Safety of sitagliptin in elderly patients with type 2 diabetes: a pooled analysis of 25 clinical studies

Sitagliptin elevates plasma and CSF incretin levels following oral administration to nonhuman primates: relevance for neurodegenerative disorders

The endogenous incretins glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) possess neurotrophic, neuroprotective, and anti-neuroinflammatory actions. The dipeptidyl peptidase 4 (DPP-4) inhibitor sitagliptin reduces degradation of endogenous GLP-1 and GIP, and, thereby, extends the circulation of these protective peptides. The current nonhuman primate (NHP) study evaluates whether human translational sitagliptin doses can elevate systemic and central nervous system (CNS) levels of GLP-1/GIP in naive, non-lesioned NHPs, in line with our prior rodent studies that demonstrated sitagliptin efficacy in preclinical models of Parkinson's disease (PD). PD is an age-associated neurodegenerative disorder whose current treatment is inadequate. Repositioning of the well-tolerated and efficacious diabetes drug sitagliptin provides a rapid approach to add to the therapeutic armamentarium for PD. The pharmacokinetics and pharmacodynamics of 3 oral sitagliptin doses (5, 20, and 100 mg/kg), equivalent to the routine clinical dose, a tolerated higher clinical dose and a maximal dose in monkey, were evaluated. Peak plasma sitagliptin levels were aligned both with prior reports in humans administered equivalent doses and with those in rodents demonstrating reduction of PD associated neurodegeneration. Although CNS uptake of sitagliptin was low (cerebrospinal fluid (CSF)/plasma ratio 0.01), both plasma and CSF concentrations of GLP-1/GIP were elevated in line with efficacy in prior rodent PD studies. Additional cellular studies evaluating human SH-SY5Y and primary rat ventral mesencephalic cultures challenged with 6-hydroxydopamine, established cellular models of PD, demonstrated that joint treatment with GLP-1 + GIP mitigated cell death, particularly when combined with DPP-4 inhibition to maintain incretin levels. In conclusion, this study provides a supportive translational step towards the clinical evaluation of sitagliptin in PD and other neurodegenerative disorders for which aging, similarly, is the greatest risk factor.

Clinical Phenotypes and the Clinical Course of Bullous Pemphigoid Receiving Dipeptidyl Pepitidase-4 Inhibitor Treatment: An Analysis of Cases in a Single Japanese Center

Objective Several studies have shown an increased risk of bullous pemphigoid (BP) when receiving dipeptidyl pepitidase-4 inhibitor (DPP-4i) treatment. The present study explored the associations of DPP-4i treatment with the clinical phenotypes and clinical course of BP. Methods We analyzed data of 146 patients with BP at Tokai University School of Medicine from December 1, 2009, to December 31, 2021. We obtained data by a retrospective medical record review and compared the bullous pemphigoid disease area index (BPDAI) between diabetes patients receiving DPP-4i treatment and those not receiving DPP-4i treatment. We employed multivariable linear regression models to explore the association between the DPP-4i treatment and the BPDAI scores. Results Among 53 BP patients with diabetes, 33 had developed BP during treatment with DPP-4i agents, among which vildagliptin was the most frequently used. The urticaria/erythema scores of the BPDAI were significantly lower in patients who developed BP while receiving DPP-4i treatment than among others. Of note, 69.2% of the patients who stopped DPP-4i treatment experienced complete remission, and the clinical course was more favorable in patients with lower scores for urticaria/erythema than among others. Conclusion These findings suggest that, in patients who developed BP while receiving DPP-4i treatment, a noninflammatory phenotype may indicate a high likelihood that DPP-4i treatment contributes to the development of BP. The discontinuation of DPP-4i should be carefully considered in close consultation with dermatologists.

Efficacy / safety balance of DPP-4 inhibitors versus SGLT2 inhibitors in elderly patients with type 2 diabetes

Dipeptidyl peptidase-4 inhibitors (DPP-4is) and sodium-glucose cotransporter type 2 inhibitors (SGLT2is) offer new options for the oral management of type 2 diabetes mellitus (T2DM), with the advantage in the elderly population to be devoid of a high risk of hypoglycaemia. SGLT2is have also shown benefits regarding cardiovascular (heart failure) and renal protection, including in patients with T2DM aged ≥ 65 years while DPP-4is have only proved cardiovascular and renal safety without superiority compared with placebo. The glucose-lowering efficacy of the two pharmacological classes is almost similar including in older patients with T2DM. However, the tolerance and safety profile may be highly different and overall more favourable with DPP-4is than with SGLT2is. Some adverse events have been reported with SGLT2is which may be more prevalent or severe in older patients than in younger patients. The present comprehensive review focuses on the benefit/risk balance in the elderly population with T2DM by comparing the profile of DPP-4is and SGLT2is regarding the following potential issues: metabolic disorders (hypoglycaemia and diabetic ketoacidosis); cardiac and vascular issues (atheromatous cardiovascular disease, heart failure, volume reduction hypotension, and lower limb amputations); renal endpoints including acute renal injury; risk of infections; digestive disorders; bone and skin adverse events; and cancer risk. Both DPP-4is and SGLT2is have their own advantages and disadvantages. Personalised treatment is recommended based upon the efficacy/safety profile of each drug class and individual patient characteristics that may be markedly different among the heterogeneous population of older individuals with T2DM.

