Combined therapy with insulin plus oral agents: is there any advantage? An argument in favor

Trends in glycemic control in patients with insulin therapy compared with non-insulin or no drugs in type 2 diabetes in Japan: a long-term view of real-world treatment between 2002 and 2018 (JDDM 66)

INTRODUCTION

We investigated trends in the proportion of diabetes treatment and glycemic control, which may be altered by recent advances in insulin and non-insulin drugs, in Japanese patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A serial cross-sectional study was performed using a multicenter large-population database from the Japan Diabetes Clinical Data Management study group. Patients with type 2 diabetes who attended clinics belonging to the study group between 2002 and 2018 were included to examine trends in glycated hemoglobin A1c (HbA1c) by treatment group using multivariable non-linear regression model.

RESULTS

The proportion of patients with insulin only decreased from 15.0% to 3.6%, patients with insulin+non-insulin drugs increased from 8.1% to 15.1%, patients with non-insulin drugs increased from 50.8% to 67.0%, and those with no drugs decreased from 26.1% to 14.4% from 2002 to 2018, respectively. The HbA1c levels of each group, except for no drugs, continued to decrease until 2014 (unadjusted mean HbA1c (%) from 2002 to 2014: from 7.89 to 7.45 for insulin only, from 8.09 to 7.63 for insulin+non-insulin, and from 7.51 to 6.98 for non-insulin) and remained unchanged thereafter. Among insulin-treated patients, use of human insulin decreased, use of long-acting analog insulin increased, and concomitant use of non-insulin drugs increased (from 35.1% in 2002 to 80.9% in 2018), which included increased use of dipeptidyl peptidase 4 inhibitors, sodium-glucose cotransporter 2 inhibitors, and glucagon-like peptide 1 receptor agonists, and the persistently high use of metformin.

CONCLUSIONS

During the past two decades, combined use of insulin and non-insulin drugs increased and glycemic control improved and leveled off after 2014 in Japanese patients with type 2 diabetes. Further studies of the trend in association with age and factors related to metabolic syndrome are necessary to investigate strategies aiming at personalized medicine in diabetes care.

The current schemes of insulin therapy: Pro and contra

Insulin regimens have been evolving for a century. The schemes used for type 1 (T1D) and type 2 (T2D) diabetes differ due to differences in pathophysiology but share important features. Insulin is required for both types of diabetes when other means of controlling glucose are insufficient. For T1D this requires multiple daily injections or continuous subcutaneous infusion assisted by CGM, whereas in early T2D basal insulin together with oral agents or GLP-1RA is usually effective. In both cases current schemes typically maintain HbA1c levels between 7 and 8%, a range that limits but does not eliminate the long-term complications of diabetes, but do not restore glycemic control to a fully protective level. Inability to control postprandial hyperglycemia without problematic weight gain and hypoglycemia is a leading obstacle in both T1D and long-duration T2D. A greater share of prandial dosing decisions will have to be provided by smart electronic systems. Further changes in the structure or formulation of insulin are of uncertain potential, but schemes including delivery of amylin, GLP-1, and glucagon show promise. More reliable access to insulins, delivery devices, and capable medical advisors will be needed to optimize replacement of this essential hormone.

Treatment intensification in type 2 diabetes management after the failure of two oral hypoglycemic agents: A non-interventional comparative study

OBJECTIVES

The safety and efficacy of treatment approaches in patients with type 2 diabetes mellitus (T2DM) after the failure of two oral hypoglycemic agents (OHAs) was studied.

METHODS

A combination of the ambispective study was conducted between June 2013 to June 2014 at the Asir Diabetes Center, Abha, Kingdom of Saudi Arabia (KSA). Patients with poorly controlled T2DM who were administered two OHAs for at least 6 months and had HbA1c levels greater than 7.0% were included. Subjects were treated with three OHAs (Group I), biphasic insulin and metformin (Group II), two existing OHAs and basal insulin (Group III), and insulin monotherapy (Group IV). Relevant data were collected at baseline at the interval of 3 months for one year.

RESULTS

Amongst 255 patients enrolled, 20.8, 29.8, 32.5, and 16.8% were in Groups I, II, III, and IV, respectively. The mean (Glycated hemoglobin) HbA1c levels were decreased significantly in the groups where insulin was an add-on therapy with the OHAs. Acceptable level of HbA1C (7 %) was significantly higher amongst patients in groups II and III, whereas hypoglycemic events were higher in Group IV.

