Effect of baseline body mass index on glycemic control and weight change with exenatide monotherapy in Chinese drug-naïve type 2 diabetic patients

Association between variants in TCF7L2, CTRB1/2, and GLP-1R genes and response to therapy with glucagon-like peptide-1 receptor agonists

OBJECTIVES

The factors determining the response to treatment with glucagon-like peptide-1 receptor agonists (GLP-1- RAs) have not been clarified. The present study investigated the association between polymorphisms in TCF7L2, CTRB1/2, and GLP-1 R genes and response to GLP-1 RAs regarding glycemic control and weight loss among Greek patients with type 2 diabetes mellitus (T2DM).

METHODS

Patients (n = 191) treated with GLP-1 RAs for at least 6 months were included. Participants were genotyped for TCF7L2 rs7903146 (C>T), CTRB1/2 rs7202877 (T>G) and GLP-1 R rs367543060 (C>T) polymorphisms. Clinical and laboratory parameters were measured before, 3, and 6 months after treatment initiation. The patients were classified into responders and non-responders according to specific criteria.

RESULTS

Carriers of at least one rs7903146 'T' allele and rs7202877 'G' allele presented similar glucose control and weight loss response to GLP-1 RAs with the respective homozygous wild-type genotypes [odds ratio (OR): 1.08, 95% confidence interval (CI): 0.5, 2.31, p = 0.85 and OR: 1.35, 95% CI: 0.66, 2.76, p = 0.42; OR: 1.4, 95% CI: 0.56, 3.47, p = 0.47 and OR: 1.28, 95% CI: 0.55, 2.98, p = 0.57, respectively]. Regarding the GLP-1 R polymorphism, all participants were homozygous for the wild-type allele; thus, no comparisons were feasible. Female sex (p = 0.03) and lower baseline weight (p = 0.024) were associated with an improved glycemic and weight loss response, respectively.

CONCLUSION

There is no evidence suggesting a role for the variants studied in response to GLP-1 RA therapy in people with T2DM. However, specific demographic and clinical factors may be related to a better response to treatment with these agents.

Impact of Weight Change on Glycemic Control and Metabolic Parameters in T2D: A Retrospective US Study Based on Real-World Data

INTRODUCTION

Weight loss has been identified as a key strategy for improving glycemic and metabolic outcomes in people with type 2 diabetes (T2D). However, the long-term, real-world impact of weight loss on these outcomes remains unclear. This study aimed to investigate (1) the association between weight loss and glycemic control, (2) association between weight loss and metabolic parameters, and (3) predictors of weight loss and how weight change trajectory varies based on index body mass index (BMI).

METHODS

A retrospective, longitudinal cohort study using the linked IQVIA Ambulatory electronic medical records and PharMetrics® Plus databases was performed from January 1, 2010 through December 31, 2019 in adults with T2D. Participants were categorized into 1-year and 5-year follow-up cohorts based on their observed weight change over time. Longitudinal values for vital signs and laboratory parameters, including BMI, weight, glycated hemoglobin (HbA1c), and metabolic parameters (liver enzymes and cholesterol), were reported at index date and every 6 months post index date. Multivariable logistic regression analysis was used to evaluate the factors associated with weight loss.

RESULTS

Of 1,493,964 people evaluated, 1,061,354 (71%) and 308,320 (20.6%) were classified into the 1-year and 5-year follow-up cohorts. Average HbA1c reductions of 1.2% and 0.5% were observed among people who lost ≥ 15% of index weight in the 1-year and 5-year follow-up cohorts, respectively. Higher weight loss percentages were associated with numerically greater improvements in metabolic parameters. The presence of bariatric surgery and higher index BMIs were identified as the strongest predictors of ≥ 15% and ≥ 10% weight loss in both follow-up cohorts.

CONCLUSION

Results from this study suggest that modest and sustained weight loss can lead to clinically meaningful improvements in glycemic and metabolic parameters among people with T2D. These findings highlight the importance of weight management in managing T2D and preventing its associated complications.

