providers prioritise all of the significant variables discovered before initiating vildagliptin for their patients.

Early treatment with dipeptidyl-peptidase 4 inhibitors reduces glycaemic variability and delays insulin initiation in type 2 diabetes: A propensity score-matched cohort study

AIMS

To examine whether early treatment intensification using dipeptidyl-peptidase 4 inhibitors (DPP4i) delays insulin initiation in Chinese patients diagnosed with type 2 diabetes for less than 5 years.

MATERIALS AND METHODS

In a territory-wide prospective cohort study, patients with type 2 diabetes initiating DPP4i at diabetes duration <2 years (early intensification) and 3-5 years (late intensification) were matched using 1:1 propensity-score matching (n = 908 in each arm). We used Cox regression to compare the risk of insulin initiation between the two groups. We explored the interactive and mediation effects of glycated haemoglobin (HbA1c) variability score (HVS), defined as the percentage of HbA1c varying by ≥0.5% compared with preceding values.

RESULTS

Of 1816 patients (60.7% men, mean age 54.4 ± 11.9 years), 92.4% and 71.9% were treated with metformin and sulphonylureas respectively at DPP4i initiation. Early DPP4i intensification [hazard ratio (HR) 0.71, (95% CI 0.58-0.68)] and low HVS (<50%) (HR = 0.40, 0.33-0.50) were associated with delayed insulin initiation during a median 4.08 years of follow-up. Early intensification with low HVS had the lowest risk versus late intensification with high HVS (HR = 0.30, 0.22-0.40) (pinteraction  = 0.013). HVS mediated 19.5% of the total effect of early DPP4i intensification on delaying insulin initiation. The late and early intensification groups had similar HbA1c at month 0 (8.4 ± 1.3% vs. 8.4 ± 1.5%) and month 3 (7.6 ± 1.2% vs. 7.6 ± 1.3%) after DPP4i initiation. By month 12, HbA1c in the late intensification group deteriorated (7.9 ± 1.4%) but remained stable in the early intensification group (7.6 ± 1.4%, p = 0.001) with persistent between-group difference over 72 months (8.2 ± 1.7% vs. 7.7 ± 1.6%, p = 0.001).

CONCLUSIONS

In type 2 diabetes, early DPP4i intensification delayed insulin initiation, partially explained by reduced glycaemic variability.

A Quantitative Systems Pharmacology Model of the Incretin Hormones GIP and GLP1, Glucagon, Glucose, Insulin, and the Small Molecule DPP-4 Inhibitor, Linagliptin

In the current study, we established a comprehensive quantitative systems pharmacology (QSP) model using linagliptin as the model drug, where drug disposition, drug intervention on dipeptidyl peptidase-4 (DPP-4), glucose-dependent insulinotropic peptide (GIP), Glucagon-like peptide-1 (GLP-1), glucagon, glucose, and insulin are integrated together with the cross talk and feedback loops incorporated among the whole glycemic control system. In the final linagliptin QSP model, the complicated disposition of linagliptin was characterized by a 2-compartment pharmacokinetic (PK) model with an enterohepatic cycling (EHC) component as well as target-mediated drug disposition (TMDD) processes occurring in both tissues and plasma, and the inhibitory effect of linagliptin on DPP-4 was determined by the linagliptin-DPP-4 complex in the central compartment based on target occupancy principle. The integrated GIP-GLP1-glucagon-glucose-insulin system contains five indirect response models as the "skeleton" structure with 12 feedback loops incorporated within the glucose control system. Our model adequately characterized the substantial nonlinear PK of linagliptin, time course of DPP-4 inhibition, as well as the kinetics of GIP, GLP-1, glucagon, and glucose simultaneously in humans. Our model provided valuable insights on linagliptin pharmacokinetics/pharmacodynamics and complicated glucose homeostasis. Since the glucose regulation modeling framework within the QSP model is "drug-independent", our model can be easily adopted by others to evaluate the effect of other DPP-4 inhibitors on the glucose control system. In addition, our QSP model, which contains more components than other reported glucose regulation models, can potentially be used to evaluate the effect of combination antidiabetic therapy targeting different components of glucose control system.

Stratified analysis in comparative effectiveness studies that emulate randomized trials

PURPOSE

For observational cohort studies that employ matching by propensity scores (PS), preliminary stratification by consequential predictors of outcome better emulates stratified randomization and potentially reduces variance and bias through relaxed dependence on modeling assumptions. We assessed the impact of pre-stratification in two real-life examples. For both, prior evidence from placebo-controlled randomized clinical trials (RCTs) suggested small or no risk reduction, but observational analysis suggested protection, presumably the result of confounding bias.

STUDY DESIGN AND SETTING

The study populations consisted of Medicare beneficiaries (2014-18) with type 2 diabetes initiating either (i) empagliflozin versus dipeptidyl peptidase-4 inhibitors (DPP-4i) or (ii) empagliflozin versus glucagon-like peptide-1 receptor agonists (GLP-1RA). The outcome was myocardial infarction or stroke. We estimated hazard ratios (HR) and rate differences (RD) after controlling for 143 pre-exposure covariates via 1:1 PS matching after (1) PS estimation in the total cohort (total-cohort PS-matching) and (2) PS estimation separately by baseline cardiovascular disease (stratified PS matching).

