Dipeptidyl peptidase-4 inhibitors and cancer risk in patients with type 2 diabetes: a meta-analysis of randomized clinical trials

Comparative effectiveness of sodium-glucose cotransporter-2 inhibitors for new-onset gastric cancer and gastric diseases in patients with type 2 diabetes mellitus: a population-based cohort study

OBJECTIVE

To compare the risks of gastric cancer and other gastric diseases in patients with type-2 diabetes mellitus (T2DM) exposed to sodium-glucose cotransporter 2 inhibitors (SGLT2I), dipeptidyl peptidase-4 inhibitors (DPP4I) or glucagon-like peptide-1 receptor agonists (GLP1a).

DESIGN

This was a population-based cohort study of prospectively collected data on patients with T2DM prescribed SGLT2I, DPP4I or GLP1a between January 1st 2015 and December 31st 2020 from Hong Kong. The outcomes were new-onset gastric cancer, peptic ulcer (PU), acute gastritis, non-acute gastritis, and gastroesophageal reflux disease (GERD). Propensity score matching (1:1) using the nearest neighbour search was performed, and multivariable Cox regression was applied. A three-arm comparison between SGLT2I, DPP4I and GLP1a was conducted using propensity scores with inverse probability of treatment weighting.

RESULTS

A total of 62,858 patients (median age: 62.2 years old [SD: 12.8]; 55.93% males; SGLT2I: n = 23,442; DPP4I: n = 39,416) were included. In the matched cohort, the incidence of gastric cancer was lower in SGLT2I (Incidence rate per 1000 person-year, IR: 0.32; 95% confidence interval, CI 0.23-0.43) than in DPP4I (IR per 1000 person-year: 1.22; CI 1.03-1.42) users. Multivariable Cox regression found that SGLT2I use was associated with lower risks of gastric cancer (HR 0.30; 95% CI 0.19-0.48), PU, acute gastritis, non-acute gastritis, and GERD (p < 0.05) compared to DPP4I use. In the three-arm analysis, GLP1a use was associated with higher risks of gastric cancer and GERD compared to SGLT2I use.

CONCLUSIONS

The use of SGLT2I was associated with lower risks of new-onset gastric cancer, PU, acute gastritis, non-acute gastritis, and GERD after matching and adjustments compared to DPP4I use. SGLT2I use was associated with lower risks of GERD and gastric cancer compared to GLP1a use.

Role of SGLT2 Inhibitors, DPP-4 Inhibitors, and Metformin in Pancreatic Cancer Prevention

Pancreatic carcinoma is a highly aggressive tumor that usually presents when it has already metastasized. Therapeutic options for cure remain scarce and rely on combination chemotherapy with limited sustainability. Diabetes is considered an important risk factor for the development of pancreatic cancer due to the production of proinflammatory cytokines, which result in increased cell proliferation. More than half of patients diagnosed with pancreatic cancer eventually develop diabetes due to the destruction of insulin-producing cells. The interlinkage of both diseases might identify a possible preventative strategy for reducing the incidence of pancreatic carcinoma. This study reviewed the recent literature on the association between pancreatic cancer risk and SGLT2 inhibitors, GLP-1 RA, DPP-4 inhibitors, and biguanides. There are mixed data regarding the relationship between GLP-1 RA and DPP-4 inhibitors and pancreatic cancer, with some trials suggesting that they might increase the risk. In contrast, studies have mostly revealed that SGLT2 inhibitors have an antiproliferative effect on various tumors, such as liver, pancreatic, prostate, bowel, lung, and breast carcinoma, which might be due to their mechanism of blockage of reabsorption of glucose by cells, lowering the amount of available glucose for the growth of tumor cells. Metformin, the first-line agent for diabetes, has also been shown to be associated with decreasing pancreatic cancer risk and improving prognosis in those who already have the disease. Dedicated trials are needed to further delineate the association of antidiabetic drugs with the risk of pancreatic cancer in the general population, as previous studies have mostly focused on diabetic patients.

Risk of thyroid cancer associated with glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors in patients with type 2 diabetes: A population-based cohort study

AIMS

To determine the potential association between the use of either glucagon-like peptide-1 receptor agonists (GLP-1RAs) or dipeptidyl peptidase-4 (DPP-4) inhibitors, and the risk of thyroid cancer in individuals with type 2 diabetes.

MATERIALS AND METHODS

This population-based cohort study used claims data from the Korean National Health Insurance Database, 2014-2020. Two distinct cohorts were established to compare each incretin-based drug with sodium-glucose cotransporter-2 (SGLT2) inhibitors, chosen as active comparators because of their previous non-association with thyroid cancer, and their common usage as add-on therapy to metformin along with GLP-1RAs and DPP-4 inhibitors. The first cohort included 21 722 new users of GLP-1RAs and 326 993 new users of SGLT2 inhibitors, whereas the second cohort included 904 300 DPP-4 inhibitor new users and 112 017 SGLT2 inhibitor new users. The outcome was the time to incident thyroid cancer. Weighted Cox proportional models were used to estimate hazard ratios of thyroid cancer incidence associated with incretin-based drugs of interest.

RESULTS

The use of GLP-1RAs was not associated with an increased risk of thyroid cancer (weighted hazard ratio 0.98, 95% confidence interval 0.62-1.53) compared with that of SGLT2 inhibitors. Using DPP-4 inhibitors was also not associated with an increased risk of thyroid cancer (0.95, 0.79-1.14) compared with that of SGLT2 inhibitors. No significant effect modifications were observed across subgroup analyses. Sensitivity analyses, including alternative outcome definition analysis of medullary thyroid cancer, were consistent with the primary analysis results.

CONCLUSIONS

GLP-1RAs and DPP-4 inhibitors were not associated with an increased risk of thyroid cancer in individuals with type 2 diabetes.

Dipeptidyl peptidase-4 inhibitors and the risk of skin cancer among patients with type 2 diabetes: a UK population-based cohort study

INTRODUCTION

The dipeptidyl peptidase-4 (DPP-4) enzyme significantly influences carcinogenic pathways in the skin. The objective of this study was to determine whether DPP-4 inhibitors are associated with the incidence of melanoma and nonmelanoma skin cancer, compared with sulfonylureas.

RESEARCH DESIGN AND METHODS

Using the United Kingdom Clinical Practice Research Datalink, we assembled two new-user active comparator cohorts for each skin cancer outcome from 2007 to 2019. For melanoma, the cohort included 96 739 DPP-4 inhibitor users and 209 341 sulfonylurea users, and 96 411 DPP-4 inhibitor users and 208 626 sulfonylurea users for non-melanoma skin cancer. Propensity score fine stratification weighted Cox proportional hazards models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs of melanoma and non-melanoma skin cancer, separately.

RESULTS

Overall, DPP-4 inhibitors were associated with a 23% decreased risk of melanoma compared with sulfonylureas (49.7 vs 65.3 per 100 000 person-years, respectively; HR 0.77, 95% CI 0.61 to 0.96). The HR progressively reduced with increasing cumulative duration of use (0-2 years HR 1.14, 95% CI 0.84 to 1.54; 2.1-5 years HR 0.44, 95% CI 0.29 to 0.66; >5 years HR 0.33, 95% CI 0.14 to 0.74). In contrast, these drugs were not associated with the incidence of non-melanoma skin cancer, compared with sulfonylureas (448.1 vs 426.1 per 100 000 person-years, respectively; HR 1.06, 95% CI 0.98 to 1.15).

CONCLUSIONS

In this large, population-based cohort study, DPP-4 inhibitors were associated with a reduced risk of melanoma but not non-melanoma skin cancer, compared with sulfonylureas.