CONCLUSION

Insulin as add-on therapy with OHAs is an option for the management of T2DM where glycemic control is insufficient with two OHAs.

Development and validation of multivariable clinical diagnostic models to identify type 1 diabetes requiring rapid insulin therapy in adults aged 18-50 years

OBJECTIVE

To develop and validate multivariable clinical diagnostic models to assist distinguishing between type 1 and type 2 diabetes in adults aged 18-50.

DESIGN

Multivariable logistic regression analysis was used to develop classification models integrating five pre-specified predictor variables, including clinical features (age of diagnosis, body mass index) and clinical biomarkers (GADA and Islet Antigen 2 islet autoantibodies, Type 1 Diabetes Genetic Risk Score), to identify type 1 diabetes with rapid insulin requirement using data from existing cohorts.

SETTING

UK cohorts recruited from primary and secondary care.

PARTICIPANTS

1352 (model development) and 582 (external validation) participants diagnosed with diabetes between the age of 18 and 50 years of white European origin.

MAIN OUTCOME MEASURES

Type 1 diabetes was defined by rapid insulin requirement (within 3 years of diagnosis) and severe endogenous insulin deficiency (C-peptide <200 pmol/L). Type 2 diabetes was defined by either a lack of rapid insulin requirement or, where insulin treated within 3 years, retained endogenous insulin secretion (C-peptide >600 pmol/L at ≥5 years diabetes duration). Model performance was assessed using area under the receiver operating characteristic curve (ROC AUC), and internal and external validation.

RESULTS

Type 1 diabetes was present in 13% of participants in the development cohort. All five predictor variables were discriminative and independent predictors of type 1 diabetes (p<0.001 for all) with individual ROC AUC ranging from 0.82 to 0.85. Model performance was high: ROC AUC range 0.90 (95% CI 0.88 to 0.93) (clinical features only) to 0.97 (95% CI 0.96 to 0.98) (all predictors) with low prediction error. Results were consistent in external validation (clinical features and GADA ROC AUC 0.93 (0.90 to 0.96)).

CONCLUSIONS

Clinical diagnostic models integrating clinical features with biomarkers have high accuracy for identifying type 1 diabetes with rapid insulin requirement, and could assist clinicians and researchers in accurately identifying patients with type 1 diabetes.

Achievement of Target A1C <7.0% (<53 mmol/mol) by U.S. Type 2 Diabetes Patients Treated With Basal Insulin in Both Randomized Controlled Trials and Clinical Practice

OBJECTIVE

Many patients with type 2 diabetes do not reach glycemic goals despite basal insulin treatment. This study assessed the achievement of a target A1C <7.0% (<53 mmol/mol) after initiation of basal insulin in two settings.

METHODS

This was a retrospective analysis of pooled randomized controlled trial (RCT) data, from 11 24-week studies of patients initiating basal insulin performed between 2000 and 2005 and of outpatient electronic medical record (EMR) data from the General Electric Centricity database for insulin-naive patients initiating basal insulin between 2005 and 2012. Baseline characteristics stratified by target A1C and fasting plasma glucose (FPG) attainment were compared descriptively.

RESULTS

In the RCT dataset, 49.0% of patients failed to achieve the target A1C at 6 months versus 72.4% and 72.9% at 6 and 12 months in the EMR dataset, respectively. Despite this, in the RCT dataset, 79.4% of patients achieved the target A1C and/or an FPG <130 mg/dL. In the EMR dataset, only 47.6% and 47.3% of patients achieved an A1C <7.0% and/or FPG <130 mg/dL at 6 and 12 months, respectively. Overall, patients with an A1C >7.0% had a longer diabetes duration and were more likely to be female, nonwhite, and self-funding or covered by Medicaid. Among patients with an A1C >7.0%, more RCT patients (58.0%) had an FPG <130 mg/dL than EMR patients at 6 months (27.8%) and 12 months (27.7%).

CONCLUSION

Unmet needs remain after basal insulin initiation, particularly in real-world settings, where many patients require further insulin titration. In both populations, patients failing to achieve the target A1C despite attaining an FPG <130 mg/dL require interventions to improve postprandial control.