RESULTS

Stratified PS matching resulted in HRs that exceeded those from total-cohort PS-matching by 13% and 9%, respectively, for the comparisons of empagliflozin to DPP-4i and GLP-1RA. Against both comparators, HRs and RDs after stratified PS matching were closer to the null, with slightly higher variances (2%-3%) than those after total-cohort PS matching.

CONCLUSION

Stratified PS matching produced effect estimates closer to the expected trial findings than total-cohort PS matching. The price paid in increased variance was minimal.

Weight Loss-Independent Effect of Liraglutide on Insulin Sensitivity in Individuals With Obesity and Prediabetes

Metabolic effects of glucagon-like peptide 1 (GLP-1) receptor agonists are confounded by weight loss and not fully recapitulated by increasing endogenous GLP-1. We tested the hypothesis that GLP-1 receptor (GLP-1R) agonists exert weight loss-independent, GLP-1R-dependent effects that differ from effects of increasing endogenous GLP-1. Individuals with obesity and prediabetes were randomized to receive for 14 weeks the GLP-1R agonist liraglutide, a hypocaloric diet, or the dipeptidyl peptidase 4 (DPP-4) inhibitor sitagliptin. The GLP-1R antagonist exendin(9-39) and placebo were administered in a two-by-two crossover study during mixed-meal tests. Liraglutide and diet, but not sitagliptin, caused weight loss. Liraglutide improved insulin sensitivity measured by HOMA for insulin resistance (HOMA-IR), the updated HOMA model (HOMA2), and the Matsuda index after 2 weeks, prior to weight loss. Liraglutide decreased fasting and postprandial glucose levels, and decreased insulin, C-peptide, and fasting glucagon levels. In contrast, diet-induced weight loss improved insulin sensitivity by HOMA-IR and HOMA2, but not the Matsuda index, and did not decrease glucose levels. Sitagliptin increased endogenous GLP-1 and GIP values without altering insulin sensitivity or fasting glucose levels, but decreased postprandial glucose and glucagon levels. Notably, sitagliptin increased GIP without altering weight. Acute GLP-1R antagonism increased glucose levels in all groups, increased the Matsuda index and fasting glucagon level during liraglutide treatment, and increased endogenous GLP-1 values during liraglutide and sitagliptin treatments. Thus, liraglutide exerts rapid, weight loss-independent, GLP-1R-dependent effects on insulin sensitivity that are not achieved by increasing endogenous GLP-1.

ARTICLE HIGHLIGHTS

Metabolic benefits of glucagon-like peptide 1 (GLP-1) receptor agonists are confounded by weight loss and are not fully achieved by increasing endogenous GLP-1 through dipeptidyl peptidase 4 (DPP-4) inhibition. We investigated weight loss-independent, GLP-1 receptor (GLP-1R)-dependent metabolic effects of liraglutide versus a hypocaloric diet or the DPP-4 inhibitor sitagliptin. GLP-1R antagonism with exendin(9-39) was used to assess GLP-1R-dependent effects during mixed meals. Liraglutide improved insulin sensitivity and decreased fasting and postprandial glucose prior to weight loss, and these benefits were reversed by exendin(9-39). GLP-1R agonists exert rapid, weight loss-independent, GLP-1R-dependent effects on insulin sensitivity not achieved by increasing endogenous GLP-1.

Diabetic individuals with COVID-19 exhibit reduced efficacy of gliptins in inhibiting dipeptidyl peptidase 4 (DPP4). A suggested explanation for increased COVID-19 susceptibility in patients with type 2 diabetes mellitus (T2DM)

AIMS

Dipeptidyl peptidase 4 (DPP4) has been proposed as a coreceptor for SARS-CoV-2 cellular entry. Considering that type 2 diabetes mellitus (T2DM) has been identified as the most important risk factor for SARS-CoV-2, and that gliptins (DPP4 inhibitors) are a prescribed diabetic treatment, this study aims to unravel the impact of DPP4 in the intersection of T2DM/COVID-19.

MATERIALS AND METHODS

We analyzed 189 serum human samples, divided into six clinical groups (controls, T2DM, T2DM + gliptins, COVID-19, COVID-19 + T2DM, and COVID-19 + T2DM + gliptins), measuring DPP4 protein concentration and activity by Western blot, ELISA, and commercial activity kits. The obtained results were verified in Huh-7 cellular models.

KEY FINDINGS

Both DPP4 concentration and activity were decreased in COVID-19 patients, and as in T2DM patients, compared to controls. Despite these lower levels, the ratio of DPP4 activity/concentration in COVID-19 sera was the highest (0.782 ± 0.289 μU/ng vs. 0.547 ± 0.050 μU/ng in controls, p < 0.0001), suggesting a compensating mechanism in these patients. Supernatants of Huh-7 cells incubated with COVID-19 serum showed a consistent and significantly lower DPP4 concentration and activity. Furthermore, COVID-19 + T2DM + gliptins patients showed a higher serum DPP4 concentration and activity than T2DM + gliptin subjects (p < 0.05), indicating that sera from COVID-19 convalescents interfere with gliptins.