Sodium-glucose cotransporter 2 inhibitors versus dipeptidyl peptidase 4 inhibitors on new-onset overall cancer in Type 2 diabetes mellitus: A population-based study

BACKGROUND

Cancer is currently the second leading cause of death globally. There is much uncertainty regarding the comparative risks of new-onset overall cancer and pre-specified cancer for Type 2 diabetes mellitus (T2DM) patients on sodium-glucose cotransporter 2 inhibitors (SGLT2I) versus DPP4I.

METHODS

This population-based cohort study patients included patients who were diagnosed with T2DM and administered either SGLT2 or DPP4 inhibitors between 1 January 2015 and 31 December 2020 in public hospitals of Hong Kong.

RESULTS

This study included 60,112 T2DM patients (mean baseline age: 62.1 ± 12.4 years, male: 56.36%), of which 18,167 patients were SGLT2I users and 41,945 patients were dipeptidyl peptidase 4 inhibitor (DPP4I) users. Multivariable Cox regression found that SGLT2I use was associated with lower risks of all-cause mortality (HR: 0.92; 95% CI: 0.84-0.99; p= 0.04), cancer-related mortality (HR: 0.58; 95% CI: 0.42-0.80; p ≤ 0.001) and new diagnoses of any cancer (HR: 0.70; 95% CI: 0.59-0.84; p ≤ 0.001). SGLT2I use was associated with a lower risk of new-onset breast cancer (HR: 0.51; 95% CI: 0.32-0.80; p ≤ 0.001), but not of other malignancies. Subgroup analysis on the type of SGLT2I, dapagliflozin (HR: 0.78; 95% CI: 0.64-0.95; p = 0.01) and ertugliflozin (HR: 0.65; 95% CI: 0.43-0.98; p = 0.04) use was associated with lower risks of new cancer diagnosis. Dapagliflozin use was also linked to lower risks of breast cancer (HR: 0.48; 95% CI: 0.27-0.83; p = 0.001).

CONCLUSION

Sodium-glucose cotransporter 2 inhibitor use was associated with lower risks of all-cause mortality, cancer-related mortality and new-onset overall cancer compared to DPP4I use after propensity score matching and multivariable adjustment.

Dipeptidyl peptidase 4 (DPP-4) inhibitors and the risk of lung cancer: current evidence and future directions

INTRODUCTION

Recent evidence has linked long-term use of angiotensin converting enzyme (ACE) inhibitors with the risk of developing lung cancer by increasing levels of substance P (SP) and bradykinin in lung tissue. DPP-4 inhibitors, by virtue of their mechanism of action, may increase the level of SP and pose a similar risk of incident lung cancer. Concomitant use of DPP-4 inhibitors and ACE inhibitors may further exaggerate this plausible risk.

AREA COVERED

Here we discuss both direct and indirect evidence involving mechanisms by which DPP-4 inhibitors may increase the risk of lung cancer in treated patients. We highlight that increased levels of SP with DPP-4 inhibitor monotherapy and raised levels of both SP and bradykinin with add-on ACE inhibitor therapy may further enhance this risk.

EXPERT OPINION

DPP-4 inhibitors are prescribed in type-2 diabetes mellitus patients with or without cardiovascular disease. When used together, ACE inhibitors and DPP-4 inhibitors may act synergistically and further amplify the lung cancer risk. Consequently, physicians should consider this plausible association while prescribing them concomitantly especially in high-risk individuals. Well-planned research studies are required to assess the association of DPP-4 inhibitors with lung cancer and other adverse effects linked to increased levels of SP and bradykinin.

Antitumor Effects and Mechanisms of Metabolic Syndrome Medications on Hepatocellular Carcinoma

Liver cancer has a high incidence and mortality rate worldwide, with hepatocellular carcinoma (HCC) being the most common histological type. With the decrease in the number of newly infected patients and the spread of antiviral therapy, hepatitis virus-negative chronic liver diseases including steatohepatitis are increasingly accounting for a large proportion of HCC, and an important clinical characteristic is the high prevalence of metabolic syndrome including hypertension, type 2 diabetes (T2D), dyslipidemia, and obesity. Since patients with steatohepatitis are less likely to undergo surveillance for early detection of HCC, they may be diagnosed at an advanced stage and have worse prognosis. Therefore, treatment strategies for patients with HCC caused by steatohepatitis, especially in advanced stages, become increasingly important. Further, hypertension, T2D, and dyslipidemia may occur as side effects during systemic treatment, and there will be increasing opportunities to prescribe metabolic syndrome medications, not only for originally comorbid diseases, but also for adverse events during HCC treatment. Interestingly, epidemiological studies have shown that patients taking some metabolic syndrome medications are less likely to develop various types of cancers, including HCC. Basic studies have also shown that these drugs have direct antitumor effects on HCC. In particular, angiotensin II receptor blockers (a drug group for treating hypertension), biguanides (a drug group for treating T2D), and statins (a drug group for treating dyslipidemia) have shown to elucidate antitumor effects against HCC. In this review, we focus on the antitumor effects of metabolic syndrome medications on HCC and their mechanisms based on recent literature. New therapeutic agents are also increasingly being reported. Analysis of the antitumor effects of metabolic syndrome medications on HCC and their mechanisms will be doubly beneficial for HCC patients with metabolic syndrome, and the use of these medications may be a potential strategy against HCC.

Sodium-Glucose Cotransporter 2 Inhibitors and the Short-term Risk of Bladder Cancer: An International Multisite Cohort Study

OBJECTIVE

To determine whether sodium-glucose cotransporter 2 (SGLT2) inhibitors, compared with glucagon-like peptide 1 receptor agonists (GLP-1RAs) or dipeptidyl peptidase 4 (DPP-4) inhibitors, are associated with an increased risk of early bladder cancer events.

RESEARCH DESIGN AND METHODS

We conducted a multisite, population-based, new-user, active comparator cohort study using the U.K. Clinical Practice Research Datalink, Medicare fee-for-service, Optum's de-identifed Clinformatics Data Mart Database (CDM), and MarketScan Health databases from January 2013 through December 2020. We assembled two cohorts of adults with type 2 diabetes initiating 1) SGLT2 inhibitors or GLP-1RAs and 2) SGLT2 inhibitors or DPP-4 inhibitors. Cox proportional hazards models were fit to estimate hazard ratios (HRs) and 95% CIs of incident bladder cancer. The models were weighted using propensity score fine stratification. Site-specific HRs were pooled using random-effects models.

RESULTS

SGLT2 inhibitor (n = 453,560) and GLP-1RA (n = 375,997) users had a median follow-up ranging from 1.5 to 2.2 years. Overall, SGLT2 inhibitors were not associated with an increased risk of bladder cancer compared with GLP-1RAs (HR 0.90, 95% CI 0.81-1.00). Similarly, when compared with DPP-4 inhibitors (n = 853,186), SGLT2 inhibitors (n = 347,059) were not associated with an increased risk of bladder cancer (HR 0.99, 95% CI 0.91-1.09) over a median follow-up ranging from 1.6 to 2.6 years. Results were consistent across sensitivity analyses.

CONCLUSIONS

Contrary to previous randomized controlled trials, these findings indicate that the use of SGLT2 inhibitors is not associated with an increased risk of bladder cancer compared with GLP-1RAs or DPP-4 inhibitors. This should provide reassurance on the short-term effects of SGLT2 inhibitors on bladder cancer incidence.

Association Between DPP-4 Inhibitors and Events of Colorectal and Liver Cancers in Patients With Diabetes Receiving Second-Line Agents: A Nested Case-Control Study

Objective

Plasma dipeptidyl peptidase-4 (DPP4) levels were significantly lower in patients with colorectal and liver cancers, and animal studies also showed DPP4 inhibitors (DPP4is) have procarcinogenic effects in colorectal cancer. Until now, whether DPP4is therapy affects the progression of liver cancer and colorectal cancer in patients with T2DM has not been well investigated. We investigated the association between cumulative defined daily dose (cDDD) of DPP4is exposure and risks of liver and colorectal cancers in patients with type 2 diabetes.

