An abnormal increase in CD26(-)CD28(-) cytotoxic effector CD4 and CD8 T cell populations in patients with systemic lupus erythematosus.

CD26 is a human T cell costimulatory molecule as well as a T cell subset marker, and increase of CD26+ T cells in inflamed tissues and peripheral blood has been reported in diverse autoimmune diseases. In contrast, our group has previously shown that levels of circulating CD26+ T cells are decreased in patients with systemic lupus erythematosus (SLE), although the role of reduced CD26 T cell surface expression in SLE pathology remains to be elucidated. In the present study, we conducted CD26-based T cell subset analyses utilizing peripheral blood mononuclear cells from 57 SLE patients and 31 healthy adult volunteers. We show that the increase in CD26(-) T cell population reflects the abnormal expansion of CD26(-)CD28(-) cytotoxic subsets of both CD8 T cells and CD4 T cells in SLE patients. Single cell RNA sequencing analysis of the CD26(-)CD28(-) CD4 and CD8 T cell populations reveals unique characteristics with similarities to natural killer T cells. In addition, the level of CD26(-)CD28(-) T cells is increased in some active stage SLE patients with renal manifestation. Meanwhile, effect of prednisolone treatment on these populations varies from patient to patient, with levels of these cytotoxic effector populations still being elevated in some inactive stage SLE patients. Taken together, our data suggest that analysis of these populations in SLE may be a useful tool to classify this markedly heterogeneous condition.

Hepatoprotective effects of vildagliptin mitigates lung biochemical and histopathological changes in experimental hepatopulmonary syndrome model in rat.

Hepatopulmonary syndrome (HPS) is a liver disease-induced pulmonary complication manifested with arterial hypoxemia. Hepatic cholestasis, encountered in several clinical situations, leads to biliary cirrhosis and HPS, both of which are best reproduced by rat common bile duct ligation (CBDL). Experience from liver transplantation suggests hepatoprotective-based therapy would be most effective in HPS treatment Dipeptidyl peptidase-4 (DPP-4) enzyme is involved in different pathogenic mechanisms of liver diseases. Vildagliptin (Vild) is a DPP-4 inhibitor which possesses favorable anti-inflammatory, anti-oxidant and anti-fibrotic effects. The present work explored hepatoprotective mechanisms of Vild and their participation in its prophylactic effectiveness in HPS induced by CBDL in rats. Male Wistar rats weighing 220-280 g were allocated into 4 groups: normal control, sham, CBDL and CBDL + Vild groups. i.p. saline was administered to the first 3 groups and i.p. Vild (10 mg/kg/day) was given to the fourth group for 6 weeks starting 2 week before CBDL. CBDL produced liver fibrosis, arterial hypoxemia and decreased survivability of rats. It altered liver functions and induced oxidative stress, pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6)], vasodilatory molecules [endothelin-1 (ET-1), and inducible and endothelial nitric oxide synthases] and angiogenesis-associated protein [vascular endothelial growth factor-A (VEGF-A)] in liver and lung. Vild ameliorated liver fibrosis, and improved hypoxemia and survivability of CBDL rats and reversed these biochemical alterations. Prophylactic Vild administration attenuated CBDL-induced HPS in rats via direct hepatoprotective effects in the form of anti-oxidant, anti-inflammatory, anti-angiogenic and anti-fibrotic effects beside inhibition of pathological intrahepatic vasodilatation.

Association between incretin-based drugs and risk of cholangiocarcinoma among patients with type 2 diabetes: A large population-based matched cohort study.

Aim: To examine the association between the use of incretin-based drugs [glucagon-like peptide-1 receptor agonists (GLP-1RAs), dipeptidyl peptidase-4 inhibitors (DPP-4Is)] and the risk of cholangiocarcinoma (CCA) in the United States. Methods: This large population-based, retrospective cohort study using the TriNetX datasets included adult patients with type 2 diabetes mellitus (T2DM) who were new users of GLP-1RAs, DPP-4Is, or other second- or third-line antidiabetic drugs between 2010 and 2021. The primary outcome was the incidence of CCA. Results: A total of 3,816,071 patients were included (mean age, 61.4 years, female, 49.3 %). A 51 % and 23 % risk reduction in CCA after 1 year of exposure to GLP-1RAs (hazard ratio 0.49; 95 % CI 0.40-0.60) and DPP4Is (0.77, 95 % CI 0.67-0.90), respectively compared to new second-or third-line users. Results were consistent at 3, 5, and 7 years of follow-up (0.66, 0.71, and 0.72 for GLP-1RAs and 0.84, 0.87, and 0.85 for DPP-4Is, respectively). Compared to new metformin users, GLP-1RA users were associated with a 42 % lower risk of developing CCA, whereas DPP-4I group was not associated with an increased risk. Conclusions: GLP-1RAs and DPP-4Is were not associated with a significantly increased risk of CCA. GLP-1RAs even showed a reduced risk of CCA development. They can be considered as safe and effective treatment options for patients with T2DM at risk of CCA.