Efficacy and safety of linagliptin as add-on therapy to basal insulin and metformin in people with Type 2 diabetes

AIM

To evaluate the efficacy and safety of linagliptin in people with Type 2 diabetes inadequately controlled on basal insulin and metformin.

METHODS

This was a post hoc subanalysis of participants who received basal insulin and metformin in a global phase III study that randomized participants (1:1) to receive linagliptin 5 mg once daily or placebo for ≥52 weeks as add-on therapy to basal insulin alone or in combination with metformin and/or pioglitazone. During the first 24 weeks, the background dose of basal insulin remained stable; thereafter, adjustments based on glucose concentrations were recommended. The primary endpoint of the subanalysis was the change from baseline in HbA1c after 24 weeks. The safety analysis incorporated data up to a maximum of 110 weeks.

RESULTS

A total of 950 participants receiving background insulin and metformin were included in this subanalysis (linagliptin and placebo, both n = 475). At week 24, the placebo-corrected adjusted mean (±se) change from baseline in HbA1c with linagliptin was -7 (±1) mmol/mol [-0.7 (±0.1) %; 95% CI -0.8, -0.6; P < 0.0001]. The overall frequency of drug-related adverse events (linagliptin, 18.9%; placebo, 21.9%) and investigator-reported hypoglycaemia (linagliptin, 30.7%; placebo, 31.6%) were similar in both groups at the end of treatment. The frequency of severe hypoglycaemia was low (linagliptin, 1.7%; placebo, 0.8%). No meaningful changes in mean (±sd) body weight were noted in either group [week 52: linagliptin, -0.5 (±3.2) kg; placebo, 0.0 (±3.1) kg].

CONCLUSIONS

Linagliptin added to basal insulin and metformin improved glycaemic control, without increasing the risk of hypoglycaemia or body weight gain.

Reported Benefits of Insulin Therapy for Better Glycemic Control in Type 2 Diabetic Patients-Is This Applicable in Saudi Patients?

AIM

To compare the effect of different treatment regimens (oral hypoglycemic agents [OHGs], insulin therapy, and combination of both) on glycemic control and other cardiometabolic risk factors in type 2 diabetes mellitus (T2DM) patients in Saudi.

SUBJECTS AND METHODS

Patients with T2DM, but no serious diabetic complications, were randomly recruited from the diabetes clinics at two large hospitals in Jeddah, Saudi Arabia, during June 2013 to July 2014. Only those without change in treatment modality for the last 18 months were included. Blood pressure and anthropometric measurements were measured. Treatment plan was recorded from the patients’ files. Fasting blood sample was obtained to measure glucose, HbA1c, and lipid profile.

RESULTS

A total of 197 patients were recruited; 41.1% were men and 58.9% were women. The mean (±SD) age was 58.5 ± 10.5 years. Most patients (60.7%) were on OHGs, 11.5% on insulin therapy, and 27.7% were using a combination of insulin and OHGs. The mean HbA1c was lower in patients using OHGs only, compared with means in those using insulin, or combined therapy in patients with disease duration of ≤10 years (P = 0.001) and also in those with a longer duration of the disease (P < 0.001). A lower mean diastolic and systolic blood pressure was found among patients on insulin alone (P < 0.01). No significant differences were found in lipid profiles among the groups.

CONCLUSION

Insulin therapy, without adequate diabetes education, fails to control hyperglycemia adequately in Saudi T2DM patients. There is a challenge to find out reasons for poor control and the ways as to how to improve glycemic control in T2DM.

Markers of β-Cell Failure Predict Poor Glycemic Response to GLP-1 Receptor Agonist Therapy in Type 2 Diabetes

OBJECTIVE

To assess whether clinical characteristics and simple biomarkers of β-cell failure are associated with individual variation in glycemic response to GLP-1 receptor agonist (GLP-1RA) therapy in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

We prospectively studied 620 participants with type 2 diabetes and HbA1c ≥58 mmol/mol (7.5%) commencing GLP-1RA therapy as part of their usual diabetes care and assessed response to therapy over 6 months. We assessed the association between baseline clinical measurements associated with β-cell failure and glycemic response (primary outcome HbA1c change 0-6 months) with change in weight (0-6 months) as a secondary outcome using linear regression and ANOVA with adjustment for baseline HbA1c and cotreatment change.