Materials and Methods

We identified 268,520 patients with diabetes receiving DPP4is as second-line agents between March 1, 2009, and December 31, 2013, from Taiwan’s National Health Insurance Research Database, Taiwan Cancer Registry, and National Death Registry of Taiwan. The amount of DPP4is were divided into three groups (low, medium, and high) based on the interquartile range of the cDDD of the DPP4is.

Results

The data showed that the low cDDD of DPP-4is was associated with a reducing risk of colorectal cancer [adjusted odds ratio (OR), 0.49; 95% CI, 0.32–0.75; P=0.001]. However, the high cDDD of DPP-4is was associated with an increasing risk of colorectal cancer (adjusted OR, 1.86; 95% CI, 1.32–2.61; P&lt;0.001). No association between DPP4is use and liver cancer risk was observed.

Conclusions

This nested case study revealed a J-shaped association between the cDDD of DPP-4is and colorectal cancer risk, but not liver cancer risk. Therefore, the effects of long-term DPP4is use on colorectal cancer risk warrant further study.

Does DPP-IV Inhibition Offer New Avenues for Therapeutic Intervention in Malignant Disease?

Simple Summary

There is growing interest in identifying the effects of antidiabetic agents on cancer risk, progression, and anti-cancer treatment due to the long-term use of these medications and the inherently increased risk of malignancies in diabetic patients. Tumor development and progression are affected by multiple mediators in the tumor microenvironment, several of which may be proteolytically modified by the multifunctional protease dipeptidyl peptidase-IV (DPP-IV, CD26). Currently, low-molecular-weight DPP-IV inhibitors (gliptins) are used in patients with type 2 diabetes based on the observation that DPP-IV inhibition enhances insulin secretion by increasing the bioavailability of incretins. However, the DPP-IV-mediated cleavage of other biopeptides and chemokines is also prevented by gliptins. The potential utility of gliptins in other areas of medicine, including cancer, is therefore being evaluated. Here, we critically review the existing evidence on the role of DPP-IV inhibitors in cancer pathogenesis, their potential to be used in anti-cancer treatment, and the possible perils associated with this approach.

Abstract

Dipeptidyl peptidase IV (DPP-IV, CD26) is frequently dysregulated in cancer and plays an important role in regulating multiple bioactive peptides with the potential to influence cancer progression and the recruitment of immune cells. Therefore, it represents a potential contributing factor to cancer pathogenesis and an attractive therapeutic target. Specific DPP-IV inhibitors (gliptins) are currently used in patients with type 2 diabetes mellitus to promote insulin secretion by prolonging the activity of the incretins glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Nevertheless, the modulation of the bioavailability and function of other DPP-IV substrates, including chemokines, raises the possibility that the use of these orally administered drugs with favorable side-effect profiles might be extended beyond the treatment of hyperglycemia. In this review, we critically examine the possible utilization of DPP-IV inhibition in cancer prevention and various aspects of cancer treatment and discuss the potential perils associated with the inhibition of DPP-IV in cancer. The current literature is summarized regarding the possible chemopreventive and cytotoxic effects of gliptins and their potential utility in modulating the anti-tumor immune response, enhancing hematopoietic stem cell transplantation, preventing acute graft-versus-host disease, and alleviating the side-effects of conventional anti-tumor treatments.

Potential Effect of DPP-4 Inhibitors Towards Hepatic Diseases and Associated Glucose Intolerance

Dipeptidyl-peptidase-4 (DPP-4) is an enzyme having various properties and physiological roles in lipid accumulation, resistance to anticancer agents, and immune stimulation. DPP-4 includes membrane-bound peptidases and is a kind of enzyme that cleaves alanine or proline-containing peptides such as incretins, chemokines, and appetite-suppressing hormones (neuropeptide) at their N-terminal dipeptides. DPP-4 plays a role in the final breakdown of peptides produced by other endo and exo-peptidases from nutritious proteins and their absorption in these tissues. DPP-4 enzyme activity has different modes of action on glucose metabolism, hunger regulation, gastrointestinal motility, immune system function, inflammation, and pain regulation. According to the literature survey, as DPP-4 levels increase in individuals with liver conditions, up-regulation of hepatic DPP-4 expression is likely to be the cause of glucose intolerance or insulin resistance. This review majorly focuses on the cleavage of alanine or proline-containing peptides such as incretins by the DPP-4 and its resulting conditions like glucose intolerance and cause of DPP-4 level elevation due to some liver conditions. Thus, we have discussed the various effects of DPP-4 on the liver diseases like hepatitis C, non-alcoholic fatty liver, hepatic regeneration and stem cell, hepatocellular carcinoma, and the impact of elevated DPP-4 levels in association with liver diseases as a cause of glucose intolerance and their treatment drug of choices. In addition, the effect of DPP-4 inhibitors on obesity and their negative aspects are also discussed in brief.

Dipeptidyl Peptidase (DPP)-4 Inhibitor Impairs the Outcomes of Patients with Type 2 Diabetes Mellitus After Curative Resection for Colorectal Cancer

Dipeptidyl peptidase IV inhibitor (DPP-4i) has been shown to act either as a promoter or as a suppressor for cancer. Although epidemiologic studies suggest that DPP-4i does not correlate with the development of malignancies, its effects on cancer metastases are controversial. We evaluated the impact of DPP-4i on postoperative outcomes of the diabetic patients with colorectal cancer and microscopic features of the resected tumors. In 260 consecutive patients with type 2 diabetes mellitus (T2DM) who underwent curative resection of colorectal cancer, the correlation between DPP-4i use and prognosis was retrospectively examined. Expression of Zeb1 on tumor cells and density of infiltrating immune cells were quantitatively evaluated with multicolor IHC in 40 tumors from DPP-4i users, 40 tumors from propensity score-matched users, and 40 tumors from nonusers. Postoperative disease-free survival (DFS) was significantly lower in 135 patients treated with DPP-4i compared with 125 nontreated patients [5-year DFS, 73.7% vs. 87.4%; HR, 1.98; 95% confidence interval (CI), 1.05-3.71; P = 0.035]. IHC revealed that the number of Zeb1⁺ tumor cells increased in tumors from DPP-4i-treated patients than tumors from nonusers (P < 0.01). The densities of CD3⁺ and CD8⁺ T cells were significantly lower in tumors from DPP-4i users (P < 0.01) with decreased density of tertiary lymphoid structures (P < 0.001). However, the density of M2-type tumor-associated macrophages with CD68⁺ CD163⁺ phenotypes was significantly higher (P < 0.01) in tumors from DPP-4i users. Exposure of colorectal cancer to DPP-4i may accelerate epithelial-to-mesenchymal transition (EMT) creating a tumor-permissive immune microenvironment, which might impair the outcomes of the patients with colorectal cancer and T2DM.

Significance

DPP-4i has been shown to enhance the antitumor effects of immunotherapy. However, we found that DPP-4i significantly impairs the outcomes of patients with colorectal cancer who underwent curative resection, possibly through acceleration of EMT and creation of a tumor-permissive immune microenvironment. This suggests that DPP-4i must be used with caution until its safety is fully confirmed by further studies of the mechanistic effects on existing cancers in humans.

Sodium-Glucose Co-Transporter 2 Inhibitors May Change the Development of Urinary Tract and Hematological Malignancies as Compared With Dipeptidyl Peptidase-4 Inhibitors: Data of the Post-Hoc Analysis of a Nationwide Study

Background

In diabetes mellitus, during the last years, cancer became of equivalent importance as a cardiovascular disease in terms of mortality. In an earlier study, we have analyzed data of the National Health Insurance Fund (NHIF) of Hungary with regards all patients treated with sodium-glucose co-transporter 2 (SGLT2) inhibitors (SGLT2is) vs. those treated with dipeptidyl peptidase-4 (DPP-4) inhibitors (DPP-4is) in a given timeframe. In propensity score-matched groups of SGLT2i- vs. DPP-4i-treated patients, we found a lower incidence of cancer in general. In this post-hoc analysis, we aimed to obtain data on the incidence of site-specific cancer.