SIGNIFICANCE

Either SARS-CoV-2 or some metabolites present in the sera of COVID-19-convalescent patients interact with soluble DPP4 or even gliptins themselves since the inhibitory effect of gliptins on DPP4 activity is being prevented. The interactions between DPP4, gliptins, and SARS-CoV-2 should be further elucidated to reveal the mechanism of action for these interesting observations.

Comparison of teneligliptin and other gliptin-based regimens in addressing insulin resistance and glycemic control in type 2 diabetic patients: a cross-sectional study

INTRODUCTION

The objective of this study was to compare the effects of teneligliptin-based regimens and other gliptin-based regimens with respect to insulin resistance and glycemic control in patients with type 2 diabetes mellitus (T2DM).

METHODS

We enrolled T2DM subjects, inadequately controlled with metformin and glimepiride and taking one of the gliptins, and divided them into two groups, i.e. group 1 (teneligliptin-based regimens) and group 2 (other gliptin-based regimens). Fasting plasma insulin, adiponectin levels, homeostatic model assessment for insulin resistance (HOMA-IR), glycated hemoglobin (HbA1c), and fasting blood glucose (FBG) were measured and compared. Costs of different gliptins were noted, and mean cost of per day therapy was compared.

RESULTS

Eighty-six subjects participated in this study (43 each in group 1 and group 2). No significant differences were observed in FBG, HbA1c, insulin levels, and HOMA-IR, but the trend was in favor of teneligliptin-based regimens. A significantly higher number of subjects achieved HbA1c target in group 1 (P < 0.001). Teneligliptin had significantly lower cost of per day therapy as compared to other dipeptidyl peptidase-4 inhibitors.

CONCLUSION

Teneligliptin seems to be cost-effective and safer option in T2DM subjects who were not adequately controlled with metformin and sulfonylureas. However, further prospective studies are needed.

Favorable effect of CD26/DPP-4 inhibitors on postoperative outcomes after lung transplantation: A propensity-weighted analysis

BACKGROUND

We have shown the efficacy of CD26/dipeptidyl peptidase 4 (CD26/DPP-4) inhibitors, antidiabetic agents, in allograft protection after experimental lung transplantation (LTx). We aimed to elucidate whether CD26/DPP-4 inhibitors effectively improve postoperative outcomes after clinical LTx.

METHODS

We retrospectively reviewed the records of patients undergoing LTx at our institution between 2010 and 2021 and extracted records of patients with diabetes mellitus (DM) at 6 months post-LTx. The patient characteristics and postoperative outcomes were analyzed. We established 6 months post-LTx as the landmark point for predicting overall survival (OS) and chronic lung allograft dysfunction (CLAD)-free survival. Hazard ratios were estimated by Cox regression after propensity score weighting, using CD26/DPP-4 inhibitor treatment up to 6 months post-LTx as the exposure variable. We evaluated CLAD samples pathologically, including for CD26/DPP-4 immunohistochemistry.

RESULTS

Of 102 LTx patients with DM, 29 and 73 were treated with and without CD26/DPP-4 inhibitors, respectively. Based on propensity score adjustment using standardized mortality ratio weighting, the 5-year OS rates were 77.0% and 44.3%, and the 5-year CLAD-free survival rates 77.8% and 49.1%, in patients treated with and without CD26/DPP-4 inhibitors, respectively. The hazard ratio for CD26/DPP-4 inhibitor use was 0.34 (95% confidence interval (CI) 0.14-0.82, p = 0.017) for OS and 0.47 (95% CI 0.22-1.01, p = 0.054) for CLAD-free survival. We detected CD26/DPP-4 expression in the CLAD grafts of patients without CD26/DPP-4 inhibitors.

CONCLUSIONS

Analysis using propensity score weighting showed that CD26/DPP-4 inhibitors positively affected the postoperative prognosis of LTx patients with DM.

[Features of the course of COVID-19 in patients with type 2 diabetes mellitus]

AIM

To identify the features of the course of COVID-19 in patients with type 2 diabetes mellitus (T2DM), depending on the intake of hypoglycemic therapy at the prehospital stage, in conjunction with the functional state of the kidneys.