RESULTS

Reduced glycemic response to GLP-1RAs was associated with longer duration of diabetes, insulin cotreatment, lower fasting C-peptide, lower postmeal urine C-peptide-to-creatinine ratio, and positive GAD or IA2 islet autoantibodies (P ≤ 0.01 for all). Participants with positive autoantibodies or severe insulin deficiency (fasting C-peptide ≤0.25 nmol/L) had markedly reduced glycemic response to GLP-1RA therapy (autoantibodies, mean HbA1c change -5.2 vs. -15.2 mmol/mol [-0.5 vs. -1.4%], P = 0.005; C-peptide <0.25 nmol/L, mean change -2.1 vs. -15.3 mmol/mol [-0.2 vs. -1.4%], P = 0.002). These markers were predominantly present in insulin-treated participants and were not associated with weight change.

CONCLUSIONS

Clinical markers of low β-cell function are associated with reduced glycemic response to GLP-1RA therapy. C-peptide and islet autoantibodies represent potential biomarkers for the stratification of GLP-1RA therapy in insulin-treated diabetes.

Combination therapy in type 2 diabetes mellitus: adding empagliflozin to basal insulin

Type 2 diabetes mellitus (T2DM) management is complex, with few patients successfully achieving recommended glycemic targets with monotherapy, most progressing to combination therapy, and many eventually requiring insulin. Sodium glucose cotransporter 2 (SGLT2) inhibitors are an emerging class of antidiabetes agents with an insulin-independent mechanism of action, making them suitable for use in combination with any other class of antidiabetes agents, including insulin. This review evaluates a 78-week, randomized, double-blind, placebo-controlled trial investigating the impact of empagliflozin, an SGLT2 inhibitor, as add-on to basal insulin in patients with inadequate glycemic control on basal insulin, with or without metformin and/or a sulfonylurea. Empagliflozin added on to basal insulin resulted in significant and sustained reductions in glycated hemoglobin (HbA1c) levels compared with placebo. Empagliflozin has previously been shown to induce weight loss, and was associated with sustained weight loss in this study. This combination therapy was well tolerated, with similar levels of hypoglycemic adverse events in the empagliflozin and placebo groups over the 78-week treatment period. Urinary tract infections and genital infections, side effects associated with SGLT2 inhibitors, were reported more commonly in the empagliflozin group; however, such events led to treatment discontinuation in very few patients. These findings suggest that, with their complementary mechanisms of action, empagliflozin added on to basal insulin may be a useful treatment option in patients on basal insulin who need additional glycemic control without weight gain.

A reliable serum C-peptide index for the selection of an insulin regimen to achieve good glycemic control in obese patients with type 2 diabetes: an analysis from a short-term study with intensive insulin therapy

Insulin regimens achieving favorable glycemic control in patients with type 2 diabetes are expected to closely relate to residual insulin secretory ability. We herein attempted to identify a reliable C-peptide immunoreactivity (CPR) index as an insulin secretory marker that would contribute to the selection of an appropriate insulin regimen for patients with type 2 diabetes. We near-normalized blood glucose in 246 obese patients with type 2 diabetes using our protocol (which included short-term intensive insulin therapy, IIT), and administered an oral hypoglycemic agent (OHA). Based on responsiveness to OHA, patients were classified into three therapy groups: non-insulin therapy (n = 78), basal-insulin supported oral therapy (BOT) (n = 109), and multiple daily insulin injection (MDI) therapy (n = 59). Glucagon-loading CPR increment (ΔCPR), fasting CPR (FCPR), CPR2h after breakfast (CPR2h), ratio of FCPR to fasting plasma glucose (CPI), CPI2h after breakfast (CPI2h), and secretory unit of islets in transplantation (SUIT) were assessed with receiver operating characteristic (ROC) and multiple logistic analyses to discriminate the MDI group from the other therapy groups. ROC analysis revealed that CPR2h had the greatest area under the curve and specificity. Multiple logistic analysis identified CPR2h and CPI2h as the most significant explanatory variables for identifying patients assigned to the MDI group. A postprandial serum CPR marker such as CPR2h or CPI2h was shown to be the best index for predicting an appropriate insulin regimen to achieve good glycemic control in obese patients with type 2 diabetes.