Patients and Methods

All patients starting an SGLT2i or a DPP-4i between 2014 and 2017 in Hungary were included; the two groups (SGLT2i vs. DPP-4i) were matched for 54 clinical and demographical parameters. The follow-up period was 639 vs. 696 days, respectively. Patients with a letter “C” International Classification of Diseases, 10th Revision (ICD-10) code have been chosen, and those with a known malignancy within a year before the onset of the study have been excluded from the analysis.

Results

We found a lower risk of urinary tract [HR 0.50 (95% CI: 0.32–0.79) p = 0.0027] and hematological malignancies [HR 0.50 (95% CI: 0.28–0.88) p = 0.0174] in patients treated with SGLT2i vs. those on DPP-4i. Risk of other types of cancer (including lung and larynx, lower gastrointestinal (GI) tract, rectum, pancreas, non-melanoma skin cancers, breast, or prostate) did not differ significantly between the two groups. When plotting absolute risk difference against follow-up time, an early divergence of curves was found in case of prostate, urinary tract, and hematological malignancies, whereas late divergence can be seen in case of cancers of the lung and larynx, the lower GI tract, and the breast.

Conclusions

Urinary tract and hematological malignancies were less frequent in patients treated with SGLT2i vs. DPP-4i. An early vs. late divergence could be observed for different cancer types, which deserves further studies.

Dipeptidyl Peptidase 4 Inhibitors Decrease the Risk of Hepatocellular Carcinoma in Patients With Chronic Hepatitis C Infection and Type 2 Diabetes Mellitus: A Nationwide Study in Taiwan

Introduction: Dipeptidyl peptidase 4 inhibitors (DPP-4 inhibitors) are incretin-based oral antidiabetic drugs. Previous studies have shown an association between increased plasma activity of DPP-4 and chronic hepatitis C virus (HCV) infection. Dipeptidyl peptidase 4 inhibitors may be associated with preventing the development of chronic HCV infection. The aim of this study was to investigate whether the use of DPP-4 inhibitors is associated with a decreased risk of hepatocellular carcinoma (HCC) in patients with diabetes mellitus (DM) and chronic HCV infection.

Methods: In this retrospective cohort study, we enrolled patients with type 2 diabetes and chronic HCV infection from the National Health Insurance Research Database (NHIRD) in Taiwan. The patients were divided into two groups (DPP-4 inhibitor cohort and non-DPP-4 inhibitor cohort) according to whether or not they received DPP-4 inhibitor treatment.

Results: Multivariate Cox proportional hazard regression analysis showed a significantly lower risk of HCC in the patients who took DPP-4 inhibitors compared to those who did not. Kaplan-Meier survival analysis demonstrated a significantly higher HCC-free rate in the DPP-4 inhibitor cohort than in the non-DPP-4 inhibitor cohort.

Conclusion: The use of DPP-4 inhibitors was associated with a lower risk of HCC in patients with type 2 DM and chronic HCV infection.

Repurposing DPP-4 Inhibitors for Colorectal Cancer: A Retrospective and Single Center Study

Simple Summary

Colorectal cancer is one of the most common causes and the leading cause of cancer deaths worldwide. Its poor prognosis highlights the urgent need for more effective treatments. Repurposing approved drugs is a promising strategy as preclinical screenings can be minimized. The aim of our retrospective study was to investigate the potential of Dipeptidyl-peptidase 4 (DPP4)-inhibitors, which are safe Food and Drug Association (FDA)-approved drugs for treating diabetes, in treating CRC patients. Our findings conclude that CRC patients with diabetes and treated with DPP4-inhibitors in our hospital during 2006–2015, their 5-year prognosis following curative resection was significantly better than those treated with metformin. We further showed that their prognosis was associated with immune cell population features that associated with better prognosis, and immune cell profile is a biomarker for predicting the prognosis of DPP4-inhibitors treated CRC patients.

Abstract

Background: There have been studies reporting the crucial roles of Dipeptidyl-peptidase 4 (DPP4) in colorectal cancer (CRC) initiation and progression, whereas DPP4-inhibitors are safe Food and Drug Association (FDA)-approved drugs for treating diabetes. This study aims to investigate the association between DPP4-inhibitor treatment and the prognosis of CRC patients. Methods: Clinical data of CRC patients with diabetes and the prescription of DPP4-inhibitors who had undergone curative surgery in our hospital between January 2006 and December 2015 were retrieved. Their survival data and immune cell population in circulatory blood were compared to those treated with metformin. Results: The DPP4-inhibitor patient group showed a significantly better 5-year disease-free survival (median DFS = 1733 days, 95% CI = 1596 to 1870 days) when compared to the metformin group (p = 0.030, median DFS = 1382 days, 95% CI = 1246 to 1518 days). 33 out of the 92 patients in the metformin group showed recurrence whereas only 3 of the 26 patients in the DPP4-inhibitor group showed recurrence (p = 0.033). Cox regression analysis demonstrated that DPP4-inhibitor application is a favorable factor associated with a lower risk of recurrence (Hazard ratio = 0.200, p = 0.035). Furthermore, our results suggested that the immune cell profile of CRC patients is a potential biomarker for response to DPP4-inhibitor treatment. Conclusion: This study demonstrated the association of DPP4-inhibitor treatment with a better prognosis of CRC patients.

The Triple Health Threat of Diabetes, Obesity, and Cancer-Epidemiology, Disparities, Mechanisms, and Interventions

Obesity and type 2 diabetes are both chronic, relapsing, progressive diseases that are recognized as risk factors for the development of multiple types of cancer. In a recent symposium titled "Hitting A Triple-Diabetes, Obesity, and the Emerging Links to Cancer Risk," convened by The Obesity Society during ObesityWeek 2019, experts in the field presented the current science and highlighted existing research gaps. Topics included (1) the epidemiology of obesity and diabetes and their links to cancer risk; (2) racial and ethnic differences in obesity, diabetes, and cancer risk; (3) biological mechanisms common to obesity and diabetes that may increase cancer risk; and (4) innovative interventions that can be used to prevent the development of cancers related to obesity and diabetes. This report provides an overview of the symposium and describes key research gaps and pressing questions in need of answers to advance the field. The collective burden of obesity, diabetes, and cancer represents one of the largest public health challenges of the century. Although the symposium was titled "hitting a triple," it was recognized that being able to disrupt the linkages among obesity, diabetes, and cancer would be a "grand slam" for public health and medicine.

Photosensitizing Medications and Skin Cancer: A Comprehensive Review

(1) The incidence of skin cancer is increasing in the United States (US) despite scientific advances in our understanding of skin cancer risk factors and treatments. In vitro and in vivo studies have provided evidence that suggests that certain photosensitizing medications (PSMs) increase skin cancer risk. This review summarizes current epidemiological evidence on the association between common PSMs and skin cancer. (2) A comprehensive literature search was conducted to identify meta-analyses, observational studies and clinical trials that report on skin cancer events in PSM users. The associated risks of keratinocyte carcinoma (squamous cell carcinoma and basal cell carcinoma) and melanoma are summarized, for each PSM. (3) There are extensive reports on antihypertensives and statins relative to other PSMs, with positive and null findings, respectively. Fewer studies have explored amiodarone, metformin, antimicrobials and vemurafenib. No studies report on the individual skin cancer risks in glyburide, naproxen, piroxicam, chlorpromazine, thioridazine and nalidixic acid users. (4) The research gaps in understanding the relationship between PSMs and skin cancer outlined in this review should be prioritized because the US population is aging. Thus the number of patients prescribed PSMs is likely to continue to rise.