MATERIALS AND METHODS

A retrospective analysis of 291 case histories of patients with COVID-19 and T2DM hospitalized in the infection department of Semashko Regional Clinical Hospital from January to December 2021, including the main clinical and laboratory parameters. Results. Among hospitalized patients with COVID-19, patients with T2DM had a higher mortality rate. An analysis of the case histories of deceased patients with COVID-19 and T2DM showed that at admission, body mass index (BMI), C-reactive protein, and creatinine were higher than those of survivors and amounted to BMI - 33 [30; 39] and 33 [28; 36] kg/m3; p=0.039, C-reactive protein - 77 [47.5; 106.0] and 57 [27.0; 89.0] mg/l; p=0.015, in terms of creatinine level - 89 [70.0; 144.0] and 82 [66.0; 101.0] µmol/l; p=0.039, respectively. It was found that in the second week of hospitalization in the group of deceased patients with COVID-19 and T2DM, the creatinine level was statistically significantly higher than in surviving patients and amounted to 94.5 [71.5; 141.0] and 72.5 [57.0; 88.0] µmol/L; p<0.001, respectively. The probability of death in hospitalized patients with type 2 COVID-19 and T2DM depended on BMI and creatinine levels at the second week of hospitalization. Patients with prehospital correction of hyperglycemia dipeptidyl peptidase-4 inhibitors (iDPP-4)/ glucagon-like peptide-1 receptor agonists (agGLP-1)/ sodium-glucose co-transporter 2 inhibitors (iSGLT-2) had significantly lower creatinine levels at week 2 of hospitalization.

CONCLUSION

In patients with moderate to severe COVID-19 with concomitant T2DM, special attention should be paid to the combination of high BMI and creatinine in the second week of hospitalization, which is a prognostically unfavorable predictor of death in such patients.

Use of dipeptidyl peptidase-4 inhibitors was associated with a lower risk of Parkinson's disease in diabetic patients

Diabetes mellitus is a risk factor for Parkinson's disease (PD). While animal studies have supported the benefits of incretin-based therapies, including dipeptidyl peptidase-4 (DPP4) inhibitors, in PD, clinical research has yielded controversial results. This cohort study aimed to assess the relationship between PD incidence and the utilization of DPP4 inhibitor in diabetic patients. Using Taiwan's National Health Insurance Research Database from 2009 to 2018, diabetic patients receiving metformin plus at least one second-line oral antidiabetic (OAD) were enrolled. The patients were categorized as DPP4 inhibitor users and non-users. Propensity score matching was employed to establish a 1:1 ratio between DPP4 inhibitor users and non-users. Among the 205,910 patients enrolled, 149 were diagnosed with PD during follow-up. The incidence rate was 0.29 per 1000 person-years for DPP4 inhibitor users and 0.55 per 1000 person-years for the non-users. DPP4 inhibitor users exhibited a significantly lower risk of PD (adjusted hazard ratio, 0.51; 95% CI 0.39-0.68). Among DPP4 inhibitor users, vildagliptin showed the strongest correlation with a reduction in the risk of PD. This study demonstrates that the use of DPP4 inhibitors along with metformin in diabetic patients is associated with a lower risk of PD compared to those using other OADs.

Dipeptidyl peptidase-4 inhibitors alleviate cognitive dysfunction in type 2 diabetes mellitus

BACKGROUND

Patients with type 2 diabetes mellitus (T2DM) are commonly at high risk for developing cognitive dysfunction. Antidiabetic agents might be repurposed for targeting cognitive dysfunction in addition to modulation on glucose homeostasis. This study aimed to evaluate the impact of dipeptidyl peptidase-4 inhibitors (DPP-4i) on cognitive function in T2DM.

METHODS

PubMed, Embase, Cochrane Library and Web of Science were systematically searched from inception to September 30, 2023. Weighted mean differences were calculated using the Mantel-Haenszel (M-H) fixed or random effects model based on the degree of heterogeneity among studies. Heterogeneity was evaluated using a Chi-squared test and quantified with Higgins I2. Sensitivity analysis was performed with the leave-one-out method, and publication bias was evaluated according to Begg's and Egger's tests.

RESULTS

Six clinical trials involving 5,178 participants were included in the pooled analysis. Administration of DPP-4i generally correlated with an increase of Mini-Mental State Examination (MMSE) scores (1.09, 95% CI: 0.22 to 1.96). DPP-4i alleviated cognitive impairment in the copying skill subdomain of MMSE (0.26, 95% CI: 0.12 to 0.40). Treatment with DPP-4i also resulted in an increase of Instrumental Activities of Daily Living (IADL) scores (0.82, 95% CI: 0.30 to 1.34). However, DPP-4i produced no significant effects on Barthel Activities of Daily Living (BADL) scores (0.37, 95% CI: -1.26 to 1.99) or other test scores.

CONCLUSIONS

DPP-4i treatment favourably improved cognitive function in patients with T2DM. Further trials with larger samples should be performed to confirm these estimates and investigate the association of different DPP-4i with cognitive function among diabetic patients.

TRIAL REGISTRATION IN PROSPERO

CRD42023430873.

