Oral glucose-stimulated serum C-peptide predicts successful switching from insulin therapy to liraglutide monotherapy in Japanese patients with type 2 diabetes and renal impairment

De-Intensification from Basal-Bolus Insulin Therapy to Liraglutide in Type 2 Diabetes: Predictive Value of Mean Glycaemia during Fasting Test

BACKGROUND

Successful conversion from insulin therapy to glucagon-like peptide 1 receptor agonist (GLP-1RA) with basal insulin in well-controlled patients has already been demonstrated. However, the data concerning individuals with poor glycaemic control are scarce. The aim of this work was to assess the success rate of insulin therapy to liraglutide transition in poorly controlled diabetes in a real-world clinical setting and to define predictors of success. We are the first to present the method of a fasting test as a way to identify the patients at higher risk of failure after treatment de-intensification.

METHODS

The retrospective observational study analyzed data of 62 poorly controlled obese diabetic patients on high-dose insulin therapy, who were subjected to a 72 h fasting test during hospitalization and subsequently switched to liraglutide ± basal insulin therapy. During the fasting, all antidiabetic treatment was discontinued. Patients were classified as responders if they remained on GLP-1RA treatment after 12 months. Non-responders restarted the basal-bolus insulin (BBI) regimen. Development of glycated hemoglobin (HbA1c) and body weight in both groups, alongside with parameters associated with the higher risk of return to the BBI regimen, were analyzed.

RESULTS

A total of 71% of patients were switched successfully (=responders). Responders had more significant improvement in HbA1c (-6.4 ± 19.7 vs. -3.4 ± 22.9 mmol/mol) and weight loss (-4.6 ± 7.1 vs. -2.5 ± 4.0). Statistically significant difference between groups was found in initial HbA1c (75.6 ± 17.9 vs. 90.5 ± 23.6; p = 0.04), total daily dose of insulin (67.6 ± 36.4 vs. 90.8 ± 32.4; p = 0.02), and mean glycaemia during the fasting test (6.9 ± 1.7 vs. 8.6 ± 2.2 mmol/L; p < 0.01).

CONCLUSIONS

This study confirms that therapy de-intensification in poorly controlled patients with a BBI regimen is possible. Higher baseline HbA1c, total daily insulin dose, and mean glucose during fasting test are negative predictive factors of successful therapy de-escalation.

Exploring a Suitable Marker of Glycemic Response to Dulaglutide in Patients with Type 2 Diabetes: A Retrospective Study

INTRODUCTION

Previous studies suggested that β-cell function markers such as fasting and postprandial serum C-peptide and C-peptide increment (FCPR, PCPR, and ΔCPR, respectively) may be useful in estimating glycemic response to glucagon-like peptide-1 receptor agonists. However, it remains elusive whether baseline glycemic control confounds these markers. Here we aimed to identify the least confounded β-cell function markers and investigate whether these markers could predict glycemic response to dulaglutide.

METHODS

We evaluated FCPR, PCPR, and ΔCPR levels in patients with type 2 diabetes who initiated dulaglutide treatment after a standardized meal tolerance test (MTT). We first investigated the confounding effects of baseline HbA1c on β-cell function markers using Pearson's correlation test. Then, we evaluated the association between each β-cell function marker and glycemic response (HbA1c change 0-6 months) to dulaglutide using generalized linear model and logistic regression analysis with adjustment for baseline HbA1c.

RESULTS

In 141 patients, baseline HbA1c was significantly inversely correlated with PCPR and ΔCPR (P < 0.01 for both) but not with FCPR (r = 0.02; P = 0.853), suggesting that FCPR was the marker least confounded by baseline glycemic control. Of all patients, 59 continued dulaglutide for at least 6 months without initiating any additional glucose-lowering medications. Mean ± SE HbA1c change 0-6 months was - 1.16 ± 0.17% (P < 0.001 vs. baseline). The β-cell function markers were significantly associated with HbA1c change 0-6 months in the generalized linear model. FCPR was also a significant predictor for achieving a reduction in HbA1c of at least 1% (P = 0.044) with an area under the receiver operating characteristic curve of 0.83 (sensitivity = 0.81 and specificity = 0.79).

CONCLUSION

Fasting and meal-induced C-peptide levels are associated with glycemic response to dulaglutide, among which FCPR is least confounded by baseline glycemic control, suggesting its utility as a marker for glycemic response to dulaglutide.

Association of glucagon-like peptide-1 receptor-targeted imaging probe with in vivo glucagon-like peptide-1 receptor agonist glucose-lowering effects

Aims/Introduction

Glucagon‐like peptide‐1 receptor agonists (GLP‐1RA) are used for treatment of type 2 diabetes mellitus worldwide. However, some patients do not respond well to the therapy, and caution must be taken for certain patients, including those with reduced insulin secretory capacity. Thus, it is clinically important to predict the efficacy of GLP‐1RA therapy. GLP‐1R‐targeted imaging has recently emerged to visualize and quantify β‐cells. We investigated whether GLP‐1R‐targeted imaging can predict the efficacy of GLP‐1RA treatment.