CD26/DPP-4: Type 2 Diabetes Drug Target with Potential Influence on Cancer Biology

Simple Summary

Dipeptidyl peptidase (DPP)-4 inhibitor is widely used for type 2 diabetes. Although DPP-4/CD26 has been recognized as both a suppressor and inducer in tumor biology due to its various functions, how DPP-4 inhibitor affects cancer progression in diabetic patients is still unknown. The aim of this review is to summarize one unfavorable aspect of DPP-4 inhibitor in cancer-bearing diabetic patients.

Abstract

DPP-4/CD26, a membrane-bound glycoprotein, is ubiquitously expressed and has diverse biological functions. Because of its enzymatic action, such as the degradation of incretin hormones, DPP-4/CD26 is recognized as the significant therapeutic target for type 2 diabetes (T2DM); DPP-4 inhibitors have been used as an anti-diabetic agent for a decade. The safety profile of DPP-4 inhibitors for a cardiovascular event in T2DM patients has been widely analyzed; however, a clear association between DPP-4 inhibitors and tumor biology is not yet established. Previous preclinical studies reported that DPP-4 suppression would impact tumor progression processes. With regard to this finding, we have shown that the DPP-4 inhibitor induces breast cancer metastasis and chemoresistance via an increase in its substrate C-X-C motif chemokine 12, and the consequent induction of epithelial-mesenchymal transition in the tumor. DPP-4/CD26 plays diverse pivotal roles beyond blood glucose control; thus, DPP-4 inhibitors can potentially impact cancer-bearing T2DM patients either favorably or unfavorably. In this review, we primarily focus on the possible undesirable effect of DPP-4 inhibition on tumor biology. Clinicians should note that the safety of DPP-4 inhibitors for diabetic patients with an existing cancer is an unresolved issue, and further mechanistic analysis is essential in this field.

Dual Inhibition of DPP-4 and Cholinesterase Enzymes by the Phytoconstituents of the Ethanolic Extract of Prosopis cineraria Pods: Therapeutic Implications for the Treatment of Diabetes-associated Neurological Impairments

BACKGROUND

Insulin resistance causes decreased uptake of glucose which promotes the susceptibility of type 2 associated neurological impairments.

METHODS

The study was aimed to evaluate the inhibition potential of the ethanolic extract of Prosopis cineraria (EPC) pods against DPP-4 and cholinesterase enzymes by in-vitro, in-vivo and in-silico assessments. The present study consists of in vivo studies on a diabetes-induced rat model by HOMA (Homeostasis model assessment) and related parameters, in vitro studies through the DPP-4 enzyme assay and cholinesterase assays using Ellman's reaction. The in-silico studies were conducted by the molecular docking of Cinerin C with targeted enzymes. The phytochemical characterization of the extract was demonstrated through LCMS studies. The antioxidant studies on the extract were performed by FRAP and TEAC assays.

RESULTS

The extract showed 64.8% maximum inhibition of DPP-4, 34.91% inhibition of AChE and 74.35% inhibition of BuChE. The antioxidant capacity of the extract was observed to be 847.81±16.25μM Fe2+ equivalent in the FRAP assay and 0.40 ± 0.08 mmol/l of Trolox equivalent in the TEAC assay. The in vivo study showed competent glycaemic control against significant HOMA IR (1.5), HOMA % β (26.5) and HOMA % S (68.8) as well as pancreatic cell mass proliferation. The insilico analysis also revealed positive interactions of Cinerin C with targeted enzymes (DPP4 and cholinesterase).

CONCLUSION

It can be concluded that the phytoconstituents of Prosopis cineraria pod extract can be significantly considered in neuropharmacology to resolve insulin resistance-induced neurological complications as it showed inhibition against DPP-4, AChE and BuChE target enzymes.

Dipeptidyl peptidase-4 inhibitors and the risks of autoimmune diseases in type 2 diabetes mellitus patients in Taiwan: a nationwide population-based cohort study

AIMS

Dipeptidyl peptidase-4, a transmembrane glycoprotein expressed in various cell types, serves as a co-stimulator molecule to influence immune response. This study aimed to investigate associations between DPP-4 inhibitors and risk of autoimmune disorders in patients with type 2 diabetes mellitus in Taiwan.

METHODS

This retrospective cohort study used the nationwide data from the diabetes subsection of Taiwan National Health Insurance Research Database between January 1, 2009, and December 31, 2013. Cox proportional hazards models were developed to compare the risk of autoimmune disorders and the subgroup analyses between the DPP-4i and DPP-4i-naïve groups.

RESULTS

A total of 774,198 type 2 diabetic patients were identified. The adjusted HR of the incidence for composite autoimmune disorders in DPP-4i group was 0.56 (95% CI 0.53-0.60; P < 0.001). The subgroup analysis demonstrated that the younger patients (aged 20-40 years: HR 0.47, 95% CI 0.35-0.61; aged 41-60 years: HR 0.50, 95% CI 0.46-0.55; aged 61-80 years: HR 0.63, 95% CI 0.58-0.68, P = 0.0004) and the lesser duration of diabetes diagnosed (0-5 years: HR 0.48, 95% CI 0.44-0.52; 6-10 years: HR 0.48, 95% CI 0.43-0.53; ≧ 10 years: HR 0.86, 95% CI 0.78-0.96, P < 0.0001), the more significant the inverse association of DPP-4 inhibitors with the incidence of composite autoimmune diseases.

CONCLUSIONS

DPP-4 inhibitors are associated with lower risk of autoimmune disorders in type 2 diabetes mellitus patients in Taiwan, especially for the younger patients and the lesser duration of diabetes diagnosed. The significant difference was found between the four types of DPP-4 inhibitors and the risk of autoimmune diseases. This study provides clinicians with useful information regarding the use of DPP-4 inhibitors for treating diabetic patients.

In Silico ADMET Evaluation of Natural DPP-IV Inhibitors for Rational Drug Design against Diabetes

BACKGROUND

As a metabolic and lifestyle disorder, diabetes mellitus poses a prodigious health risk. Out of the many key targets, DPP-IV is one of the very imperative therapeutic targets for the treatment of diabetic patients.

METHODS

In our current study, we have done the in silico simulations of ADME-T properties for naturally originated potent DPP-IV inhibitors like quinovic acid, stigmasterol, quinovic acid-3-beta-D-glycopyranoside, zygophyloside E, and lupeol. Structural topographies associated with different pharmacokinetic properties have been systematically assessed.

RESULTS

Glycosylation on quinovic acid is found to be noteworthy for the improvement of pharmacokinetic and toxicological properties, which leads to the prediction that zygophyloside E can be further tailored down to get the lead DPP-IV inhibitor.

CONCLUSION

This assessment provides useful insight into the future development of novel drugs for the treatment of diabetes mellitus.

Review of Associations Between Type 2 Diabetes and Cancer

Debate is ongoing regarding the relationship between type 2 diabetes and cancer, and the pathways linking the two are incompletely understood. Some posit that the relationship hinges on a common predisposing factor such as obesity, insulin resistance, or chronic inflammation that increases the risk of cancer independently. Others speculate that diabetes acts as an independent risk factor for cancer because of other molecular pathways and interactions. Additionally, antidiabetic medications have been associated with changes in cancer risk. This review presents a summary of the latest studies and data concerning the relationships among type 2 diabetes, antidiabetic medications, cancer risk, and cancer prognosis.