The effect of gemigliptin treatment on immune parameters including regulatory T cells in patients with type 2 diabetes and moderate to very severe chronic renal impairment

It is crucial to understand the impact of DPP-4 inhibitors on the immune system, particularly T cell differentiation, maturation, and proliferation, in patients with type 2 diabetes and CKD. This prospective observational study aimed to investigate the distribution of immune cells (particularly regulatory T cells), following the administration of gemigliptin, a DPP-4 inhibitor, in patients with type 2 diabetes mellitus and chronic kidney disease. We enrolled 28 patients with type 2 diabetes, aged 20 to 69, who had been taking a daily dose of 50mg gemigliptin for <3 months and had chronic kidney disease stages 3, 4, or 5, including that undergoing dialysis. T regulatory cells were defined as CD4 + CD25 high CD127 low/- FoxP3 + phenotype, and flow cytometry was used to examine the distribution of T regulatory cells. In the patient group, blood samples were collected at baseline, as well as at 3 and 6 months after initiating medication. Of the 28 patients, 17 (60.7%) were male and the mean age was 61.82 ± 8.03 years. Serum Cr ≥ 1.5 mg/dL was 16 (57%), and Cr < 1.5 mg/dL was 12 (43%). The number of CD4(+)/CD25(+) cells did not significantly increase or decrease in baseline, 3 months, and 6 months time changes, and the number of CD127(-/FoxP3(+) cells did not change significantly. Treatment with gemigliptin for 3 and 6 months did not significantly alter the number, percentage, or ratio of circulating Treg cells in patients with type 2 diabetes and CKD. Therefore, the administration of gemigliptin may help maintain regulatory T cells or have no significant impact.

Tetrazoles and Related Heterocycles as Promising Synthetic Antidiabetic Agents

Tetrazole heterocycle is a promising scaffold in drug design, and it is incorporated into active pharmaceutical ingredients of medications of various actions: hypotensives, diuretics, antihistamines, antibiotics, analgesics, and others. This heterocyclic system is metabolically stable and easily participates in various intermolecular interactions with different biological targets through hydrogen bonding, conjugation, or van der Waals forces. In the present review, a systematic analysis of the activity of tetrazole derivatives against type 2 diabetes mellitus (T2DM) has been performed. As it was shown, the tetrazolyl moiety is a key fragment of many antidiabetic agents with different activities, including the following: peroxisome proliferator-activated receptors (PPARs) agonists, protein tyrosine phosphatase 1B (PTP1B) inhibitors, aldose reductase (AR) inhibitors, dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide 1 (GLP-1) agonists, G protein-coupled receptor (GPCRs) agonists, glycogen phosphorylases (GP) Inhibitors, α-glycosidase (AG) Inhibitors, sodium glucose co-transporter (SGLT) inhibitors, fructose-1,6-bisphosphatase (FBPase) inhibitors, IkB kinase ε (IKKε) and TANK binding kinase 1 (TBK1) inhibitors, and 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). In many cases, the tetrazole-containing leader compounds markedly exceed the activity of medications already known and used in T2DM therapy, and some of them are undergoing clinical trials. In addition, tetrazole derivatives are very often used to act on diabetes-related targets or to treat post-diabetic disorders.

Gemigliptin, a DPP4 inhibitor, ameliorates nonalcoholic steatohepatitis through AMP-activated protein kinase-independent and ULK1-mediated autophagy

OBJECTIVE

Abnormal autophagic function and activated inflammasomes are typical features in the liver of patients with non-alcoholic steatohepatitis (NASH). Here, we explored whether gemigliptin, a dipeptidyl peptidase 4 (DPP4) inhibitor for treatment of type 2 diabetes, can induce autophagy and regulate inflammasome activation as a potential NASH treatment independent of its anti-diabetic effect.

METHODS

Expression analysis was performed using human liver samples obtained from 18 subjects who underwent hepatectomy. We explored the function and mechanism of gemigliptin using a methionine- and choline-deficient diet (MCD)-induced NASH mouse model and HepG2 cells cultured in MCD-mimicking medium.

RESULTS

Autophagy was suppressed by marked decreases in the expression of ULK1 and LC3II/LC3I ratio in human NAFLD/NASH patients, a NASH mouse model, and HepG2 cells cultured with MCD-mimicking media. Surprisingly, we found that the expression of p-AMPK decreased in liver tissues from patients with steatosis but was restored in NASH patients. The expression of p-AMPK in the NASH mouse model was similar to that of the control group. Hence, these results indicate that autophagy was reduced in NASH via an AMPK-independent pathway. However, gemigliptin treatment attenuated lipid accumulation, inflammation, and fibrosis in the liver of MCD diet-fed mice with restoration of ULK1 expression and autophagy induction. In vitro, gemigliptin alleviated inflammasome activation through induction of ULK1-dependent autophagy. Furthermore, gemigliptin treatment upregulated ULK1 expression and activated AMPK even after siRNA-mediated knockdown of AMPKα1/2 and ULK1, respectively.

CONCLUSIONS

Collectively, these results suggest that gemigliptin ameliorated NASH via AMPK-independent, ULK1-mediated effects on autophagy.

Efficacy and Safety of Switching from Sitagliptin to Ipragliflozin in Obese Japanese Patients with Type 2 Diabetes Mellitus: A Single-Arm Multicenter Interventional Study

BACKGROUND

Dipeptidyl peptidase-4 inhibitors have limited efficacy in improving glycemic control for obese Japanese patients with type 2 diabetes mellitus. Sodium-glucose co-transporter 2 inhibitors are recommended for use in patients with type 2 diabetes with obesity. Nevertheless, there has been no previously published study on the effect of switching from dipeptidyl peptidase-4 inhibitors to sodium-glucose co-transporter 2 inhibitors on the systemic and organic effects in obese Japanese patients with type 2 diabetes.