Sodium-dependent glucose transporter 2 inhibitors effects on myocardial function in patients with type 2 diabetes and asymptomatic heart failure.

BACKGROUND: Sodium-dependent glucose transporter 2 inhibitors (SGLT2i) have shown efficacy in reducing heart failure (HF) burden in a very heterogeneous groups of patients, raising doubts about some contemporary assumptions of their mechanism of action. We previously published a prospective observational study that evaluated mechanisms of action of SGLT2i in patients with type 2 diabetes who were in HF stages A and B on dual hypoglycemic therapy. Two groups of patients were included in the study: the ones receiving SGLT2i as an add-on agent to metformin and the others on dipeptidyl peptidase-4 inhibitors as an add-on to metformin due to suboptimal glycemic control. AIM: To evaluate the outcomes regarding natriuretic peptide, oxidative stress, inflammation, blood pressure, heart rate, cardiac function, and body weight. METHODS: The study outcomes were examined by dividing each treatment arm into two subgroups according to baseline parameters of global longitudinal strain (GLS), N-terminal pro-brain natriuretic peptide, myeloperoxidase (MPO), high-sensitivity C-reactive protein (hsCRP), and systolic and diastolic blood pressure. To evaluate the possible predictors of observed changes in the SGLT2i arm during follow-up, a rise in stroke volume index, body mass index (BMI) decrease, and lack of heart rate increase, linear regression analysis was performed. RESULTS: There was a greater reduction of MPO, hsCRP, GLS, and blood pressure in the groups with higher baseline values of mentioned parameters irrespective of the therapeutic arm after 6 months of follow-up. Significant independent predictors of heart rate decrease were a reduction in early mitral inflow velocity to early diastolic mitral annular velocity at the interventricular septal annulus ratio and BMI, while the predictor of stroke volume index increase was SGLT2i therapy itself. CONCLUSION: SGLT2i affect body composition, reduce cardiac load, improve diastolic/systolic function, and attenuate the sympathetic response. Glycemic control contributes to the improvement of heart function, blood pressure control, oxidative stress, and reduction in inflammation.

A Systematic Approach to Evaluating Instrumental Variable Assumptions: Applied Example of Glucose-lowering Medications and Risk for Hospitalized Heart Failure in Older Adults.

One obstacle to adopting instrumental variable (IV) methods in pharmacoepidemiology is their reliance on strong, unverifiable assumptions. We can falsify IV assumptions by leveraging the causal structure, which can strengthen or refute their plausibility and increase the validity of effect estimates. We illustrate a systematic approach to evaluate calendar time IV assumptions in estimating the known effect of thiazolidinediones on hospitalized heart failure. Using cohort entry time before and after 09/2010, when the U.S. Food and Drug Administration issued a safety communication as a proposed IV, we estimated IV and propensity score-weighted 2-year risk differences (RDs) using Medicare data (2008-2014). We (i) performed inequality tests, (ii) identified the negative control IV/outcome using causal assumptions, (iii) estimated RDs after narrowing the calendar time range and excluding patients likely associated with unmeasured confounding, (iv) derived bounds for RDs, and (v) estimated the proportion of compliers and their characteristics. The findings revealed that IV assumptions were violated and RDs were extreme, but the assumptions became more plausible upon narrowing the calendar time range and restricting the cohort by excluding prevalent heart failure (the strongest measured predictor of outcome). Systematically evaluating IV assumptions could help detect bias in IV estimators and increase their validity.

Macrophage modulation with dipeptidyl peptidase-4 inhibitors: A new frontier for treating diabetic cardiomyopathy?