Cancer Biology and Prevention in Diabetes

The available evidence suggests a complex relationship between diabetes and cancer. Epidemiological data suggest a positive correlation, however, in certain types of cancer, a more complex picture emerges, such as in some site-specific cancers being specific to type I diabetes but not to type II diabetes. Reports share common and differential mechanisms which affect the relationship between diabetes and cancer. We discuss the use of antidiabetic drugs in a wide range of cancer therapy and cancer therapeutics in the development of hyperglycemia, especially antineoplastic drugs which often induce hyperglycemia by targeting insulin/IGF-1 signaling. Similarly, dipeptidyl peptidase 4 (DPP-4), a well-known target in type II diabetes mellitus, has differential effects on cancer types. Past studies suggest a protective role of DPP-4 inhibitors, but recent studies show that DPP-4 inhibition induces cancer metastasis. Moreover, molecular pathological mechanisms of cancer in diabetes are currently largely unclear. The cancer-causing mechanisms in diabetes have been shown to be complex, including excessive ROS-formation, destruction of essential biomolecules, chronic inflammation, and impaired healing phenomena, collectively leading to carcinogenesis in diabetic conditions. Diabetes-associated epithelial-to-mesenchymal transition (EMT) and endothelial-to-mesenchymal transition (EndMT) contribute to cancer-associated fibroblast (CAF) formation in tumors, allowing the epithelium and endothelium to enable tumor cell extravasation. In this review, we discuss the risk of cancer associated with anti-diabetic therapies, including DPP-4 inhibitors and SGLT2 inhibitors, and the role of catechol-o-methyltransferase (COMT), AMPK, and cell-specific glucocorticoid receptors in cancer biology. We explore possible mechanistic links between diabetes and cancer biology and discuss new therapeutic approaches.

Risk of cancer in patients treated with dipeptidyl peptidase-4 inhibitors: an extensive meta-analysis of randomized controlled trials

AIMS

Observational studies and meta-analyses of randomized trials on dipeptidyl peptidase-4 inhibitors (DPP4i) reported discordant results on the risk of malignancies with this class of drugs. Aim of the present meta-analysis is the assessment of the effect of DPP4i treatment on the incidence of different types of cancer, collecting all available evidence from randomized controlled trials.

METHODS

An extensive MEDLINE, EMBASE, and Cochrane database search for sitagliptin or vildagliptin or omarigliptin or saxagliptin or alogliptin or trelagliptin or anagliptin or linagliptin or gemigliptin or evogliptin or teneligliptin was performed up to September 30th, 2019. All trials performed on type 2 diabetes, with duration ≥ 24 weeks, and comparing of DPP4i with placebo or active drugs were collected. The study has been registered on PROSPERO (#153344). Mantel-Haenszel odds ratio (MH-OR) with 95% confidence interval (95% CI) was calculated for all outcomes.

RESULTS

A total of 157 eligible trials were identified. DPP-4i were not associated with an increased risk of overall cancer (MH-OR 0.93 [0.86, 1.00]; p = 0.07), with no significant differences across individual molecules of the class. When compared with placebo/none, a lower risk of cancer with DPP-4i was observed in placebo-controlled trials (MH-OR 0.90 [0.82, 0.99], p = 0.030), whereas no significant differences have been detected with any other comparators. DPP-4i was associated with a significant reduction in colorectal cancer (MH-OR 0.70 [0.53, 0.94], p = 0.020).

CONCLUSIONS

Available data do not support the hypothesis of an association of DPP4i treatment with malignancies, with a possible beneficial effect for colon-rectal cancer.

DPP4i, thiazolidinediones, or insulin and risks of cancer in patients with type 2 diabetes mellitus on metformin-sulfonylurea dual therapy with inadequate control

INTRODUCTION

This study aims to compare the risks of cancer among patients with type 2 diabetes mellitus (T2DM) on metformin-sulfonylurea dual therapy intensified with dipeptidyl peptidase 4 inhibitors (DPP4i), thiazolidinediones, or insulin.

RESEARCH DESIGN AND METHODS

We assembled a retrospective cohort data of 20 577 patients who were free of cancer and on metformin-sulfonylurea dual therapy, and whose drug treatments were intensified with DPP4i (n=9957), insulin (n=7760), or thiazolidinediones (n=2860) from January 2006 to December 2017. Propensity-score weighting was used to balance out baseline covariates across the three groups. HRs for any types of cancer, cancer mortality, and all-cause mortality were assessed using Cox proportional-hazards models.

RESULTS

Over a mean follow-up period of 34 months with 58 539 person-years, cumulative incidences of cancer, cancer mortality, and all-cause mortality were 0.028, 0.009, and 0.072, respectively. Patients intensified with insulin had the highest incidence of all-cause mortality (incidence rate=3.22/100 person-years) and the insulin itself posed the greatest risk (HR 2.46, 95% CI 2.25 to 2.70, p<0.001; 2.44, 95% CI 2.23 to 2.67) compared with thiazolidinediones and DPP4i, respectively. Comparing between thiazolidinediones and DPP4i, thiazolidinediones was associated with higher risk of cancer (HR 1.43, 95% CI 1.25 to 1.63) but not cancer mortality (HR 1.21, 95% CI 0.92 to 1.58) and all-cause mortality (HR 0.99, 95% CI 0.88 to 1.11). Insulin was associated with the greatest risk of cancer mortality (HR 1.36, 95% CI 1.09 to 1.71; 1.65, 95% CI 1.31 to 2.07) compared with thiazolidinediones and DPP4i, respectively.

CONCLUSIONS

For patients with T2DM on metformin-sulfonylurea dual therapy, the addition of DPP4i was the third-line medication least likely to be associated with cancer mortality and cancer effect among three options, and posed no increased risk for all-cause mortality when compared with thiazolidinediones.

Repurposing of drugs: An attractive pharmacological strategy for cancer therapeutics

Human malignancies are one of the major health-related issues though out the world and anticipated to rise in the future. The development of novel drugs/agents requires a huge amount of cost and time that represents a major challenge for drug discovery. In the last three decades, the number of FDA approved drugs has dropped down and this led to increasing interest in drug reposition or repurposing. The present review focuses on recent concepts and therapeutic opportunities for the utilization of antidiabetics, antibiotics, antifungal, anti-inflammatory, antipsychotic, PDE inhibitors and estrogen receptor antagonist, Antabuse, antiparasitic and cardiovascular agents/drugs as an alternative approach against human malignancies. The repurposing of approved non-cancerous drugs is an effective strategy to develop new therapeutic options for the treatment of cancer patients at an affordable cost in clinics. In the current scenario, most of the countries throughout the globe are unable to meet the medical needs of cancer patients because of the high cost of the available cancerous drugs. Some of these drugs displayed potential anti-cancer activity in preclinic and clinical studies by regulating several key molecular mechanisms and oncogenic pathways in human malignancies. The emerging pieces of evidence indicate that repurposing of drugs is crucial to the faster and cheaper discovery of anti-cancerous drugs.

Incretin-based drugs and risk of lung cancer among individuals with type 2 diabetes

AIM

To assess whether dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists are associated with an increased lung cancer risk among individuals with type 2 diabetes.

METHODS

We conducted a population-based cohort study using the UK Clinical Practice Research Datalink. We identified 130 340 individuals newly treated with antidiabetes drugs between January 2007 and March 2017, with follow-up until March 2018. We used a time-varying approach to model use of dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists compared with use of other second- or third-line antidiabetes drugs. We used Cox proportional hazards models to estimate the adjusted hazard ratios, with 95% CIs, of incident lung cancer associated with use of dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists, separately, by cumulative duration of use, and by time since initiation.

RESULTS

A total of 790 individuals were newly diagnosed with lung cancer (median follow-up 4.6 years, incidence rate 1.5/1000 person-years, 95% CI 1.4-1.6). Compared with use of second-/third-line drugs, use of dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists was not associated with an increased lung cancer risk (hazard ratio 1.07, 95% CI 0.87-1.32, and hazard ratio 1.02, 95% CI 0.68-1.54, respectively). There was no evidence of duration-response relationships.

CONCLUSIONS

In individuals with type 2 diabetes, use of incretin-based drugs was not associated with increased lung cancer risk.