OBJECTIVES

We evaluated the efficacy and safety of switching from sitagliptin to ipragliflozin for 24 weeks in obese Japanese patients with inadequately controlled type 2 diabetes.

METHODS

Fifty-one obese patients with type 2 diabetes (body mass index > 25 kg/m2) treated with sitagliptin (50 mg) and metformin but with inadequate glycemic control (glycosylated hemoglobin [HbA1c] > 7.5% and < 9.0%) were enrolled. After a 4-week observation period, sitagliptin was switched to ipragliflozin (50 mg) for 24 weeks. The primary outcome was the change in HbA1c from baseline to the end of treatment. The secondary outcomes were changes in clinical characteristics and other biochemical variables.

RESULTS

Fifty-one patients with an average HbA1c of 8.37 ± 0.48% and body mass index of 28.8 ± 3.8 kg/m2 were enrolled. Fifty patients completed the study, one patient stopped ipragliflozin at 4 weeks because of the development of hyperosmolar hyperglycemic syndrome. No significant change in HbA1c from baseline to the end of treatment was observed (- 0.02 ± 0.75%). However, fasting plasma glucose was reduced (- 16.2 ± 28.4 mg/dL, p < 0.001), and biochemical variables associated with insulin resistance, oxidative stress, and hepatic and renal functions showed significant improvements. No severe adverse effects were observed, except in the one aforementioned case.

CONCLUSIONS

Switching from sitagliptin to ipragliflozin did not alter HbA1c in obese patients with type 2 diabetes, while improving parameters related to organ homeostasis. These data provide novel information useful for selecting oral anti-diabetic agents for patients with type 2 diabetes with obesity, a risk factor for developing various complications of diabetes.

CLINICAL TRIAL REGISTRATION

Japan Registry of Clinical Trials identifier: jRCT#031190022.

SGLT2 and DPP4 inhibitors improve Alzheimer's disease-like pathology and cognitive function through distinct mechanisms in a T2D-AD mouse model

Alzheimer's disease (AD) and type 2 diabetes mellitus (T2D) share common features, including insulin resistance. Brain insulin resistance has been implicated as a key factor in the pathogenesis of AD. Recent studies have demonstrated that anti-diabetic drugs sodium-glucose cotransporter-2 inhibitor (SGLT2-i) and dipeptidyl peptidase-4 inhibitor (DPP4-i) improve insulin sensitivity and provide neuroprotection. However, the effects of these two inhibitors on the brain metabolism and insulin resistance remain uninvestigated. We developed a T2D-AD mouse model using a high-fat diet (HFD) for 19 weeks along with a single dose of streptozotocin (100 mg/kg, intraperitoneally) at the fourth week of HFD initiation. Subsequently, the animals were treated with SGLT2-i (empagliflozin, 25 mg/kg/day orally [p.o.]) and DPP4-i (sitagliptin, 100 mg/kg/day p.o.) for 7 weeks. Subsequently, behavioral tests were performed, and the expression of insulin signaling, AD-related, and other signaling pathway proteins in the brain were examined. T2D-AD mice not only showed increased blood glucose levels and body weight but also insulin resistance. SGLT2-i and DPP4-i effectively ameliorated insulin sensitivity and reduced body weight in these mice. Furthermore, SGLT2-i and DPP4-i significantly improved hippocampal-dependent learning, memory, and cognitive functions in the T2D-AD mouse model. Interestingly, SGLT2-i and DPP4-i reduced the hyperphosphorylated tau (pTau) levels and amyloid β (Aβ) accumulation and enhanced brain insulin signaling. SGLT2-i reduced pTau accumulation through the angiotensin converting enzyme-2/angiotensin (1-7)/ mitochondrial assembly receptor axis, whereas DPP4-i reduced Aβ accumulation by increasing insulin-degrading enzyme levels. These findings suggest that SGLT2-i and DPP4-i prevent AD-like pathology and cognitive dysfunction in T2D mice potentially through affecting brain insulin signaling via different mechanisms.

Immunomodulatory activity of dipeptidyl peptidase-4 inhibitors in immune-related diseases

Dipeptidyl peptidase-4 (DPP-4), also known as CD26, is a 110-kDa cell surface glycoprotein with enzymatic and signal transducing activity. DPP-4/CD26 is expressed by various cells, including CD4+ and CD8+ T cells, B cells, dendritic cells, macrophages, and NK cells. DPP-4 inhibitors (DPP-4i) were introduced to clinics in 2006 as new oral antihyperglycemic drugs approved for type 2 diabetes mellitus treatment. In addition to glucose-lowering effects, emerging data, from clinical studies and their animal models, suggest that DPP-4i could display anti-inflammatory and immunomodulatory effects as well, but the molecular and immunological mechanisms of these actions are insufficiently investigated. This review focuses on the modulatory activity of DPP-4i in the immune system and the possible application of DPP-4i in other immune-related diseases in patients with or without diabetes.