Careful use to minimize adverse events of oral antidiabetic medications in the elderly

INTRODUCTION

An increasing number of older patients has type 2 diabetes treated with different oral antidiabetic agents whose safety may raise concern considering some particularities of a heterogeneous elderly population.

AREAS COVERED

This article discusses some characteristics of older patients that could increase the risk of adverse events, with a focus on hypoglycemia. It describes the most frequent and/or severe complications reported in the elderly in both randomized controlled trials and observational studies with metformin, sulfonylureas, meglitinides, alpha-glucosidase inhibitors, thiazolidinediones, dipeptidyl peptidase-4 inhibitors (gliptins) and sodium-glucose cotransporter type 2 inhibitors (gliflozins).

EXPERT OPINION

Old patients may present comorbidities (renal impairment, vascular disease, heart failure, risk of dehydration, osteoporosis, cognitive dysfunction) that could increase the risk of severe adverse events. Sulfonylureas (and meglitinides) induce hypoglycemia, which may be associated with falls/fractures and cardiovascular events. Medications lacking hypoglycemia should be preferred. Gliptins appear to have the best tolerance/safety profile whereas gliflozins exert a cardiorenal protection. However, data are lacking in very old or frailty old patients so that caution and appropriate supervision of such patients are required. Taking advantage of a large choice of pharmacotherapies, personalized treatment is recommended based upon both drug safety profiles and old patient individual characteristics.

Efficacy and Safety of Sitagliptin Compared with Dapagliflozin in People ≥ 65 Years Old with Type 2 Diabetes and Mild Renal Insufficiency

INTRODUCTION

Older patients with type 2 diabetes (T2D) are at increased risk of diabetic nephropathy and mild renal insufficiency. This analysis compared the anti-hyperglycemic efficacy and safety of sitagliptin with dapagliflozin in patients ≥ 65 years of age with T2D and mild renal insufficiency.

METHODS

This was a post hoc analysis of data from 410 patients ≥ 65 years old who participated in a 24-week, randomized, double-blind clinical trial (CompoSIT-R [comparison of sitagliptin with dapagliflozin in mild renal impairment]; NCT02532855) in T2D patients with mild renal insufficiency and on metformin ± a sulfonylurea; the primary efficacy end point was change in HbA1c at week 24.

RESULTS

Treatment groups were well balanced at baseline (mean HbA1c = 7.7/7.7% and eGFR = 79/76 ml/min/1.73 m² for sitagliptin/dapagliflozin). At week 24, LS mean (95% CI) change in HbA1c and percentage of patients with HbA1c < 7% were greater with sitagliptin, - 0.48% and 41%, respectively, compared with dapagliflozin, - 0.36% and 28%; between-group differences = - 0.12% (- 0.36, 0.01) and 12.8% (3.3, 22.2) for change in HbA1c and percentage with HbA1c < 7%, respectively. The sitagliptin group had greater reductions in PPG end points, while the dapagliflozin group had greater reductions in FPG. Treatments were generally well tolerated. There were fewer drug-related adverse events (AEs) with sitagliptin than with dapagliflozin but AE profiles were otherwise similar.

CONCLUSIONS

In patients ≥ 65 years of age with T2D and mild renal insufficiency with inadequate glycemic control on metformin ± sulfonylurea, treatment with sitagliptin for 24 weeks resulted in improvement in HbA1c relative to treatment with dapagliflozin that is consistent with that previously observed in the overall population. Both treatments were generally well tolerated.

Antiproteinuric effect of DPP-IV inhibitors in diabetic and non-diabetic kidney diseases