This editorial introduces the potential of targeting macrophage function for diabetic cardiomyopathy (DCM) treatment by dipeptidyl peptidase-4 (DPP-4) inhibitors. Zhang et al studied teneligliptin, a DPP-4 inhibitor used for diabetes management, and its potential cardioprotective effects in a diabetic mouse model. They suggested teneligliptin administration may reverse established markers of DCM, including cardiac hypertrophy and compromised function. It also inhibited the NLRP3 inflammasome and reduced inflammatory cytokine production in diabetic mice. Macrophages play crucial roles in DCM pathogenesis. Chronic hyperglycemia disturbs the balance between pro-inflammatory (M1) and anti-inflammatory (M2) macrophages, favoring a pro-inflammatory state contributing to heart damage. Here, we highlight the potential of DPP-4 inhibitors to modulate macrophage function and promote an anti-inflammatory environment. These compounds may achieve this by elevating glucagon-like peptide-1 levels and potentially inhibiting the NLRP3 inflammasome. Further studies on teneligliptin in combination with other therapies targeting different aspects of DCM could be suggested for developing more effective treatment strategies to improve cardiovascular health in diabetic patients.

Dipeptidyl peptidase 4: A predictor of ferroptosis in ulcerative colitis.

BACKGROUND: With its rapidly increasing incidence and prevalence, ulcerative colitis (UC) has become a major global health challenge. Recent evidence suggests that ferroptosis plays a significant role in the development of UC. However, the relationship between ferroptosis and the progression of UC needs to be extensively studied. METHODS: The differentially expressed genes in UC patients were screened from the GEO database. The ferroptosis-related genes were obtained from FErrDB and GeneCards. The UC subtypes were identified with the R package "CancerSubtype" and evaluated with consensus clustering (CC) to identify gene expression patterns in patients with UC. The key genes were detected with qRT-PCR, Western blot, and immunohistochemistry in vitro and in vivo models. Ferroptosis was identified with western blotting on ferrotic-associated proteins and staining on Fe2+ with commercial FerroOrange kits. RESULTS: Dipeptidyl peptidase 4 (DPP4), also known as CD26, is a potential biomarker for ferroptosis in UC patients. Transcriptome sequencing data showed a positive correlation between decreased DPP4 expression and proinflammatory cytokines such as TNF-α, IL-6, and IL-ß, as well as immune cell infiltration in the colon tissues of UC patients. Furthermore, DPP4 was strongly associated with ferroptosis biomarkers, particularly in Subtype 2 of UC. Interestingly, our study also found that DPP4 expression was significantly reduced in RSL3-treated ferroptotic intestinal epithelial cells, more so than in LPS-treated cell models. Inhibition of DPP4 had a significant impact on the expression of ferroptotic biomarkers. Additionally, DPP4 expression was decreased in the colon tissues of DSS-treated mice, and the ferroptosis inhibitor Ferritin-1 effectively counteracted the effects of DSS on immune cell infiltration, colon length, and DPP4 expression. CONCLUSIONS: DPP4 can serve as a biomarker for ferroptosis in the diagnosis and management of UC.

Dipeptidyl peptidase-4 marks distinct subtypes of human adipose stromal/stem cells with different hepatocyte differentiation and immunoregulatory properties.

BACKGROUND: Human adipose-derived stromal/stem cells (hASCs) play important roles in regenerative medicine and numerous inflammatory diseases. However, their cellular heterogeneity limits the effectiveness of treatment. Understanding the distinct subtypes of hASCs and their phenotypic implications will enable the selection of appropriate subpopulations for targeted approaches in regenerative medicine or inflammatory diseases. METHODS: hASC subtypes expressing dipeptidyl peptidase-4 (DPP4) were identified via fluorescence-activated cell sorting (FACS) analysis. DPP4 expression was knocked down in DPP4+ hASCs via DPP4 siRNA. The capacity for proliferation, hepatocyte differentiation, inflammatory factor secretion and T-cell functionality regulation of hASCs from DPP4-, DPP4+, and control siRNA-treated DPP4+ hASCs and DPP4 siRNA-treated DPP4+ hASCs were assessed. RESULTS: DPP4+ hASCs and control siRNA-treated DPP4+ hASCs presented a lower proliferative capacity but greater hepatocyte differentiation capacity than DPP4- hASCs and DPP4 siRNA-treated DPP4+ hASCs. Both DPP4+ hASCs and DPP4- hASCs secreted high levels of vascular endothelial growth factor-A (VEGF-A), monocyte chemoattractant protein-1 (MCP-1), and interleukin 6 (IL-6), whereas the levels of other factors, including matrix metalloproteinase (MMP)-1, eotaxin-3, fractalkine (FKN, CX3CL1), growth-related oncogene-alpha (GRO-alpha, CXCL1), monokine induced by interferon-gamma (MIG), macrophage inflammatory protein (MIP)-1beta, and macrophage colony-stimulating factor (M-CSF), were significantly greater in the supernatants of DPP4+ hASCs than in those of DPP4- hASCs. Exposure to hASC subtypes and their conditioned media triggered changes in the secreted cytokine profiles of T cells from healthy donors. The percentage of functional T cells that secreted factors such as MIP-1beta and IL-8 increased when these cells were cocultured with DPP4+ hASCs. The percentage of polyfunctional CD8+ T cells that secreted multiple factors, such as IL-17A, tumour necrosis factor alpha (TNF-α) and TNF-ß, decreased when these cells were cocultured with supernatants derived from DPP4+ hASCs. CONCLUSIONS: DPP4 may regulate proliferation, hepatocyte differentiation, inflammatory cytokine secretion and T-cell functionality of hASCs. These data provide a key foundation for understanding the important role of hASC subpopulations in the regulation of T cells, which may be helpful for future immune activation studies and allow them to be customized for clinical application.