Treatment modification after initiating second-line medication for type 2 diabetes

OBJECTIVES

To describe changes in antidiabetic medication (ADM) use and characteristics associated with changes in ADM use after initiation of noninsulin second-line therapy.

STUDY DESIGN

Retrospective cohort study.

METHODS

This study analyzed private health plan claims for adults with type 2 diabetes who initiated 1 of 5 index ADM classes: sulfonylureas, dipeptidyl peptidase 4 inhibitors (DPP4is), sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1 RAs), or thiazolidinediones. Analyses evaluated 3 treatment modification outcomes-discontinuation, switching, and intensification-over 12-month follow-up.

RESULTS

Of 82,624 included adults, nearly two-thirds (63.6%) experienced any treatment modification. Discontinuation was the most common modification (38.6%), especially among patients prescribed GLP-1 RAs (50.3%). Switching occurred in 5.2% of patients and intensification in 19.8%. In adjusted analysis, compared with patients prescribed sulfonylureas, discontinuation risk was 7% higher (HR, 1.07; 95% CI, 1.04-1.10) among patients prescribed DPP4is and 28% higher (HR, 1.28; 95% CI, 1.23-1.33) among patients prescribed GLP-1 RAs. Compared with sulfonylureas, all other index ADM classes had higher risks of switching and lower risks of intensification. Younger age group and female sex were both associated with higher risks of all modifications. Compared with index ADM prescription by a family medicine or internal medicine physician, index prescription by an endocrinologist was associated with both lower discontinuation risk and higher intensification risk.

CONCLUSIONS

Most patients experienced a treatment modification within 1 year. Results highlight the need for new prescribing approaches and patient supports that can maximize medication adherence and reduce health system waste.

Outcomes of SGLT-2i and GLP-1RA Therapy Among Patients With Type 2 Diabetes and Varying NAFLD Status

Importance

Nonalcoholic fatty liver disease (NAFLD) is a cardiovascular risk factor, but whether sodium-glucose cotransporter-2 inhibitors (SGLT-2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) are associated with reduced cardiovascular risk in patients with type 2 diabetes (T2D) and concomitant NAFLD remains uncertain.

Objective

To investigate the outcomes of SGLT-2i and GLP-1RA therapy among patients with T2D varied by the presence or absence of NAFLD.

Design, Setting, and Participants

This retrospective, population-based, nationwide cohort study used an active-comparator new-user design. Two distinct new-user active-comparator cohorts of patients aged 40 years and older who initiated SGLT-2i or GLP-1RA were propensity score matched to patients who initiated dipeptidyl peptidase-4 inhibitors (DPP-4i). The study was conducted in South Korea from January 2013 to December 2020, and data analysis was conducted from October 2022 to March 2023.

Main Outcomes and Measures

The main outcomes were (1) major adverse cardiovascular events (MACE), a composite end point of hospitalization for myocardial infarction, hospitalization for stroke, and cardiovascular death, and (2) hospitalization for heart failure (HHF). Cox proportional hazards models were used to estimate hazard ratios (HRs). The Wald test was applied to assess heterogeneity by NAFLD.

Results

After 1:1 propensity score matching, 140 438 patients were retrieved in the first cohort (SGLT-2i vs DPP-4i; mean [SD] age, 57.5 [10.3] years; 79 633 [56.7%] male) and 34 886 patients were identified in the second cohort (GLP-1RA vs DPP-4i; mean [SD] age, 59.5 [10.5] years; 17 894 [51.3%] male). Compared with DPP-4i, SGLT-2i therapy was associated with a lower risk of MACE (HR, 0.78 [95% CI, 0.71-0.85]) and HHF (HR, 0.62 [95% CI, 0.48-0.81]). GLP-1RA therapy was associated with a decreased risk of MACE (HR, 0.49 [95% CI, 0.39-0.62]) but had statistically nonsignificant findings regarding HHF (HR, 0.64 [95% CI, 0.39-1.07]). Stratified analysis by NAFLD status yielded consistent results for SGLT-2i (MACE with NAFLD: HR, 0.73 [95% CI, 0.62-0.86]; without NAFLD: HR, 0.81 [95% CI, 0.72-0.91]; HHF with NAFLD: HR, 0.76 [95% CI, 0.49-1.17]; without NAFLD: HR, 0.56 [95% CI, 0.40-0.78]) and for GLP-1RA (MACE with NAFLD: HR, 0.49 [95% CI, 0.32-0.77]; without NAFLD: HR, 0.49 [95% CI, 0.37-0.65]; HHF with NAFLD: HR, 0.82 [95% CI, 0.38-1.76]; without NAFLD: HR, 0.54 [95% CI, 0.27-1.06]).

Conclusions and Relevance

In this population-based cohort study, SGLT-2i therapy was associated with a decreased risk of MACE and HHF, while GLP-1RA therapy was associated with a decreased risk of MACE among patients with T2D, irrespective of baseline NAFLD status.

