Dose response of continuous subcutaneous infusion of recombinant glucagon-like peptide-1 in combination with metformin and sulphonylurea over 12 weeks in patients with type 2 diabetes mellitus

Pharmacotherapy for Type 2 Diabetes Mellitus: What's Up and Coming in the Glucagon-Like Peptide-1 (GLP-1) Pipeline?

Glucagon-like peptide-1 (GLP-1), an incretin hormone, is known to lower glucose levels, suppress glucagon secretion, and slow gastric emptying. These properties make GLP-1 an ideal target in treating type 2 diabetes mellitus (T2DM). There are many FDA-approved GLP-1 agonists on the market today, several of which have demonstrated benefit beyond improving glycemic control. Given the beneficial effects of GLP-1 agonists in patients with T2DM, new drugs are in development that combine the mechanism of action of GLP-1 receptor agonism with novel mechanisms and with drugs that promote GLP-1 secretion. These agents are designed to improve glycemic control and target greater body weight reduction. This article discusses new GLP-1 drugs in the pipeline for the treatment of T2DM.

Protocol for a randomised controlled trial of the combined effects of the GLP-1 receptor agonist liraglutide and exercise on maintenance of weight loss and health after a very low-calorie diet

INTRODUCTION

The success rate of weight loss maintenance is limited. Therefore, the purpose of this study is to investigate the maintenance of weight loss and immunometabolic health outcomes after diet-induced weight loss followed by 1-year treatment with a glucagon-like peptide-1 receptor agonist (liraglutide), physical exercise or the combination of both treatments as compared with placebo in individuals with obesity.

METHODS AND ANALYSIS

This is an investigator-initiated, randomised, placebo-controlled, parallel group trial. We will enrol expectedly 200 women and men (age 18-65 years) with obesity (body mass index 32-43 kg/m2) to adhere to a very low-calorie diet (800 kcal/day) for 8 weeks in order to lose at least 5% of body weight. Subsequently, participants will be randomised in a 1:1:1:1 ratio to one of four study groups for 52 weeks: (1) placebo, (2) exercise 150 min/week+placebo, (3) liraglutide 3.0 mg/day and (4) exercise 150 min/week+liraglutide 3.0 mg/day. The primary endpoint is change in body weight from randomisation to end-of-treatment.

ETHICS AND DISSEMINATION

The trial has been approved by the ethical committee of the Capital Region of Denmark and the Danish Medicines Agency. The trial will be conducted in agreement with the Declaration of Helsinki and monitored to follow the guidelines for good clinical practice. Results will be submitted for publication in international peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

2015-005585-32.

Sugar-Lowering Drugs for Type 2 Diabetes Mellitus and Metabolic Syndrome-Review of Classical and New Compounds: Part-I

Diabetes mellitus (DM) is a metabolic disorder characterized by chronic hyperglycemia together with disturbances in the metabolism of carbohydrates, proteins and fat, which in general results from an insulin availability and need imbalance. In a great number of patients, marketed anti-glycemic agents have shown poor effectiveness in maintaining a long-term glycemic control, thus being associated with severe adverse effects and leading to an emerging interest in natural compounds (e.g., essential oils and other secondary plant metabolites, namely, flavonoid-rich compounds) as a novel approach for prevention, management and/or treatment of either non-insulin-dependent diabetes mellitus (T2DM, type 2 DM) and/or Metabolic Syndrome (MS). In this review, some of these promising glucose-lowering agents will be comprehensively discussed.

Greater glucagon-like peptide-1 responses to oral glucose are associated with lower central and peripheral blood pressures

Background and aim

Cardiovascular diseases (CVDs) are globally the leading cause of death and hypertension is a significant risk factor. Treatment with glucagon-like peptide-1 (GLP-1) receptor agonists has been associated with decreases in blood pressure and CVD risk. Our aim was to investigate the association between endogenous GLP-1 responses to oral glucose and peripheral and central haemodynamic measures in a population at risk of diabetes and CVD.