Diabetes Mellitus (DM) is a chronic and severe metabolic disease, characterized by chronic hyperglycemia due to insulin resistance and/or reduced insulin secretion. Concerning the non-insulin glucose-lowering therapy for diabetes, Dipeptidyl-peptidase-4 (DPP-4) inhibitors, members of the incretin family, represent new agents, capable of a glycemic control improvement with an advantageous safety profile, given the absence of weight gain, the low incidence of hypoglycemia and the good renal tolerance in patients suffering from chronic renal failure. In addition to demonstrating efficacy in glycemic control through inhibition of GLP-1 degradation, DPP-4 inhibitors (DPP-4is) seem to demonstrate pleiotropic effects, which also make them interesting in both diabetic and non-diabetic nephropathies, especially for their capacity of reducing proteinuria. Several studies about diabetic nephropathy on patients' cohorts and murine models have demonstrated a solid direct relationship between DPP-4 activity and urinary albumin excretion (UAE), thus confirming the capacity of DPP-4is to reduce proteinuria; the mechanism responsible for that effect was studied to assess if it was the result of a direct action on renal impairment or a secondary consequence of the better glycemic control related to these agents. As a result of these more in-depth studies, DPP-4is have demonstrated an improvement of renal inflammation markers and consequent proteinuria reduction, regardless of glucose concentrations. Considering the nephroprotective effects of DPP-4is might be glycemic independent, several studies were conducted to prove the validity of the same effects in non-diabetic nephropathies. Among these studies, DPP-4is demonstrated an improvement of various renal inflammatory markers on several models of non-diabetes dependent renal impairment, confirming their capacity to reduce proteinuria, independently from the action on glucose metabolism. The objective of this review is to present and discuss the so far demonstrated antiproteinuric effect of DPP-4is and their effects on diabetic and non-diabetic nephropathies.

Diabetes Treatment in the Elderly: Incorporating Geriatrics, Technology, and Functional Medicine

PURPOSE OF REVIEW

The current approach to diabetes in the elderly incorporates components from the comprehensive geriatric approach. The most updated guidelines from the American Diabetes Association reflect influence from the consensus made in 2012 with the American Geriatrics Society. Notably, the framework included the evaluation for geriatric syndromes (falls and urinary incontinence), functional and cognitive abilities. The goal for this review is to provide an updated summary of treatment strategies for community-dwelling older adults. We identified the need to expand our approach by addressing innovative approaches and scientific concepts from telemedicine, functional medicine, and geriatrics.

RECENT FINDINGS

Findings on cardiovascular protection with sodium-glucose co-transporter 2 inhibitors (SGLT-2i) and some glucagon-like peptide 1 receptor agonists (GLP-1RA) support their use for older patients with diabetes. However, careful consideration for agent selection must incorporate the presence of geriatric issues, such as geriatric syndromes, or functional and cognitive decline, as they could increase the risk and impact adverse reactions. Telemedicine interventions can improve communication and connection between older patients and their providers, and improve glycemic control. Functional medicine concepts can offer additional adjuvant strategies to support the therapeutic interventions and management of diabetes in the elderly. A systematic review confirmed the efficacy and safety of metformin as first-line therapy of type 2 diabetes in the older adult, but multiple reports highlighted the risk for vitamin B12 deficiency. Randomized controlled trials showed the efficacy and safety of antihyperglycemic agents in the elderly, including some with longer duration and lesser risk for hypoglycemia. Randomized clinical trials showed cardiovascular protection with SGLT-2i (empagliflozin, canagliflozin) and GLP-1RA (liraglutide, semaglutide). The most current guidelines recommend addressing for geriatric syndromes, physical and cognitive function in the elderly, in order to individualize targets and therapeutic strategies. Clinicians managing diabetes in the elderly can play a major role for the early detection and evaluation of geriatric issues in their patients. Telemedicine interventions improve glycemic control, and certain functional medicine strategies could be adjuvant interventions to reduce inflammation and stress, but more studies focused on the elderly population are needed.

[Treatment of type 2 diabetes mellitus in elderly patients]

The prevalence of type 2 diabetes mellitus (DM2) increases markedly with age. Antidiabetic treatment and the objectives of glycaemic control in elderly patients with DM2 should be individualised according to their biopsychosocial characteristics. In elderly patients for whom the benefits of intensive antidiabetic treatment are limited, the basic objectives should be to improve the quality of life, preserve functionality and avoid adverse effects, especially hypoglycaemia. Treatment of DM2 in the elderly was the subject of a consensus document published in 2012 and endorsed by several Spanish scientific societies. Since then, new therapeutic groups and evidence have emerged that warrant an update to this consensus document. The present document focuses on the therapeutic aspects of DM2 in elderly patients, understood as being older than 75 years or frail.

Treatment of type 2 diabetes mellitus in elderly patients

The prevalence of type 2 diabetes mellitus (DM2) increases markedly with age. Antidiabetic treatment and the objectives of glycaemic control in elderly patients with DM2 should be individualised according to their biopsychosocial characteristics. In elderly patients for whom the benefits of intensive antidiabetic treatment are limited, the basic objectives should be to improve the quality of life, preserve functionality and avoid adverse effects, especially hypoglycaemia. Treatment of DM2 in the elderly was the subject of a consensus document published in 2012 and endorsed by several Spanish scientific societies. Since then, new therapeutic groups and evidence have emerged that warrant an update to this consensus document. The present document focuses on the therapeutic aspects of DM2 in elderly patients, understood as being older than 75 years or frail.