Post-initiation predictors of discontinuation of the sodium-glucose cotransporter-2 inhibitors: A comparative cohort study from the United Kingdom

AIMS

To assess post-initiation predictors of discontinuation of sodium-glucose cotransporter-2 (SGLT2) inhibitors compared to dipeptidyl-peptidase-4 (DPP-4) inhibitors in the United Kingdom.

MATERIALS AND METHODS

We conducted a comparative population-based retrospective cohort study using primary care data from the UK Clinical Practice Research Datalink (CPRD) with linked data to hospital and death records. We included new metformin users who initiated either SGLT2 inhibitors or DPP-4 inhibitors between January 2013 and October 2019. The main outcome was treatment discontinuation, defined as the first 90-day gap after the estimated treatment end date. We used a series of extended Cox models to assess which time-dependent predictors were associated with treatment discontinuation. To test if the hazard ratio of discontinuation for each predictor was statistically different between SGLT2 and DPP-4 inhibitors, an exposure-predictor interaction term was added to each model.

RESULTS

There were 2550 new users of SGLT2 inhibitors and 8195 new users of DPP-4 inhibitors. Approximately 69% of SGLT2 inhibitor and 74% of DPP-4 inhibitor users had discontinued treatment by the end of follow-up. Occurrence of fractures after treatment initiation was a significant predictor of discontinuation of SGLT2 inhibitors (hazard ratio [HR] 4.13, 95% confidence interval [CI] 2.12-8.06) but not DPP-4 inhibitors (HR 0.93, 95% CI 0.79-1.11). The rate of treatment discontinuation was significantly higher for those with low estimated glomerular filtration rate and minimal contact with the healthcare system. Efficacy endpoints, such as heart failure and glycated haemoglobin level, were not associated with treatment discontinuation.

CONCLUSIONS

Our findings reflect some discrepancy between the available evidence and prescribing behaviour for SGLT2 inhibitors.

Predictors of HbA1c treatment response to add-on medication following metformin monotherapy: a population-based cohort study

Evidence on the influence of patient characteristics on HbA1c treatment response for add-on medications in patients with type 2 diabetes (T2D) is unclear. This study aims to investigate the predictors of HbA1c treatment response for three add-on medications (sulfonylureas (SU), dipeptidyl peptidase-4 (DPP-4) and sodium-glucose cotransporter-2 (SGLT-2) inhibitor) in metformin monotherapy treated patients with T2D. This retrospective cohort study was conducted using the electronic health record data from six primary care clinics in Singapore. A total of 9748 adult patients with T2D on metformin monotherapy receiving SU, DPP-4 or SGLT-2 add-on were 1:1 propensity score matched to patients receiving other add-on medications. Patient demographics, laboratory results, diabetes related complications, comedications, and treatment response at two endpoints (HbA1c reduction ≥ 1% at 6th month, HbA1c goal attainment < 7% at 12th month) were examined. Multiple logistic regression analyses were used to identify patient characteristics associated with the treatment responses. After matching, there were 1073, 517, and 290 paired cohorts of SU, DPP-4 and SGLT-2 respectively. Besides baseline HbA1c, patients with longer hypertension disease duration and higher cholesterol HDL were associated with better treatment response to SU medication add-on. Lower estimated glomerular filtration rate (eGFR), and angiotensin-II receptor medications were associated with better treatment response to DPP-4 add-on. Lower cholesterol HDL, higher creatinine serum, absence of renal complications and beta-blockers medications were associated with better treatment response to SGLT-2 add-on. The cholesterol HDL, creatinine serum, eGFR, hypertension disease duration, angiotensin-II receptors and beta-blockers class of medications can influence the HbA1c treatment response for SU, DPP-4 and SGLT-2 add-on medications. Knowing the patients' characteristics that influence treatment response can assist in guiding clinical decisions when selecting the appropriate add-on medication, ultimately helping to prevent the development of diabetes-related complications.

From Molecular Insights to Clinical Perspectives in Drug-Associated Bullous Pemphigoid

Bullous pemphigoid (BP), the most common autoimmune blistering disease, is characterized by the presence of autoantibodies targeting BP180 and BP230 in the basement membrane zone. This leads to the activation of complement-dependent and independent pathways, resulting in proteolytic cleavage at the dermoepidermal junction and an eosinophilic inflammatory response. While numerous drugs have been associated with BP in the literature, causality and pathogenic mechanisms remain elusive in most cases. Dipeptidyl peptidase 4 inhibitors (DPP4i), in particular, are the most frequently reported drugs related to BP and, therefore, have been extensively investigated. They can potentially trigger BP through the impaired proteolytic degradation of BP180, combined with immune dysregulation. DPP4i-associated BP can be categorized into true drug-induced BP and drug-triggered BP, with the latter resembling classic BP. Antineoplastic immunotherapy is increasingly associated with BP, with both B and T cells involved. Other drugs, including biologics, diuretics and cardiovascular and neuropsychiatric agents, present weaker evidence and poorly understood pathogenic mechanisms. Further research is needed due to the growing incidence of BP and the increasing identification of new potential triggers.