Materials and Methods

We developed ¹¹¹Indium‐labeled exendin‐4 derivative (¹¹¹In‐Ex4) as a GLP‐1R‐targeting probe. Diabetic mice were selected from NONcNZO10/LtJ male mice that were fed for different durations with 11% fat chow. After 3‐week administration of dulaglutide as GLP‐1RA therapy, mice with non‐fasting blood glucose levels <300 mg/dL and >300 mg/dL were defined as responders and non‐responders, respectively. In addition, ex vivo¹¹¹In‐Ex4 pancreatic accumulations (¹¹¹In‐Ex4 pancreatic values) were examined.

Results

The non‐fasting blood glucose levels after treatment were 172.5 ± 42.4 mg/dL in responders (n = 4) and 330.8 ± 20.7 mg/dL in non‐responders (n = 5), respectively. Ex vivo¹¹¹In‐Ex4 pancreatic values showed significant correlations with post‐treatment glycohemoglobin and glucose area under curve during an oral glucose tolerance test (R² = 0.76 and 0.80; P < 0.01 and <0.01, respectively). The receiver operating characteristic area under curve for identifying responders by ex vivo¹¹¹In‐Ex4 pancreatic values was 1.00 (P < 0.01).

Conclusion

Ex vivo¹¹¹In‐Ex4 pancreatic values reflected dulaglutide efficacy, suggesting clinical possibilities for expanding GLP‐1R‐targeted imaging applications.

Retrospective Analysis of an Insulin-to-Liraglutide Switch in Patients with Type 2 Diabetes Mellitus

INTRODUCTION

Insulin and the GLP-1 receptor agonist liraglutide are both effective in reaching glycemic targets. The efficacy of an insulin-to-liraglutide switch in an obese population with concurrent use of sulfonylurea and metformin is unknown. We assessed the efficacy and determinants of success of an insulin-to-liraglutide switch in these patients.

METHODS

In a retrospective study we analyzed all patients that underwent an insulin-to-liraglutide switch during routine medical care (January 2009-February 2015). It was assessed if patients still continued liraglutide 12 months after the switch or discontinued because of poor glycemic control or side effects. Baseline characteristics were compared between the groups to establish determinants of success.

RESULTS

A total of 104 patients made an insulin-to-liraglutide switch (43% male; mean age 57.2 ± 9.9 years; mean BMI 39.8 ± 5.4 kg/m²). Sixty patients still continued liraglutide after 12 months (58%) whereas 37 patients discontinued treatment because of poor glycemic control within 12 months (36%) and seven patients discontinued liraglutide because of intolerable side effects (7%). Insulin dose and insulin frequency at baseline were significantly lower in patients that continued liraglutide. Patients reaching HbA1c ≤ 7% (53 mmol/mol) showed lower baseline HbA1c levels, shorter duration of diabetes, and shorter duration of insulin therapy.

CONCLUSION

The majority of patients continued liraglutide after a switch from insulin therapy with on average no change in glycemic control and decrease of body weight. HbA1c levels at baseline, duration of insulin therapy, and duration of diabetes were predictive of reaching glycemic control on liraglutide alone. In current practice this also indicates which patients on insulin can reduce their insulin dose after adding a GLP-1 receptor agonist. Plain language summary available for this article.

Oral glucose-stimulated serum C-peptide predicts successful switching from insulin therapy to liraglutide monotherapy in Japanese patients with type 2 diabetes and renal impairment

AIMS/INTRODUCTION

In Japan, liraglutide was recently approved for patients with type 2 diabetes. To our knowledge, there are no markers predicting successful switching from insulin therapy to liraglutide monotherapy in Japanese patients with type 2 diabetes and renal impairment. We therefore assessed clinical characteristics predicting successful switching.

MATERIALS AND METHODS

We analyzed 21 patients with type 2 diabetes and estimated glomerular filtration rates <60 mL/min/1.73 m(2) receiving long-term insulin in Shiga University of Medical Science Hospital, Otsu, Shiga, Japan. Their β-cell function was assessed by measuring urinary C-peptide and C-peptide immunoreactivity (CPR) index, along with glucagon loading and oral glucose tolerance tests. Blood glucose concentration and blood pressure were measured daily before and after switching from insulin to liraglutide, and glycated hemoglobin (HbA1c; National Glycohemoglobin Standardization Program) was assessed 12 weeks after switching to liraglutide.

RESULTS

Baseline HbA1c was significantly lower in successfully switched than in unsuccessfully switched patients. CPR index, urinary C-peptide concentration and 6-min post-glucagon increment in CPR (ΔCPR) did not differ significantly in the two groups. ΔCPR 120 min after 75 g oral glucose was significantly higher in successfully than unsuccessfully switched patients. Mean blood glucose concentrations before breakfast, after breakfast, before lunch and after dinner were significantly lower in successfully switched patients. HbA1c did not change significantly in either group.

CONCLUSIONS

Measurement of oral glucose-stimulated ΔCPR120 min is recommended when considering switching Japanese type 2 diabetes patients with renal impairment from insulin to liraglutide monotherapy.