Impact of DPP4 Inhibitors in Survival of Patients With Prostate, Pancreas, and Breast Cancer

Background: Dipeptidyl peptidase-4 (DPP4), a cell surface protein, exhibits a crucial role in tumor biology and regulation of the immune system. We aim to study the impact of DPP4 inhibitors (DPP4i) in patients with prostate cancer (PRC), pancreatic cancer (PC) and breast cancer (BC).

Methods: Using the SEER and Medicare linked database, we identified patients with PRC or PC or BC with coexisting type II diabetes mellitus between 2007 and 2015. Patients were classified into four groups: (1) not on either DPP4i or metformin (reference group), this group included patient that were on anti-diabetic agents other than metformin or DPP4i (2) metformin only, (3) DPP4i only, and (4) DPP4i along with metformin (combination group). Overall survival (OS) analyses were performed using SAS®, version 9.4.

Results: We identified 15,330 patients with PRC, 5,359 patients with PC and 16,085 patients with BC. In PRC cohort, patients on DPP4i had significant survival advantage with HR 0.77 (95% CI: 0.64–0.93), P = 0.005 when compared to the reference group. Patients taking metformin also had significant OS benefit with HR 0.87 (95% CI: 0.81–0.93), P < 0.0001 when compared to the reference group. However, in BC cohort, OS did not favor the patients taking DPP4i with HR 1.07 (95% CI: 0.93–1.25, P = 0.33). Similarly, in PC cohort, OS was indifferent for the patients on DPP4i with HR 1.07 (95% CI: 0.93–1.24, P = 0.68). Upon subgroup analyses of PRC patients, the survival favored the group taking DPP4i, irrespective of stage, use of chemotherapy, androgen-deprivation therapy, and prostatectomy or radiation therapy.

Conclusions: DPP4i seems to improve survival in PRC patients; however, not in PC or BC patients. While the exact mechanism involved remains to be elucidated, a prospective clinical trial would help to confirm these findings.

The paradox of dipeptidyl peptidase IV inhibition in enterocytic differentiation and epithelial-mesenchymal transition in rat cholestatic sepsis

Proper enterocytic proliferation/differentiation, besides providing adequate adherens junctions (AJ) integrity, are responsible for strengthening of the gut barrier that acts as a first line defense against endotoxemia. However, the preferential role of the underlying PI3K/Akt (PKB) axis in triggering enterocytic proliferation/differentiation signaling and AJ assembly is still obscure in sepsis. Additionally, the potential involvement of dipeptidyl peptidase (DPP)-IV in cholestatic sepsis has not yet been reported. Common bile duct ligation (CBDL) insult was performed in adult male Sprague-Dawley rats except for sham operated animals; three doses of vildagliptin (VLD3, 10 and 30 mg/kg/d; p.o) were administered for 10 consecutive days post CBDL. VLD3/10/30 dose-dependently decreased DPP-IV and elevated GLP-1, IGF-1, PI3K, pS473-Akt (PKB), pS9-GSK-3β, pS133-CREB and cyclin-D1. VLD3/10 reduced fever, portal/aortic endotoxin and IgG, body weight loss as well as ileal NF-κB, TNF-α, MPO, TBARS, subepithelial/pericryptal and submucosal collagen deposition, vimentin immunoreactivity, N-cadherin, Zeb1 and pY654-β-catenin but increased E-cadherin, NPSH and colon/spleen indices - effects that were quite the opposite of VLD30. Accordingly, maintaining proper enterocytic proliferation/differentiation and phosphorylation inputs consequent to adequate DPP-IV inhibition is integral to AJ assembly in cholestatic sepsis; however, perturbed signals by excessive suppression of the enzyme activity induce toxic effects manifested as AJ disassembly and EMT, hence gut leakage and overt endotoxemia.

Dipeptidyl peptidase 4 inhibitors and their potential immune modulatory functions

Dipeptidyl peptidase 4 (DPP4) inhibitors (DPP4is) are oral anti-diabetic drugs (OADs) for the treatment of type 2 diabetes mellitus (T2DM) through inhibiting the degradation of incretin peptides. Numerous investigations have been focused on the effects of DPP4is on glucose homeostasis. However, there are limited evidences demonstrating their Potential modulatory functions in the immune system. DPP4, originally known as the lymphocyte cell surface protein CD26, is widely expressed in many types of immune cells including CD4(+) and CD8(+) T cells, B cells, NK cells, dendritic cells, and macrophages; and regulate the functions of these cells. In addition, DPP4 is capable of modulating plenty of cytokines, chemokines and peptide hormones. Accordingly, DPP4/CD26 is speculated to be involved in various immune/inflammatory diseases and DPP4is may become a new drug class applied in these diseases. This review focuses on the regulatory effects of DPP4is on immune functions and their possible underlying mechanisms. Further clinical studies will be necessitated to fully evaluate the administration of DPP4is in diabetic patients with or without immune diseases.

Incident cancer risk in dipeptidyl peptidase-4 inhibitor-treated patients with type 2 diabetes mellitus

Objective

It is known that patients with diabetes are susceptible to cancer development due to long-standing diabetic conditions. This study aimed to investigate new-onset cancer risk associated with dipeptidyl peptidase-4 (DPP-4) inhibitors as compared to metformin, the first-line antidiabetic agent with promising anticancer activity, in patients with type 2 diabetes mellitus (T2DM).

Methods

A retrospective cohort study of adult T2DM patients was performed at a tertiary care hospital in Korea. Patients who received comparison therapies during 2008–2017 were propensity score (PS)-matched in a 1:1 ratio either to the DPP-4 inhibitors group or to the metformin group in accordance with their primary antidiabetic therapy.

Results

A total of 1538 patients (769 in each group) were found eligible for study entry. Although the rate of newly diagnosed malignancy, irrespective of specific sites or types, was numerically less frequent in the DPP-4 inhibitors group, the difference in overall cancer risk between groups was not statistically significant (HR=1.00, 95% CI=0.56–1.80, P=0.998). The PS-matched patients were further stratified by relevant patient factors and diabetes severity. No signal of increased risk of malignant complications among DPP-4 inhibitor-receiving diabetic patients was detected in any of the individual strata, nor in the subgroup patients where insulin-exposed patients were excluded from study analyses in consideration of its carcinogenic properties. Patient death or incident pancreatitis events were seldom encountered in both treatment groups; hence such risks were assessed as negligible with the use of either antidiabetic therapy.

Conclusion

This PS-matched cohort study demonstrated no elevated risk of malignant complications with DPP-4 inhibitor treatment relative to metformin treatment among T2DM patients, irrespective of patient sex, age, comorbid conditions, and diabetes severity status. Similar results were confirmed in the subgroup analyses where a potential confounding effect due to the between-group disparity in insulin co-therapy was eliminated by excluding insulin-exposed patients from risk assessments.

Does the use of incretin-based medications increase the risk of cancer in patients with type-2 diabetes mellitus?

PURPOSE

Incretin-based medications are a novel class of agents for the treatment of type-2 diabetes mellitus (DM2). The safety profile of these medications is not firmly established, and concerns have been raised about their potential carcinogenicity. The objective of our study was to produce new evidence on the effect of incretin-based medications on cancer risk in patients with DM2.

METHODS

We conducted a "retrospective cohort" study with data from the Clinical Practice Research Datalink and the Hospital Episodes Statistics in the UK. New users of either an incretin-based medication (n = 18 885) or a sulfonylurea medication (n = 36 929) between 2007 and 2013 were identified and followed for up to 8 years. Cox proportional-hazards models were used to estimate the quasi-intention-to-treat and quasi-per-protocol hazard-ratios for the association between incretin-based medications with cancer while adjusting for potential confounders.

RESULTS

The adjusted hazard ratio (95% confidence interval) for use of incretin-based medications versus use of sulfonylurea medications for the overall-cancer outcome was 0.97 (0.90, 1.05) in the quasi-intention-to-treat analysis and 0.90 (0.81, 1.00) in the quasi-per-protocol analysis. In both analyses, the hazard-ratio functions over the 8-year follow-up seemed fairly constant, and the 8-year cumulative-risk functions in the two subcohorts were similar.