Efficacy and safety of sitagliptin as compared with glimepiride in Japanese patients with type 2 diabetes mellitus aged ≥ 60 years (START-J trial)

The aim of this study was to evaluate the efficacy and safety of sitagliptin administered to elderly patients with type 2 diabetes mellitus (T2DM) for 1 year as compared with glimepiride. Patients aged ≥60 years with T2DM and inadequately controlled blood glucose were randomly assigned to sitagliptin 50 mg once daily or glimepiride 0.5 mg once daily for 52 weeks. The primary efficacy endpoint was the change in glycated haemoglobin (HbA1c) from baseline to week 52. Secondary efficacy endpoints included self-monitored blood glucose and weight. Safety endpoints were adverse events including hypoglycaemia. Administration of sitagliptin or glimepiride to elderly patients with T2DM resulted in a significant decrease in HbA1c change from baseline. At 52 weeks, the least squares mean difference between the treatments was 0.11% (95% confidence interval [CI] -0.02 to 0.24; P = .087) (1.2 mmol/mol [-0.2 to 2.6]). The upper limit of the CI was below the predefined non-inferiority margin (0.3% [3.3 mmol/mol]), demonstrating non-inferiority of sitagliptin to glimepiride for the primary endpoint. Sitagliptin resulted in a significantly lower incidence rate of non-serious hypoglycaemia than glimepiride during the 52 weeks (4.7% vs 16.1%; P = .002); thus, sitagliptin is a useful therapeutic option for elderly patients with T2DM.

Efficacy and safety of sitagliptin in elderly patients with type 2 diabetes mellitus and comparison of hypoglycemic action of concomitant medications: a subanalysis of the JAMP study

Purpose

To determine the efficacy and safety of sitagliptin when used with some therapeutic drugs to treat elderly patients.

Methods

Sitagliptin (50 mg/day) was added to the pre-existing therapy for type 2 diabetes. Changes in the glycated hemoglobin (HbA1c) level after 3 months of treatment were compared with the baseline, and exploratory analysis was performed. These analyses were conducted as subanalyses of the JAMP study, which was an open-label observational study.

Results

For patients who were ≥65 years of age, the change in HbA1c level from baseline ranged from -0.50 to -0.87% at 3 months after starting treatment. There was no significant difference in the change in HbA1c level between the patients treated with different concomitant drugs. No significant difference in HbA1c variations at 3 and 12 months from baseline was noted among the three age groups (≥75, 65-74, and <65 years). Multiple regression analysis was performed, and it revealed that patients with higher HbA1c levels at baseline were likely to show decreased HbA1c levels, while those with higher triglyceride (TG) levels were unlikely to show decreased HbA1c levels.

Conclusion

Sitagliptin has the potential to both improve glycemic control and prevent hypoglycemia, and can be considered a potent alternative drug.

Lixisenatide Therapy in Older Patients With Type 2 Diabetes Inadequately Controlled on Their Current Antidiabetic Treatment: The GetGoal-O Randomized Trial

OBJECTIVE

To evaluate the efficacy and safety of lixisenatide versus placebo on glycemic control in older patients with type 2 diabetes uncontrolled on their current antidiabetic treatment.

RESEARCH DESIGN AND METHODS

In this phase III, double-blind, randomized, placebo-controlled, two-arm, parallel-group, multicenter trial, patients aged ≥70 years were randomized to receive once-daily lixisenatide 20 μg or placebo before breakfast concomitantly with their existing antidiabetic therapy (including insulin) for 24 weeks. Patients at risk for malnutrition or with moderate to severe cognitive impairment were excluded. The primary end point was absolute change in HbA_1c from baseline to week 24. Secondary end points included change from baseline to week 24 in 2-h postprandial plasma glucose (PPG) and body weight.

RESULTS

A total of 350 patients were randomized. HbA_1c decreased substantially with lixisenatide (-0.57% [6.2 mmol/mol]) compared with placebo (+0.06% [0.7 mmol/mol]) from baseline to week 24 (P < 0.0001). Mean reduction in 2-h PPG was significantly greater with lixisenatide (-5.12 mmol/L) than with placebo (-0.07 mmol/L; P < 0.0001). A greater decrease in body weight was observed with lixisenatide (-1.47 kg) versus placebo (-0.16 kg; P < 0.0001). The safety profile of lixisenatide in this older population, including rates of nausea and vomiting, was consistent with that observed in other lixisenatide studies. Hypoglycemia was reported in 17.6% of patients with lixisenatide versus 10.3% with placebo.

CONCLUSIONS

In nonfrail older patients uncontrolled on their current antidiabetic treatment, lixisenatide was superior to placebo in HbA_1c reduction and in targeting postprandial hyperglycemia, with no unexpected safety findings.