Impact of empagliflozin added on to basal insulin in type 2 diabetes inadequately controlled on basal insulin: a 78-week randomized, double-blind, placebo-controlled trial

AIMS

To investigate the efficacy and tolerability of empagliflozin added to basal insulin-treated type 2 diabetes.

METHODS

Patients inadequately controlled [glycated haemoglobin (HbA1c) >7 to ≤10% (>53 to ≤86 mmol/mol)] on basal insulin (glargine, detemir, NPH) were randomized to empagliflozin 10 mg (n = 169), empagliflozin 25 mg (n = 155) or placebo (n = 170) for 78 weeks. The baseline characteristics were balanced among the groups [mean HbA1c 8.2% (67 mmol/mol), BMI 32.2 kg/m(2) ]. The basal insulin dose was to remain constant for 18 weeks, then could be adjusted at investigator's discretion. The primary endpoint was change from baseline in HbA1c at week 18. Key secondary endpoints were changes from baseline in HbA1c and insulin dose at week 78.

RESULTS

At week 18, the adjusted mean ± standard error changes from baseline in HbA1c were 0.0 ± 0.1% (-0.1 ± 0.8 mmol/mol) for placebo, compared with -0.6 ± 0.1% (-6.2 ± 0.8 mmol/mol) and -0.7 ± 0.1% (-7.8 ± 0.8 mmol/mol) for empagliflozin 10 and 25 mg, respectively (both p < 0.001). At week 78, empagliflozin 10 and 25 mg significantly reduced HbA1c, insulin dose and weight vs placebo (all p < 0.01), and empagliflozin 10 mg significantly reduced systolic blood pressure vs placebo (p = 0.004). Similar percentages of patients had confirmed hypoglycaemia in all groups (35-36%). Events consistent with urinary tract infection were reported in 9, 15 and 12% of patients on placebo, empagliflozin 10 and 25 mg, and events consistent with genital infection were reported in 2, 8 and 5%, respectively.

CONCLUSIONS

Empagliflozin for 78 weeks added to basal insulin improved glycaemic control and reduced weight with a similar risk of hypoglycaemia to placebo.

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.

A prospective, randomized, multicenter trial comparing the efficacy and safety of the concurrent use of long-acting insulin with mitiglinide or voglibose in patients with type 2 diabetes

This trial was conducted to compare the efficacy and safety of combination therapy with basal insulin glargine plus mitiglinide to that of basal insulin glargine plus voglibosein patients with type 2 diabetes. This was a 20-week, randomized, multicenter non-inferiority trial. Patients with HbA1c levels over 7.0% were randomly assigned to receive either mitiglinide (10 mg tid) or voglibose (0.2 mg tid) concurrent with insulin glargine for 16 weeks after a 4-week of basal insulin glargine monotherapy. The intention-to-treat population included 156 patients; 79 were placed in the mitiglinide group, and 77 were placed in the voglibose group. At 20 weeks, there was no significant difference between the mitiglinide group and the voglibose group in terms of the mean HbA1c level or the mean decrease of the HbAlc level from baseline (-0.9% [-7.5 mmol/mol] and -0.7%, [-5.3 mmol/mol] respectively). The mean fasting plasma glucose level and data of self-monitoring blood glucosewere significantly decreased from baseline to week 20 in both groups, but there was no significant difference between the two groups. The changes in the basal insulin requirements of each group were not significant. The prevalence of adverse events and the risk of hypoglycemia were similar for both groups. Combination therapy with mitiglinide plus basal insulin glargine was non-inferior to voglibose plus basal insulin glargine in terms of the effect on overall glycemic control.

Efficacy and safety of saxagliptin as add-on therapy in type 2 diabetes

Combination therapy for type 2 diabetes using agents with complementary mechanisms of action may improve glycemic control to a greater extent than monotherapy and allow the use of lower doses of antihyperglycemic medications. Dipeptidyl peptidase-4 inhibitors, including saxagliptin, are recommended as add-on therapy to metformin and as part of two- or three-drug combinations in patients not meeting individualized glycemic goals with metformin alone or as part of a dual-therapy regimen. This article reviews the efficacy and safety of saxagliptin as an add-on therapy to metformin, glyburide, a thiazolidinedione, or insulin (with or without metformin) and as a component of triple therapy with metformin and a sulfonylurea.