Cofrogliptin once every 2 weeks as add-on therapy to metformin versus daily linagliptin in patients with type 2 diabetes in China: A randomized, double-blind, non-inferiority trial.

AIM: We evaluated the efficacy and safety of cofrogliptin, a novel dipeptidyl peptidase-4 inhibitor taken once every 2 weeks (Q2W), compared with linagliptin (taken daily) in patients with type 2 diabetes inadequately controlled on metformin in China. MATERIALS AND METHODS: In this phase 3 randomized, double-blind, active-controlled, multicentre study, patients were randomly assigned 1:1:1 to receive cofrogliptin 10 mg Q2W, cofrogliptin 25 mg Q2W, or linagliptin 5 mg daily, all as an add-on treatment to metformin, for 24 weeks. Eligible patients could enter an open-label extension period and receive cofrogliptin 25 mg Q2W for an additional 28 weeks. The primary endpoint was change in glycated haemoglobin from baseline to 24 weeks, with a non-inferiority margin of 0.4% for cofrogliptin versus linagliptin treatment. RESULTS: Overall, 465 patients entered the 24-week treatment period (median age: 57.0 years). The least-squares mean (standard error) change in glycated haemoglobin from baseline to week 24 was -0.96 (0.063), -0.99 (0.064) and -1.07 (0.065) for the cofrogliptin 10 mg, cofrogliptin 25 mg and linagliptin 5 mg groups, respectively. The between-group difference met the predefined margin for non-inferiority of cofrogliptin (10 and 25 mg) versus linagliptin treatment. The incidence of common adverse events (≥5% patients) during the 24-week treatment period was similar between treatment groups. There were no serious hypoglycaemic events. CONCLUSION: In Chinese patients with type 2 diabetes inadequately controlled on metformin, the glucose-lowering effect of cofrogliptin (Q2W) was non-inferior to linagliptin (daily), with a similar safety profile maintained over 52 weeks of treatment.

Dipeptidyl peptidase 4 deficiency improves survival after focal cerebral ischemia in mice and ameliorates microglia activation and specific inflammatory markers.

Dipeptidyl peptidase 4 (DPP4; CD26) is involved in the regulation of various metabolic, immunological, and neurobiological processes in healthy individuals. Observations based on epidemiological data indicate that DPP4 inhibition by gliptins, typically used in patients with diabetes, may reduce the risk for cerebral ischemia and may also improve related outcomes. However, as DPP4 inhibitor application is neither complete nor specific for suppression of DPP4 enzymatic activity and DPP4 has non-enzymatic functions as well, the variety of consequences is a matter of debate. Therefore, we here used DPP4 knock-out (KO) mice to analyze the specific contribution of DPP4 to cellular, immunological, and functional consequences of experimental focal cerebral ischemia. We observed a significantly higher survival rate of DPP4 KO mice after ischemia, which was accompanied by a lower abundance of the pro-inflammatory chemokine CCL2 and reduced activation of Iba1-positive microglia cells in brain tissue of DPP4 KO mice. In addition, after ischemia for 24 h to 72 h, decreased concentrations of CCL5 and CCL12 in plasma and of CCL17 in brain tissue of DPP4 KO mice were observed when compared to wild type mice. Other aspects analyzed, such as the functional Menzies score, astrocyte activation and chemokine levels in plasma and brain tissue were affected by ischemia but appeared to be unaffected by the DPP4 KO genotype. Taken together, experimental ablation of DPP4 functions in mice improves survival and ameliorates aspects of cellular and molecular inflammation after focal cerebral ischemia.

Effects of dipeptidyl peptidase 4 inhibitors on the risk of acute respiratory failure in patients with type 2 diabetes mellitus: a meta-analysis of cardiovascular outcomes trials.