Efficacy and safety of linagliptin according to patient baseline characteristics: A pooled analysis of three phase 3 trials

BACKGROUND AND AIMS

We aimed to determine if patient baseline characteristics affect responses to linagliptin and identify relevant predictors of glycated hemoglobin (HbA1c) reduction in patients with type 2 diabetes mellitus (T2DM).

METHODS AND RESULTS

Data were pooled from three 24-week, placebo-controlled trials of similar design (linagliptin, n = 1651; placebo, n = 607). Patients were categorized according to baseline characteristics: age, T2DM duration, gender, body mass index (BMI), Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), and metabolic syndrome (MetS). Changes from baseline in HbA1c after 24 weeks were assessed with analysis of covariance (ANCOVA). The proportion of patients with baseline HbA1c >7% achieving HbA1c of ≤7% at week 24 were evaluated. Independent predictors of HbA1c response with linagliptin were analyzed in a multivariate analysis with ANCOVA. Linagliptin treatment led to significant mean (SE) placebo-corrected reductions from baseline in HbA1c across all subgroups (-0.42% [±0.11] to -0.79% [0.08]; all p < 0.001). Within subgroups, HbA1c reduction was more pronounced in patients without MetS (-0.74% [0.06]; treatment interaction p = 0.0489). The proportion of patients with baseline HbA1c >7% achieving a target HbA1c ≤7% was greater with linagliptin versus placebo (30.2% vs 11.5%; odds ratio 3.82; 95% CI 2.82 to 5.17; p < 0.001). Characteristics significantly predicting HbA1c reductions after 24 weeks were fasting plasma glucose and race (both p < 0.05).

CONCLUSION

This post-hoc analysis supports that linagliptin achieved clinically meaningful improvements in hyperglycemia in patients with diverse clinical characteristics. These improvements were more pronounced in patients without MetS.

Efficacy of hypoglycemic treatment in type 2 diabetes stratified by age or diagnosed age: a meta-analysis

AIM

To compare the effects of blood glucose lowering regimens in groups of patients categorized by baseline age and diagnosed age.

METHODS

Placebo-controlled randomized trials in type 2 diabetes patients with a study length ≥12 weeks were included.

RESULTS

A total of 246 trials were included. HbA1c changes from baseline corrected by placebo were comparable in sulfonylurea treatment between older and younger patients' groups (weighted mean difference (WMD), -1.28% vs -0.92%, p > 0.05). Treatment with metformin between groups resulted in a comparable change in HbA1c levels (WMD, -0.97% vs -1.23%, p > 0.05). Treatment with α-glucosidase inhibitor (WMD, -0.68% vs -0.67%, p > 0.05), treatment with thiazolidinedione (WMD, -0.74% vs -1.01%, p > 0.05), treatment with DPP-4 inhibitors (WMD, -0.67% vs -0.67%, p > 0.05), and treatment with SGLT2 inhibitors (WMD, -0.54% vs -0.67%, p > 0.05) between groups also resulted in comparable HbA1c changes. Treatment with GLP-1 analogs between groups in HbA1c changes were also comparable (p > 0.05). Regression analysis indicated that the baseline age or diagnosed age was not associated with the HbA1c changes from baseline.

CONCLUSION

In each hypoglycemic treatment, the baseline age or diagnosed age was not associated with the HbA1c changes from baseline.

Clinical pharmacology of dipeptidyl peptidase 4 inhibitors indicated for the treatment of type 2 diabetes mellitus

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a class of oral antidiabetic drugs that improve glycaemic control without causing weight gain or increasing hypoglycaemic risk in patients with type 2 diabetes mellitus (T2DM). The eight available DPP-4 inhibitors, including alogliptin, anagliptin, gemigliptin, linagliptin, saxagliptin, sitagliptin, teneligliptin, and vildagliptin, are small molecules used orally with identical mechanism of action and similar safety profiles in patients with T2DM. DPP-4 inhibitors may be used as monotherapy or in double or triple combination with other oral glucose-lowering agents such as metformin, thiazolidinediones, or sulfonylureas. Although DPP-4 inhibitors have the same mode of action, they differ by some important pharmacokinetic and pharmacodynamic properties that may be clinically relevant in some patients. The main differences between the eight gliptins include: potency, target selectivity, oral bioavailability, elimination half-life, binding to plasma proteins, metabolic pathways, formation of active metabolite(s), main excretion routes, dosage adjustment for renal and liver insufficiency, and potential drug-drug interactions. The off-target inhibition of selective DPP-4 inhibitors is responsible for multiorgan toxicities such as immune dysfunction, impaired healing, and skin reactions. As a drug class, the DPP-4 inhibitors have become accepted in clinical practice due to their excellent tolerability profile, with a low risk of hypoglycaemia, a neutral effect on body weight, and once-daily dosing. It is unknown if DPP-4 inhibitors can prevent disease progression. More clinical studies are needed to validate the optimal regimens of DPP-4 inhibitors for the management of T2DM when their potential toxicities are closely monitored.