Characterization of a novel glucokinase activator in rat and mouse models

Glucokinase (GK) is a hexokinase isozyme that catalyzes the phosphorylation of glucose to glucose-6-phosphate. Glucokinase activators are being investigated as potential diabetes therapies because of their effects on hepatic glucose output and/or insulin secretion. Here, we have examined the efficacy and mechanisms of action of a novel glucokinase activator, GKA23. In vitro, GKA23 increased the affinity of rat and mouse glucokinase for glucose, and increased glucose uptake in primary rat hepatocytes. In vivo, GKA23 treatment improved glucose homeostasis in rats by enhancing beta cell insulin secretion and suppressing hepatic glucose production. Sub-chronic GKA23 treatment of mice fed a high-fat diet resulted in improved glucose homeostasis and lipid profile.

Combination therapy with DPP-4 inhibitors and insulin in patients with type 2 diabetes mellitus: what is the evidence?

As type 2 diabetes mellitus (T2DM) progresses, most patients will require insulin replacement therapy. Whether oral antidiabetic drug (OAD) therapy should be retained when initiating insulin is still debated. While the rationale to keep metformin with insulin is strong (mostly as an insulin-sparing agent to limit weight gain), the evidence is less clear for other OADs. In particular, the question now comes up what the expected benefit could be of combining the newer agents, such as the dipeptidyl peptidase-4 (DPP-4) inhibitors with insulin. Additionally, when metformin is no longer a treatment option, as in the case of patients with severe renal impairment, insulin is often used as monotherapy, with little evidence of benefit in maintaining other OADs. In this specific situation, it is also of interest to evaluate the potential benefit of combined treatment with a DPP-4 inhibitor and insulin. Among the classic limitations of insulin therapy in patients with T2DM, hypoglycemia remains a major barrier to glycemic control, along with weight gain exacerbation. The oral DPP-4 inhibitors improve glycemic control by increasing the sensitivity of the islet cells to glucose, and thus are not associated with an increased risk for hypoglycemia and are weight neutral. In addition to the expected benefits associated with limiting insulin dose and regimen complexity, the specific advantages the DPP-4 inhibitor drug class on hypoglycemia and weight gain could justify combining DPP-4 inhibitors with insulin; additionally, a DPP-4 inhibitor may be of special value to decrease glycemic excursions that are not properly addressed by basal insulin therapy and metformin use, even after optimizing titration of the basal insulin. However, given the common original perception that treatment with DPP-4 inhibitors may be less beneficial with increasing disease progression because of the loss of β-cell function, the potential relevance of these agents in the setting of advanced T2DM treated with insulin was not necessarily anticipated. Promising data from studies on the use of these new agents in insulin-treated patients with T2DM have started to emerge. Our article provides a comprehensive overview of the currently available evidence from controlled randomized clinical trials and we discuss the potential role of DPP-4 inhibitors in the this setting. Further clinical experience will allow to fully assess the positioning of these agents in insulin-treated T2DM populations.

Complementing insulin therapy to achieve glycemic control

INTRODUCTION

Most patients with type 2 diabetes mellitus (T2DM) will need incrementally more complex therapeutic regimens to control hyperglycemia as the disease progresses. Insulin is very effective in reducing hyperglycemia and may improve β-cell function in patients with T2DM. However, insulin therapy is associated with weight gain and increased risk of hypoglycemia. Adding other antidiabetes medications to insulin can improve glycemic control and potentially lower the required insulin dose, resulting in less weight gain and lower risk for hypoglycemia. This article summarizes the advantages and disadvantages of different classes of commonly used antidiabetes agents, with emphasis on newer classes, for use as add-on therapy to insulin in patients with T2DM inadequately controlled on insulin therapy.

METHODS

A PubMed search from July 1, 2003 to April 15, 2013 for peer-reviewed clinical and review articles relevant to insulin combination or add-on therapy in T2DM was conducted. Search terms included "insulin combination therapy," "add-on therapy diabetes," "dipeptidyl peptidase-4 (DPP-4) inhibitors," "glucagon-like peptide-1 (GLP-1) receptor agonist," "sodium-glucose cotransporter 2 (SGLT2) inhibitors", "insulin metformin," "insulin sulfonylurea," and "insulin thiazolidinedione." Bibliographies from retrieved articles were also searched for relevant articles. Study design, clinical relevance, and effect on insulin combination therapy were analyzed.