Dipeptidyl peptidase 4 (DPP-4) inhibitors are new antidiabetic drugs. Their effects on the respiratory system remain unclear. This study aimed to determine the association between DDP-4 inhibitors and acute respiratory failure (ARF) among patients with type 2 diabetes mellitus (T2DM). A meta-analysis was performed by searching the PubMed, Embase, and CENTRAL databases up to July 3rd, 2024, to identify randomized controlled, double-blind, and placebo controlled-cardiovascular outcomes trials (CVOTs) that enrolled participants with T2DM. A total of 6,532 studies were initially retrieved; ultimately, 5 large CVOTs enrolling 47,714 adult T2DM patients were included in the meta-analysis. Overall, there were a nonsignificant increase in the risk of ARF in the DDP-4 inhibitor group compared with the placebo group (RR, 1.72; 95% CI, 0.59 to 4.97; p = 0.319). This is the first meta-analysis to evaluate the association between DDP-4 inhibitors and ARF among T2DM patients. In general, these findings suggest that DPP-4 inhibitors may slightly, but non-significantly, increase the risk of ARF in T2DM patients. As few studies are available and few ARF events occurred, further well-designed large-scale studies need to be performed.

The impact of vildagliptin as an add-on therapy on matrix metalloproteinase-14 levels, liver stiffness and subclinical atherosclerosis in adolescents with type 1 diabetes and non-alcoholic steatohepatitis: A randomized controlled trial.

AIM: Many patients with type 1 diabetes mellitus (T1DM) met the histological criteria for non-alcoholic steatohepatitis (NASH), which leads to cardiovascular disease morbidity and mortality. Matrix metalloproteinase-14 (MMP-14) is involved in cardiovascular disease and atherosclerosis. OBJECTIVES: To assess the impact of oral dipeptidyl peptidase-4 inhibitor, vildagliptin, as adjunctive therapy on NASH in adolescents with T1DM and its effect on glycaemic control, MMP-14 levels and carotid intima media thickness (CIMT). METHODS: Sixty adolescents with T1DM and NASH were randomly assigned to receive oral vildagliptin (50 mg once daily) for 6 months or not. Glycated haemoglobin, lipid profile, hepatic steatosis index, triglyceride glucose (TyG) index and MMP-14 levels were assessed. Transient elastography with controlled attenuation parameter (CAP) was performed together with measuring CIMT. RESULTS: By transient elastography, 12 (20%) patients with T1DM with NASH had elevated liver stiffness ≥7 kPa (F2 stage or higher). Baseline MMP-14 was positively correlated to insulin dose (p = 0.016), triglycerides and TyG index, CIMT, liver stiffness and CAP levels among the studied patients (p < 0.001 for all). After 6 months, patients with T1DM on vildagliptin therapy had significantly lower glycated haemoglobin, lipid profile, hepatic steatosis index and TyG index, as well as MMP-14 (p < 0.001). CIMT, liver stiffness and CAP were significantly decreased post-therapy compared with baseline levels and compared with the control group (p < 0.001). Vildagliptin was safe and well-tolerated. CONCLUSIONS: Administration of vildagliptin for adolescents with T1DM and NASH improved glycaemic control, dyslipidaemia and MMP-14 levels and decreased liver stiffness and CIMT; hence, reducing subclinical atherosclerosis and disease progression.

The effects of dipeptidyl peptidase-4 inhibitors on cardiac structure and function using cardiac magnetic resonance: a meta-analysis of clinical studies.

Objective: The aim of the study was to evaluate the effect of dipeptidyl peptidase-4 inhibitors (DPP4i) on cardiac structure and function by cardiac magnetic resonance (CMR). Research Methods & Procedures: Database including PubMed, Cochrane library, Embase and SinoMed for clinical studies of DPP4i on cardiac structure and function by CMR were searched. Two authors extracted the data and evaluated study quality independently. Mean difference (MD) or standardized MD and 95% confidence intervals (CI) were used for continuous variables. Review Manager 5.3 was used to performed the analysis. Results: Ten references (nine studies) were included in this meta-analysis. Most of the studies were assessed as well quality by the assessment of methodological quality. For clinical control studies, the merged MD values of △LVEF by fixed-effect model and the pooled effect size in favor of DPP4i was 1.55 (95% CI 0.35 to 2.74, P=0.01). Compared with positive control drugs, DPP4i can significantly improve the LVEF (MD=4.69, 95%CI=2.70 to 6.69), but no such change compared to placebo (MD=-0.20, 95%CI=-1.69 to 1.29). For single-arm studies and partial clinical control studies that reported LVEF values before and after DPP4i treatment, random-effect model was used to combine effect size due to a large heterogeneity (Chi2 = 11.26, P=0.02, I2 = 64%), and the pooled effect size in favor of DPP4i was 2.31 (95% CI 0.01 to 4.62, P=0.05). DPP4i significantly increased the Peak filling rate (PFR) without heterogeneity when the effect sizes of two single-arm studies were combined (MD=31.98, 95% CI 13.69 to 50.27, P=0.0006; heterogeneity test: Chi2 = 0.56, P=0.46, I2 = 0%). Conclusions: In summary, a possible benefit of DPP4i in cardiac function (as measured by CMR) was found, both including ventricular systolic function and diastolic function.