Sitagliptin for Type 2 diabetes: a 2015 update

Sitagliptin, a dipeptidyl peptidase 4 inhibitor, was the first in its class to receive approval from the US FDA in 2006 for the treatment of Type 2 diabetes mellitus. It has been evaluated in numerous clinical trials and has several attractive features as an antidiabetic agent, including a low risk for hypoglycemia, a neutral effect on weight, and an ability to be used in chronic kidney disease and more. This article provides an up-to-date discussion of the pharmacokinetics/pharmacodynamics, clinical efficacy, safety and tolerability of sitagliptin.

Two-year assessment of the efficacy and safety of sitagliptin in elderly patients with type 2 diabetes: Post hoc analysis of the ASSET-K study

BACKGROUND

There have only been a few reports about use of dipeptidyl peptidase 4 (DPP-4) inhibitors in elderly patients with type 2 diabetes mellitus (T2DM), suggesting that the safety of these agents has not been sufficiently demonstrated. We performed a comparative review of the efficacy and safety of sitagliptin for Japanese patients with T2DM managed in the real-world clinical setting.

METHODS

An age-stratified analysis was performed of 831 patients who were treated with sitagliptin for 2 years. Parameters assessed included the hemoglobin A1c (HbA1c), body weight, serum creatinine, and adverse events. HbA1c and the incidence of hypoglycemia were also evaluated in patients treated with sitagliptin and a sulfonylurea (SU), who were divided into three age groups (<65 years, 65-74 years, and ≥75 years).

RESULTS

Comparison of glycemic control parameters, laboratory values, and adverse events revealed significant improvement of HbA1c, casual postprandial plasma glucose, and fasting plasma glucose in each age group with no change in body weight. Serum creatinine increased significantly in all age groups. Hypoglycemia only occurred in patients who received combined treatment with an SU and sitagliptin, and there was no age-related difference in its incidence.

CONCLUSIONS

HbA1c was improved by 2 years of sitagliptin therapy in all three age groups, and age did not seem to influence the incidence of hypoglycemic events. These results confirm the efficacy and safety of sitagliptin in patients ≥ 75 years old, suggesting that it is also useful for treating elderly patients with T2DM.

[Differential characteristics of type 2 diabetes in the elderly. Role of dipeptidyl peptidase 4 inhibitors]

The prevalence of type 2 diabetes mellitus increases with age, reaching rates around 30% in those over 75 years. The type 2 diabetes mellitus in the elderly has different pathophysiological and clinical characteristics from those of the younger diabetic patient. Some differential aspects in this population are the lower life expectancy and the frequent comorbidity, frailty and associated disability. Avoiding hypoglycemia is a therapeutic priority, given their increased risk of severe hypoglycemia. It is a situation in which the benefits of intensive glycemic control are virtually non-existent, thus prevention of side effects of treatments becomes a priority. Therefore, the goals of glycemic control should be less stringent than in the general population (glycated hemoglobin>7%), and the drugs of choice should be those with a low risk of side effects (especially hypoglycemia) and well tolerated. Dipeptidyl peptidase 4 inhibitors (iDPP4) are particularly useful in this age group, either as a second drug added to metformin monotherapy, or as first line when metformin is contraindicated or not tolerated. In this article the evidence available on the efficacy and tolerance of different pharmacological options available in population over 70 years is reviewed.

Combination Therapy When Metformin Is Not an Option for Type 2 Diabetes

Objective: Consensus on combination options for patients with type 2 diabetes mellitus (T2DM) unable to use metformin is lacking. This review summarizes data describing–non-metformin based combination therapy. Data Sources: PubMed searches (January 1990 to August 2014) were conducted with terms for newer drug therapies alone and with the term combination; filters were applied for Clinical Trial, Meta Analysis, and English language. Study Selection and Data Extraction: Results were reviewed for multicenter, randomized controlled trials of non-metformin–based combination therapy conducted in the past 5 years and specific to the US or multinational populations. Data Synthesis: Although multiple injectable and oral agents have been studied in combination with metformin for management of T2DM, data are more limited for combinations without metformin. Combinations of incretins (injectable glucagon-like peptide-1 receptor agonists or oral dipeptidyl peptidase-4 [DPP-4] inhibitors) with a sulfonylurea, thiazolidinedione, or insulin are well studied and provide greater glucose-lowering efficacy than monotherapy. Incretins are associated with a low risk of hypoglycemia when used as monotherapy; the dosage of sulfonylurea or insulin should be reduced when used in combination. Newer studies are investigating the combined use of an oral sodium-glucose cotransporter 2 inhibitor and a DPP-4 inhibitor. In a recent study, reductions in glycated hemoglobin (A1C) of 1.1% to 1.2% and reduced weight with no additive risk of hypoglycemia were observed. Conclusions: Selecting the most appropriate combination therapy for patients with T2DM requires balancing clinical benefits with the risks, such as weight gain and hypoglycemia. Treatment approaches should be individualized for vulnerable patient populations for whom metformin is not appropriate.