RESULTS

Therapies used as add-on to insulin include agents associated with weight gain (thiazolidinediones and sulfonylureas) and/or hypoglycemia (sulfonylureas), which, therefore, may exacerbate risks already present with insulin. GLP-1 receptor agonists, DPP-4 inhibitors, and SGLT2 inhibitors improve glycemic control when added to insulin and have a low propensity for hypoglycemia and cause no change (DPP-4 inhibitors) or a reduction (GLP-1 receptor agonists, SGLT2 inhibitors) in body weight.

CONCLUSION

GLP-1 receptor agonists, DPP-4 inhibitors, and SGLT2 inhibitors improve glycemic control when combined with insulin. They also have low propensity for weight gain and hypoglycemia and so may be preferred treatment options for insulin combination when compared with traditional therapies.

Postprandial serum C-peptide value is the optimal index to identify patients with non-obese type 2 diabetes who require multiple daily insulin injection: Analysis of C-peptide values before and after short-term intensive insulin therapy

Aims/Introduction

Type 2 diabetes is a progressive disease characterized by a yearly decline in insulin secretion; however, no definitive evidence exists showing the relationship between decreased insulin secretion and the need for insulin treatment. To determine the optimal insulin secretory index for identifying patients with non‐obese type 2 diabetes who require multiple daily insulin injection (MDI), we evaluated various serum C‐peptide immunoreactivity (CPR) values.

Materials and Methods

We near‐normalized blood glucose with intensive insulin therapy (IIT) over a 2‐week period in 291 patients with non‐obese type 2 diabetes, based on our treatment protocol. After improving hyperglycemia, we challenged with oral hypoglycemic agent (OHA), and according to the responsiveness to OHA, patients were classified into three therapy groups: OHA alone (n = 103), basal insulin plus OHA (basal insulin‐supported oral therapy [BOT]; n = 56) and MDI (n = 132). Glucagon‐loading CPR increment (ΔCPR), fasting CPR (FCPR), CPR 2 h after breakfast (CPR2h), the ratio of FCPR to FPG (CPI), CPI 2 h after breakfast (CPI2h) and secretory unit of islets in transplantation (SUIT) were submitted for the analyses. Receiver operating characteristic (ROC) and multiple logistic analyses for these CPR indices were carried out.

Results

Many CPR values were significantly lower in the MDI group compared with the OHA alone or BOT groups. ROC and multiple logistic analyses disclosed that post‐prandial CPR indices (CPR2h and CPI2h) were the most reliable CPR markers to identify patients requiring MDI.

Conclusions

Postprandial CPR level after breakfast is the most useful index for identifying patients with non‐obese type 2 diabetes who require MDI therapy.

The impact of initiating biphasic human insulin 30 therapy in type 2 diabetes patients after failure of oral antidiabetes drugs

BACKGROUND

The present study evaluated the efficacy of biphasic human insulin 30 (BHI 30) in type 2 diabetes patients who had failed in therapy with two or more oral antidiabetes drugs (OADs).

METHODS

This open-label, nonrandomized, 4-month, multicenter, clinical observational study was conducted in Shanghai, China. A total of 660 insulin-naive type 2 diabetes patients with poor glycemic control (glycosylated hemoglobin [HbA1c] ≥7.5%), despite treatment with two or more OADs for more than 6 months, were recruited and received BHI 30 monotherapy or BHI 30 plus OAD(s) (metformin only, α-glucosidase inhibitor only, or both).

RESULTS

Among the 660 subjects, 644 completed the 4-month study. At the end of the study, the median level of HbA1c decreased by 2.0% (from 9.1% to 7.0%) in the BHI 30 monotherapy group and also 2.0% (from 9.5% to 7.3%) in the BHI 30 plus OAD group. More patients achieved the HbA1c <7.0% target in the BHI 30 monotherapy group than in the BHI 30 plus OAD(s) group (47.9% vs. 35.3%, P=0.002). Compared with the expenses of the prior treatment strategy, the median daily cost decreased by 39.8% (4.5 yuan, Chinese RMB) at the end point in the BHI 30 monotherapy group but increased by 20.0% (2.2 yuan) in the BHI 30 plus OAD(s) group (P<0.0001). Moreover, patients in the BHI 30 plus OAD(s) group had fewer minor hypoglycemic episodes than in the BHI 30 monotherapy group (mean of 1.06 vs. 2.77 per patient per year, P<0.0001).