Comparison of canagliflozin and teneligliptin on energy intake and body weight in Japanese patients with Type 2 diabetes: a subanalysis of the CANTABILE study.

BACKGROUND: While the Sodium-glucose co-transporter 2 (SGLT2) inhibitors and dipeptidyl peptidase-4 (DPP4) are widely used for the glycemic control in type 2 diabetes mellitus, the differences in the effects of SGLT2 inhibitors and DPP4 inhibitors on energy intake and diabetes-related indicators are unclear. METHODS: This was a subanalysis of the CANTABILE study which compared the effects of canagliflozin and teneligliptin on metabolic factors in Japanese patients with Type 2 diabetes. The changes at 24 weeks from the baseline of the diabetes-related indicators including Hemoglobin A1c (HbA1c), energy intake and body weight were compared between the canagliflozin and teneligliptin groups. RESULTS: Seventy-five patients in the canagliflozin group and 70 patients in the teneligliptin group were analyzed. A significant decrease in HbA1c was observed in both groups. In the teneligliptin group, although energy intake was significantly reduced, there was no significant change in body weight. Conversely, in the canagliflozin group, although energy intake tended to increase, body weight significantly decreased. CONCLUSION: Canagliflozin and teneligliptin have different effects on the dietary status of patients with Type 2 diabetes. Our result suggests that canagliflozin can manage blood glucose without weight gain, even with increased energy intake.

The influence of insulin and incretin-based therapies on renal tubular transport.

The tubular function of the kidney is very complex and is finely regulated by many factors. These include a variety of hormonal signaling pathways which are involved in the expression, activation and regulation of renal transporters responsible for the handling of electrolytes. Glucose-lowering drugs such as insulin and incretin-based therapies, exert a well-known renal protective role in diabetic kidney disease, mainly acting at the glomerular level. In the literature, several studies have described the effect of insulin and the incretin hormones on tubular transport. Most of these studies focused on the variations in excretion and clearance of sodium but did not extensively and systematically investigate the possible variations that these hormones may induce in the tubular regulation of all the other electrolytes, urea metabolism, acid-base balance and urinary pH. While insulin action on the kidney is very well-described, the renal tubular impact of incretin-based therapies is less consistent and the results available are scarce. To our knowledge, this is the first review summarizing the effects induced on renal tubules by insulin, glucagon-like peptide-1 (GLP-1) receptor agonists and serine protease dipeptidyl peptidase-4 (DPP4) inhibitors in both healthy and diabetic human subjects. This is significant because it highlights the existence of a renal-gut and pancreas axis which also has a direct tubular effect and enables a deeper understanding of renal physiology.

Efficacy and safety of switching from a dipeptidyl peptidase-4 inhibitor to oral semaglutide in Japanese patients with type 2 diabetes mellitus.

Background: Dipeptidyl peptidase-4 inhibitors (DPP-4is) are the most widely used oral hypoglycemic drugs in Japan. However, once-daily oral semaglutide has been reported to reduce glycated hemoglobin (HbA1c) and body weight (BW) without causing significant hypoglycemia. Here, we aimed to evaluate the efficacy and safety of switching from a DPP-4i to oral semaglutide in Japanese patients with type 2 diabetes (T2D). Methods: We performed a single-center retrospective study of the changes in HbA1c and BW in 68 patients with T2D who were switched from a DPP-4i and took oral semaglutide for ≥ 6 months, without changes in any other oral hypoglycemic agent. Results: Mean HbA1c decreased from 7.8 to 7.0% (p < 0.001) and BW decreased from 74.2 to 71.2 kg (p < 0.001) over 6 months. The decrease in HbA1c was more pronounced in participants with high baseline HbA1c (r = - 0.542, p < 0.001). There was also a trend (r = 0.236, p = 0.052) toward a decrease in BW in individuals with shorter disease duration. There were reductions in either HbA1c or BW in 65 participants (95.6%). In addition, the larger the decrease in HbA1c was, the greater was the decrease in BW (r = 0.480, p < 0.001). Eighteen participants (20.1%) discontinued the drug within 6 months, of whom 10 (11.6% of the total) did so because of suspected adverse effects and the discontinuation rate was the highest in older, non-obese patients. Conclusions: Switching from a DPP-4i to oral semaglutide may be useful for Japanese patients with T2D who have inadequate glycemic or BW control. However, its utility may be limited by gastrointestinal adverse effects in certain patients.