Methods

This cross-sectional study included 837 Danish individuals from the ADDITION-PRO cohort (52% men, median (interquartile range) age 65.5 (59.8 to 70.7) years, BMI 26.1 (23.4 to 28.5) kg/m², without antihypertensive treatment and known diabetes). All participants received an oral glucose tolerance test with measurements of GLP-1 at 0, 30 and 120 min. Aortic stiffness was assessed by pulse wave velocity (PWV). The associations between GLP-1 response and central and brachial blood pressure (BP) and PWV were assessed in linear regression models adjusting for age and sex.

Results

A greater GLP-1 response was associated with lower central systolic and diastolic BP of − 1.17 mmHg (95% confidence interval (CI) − 2.07 to − 0.27 mmHg, P = 0.011) and − 0.74 mmHg (95% CI − 1.29 to − 0.18 mmHg, P = 0.009), respectively, as well as lower brachial systolic and diastolic BP of − 1.27 mmHg (95% CI − 2.20 to − 0.33 mmHg, P = 0.008) and − 1.00 (95% CI − 1.56 to − 0.44 mmHg, P = 0.001), respectively. PWV was not associated with GLP-1 release (P = 0.3). Individuals with the greatest quartile of GLP-1 response had clinically relevant lower BP measures compared to individuals with the lowest quartile of GLP-1 response (central systolic BP: − 4.94 (95% CI − 8.56 to − 1.31) mmHg, central diastolic BP: − 3.05 (95% CI − 5.29 to − 0.80) mmHg, brachial systolic BP: − 5.18 (95% CI − 8.94 to − 1.42) mmHg, and brachial diastolic BP: − 2.96 (95% CI − 5.26 to − 0.67) mmHg).

Conclusion

Greater glucose-stimulated GLP-1 responses were associated with clinically relevant lower central and peripheral blood pressures, consistent with beneficial effects on the cardiovascular system and reduced risk of CVD and mortality.

Trial registration ClinicalTrials.gov Identifier: NCT00237549. Retrospectively registered 10 October 2005

Efficacy and safety of liraglutide versus placebo added to basal insulin analogues (with or without metformin) in patients with type 2 diabetes: a randomized, placebo-controlled trial

AIM

To confirm the superiority, compared with placebo, of adding liraglutide to pre-existing basal insulin analogue ± metformin in adults with inadequately controlled type 2 diabetes [glycated haemoglobin (HbA1c) 7.0-10.0% (53-86 mmol/mol)].

METHODS

In this 26-week, double-blind, parallel-group study, conducted in clinics or hospitals, 451 subjects were randomized 1 : 1 to once-daily liraglutide 1.8 mg (dose escalated from 0.6 and 1.2 mg/day, respectively, for 1 week each; n = 226) or placebo (n = 225) added to their pre-existing basal insulin analogue (≥20 U/day) ± metformin (≥1500 mg/day). After randomization, insulin adjustments above the pre-study dose were not allowed. The primary endpoint was HbA1c change.

RESULTS

After 26 weeks, HbA1c decreased more with liraglutide [-1.3% (-14.2 mmol/mol)] than with placebo [-0.1% (-1.2 mmol/mol); p < 0.0001]. More subjects on liraglutide reached HbA1c targets: <7.0% (59% vs 14%; p < 0.0001) and ≤6.5% (43% vs 4%; p < 0.0001) using slightly less insulin (35.8 IU vs 40.1 IU). Greater decreases from baseline (estimated treatment differences vs placebo; p < 0.0001) occurred in fasting plasma glucose (-1.3 mmol/l), seven-point glucose profiles (-1.6 mmol/l), body weight (-3.1 kg) and systolic blood pressure (-5.0 mmHg). Transient gastrointestinal adverse events (nausea: 22.2% vs 3.1%) and minor hypoglycaemia (18.2% vs 12.4%) were more frequent with liraglutide than placebo, and pulse increased (4.5 beats/min) compared with placebo. No severe hypoglycaemia or pancreatitis occurred.