CONCLUSIONS

Our study suggests that the use of incretin-based medications in patients with DM2 does not increase the risk of cancer relative to the use of sulfonylurea medications, at least in the first several years of the use. Further research is needed to assess long-term effects of the use of incretin-based medications on cancer risk.

Association between glucose-lowering treatment and cancer metastasis among patients with preexisting type 2 diabetes and incident malignancy

Preclinical data suggested that dipeptidyl peptidase-4 (DPP-4) inhibitors may promote metastatic progression of preexisting cancer via nuclear factor erythroid 2-related factor 2 (NRF2) activation. We aimed to investigate the association between different glucose-lowering treatments, including DPP-4 inhibitors and metformin, both with potential NRF2 modulating effects, and new-onset metastatic cancer among type 2 diabetes patients with comorbid incident cancer. This population-based cohort study included 223,530 diabetic patients newly diagnosed with primary cancer during 2009-2011 in Korea. The patients were categorized into five study cohorts in accordance with treatment modalities during the follow-up until the end of 2016: no-antidiabetic drugs (no-AD), metformin, DPP-4 inhibitors, metformin+DPP-4 inhibitors, and insulin treatment. After propensity score (PS) matching in a 1:1 ratio against the no-AD group, 18,805 patients in metformin, 1,865 in DPP-4 inhibitors, 31,074 in metformin+DPP-4 inhibitors, and 1,895 patients in insulin groups were identified for cohort entry and analyzed against the corresponding number of no-AD patients in each PS-matched comparison pair. Metastatic risk was lower with metformin plus or minus DPP-4 inhibitors (HR 0.84, 95% CI 0.79-0.90 and 0.87, 0.80-0.95, respectively), not significantly associated with DPP-4 inhibitors (0.99, 0.77-1.29) except after thyroid cancer (3.89, 1.01-9.64), and higher with insulin therapy (1.81, 1.46-2.24) compared to no-AD use for all cancers combined. In conclusion, DPP-4 inhibitor therapy was not associated with significant risk of cancer metastasis relative to no-AD therapy, irrespective of patient age and sex, except after thyroid cancer, while metastatic risk was decreased with metformin treatment among type 2 diabetes patients with preexisting cancer.

Downregulation of Dipeptidyl Peptidase 4 Accelerates Progression to Castration-Resistant Prostate Cancer

The standard treatment for metastatic prostate cancer, androgen deprivation therapy (ADT), is designed to suppress androgen receptor (AR) activity. However, men invariably progress to castration-resistant prostate cancer (CRPC), and AR reactivation contributes to progression in most cases. To identify mechanisms that may drive CRPC, we examined a VCaP prostate cancer xenograft model as tumors progressed from initial androgen sensitivity prior to castration to castration resistance and then on to relapse after combined therapy with further AR-targeted drugs (abiraterone plus enzalutamide). AR activity persisted in castration-resistant and abiraterone/enzalutamide-resistant xenografts and was associated with increased expression of the AR gene and the AR-V7 splice variant. We then assessed expression of individual AR-regulated genes to identify those that persisted, thereby contributing to tumor growth, versus those that decreased and may therefore exhibit tumor suppressor activities. The most significantly decreased AR target gene was dipeptidyl peptidase 4 (DPP4), which encodes a membrane-anchored protein that cleaves dipeptides from multiple growth factors, resulting in their increased degradation. DPP4 mRNA and protein were also decreased in clinical CRPC cases, and inhibition of DPP4 with sitagliptin enhanced the growth of prostate cancer xenografts following castration. Significantly, DPP4 inhibitors are frequently used to treat type 2 diabetes as they increase insulin secretion. Together, these results implicate DPP4 as an AR-regulated tumor suppressor gene whose loss enhances growth factor activity and suggest that treatment with DPP4 inhibitors may accelerate emergence of resistance to ADT.Significance: These findings identify DPP4 as an AR-stimulated tumor suppressor gene that is downregulated during progression to castration-resistant prostate cancer, warning that treatment with DPP4 inhibitors, commonly used to treat type 2 diabetes, may accelerate prostate cancer progression following androgen deprivation therapy. Cancer Res; 78(22); 6354-62. ©2018 AACR.

Metformin combined with dipeptidyl peptidase-4 inhibitors or metformin combined with sulfonylureas in patients with type 2 diabetes: A real world analysis of the South Korean national cohort

AIMS

We explored the risks associated with metformin plus sulfonylurea (MET + SU) or MET plus a dipeptidyl peptidase-4 inhibitor (MET + DPP4i) for hypoglycemia, cardiovascular disease (CVD) events and all-cause mortality in type 2 diabetes (T2D) patients with comorbidities.

METHODS

This retrospective cohort study is based on the South Korean National Health Insurance Service-National Sample Cohort, enrolling T2D patients with one or more diabetes-related comorbidities who switched from monotherapy to MET + SU or MET + DPP4i between July 1, 2008 and December 31, 2013. The risk of hypoglycemia, CVD events and all-cause mortality was examined using Cox's proportional hazard modeling and propensity score matching.

RESULTS

Overall, 5693 patients with a mean of 2.6 comorbidities in addition to diabetes were included. Compared with MET + SU, MET + DPP4i treatment was associated with a lower risk of hypoglycemia, CVD events and all-cause mortality; adjusted HRs (95% CI), 0.39 (0.18-0.83), 0.72 (0.54-0.97), and 0.64 (0.39-1.05), respectively. Propensity score matching showed comparable results. In further subgroup analyses according to comorbidity type and number, MET + DPP4i was associated with less CVD events and all-cause mortality compared to MET + SU. This increased with more complex comorbid status.

CONCLUSIONS

In T2D patients with comorbidities, MET + DPP4i treatment is associated with lower risks of CVD events and all-cause mortality compared with MET + SU, independent of type or number of comorbidities. A more complex comorbid status further increases this effect.

Neoplasms Reported With Liraglutide or Placebo in People With Type 2 Diabetes: Results From the LEADER Randomized Trial

OBJECTIVE

This study explored neoplasm risk with liraglutide versus placebo in the LEADER (Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results) cohort.

RESEARCH DESIGN AND METHODS

LEADER (NCT01179048) was an international, phase 3b, randomized, double-blind, controlled trial. Participants aged ≥50 years with type 2 diabetes and high cardiovascular risk were assigned 1:1 to receive liraglutide (≤1.8 mg daily; n = 4,668) or placebo (n = 4,672) in addition to standard care and monitored for 3.5-5 years (median follow-up 3.8 years). The occurrence of neoplasms was a prespecified, exploratory secondary end point. Post hoc analyses of the time to the first confirmed neoplasms were conducted using a Cox regression model.

RESULTS

Neoplasm was confirmed in 10.1% of patients with liraglutide versus 9.0% with placebo (hazard ratio [HR] 1.12 [95% CI 0.99; 1.28]). The HR (95% CI) for liraglutide versus placebo was 1.06 (0.90; 1.25) for malignant neoplasms and 1.16 (0.93; 1.44) for benign neoplasms. Sensitivity analyses excluding neoplasms occurring <1 year or <2 years after randomization and analyses by sex provided similar results. In our main analyses, the 95% CI for the HR included one for all malignant neoplasms evaluated (including pancreatic and thyroid neoplasms) except for prostate neoplasms, which occurred in fewer liraglutide-treated patients.

CONCLUSIONS

LEADER was not primarily designed to assess neoplasm risk. Firm conclusions cannot be made regarding numeric imbalances observed for individual neoplasm types (e.g., pancreatic cancer) that occurred infrequently. LEADER data do, however, exclude a major increase in the risk of total malignant neoplasms with liraglutide versus placebo. Additional studies are needed to assess longer-term exposure.