Glycemic control of once-weekly and other administration frequencies for DPP-4 inhibitor in patients with type 2 diabetes: a real-world retrospective cohort study.

Aims: To assess the glycemic control of once-weekly (QW) and other administration frequencies for dipeptidyl peptidase-4 inhibitors (DPP-4i) in patients with type 2 diabetes in a real-world setting. Methods: A retrospective cohort study used Japanese medical claims data and medical check-up data between December 2015 and February 2020. Patients with type 2 diabetes had been newly prescribed a DPP-4i regimen of once-daily (QD), twice-daily (BID), or QW administration and had hemoglobin A1c (HbA1c) values from regular medical check-ups. HbA1c values and proportion of patients achieving their HbA1c target were assessed. Multivariable analyses were conducted to examine the association between DPP-4i regimen and achievement of HbA1c target. Results: Of the analysis population (N = 7229), 6098 patients were prescribed the QD regimen, 772 BID, and 359 QW. Mean HbA1c before exposure to DPP-4i was 7.31 ± 1.20% (mean ± standard deviation) for QD, 7.64 ± 1.47% for BID, and 7.06 ± 0.96% for QW, decreasing after DPP-4i exposure to 6.71 ± 0.78%, 6.77 ± 0.84%, and 6.59 ± 0.67%, respectively. HbA1c < 7% was achieved in 72.1% of patients for QD, 69.0% for BID, and 79.1% for QW. On multivariable analysis, the odds ratio (95% confidence interval) for HbA1c < 7.0% in patients < 65 years of age was 0.97 (0.73-1.30) for BID and 0.90 (0.57-1.42) for QW compared to QD. Similar achievement of HbA1c target was noted in each regimen for patients age ≥ 65 years and for age ≥ 65 years with multimorbidity. Conclusion: In this study under real-world conditions, glycemic control for the DPP-4i QW regimen was similar to that for QD and BID. Supplementary Information: The online version contains supplementary material available at 10.1007/s13340-024-00718-5.

Comparison of medication persistence and adherence in type 2 diabetes using a once-weekly regimen of DPP-4 inhibitor compared with once-daily and twice-daily regimens: a retrospective cohort study of Japanese health insurance claims data.

Aims: Assess medication persistence and adherence for dipeptidyl peptidase-4 inhibitors (DPP-4i) administered once weekly (QW), once daily (QD), and twice daily (BID) among patients with type 2 diabetes (T2D), and explore factors associated with discontinuation and non-adherence for DPP-4i regimens. Methods: This retrospective T2D cohort study used medical claims data for three DPP-4i regimens in patients newly prescribed DPP-4i between December 2016 and February 2019. Medication persistence rates were calculated at 3, 6, and 12 months by the Kaplan-Meier method. Adherence was measured as Proportion of Days Covered (PDC). We used Cox proportional hazards models for DPP-4i discontinuation and logistic regression models for non-adherence. Results: In the analysis population of 52,762 patients, DPP-4i prescriptions were 84.2% QD, 11.8% BID, and 4.0% QW. Medication persistence rates were similar up to 6 months for all regimens: approximately 90% at 3 and 80% at 6 months. The 12-month persistence rates for QD, BID, and QW were 74.8%, 67.5%, and 68.0%, respectively. Median PDC was 94.0% for QD, 91.8% for BID, and 93.2% for QW. Five specific factors were associated with discontinuation: BID or QW regimen, younger age, no concomitant medications, comorbid dementia, and comorbid chronic pulmonary disease. Non-adherence was associated with those factors plus male sex and treatment at clinics with 0-19 beds. Conclusions: The 12-month medication persistence rates were highest for QD, followed by QW and then BID. Adherence was similar for all three regimens. Medication persistence for DPP-4i may be improved by tailoring regimens to patient characteristics and needs. Supplementary Information: The online version contains supplementary material available at 10.1007/s13340-024-00714-9.

Comparative effects of canagliflozin and sitagliptin in chronically ischemic myocardium.