Management of diabetes in the elderly

Management of diabetes in the elderly necessitates careful consideration of concomitant geriatric syndromes and comorbid conditions that increase the risk of complications, including severe hypoglycemia. Whereas healthy older adults can use therapeutic approaches recommended for their younger counterparts, treatment plans for frail elderly patients need to be simplified and A1c and blood pressure goals relaxed with the development of impairments in function, cognition, vision, and dexterity. The goals of diabetes management in the elderly should be to maintain quality of life and minimize symptomatic hyperglycemia and drug side effects, including hypoglycemia.

Safety of dipeptidyl peptidase-4 inhibitors for treating type 2 diabetes

INTRODUCTION

Dipeptidyl peptidase-4 (DPP-4) inhibitors (gliptins) occupy a growing place in the armamentarium of drugs used for the management of hyperglycemia in type 2 diabetes, although some safety concerns have been raised in recent years.

AREAS COVERED

An updated review providing an analysis of available safety data (meta-analyses, randomized controlled trials, observational cohort and case-control studies and pharmacovigilance reports) with five commercialized DPP-4 inhibitors (sitagliptin, vildagliptin, saxagliptin, alogliptin, linagliptin). A special focus is given to overall safety profile; pancreatic adverse events (AEs) (acute pancreatitis, pancreatic cancer); overall cardiovascular safety (myocardial infarction and stroke); congestive heart failure concern and finally, safety in special populations (elderly, renal impairment).

EXPERT OPINION

The good tolerance/safety profile of DPP-4 inhibitors has been largely confirmed, including in more fragile populations (elderly, renal impairment) with almost no increased risk of infection or gastrointestinal AEs, no weight gain and a minimal risk of hypoglycemia. Although an increased risk of acute pancreatitis and pancreatic cancer was suspected, the complete set of available data appears reassuring so far. Cardiovascular safety of DPP-4 inhibitors has been proven but an unexpected increased risk of heart failure has been reported which should be confirmed in ongoing trials and better understood. Further postmarketing surveillance is recommended.

An updated review on cancer risk associated with incretin mimetics and enhancers

Incretin-based therapies, including the use of incretin mimetics of glucagon-like peptide-1 receptor (GLP-1R) agonists and incretin enhancers of dipeptidyl-peptidase 4 (DPP-4) inhibitors, are widely used by clinicians for glucose lowering in patients with type 2 diabetes mellitus. These agents have benefits of a lower risk of hypoglycemia, being neutral for body weight for DPP-4 inhibitors and having a potential for weight reduction with GLP-1R agonists. They may also have a neutral or beneficial cardiovascular effect. Despite these benefits, an increased risk of cancer (especially pancreatic cancer and thyroid cancer) associated with incretin-based therapies has been reported. In this article, we reviewed related literature of experimental animal and observational human studies, clinical trials, and meta-analyses published until December 15, 2014. Current studies suggested a probable role of GLP-1R activation on the development of pancreatic cancer and thyroid cancer in rodents, but such an effect in humans is not remarkable due to the lower or lack of expression of GLP-1R on human pancreatic ductal cells and thyroid tissues. Findings in human studies are controversial and inconclusive. In the analyses of the US Food and Drug Administration adverse events reporting system, a significantly higher risk of pancreatic cancer was observed for GLP-1R agonists and DPP-4 inhibitors, but a significantly higher risk of thyroid cancer was only observed for GLP-1R agonists. Such a higher risk of pancreatic cancer or thyroid cancer could not be similarly demonstrated in other human observational studies or analyses of data from clinical trials. With regards to cancers other than pancreatic cancer and thyroid cancer, available studies supported a neutral association in humans. Some preliminary studies even suggested a potentially beneficial effect on the development of other cancers with the use of incretins. Based on current evidence, continuous monitoring of the cancer issues related to incretin-based therapies is required, even though the benefits may outweigh the potential cancer risk in the general patients with type 2 diabetes mellitus.

Pharmacological treatment of diabetes in older people

The pharmacological management of diabetes in older people is complex and challenging. It requires a comprehensive understanding of the individual beyond the diabetes itself. Through the ageing years, the older individual presents with diabetes-related and non-related comorbidities and complications, develops functional limitations and psychological issues, and may lack social support and access to care. A disturbance in these categories, known as the four geriatric domains, will negatively affect diabetes self-management and self-efficacy, leading to poor outcomes and complications. Furthermore, older people with diabetes may be more interested in the management of other chronic conditions such as pain or impaired mobility, and diabetes may be lower in their list of priorities. Proper education must be provided to the older individual and caregivers, with continuous monitoring and counselling, especially when pharmacological interventions offer risks of side effects, adverse reactions and interactions with other medications. Informed shared medical decisions will help to improve adherence to the regimen; however, such discussions ought to be based on the best evidence available, which is unfortunately limited in this age group. We performed a review focused on pharmacological agents and summarize current evidence on their use for the treatment of diabetes in older people. We encourage clinicians to investigate and incorporate the four geriatrics domains in the selection and monitoring of these agents.