CONCLUSIONS

Short-term BHI 30 therapy can improve glycemic control in insulin-naive type 2 diabetes patients after failure of two or more OADs. With higher baseline glucose level, the BHI 30 plus OAD(s) group had lower pharmacoeconomic efficacy than the BHI 30 monotherapy group despite having fewer hypoglycemia events.

Insulin therapy in type 2 diabetes mellitus

Health care providers and patients have lots of choice to treat type 2 diabetes, but the blood glucose improvement is limited. The one therapy with unlimited potential (at least theoretically) is insulin. Many studies show that glucose control is achievable with insulin safely in most patients with type 2 diabetes. Effective diabetes management at the primary care or specialty level requires a belief in the importance of insulin therapy in uncontrolled patients with type 2 diabetes. This review details the theories, observed outcomes, and how-tos regarding insulin use in type 2 diabetes.

Combinations of insulin and oral hypoglycemic agents in diabetes mellitus type 2

Insulin therapy is considered to be the most effective therapy for the reduction of high glucose levels. In patients who cannot be regulated with the combination of oral hypoglycemic agents, insulin should be administrated. The first step is the combination of insulin together with the already administrated oral hypoglycemic agents. The fear for hypoglycemia, the refusal and weakness that patients face when dealing with insulin, constitute reasons for many doctors to deal with insulin therapy in a more skeptical way. As a result, the initiation of insulin therapy is delayed for those patients who need it for hyperglycemia adjustments. This article provides useful practical instructions for initiating insulin therapy.

Contribution of glimepiride to basal-prandial insulin therapy in patients with type 2 diabetes

AIM

To investigate the efficacy of continuing glimepiride in combination with basal-prandial insulin therapy in type 2 diabetes.

METHODS

An open crossover study was performed with arms of discontinuation and continuation of glimepiride in 25 subjects with mean diabetes duration of 17 years and 5 years of insulin treatment combined with glimepiride plus metformin. At entry and at the end of each 3-month arm, meal tolerance tests were performed for measurements of blood glucose and C-peptide.

RESULTS

In terms of between-treatment differences (discontinuation vs. continuation arm of glimepiride) during meal tolerance tests performed at the ends of arms, significant increases in plasma glucose were seen on the discontinuation arm at 0-, 30-, and 60-min, while significant decreases in serum C-peptide were observed at 60- and 120-min. A1C values of the discontinuation arm significantly increased (from 6.6 ± 0.6 at baseline to 7.7 ± 0.8 at 3-months, p<0.0001). Increases in A1C were closely correlated with decreases in area under the curve of meal-stimulated serum C-peptide (r=-0.61, p<0.0001).

CONCLUSIONS

Since endogenous insulin secretion is more physiological than subcutaneous insulin injection, continuing glimepiride may remain beneficial, partly through enhancing insulin secretion, in individuals with a long duration of diabetes and basal-prandial insulin therapy.

Continuation versus discontinuation of insulin secretagogues when initiating insulin in type 2 diabetes

We compared the combined use of basal insulin, metformin and insulin secretagogues with a combination of basal insulin and metformin in patients with type 2 diabetes starting basal insulin analogue therapy. This analysis was part of a 24-week trial, in which 964 insulin-naive patients with type 2 diabetes inadequately controlled on oral agents (including metformin) were randomized to insulin glargine or detemir. Secretagogues were stopped or maintained at the site-investigators' discretion. During the study, 57.6% of patients continued their secretagogue treatment. Compared with patients stopping secretagogues, those who continued experienced significantly more hypoglycaemia and weight gain. Insulin doses, however, were significantly lower: 0.6 ± 0.4 versus 0.8 ± 0.4 U/kg/day (p < 0.001). The difference between groups in mean HbA1c reduction was not statistically significant. In conclusion, in type 2 diabetic patients starting basal insulin analogue therapy, continuing both metformin and secretagogues results in more hypoglycaemia and weight gain and lower insulin doses than only maintaining metformin.