Aim: Recent studies demonstrate that sodium-glucose cotransporter 2 inhibitors (SGLT2i) and dipeptidyl peptidase-4 inhibitors (DPP4i), two classes of antidiabetic drugs, are cardioprotective. However, the mechanisms of these benefits and their comparative efficacy remain unclear. We aimed to compare the effects of these antidiabetic agents on cardiac function, perfusion, and microvascular density using a swine model of chronic myocardial ischemia. Methods: Chronic myocardial ischemia was induced in Yorkshire swine by ameroid constrictor placement to the left circumflex artery. Two weeks later, pigs were administered vehicle ("CON", 8 pigs), 300 mg SGLT2i canagliflozin, ("CANA", 8 pigs), or 100 mg DPP4i sitagliptin ("SIT", 5 pigs) daily. Five weeks later, pigs were euthanized. Cardiac function, perfusion, collateralization, and protein expression were determined by pressure-volume catheter, microsphere analysis, immunofluorescence, and immunoblotting, respectively. Results: Compared with SIT, CANA was associated with improved stroke volume and cardiac output, with a trend towards reduced left ventricular stiffness. Both CANA and SIT trended towards improved perfusion compared to CON, but there were no differences between the two treatment groups. SIT was associated with improved capillary density with a trend towards improved arteriolar density compared to CANA. Both CANA and SIT were associated with increased expression of vascular endothelial cadherin compared to CON, without differences in treatment groups. SIT pigs had decreased 5' adenosine monophosphate-activated protein kinase activation compared to CON and CANA. There was a trend towards increased endothelial nitric oxide synthase activation in the SIT group compared to CON. There were no differences in activation of extracellular signal-regulated kinase 1/2 across groups. Conclusions: In the setting of chronic myocardial ischemia, canagliflozin is associated with improved cardiac function compared to sitagliptin, with similar effects on perfusion despite differences in microvascular collateralization.

Racial Comparison of the Pharmacokinetics and Safety of Fixed-dose Combination of Dapagliflozin/Sitagliptin in Western and Korean Healthy Adults.

PURPOSE: We evaluated the pharmacokinetics, safety, and tolerability of a fixed-dose combination (FDC) of dapagliflozin/sitagliptin versus individual component (IC) tablets in healthy Western and Korean participants. The combination of these antihyperglycemic drugs provides efficient glucose control, and the use of FDC has generally been shown to improve medication adherence in individuals with type 2 diabetes mellitus (T2DM). METHODS: Two randomized, open-label, two-period, two-treatment, single-dose, single-center, crossover bioequivalence studies conducted on healthy fasted German participants (aged 18-55 years; Western study) and South Korean participants (aged 19-55 years; Korean study) were included. In both studies, pharmacokinetic parameters (maximum [peak] plasma concentration [Cmax], area under the plasma concentration-time curve from zero to the last quantifiable concentration [AUClast], and area under the plasma concentration-time curve from zero to infinity [AUCinf]) were used to assess the bioequivalence of 10 mg dapagliflozin/100 mg sitagliptin FDC (Treatment A) with their ICs (Treatment B) under fasted conditions. Safety and tolerability were assessed throughout the study. FINDINGS: Forty-six healthy participants (male, 60.9%; mean age, 39.5 years; mean body mass index [BMI], 23.9 kg/m2) were randomized in the Western study, and 51 healthy participants (male, 100.0%; mean age, 24.6 years; mean BMI, 23.9 kg/m2) were randomized in the Korean study. In both studies, the participants were randomized 1:1 into treatment sequence AB and treatment sequence BA. Dapagliflozin/sitagliptin FDC was bioequivalent to IC tablets in both Western and Korean studies, as the 90% confidence interval of the FDC to IC ratios of the geometric least-squares means of the pharmacokinetic parameters for both dapagliflozin and sitagliptin was within the 0.8000-1.2500 bioequivalence criterion limit. The observed differences in pharmacokinetic parameters, such as Cmax, AUClast, and AUCinf, between the Western and Korean studies were not clinically meaningful. Dapagliflozin/sitagliptin FDC and their ICs were well tolerated, with no serious adverse events reported in any of the study populations. IMPLICATIONS: The 10 mg dapagliflozin/100 mg sitagliptin FDC and IC formulations were bioequivalent in fasted healthy Western and Korean participants, with no new safety concerns identified, thus offering a useful alternative for patients currently receiving individual medications as part of their treatment regimen. CLINICAL TRIAL REGISTRATION: Western study (clinicaltrials.gov: NCT05266404) and Korean study (clinicaltrials.gov: NCT05453786).