CONCLUSIONS

Adding liraglutide to a basal insulin analogue ± metformin significantly improved glycaemic control, body weight and systolic blood pressure compared with placebo. Typical gastrointestinal symptoms and minor hypoglycaemia were more frequent with liraglutide.

Treatment escalation options for patients with type 2 diabetes after failure of exenatide twice daily or glimepiride added to metformin: results from the prospective European Exenatide (EUREXA) study

AIMS

To evaluate third-line thiazolidinedione (TZD) or glimepiride therapy in patients inadequately controlled on metformin + exenatide twice daily, and third-line exenatide twice daily in patients inadequately controlled on metformin + glimepiride.

METHODS

In this randomized, open-label, multicentre trial, 144 patients with type 2 diabetes inadequately controlled [glycated haemoglobin (HbA1c) >9% (75 mmol/mol) after 3 months' treatment or >7% (53 mmol/mol) at two consecutive visits 3 months apart, after 6 months' treatment] on metformin + exenatide twice daily were re-randomized to add-on TZD or glimepiride, and 166 patients inadequately controlled on metformin + glimepiride received add-on exenatide twice daily. Changes in HbA1c, body mass index (BMI), lipids, hypoglycaemia and vital signs were evaluated.

RESULTS

The median duration of triple therapy was ∼2 years. In patients inadequately controlled on metformin + exenatide twice daily, add-on TZD decreased HbA1c levels significantly better than add-on glimepiride: 130-week difference 0.48% [95% confidence interval (CI) 0.19-0.77] or 5.2 mmol/mol (95% CI 2.1-8.4; p = 0.001), but with significantly increased BMI and systolic blood pressure. The ratio of documented symptomatic (blood glucose ≤70 mg/dl [3.9 mmol/l]) hypoglycaemia rates for add-on glimepiride to add-on TZD was 8.48 (p < 0.0001). Add-on exenatide twice daily after metformin + glimepiride significantly reduced HbA1c levels: mean [standard deviation (s.d.)] change from baseline -0.35 (0.89)% [-3.8 (9.7) mmol/mol] and BMI: mean (s.d.) change from baseline -0.82 (1.9) kg/m(2) at 130 weeks, with a slightly increased rate of documented symptomatic hypoglycaemia from metformin + glimepiride (ratio 1.49).

CONCLUSIONS

TZD, but not glimepiride, was an effective and well tolerated third-line therapy in patients without glycaemic control after long-term therapy with metformin + exenatide twice daily. Exenatide twice daily was an effective and well tolerated third-line therapy in patients inadequately controlled on metformin + glimepiride.

GLP-1 Response to Oral Glucose Is Reduced in Prediabetes, Screen-Detected Type 2 Diabetes, and Obesity and Influenced by Sex: The ADDITION-PRO Study

The role of glucose-stimulated release of GLP-1 in the development of obesity and type 2 diabetes is unclear. We assessed GLP-1 response to oral glucose in a large study population of lean and obese men and women with normal and impaired glucose regulation. Circulating concentrations of glucose, insulin, and GLP-1 during an oral glucose tolerance test (OGTT) were analyzed in individuals with normal glucose tolerance (NGT) (n = 774), prediabetes (n = 525), or screen-detected type 2 diabetes (n = 163) who attended the Danish ADDITION-PRO study (n = 1,462). Compared with individuals with NGT, women with prediabetes or type 2 diabetes had 25% lower GLP-1 response to an OGTT, and both men and women with prediabetes or type 2 diabetes had 16-21% lower 120-min GLP-1 concentrations independent of age and obesity. Obese and overweight individuals had up to 20% reduced GLP-1 response to oral glucose compared with normal weight individuals independent of glucose tolerance status. Higher GLP-1 responses were associated with better insulin sensitivity and β-cell function, older age, and lesser degree of obesity. Our findings indicate that a reduction in GLP-1 response to oral glucose occurs prior to the development of type 2 diabetes and obesity, which can have consequences for early prevention strategies for diabetes.