Dipeptidyl peptidase-4 inhibitor linagliptin attenuates neointima formation after vascular injury

BACKGROUND

Recently, glucagon-like peptide-1 (GLP-1)-based therapy, including dipeptidyl peptidase-4 (DPP-4) inhibitors and GLP-1 receptor agonists, has emerged as one of the most popular anti-diabetic therapies. Furthermore, GLP-1-based therapy has attracted increased attention not only for its glucose-lowering ability, but also for its potential as a tissue-protective therapy. In this study, we investigated the vascular-protective effect of the DPP-4 inhibitor, linagliptin, using vascular smooth muscle cells (VSMCs).

METHODS

Six-week-old male C57BL/6 mice were divided into control (n =19) and linagliptin (3 mg/kg/day, n =20) treated groups. Endothelial denudation injuries were induced in the femoral artery at 8 weeks of age, followed by evaluation of neointima formation at 12 weeks. To evaluate cell proliferation of rat aortic smooth muscle cells, a bromodeoxyuridine (BrdU) incorporation assay was performed.

RESULTS

Linagliptin treatment reduced vascular injury-induced neointima formation, compared with controls (p <0.05). In these non-diabetic mice, the body weight and blood glucose levels did not change after treatment with linagliptin. Linagliptin caused an approximately 1.5-fold increase in serum active GLP-1 concentration, compared with controls. In addition, the vascular injury-induced increase in the oxidative stress marker, urinary 8-OHdG, was attenuated by linagliptin treatment, though this attenuation was not statistically significant (p =0.064). Moreover, linagliptin did not change the serum stromal cell-derived factor-1α (SDF-1α) or the serum platelet-derived growth factor (PDGF) concentration. However, linagliptin significantly reduced in vitro VSMC proliferation.

CONCLUSION

Linagliptin attenuates neointima formation after vascular injury and VSMC proliferation beyond the glucose-lowering effect.

The durability of sitagliptin in elderly patients with type 2 diabetes

AIM

To evaluate the durability of sitagliptin and to assess changes in clinical chronic complications following sitagliptin monotherapy for 48 months in elderly patients with type 2 diabetes mellitus (T2DM).

SUBJECTS AND METHODS

We enrolled 76 drug-naïve patients (40 women and 36 men; mean age: 71.3±11.7 years) with T2DM who received 25-100 mg of sitagliptin therapy from an outpatient clinic. The observational period for each patient was >48 months, beginning at the time sitagliptin therapy was initiated. The following were measured or performed at the beginning of each year: body mass index; serum total cholesterol, low-density lipoprotein, high-density lipoprotein; triglyceride levels; creatinine (Cr) levels; urine albumin and urine Cr; nonmydriatic fundusgraphy; and semiquantified neuropathy. The fasting plasma glucose and glycated hemoglobin (HbA1c) was measured every 3-6 months.

RESULTS

The change in HbA1c was significantly reduced after 6 months of therapy (7.1%±0.8% to 6.3%±0.2%). No changes in fasting plasma glucose, Cr, serum total cholesterol, triglyceride, low-density lipoprotein, high-density lipoprotein, body mass index, and microvascular complications were apparent. Using repeated measures to test the sequential changes in HbA1c from month 6 to month 48, the test of within-subjects effect was not significant (P=0.34).

CONCLUSION

Sitagliptin has a durable effect and stabilizes microvascular complication progression in elderly patients. This study can provide useful data for clinicians and health care professionals using sitagliptin monotherapy in the treatment of elderly patients with T2DM.

Pancreatic signal pathways potentially used as targets for treatment of diabetes

The pancreas is the main place where pathological changes of diabetes occur, and inflammation and oxidative stress can interfere with various cell signaling pathways, causing pancreatic lesions and diabetes. Therefore, the pancreas is an important target for the treatment of diabetes. This paper will discuss pancreatic signaling pathways potentially used as targets for the treatment of diabetes in terms of promotion of insulin secretion, inhibition of glucagon secretion, and suppression of islet beta cell apoptosis. The research of these signaling pathways is important for elucidating the pathogenesis of diabetes and developing more safe and effective new drugs. ATP sensitive potassium channel and glucagon like peptide-1 (GLP-1) receptor signaling pathways are associated with insulin secretion and have been widely used as therapeutic targets. The signaling pathway mediated by G protein coupled receptors is a hot spot of diabetes research in recent years, and other signaling pathways are being studied.