Treatment with a GLP-1 receptor agonist diminishes the decrease in free plasma leptin during maintenance of weight loss

BACKGROUND

Recent studies indicate that glucagon-like peptide (GLP)-1 inhibits appetite in part through regulation of soluble leptin receptors. Thus, during weight loss maintenance, GLP-1 receptor agonist (GLP-1RA) administration may inhibit weight loss-induced increases in soluble leptin receptors thereby preserving free leptin levels and preventing weight regain.

METHODS

In a randomized controlled trial, 52 healthy obese individuals were, after a diet-induced 12% body weight loss, randomized to treatment with or without administration of the GLP-1RA liraglutide (1.2 mg per day). In case of weight gain, low-calorie diet products were allowed to replace up to two meals per day to achieve equal weight maintenance. Glucose tolerance and hormone responses were investigated before and after weight loss and after 52 weeks weight maintenance. Primary end points: increase in soluble leptin receptor plasma levels and decrease in free leptin index after 52 weeks weight loss maintenance.

RESULTS

Soluble leptin receptor increase was 59% lower; 2.1±0.7 vs 5.1±0.8 ng ml(-1) (-3.0 (95% confidence interval (CI)=-0.5 to -5.5)), P<0.001 and free leptin index decrease was 43% smaller; -62±15 vs -109±20 (-47 (95% CI=-11 to -83)), P<0.05 with administration of GLP-1RA compared with control group. The 12% weight loss was successfully maintained in both the groups with no significant change in weight after 52 weeks follow-up. The GLP-1RA group had greater weight loss during the weight maintenance period (-2.3 kg (95% CI=-0.6 to -4.0)), and had fewer meal replacements per day compared with the control group (minus one meal per day (95% CI=-0.6 to -1)), P<0.001. Fasting glucose was decreased by an additional -0.2±0.1 mmol l(-1) in the GLP-1RA group in contrast to the control group, where glucose increased 0.3±0.1 mmol l(-1) to the level before weight loss (-0.5mmol l(-1) (95% CI=-0.1 to -0.9)), P<0.005. Meal response of peptide PYY3-36 was higher at week 52 in the GLP-1RA group compared with the control group, P<0.05.

CONCLUSIONS

The weight maintaining effect of GLP-1RAs may be mediated by smaller decrease in free leptin and higher PYY3-36 response. Low dose GLP-1RA therapy maintained 12% weight loss for 1 year and may prevent pre-diabetes in obesity.

Therapies for inter-relating diabetes and obesity - GLP-1 and obesity

INTRODUCTION

The dramatic rise in the prevalence of obesity and type 2 diabetes mellitus (T2DM) is associated with increased mortality, morbidity as well as public health care expenses worldwide. The need for effective and long-lasting pharmaceutical treatment is obvious. The record of anti-obesity drugs has been poor so far and the only efficient treatment today is bariatric surgery. Research has indicated that appetite inhibiting hormones from the gut may have a therapeutic potential in obesity. The gut incretin hormone, glucagon-like peptide-1 (GLP-1), appears to be involved in both peripheral and central pathways mediating satiety. Clinical trials have shown that two GLP-1 receptor agonists exenatide and liraglutide have a weight-lowering potential in non-diabetic obese individuals. Furthermore, they may also hold a potential in preventing diabetes as compared to other weight loss agents.

AREAS COVERED

The purpose of this review is to cover the background for the GLP-1-based therapies and their potential in obesity and pre-diabetes. Up-to-date literature on incretin-based therapies will be summarized with a special mention of their weight-lowering properties. The literature updated to August 2014 from PubMed was identified using the combinations: GLP-1, GLP-1 receptor agonists, incretins, obesity and pre-diabetes.

EXPERT OPINION

The incretin impairment, which seems to exist in both obesity and diabetes, may link these two pathologies and underlines the potential of GLP-1-based therapies in the prevention and treatment of these diseases.