Efficacy and safety of polyethylene glycol loxenatide in type 2 diabetic patients: a systematic review and meta-analysis of randomized controlled trials

Polyethylene glycol loxenatide (PEX168) is a novel glucagon-like peptide-1 receptor agonist with a longer half-life developed by modifying the chemical structure of exenatide. This study aims to assess the efficacy and safety of PEX168 and determine the best dose. We searched PubMed, Scopus, Cochrane Library, and Web of Science databases from inception to April 25, 2023, for randomized controlled trials (RCTs) comparing PEX168 therapy alone or in combination with metformin versus other therapies. We used the risk ratio (RR) for dichotomous outcomes and the mean difference (MD) for continuous outcomes, both with 95% confidence intervals (CI). Six RCTs, including 1248 participants, were included. PEX168 added to metformin was significantly better than metformin alone regarding fasting blood glucose (MD = -1.20, 95% CI (-1.78,  - 0.62), p < 0.0001), HbA1c (MD = -1.01, 95% CI (-1.48,  - 0.53), p < 0.0001), and postprandial glycemia (MD = -1.94, 95% CI (-2.99,  - 0.90), p = 0.0003). Similarly, for glycemic control, PEX168 monotherapy was superior to placebo (P < 0.05). No significant effects were noticed in terms of triglycerides, low-density lipoprotein, or high-density lipoprotein (p > 0.05). Body weight was significantly reduced in obese diabetic patients receiving PEX168 compared to the control group (MD = -5.46, 95% CI (-7.90,  - 3.01), p < 0.0001) but not in non-obese patients (MD = 0.06, 95% CI (-0.47, 0.59), p = 0.83). People who received PEX168 alone or with metformin showed more common gastrointestinal adverse effects, especially nausea and vomiting (p < 0.05). PEX168 100, 200, and 300 ug monotherapy demonstrated comparable safety and diabetes control to metformin, but when combined with metformin, PEX168 100 and 200 ug showed significant effects on diabetes control; however, only the latter showed a significantly higher incidence of nausea and vomiting (p < 0.05). PEX168 could be a viable option for treating diabetic patients whose metformin control is inadequate or who cannot tolerate metformin. PEX168 at 100 ug in combination with metformin was found to be safe and more effective compared to metformin; however, due to the small number of trials included, these findings should be interpreted with caution, and additional trials are required.

Clinical and Genetic Predictors of Glycemic Control and Weight Loss Response to Liraglutide in Patients with Type 2 Diabetes

Background: Evidence suggests a heterogeneous response to therapy with glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in patients with type 2 diabetes mellitus (T2DM). The aim of this study is to identify the genetic and clinical factors that relate to glycemic control and weight loss response to liraglutide among patients with T2DM. Methods: The medical records of 116 adults with T2DM (51% female, mean body mass index 35.4 ± 6.4 kg/m2), who had been on treatment with liraglutide for at least 6 months and were genotyped for CTRB1/2 rs7202877 (T > G) polymorphism, were evaluated. Clinical and laboratory parameters were measured at baseline, 3, and 6 months after initiating liraglutide treatment. The good glycemic response was defined as one of the following: (i) achievement of glycated hemoglobin (HbA1c) < 7% (ii) reduction of the baseline HbA1c by ≥1%, and (iii) maintenance of HbA1c < 7% that a patient already had before switching to liraglutide. Weight loss responders were defined as subjects who lost ≥3% of their baseline weight. Results: Minor allele frequency was 16%. Individuals were classified as glycemic control and weight loss responders (81 (70%) and 77 (66%), respectively). Carriers of the rs7202877 polymorphic allele had similar responses to liraglutide treatment in terms of glycemic control (odds ratio (OR): 1.25, 95% confidence interval (CI): 0.4, 3.8, p = 0.69) and weight loss (OR: 1.12, 95% CI: 0.4, 3.2, p = 0.84). In the multivariable analysis, higher baseline HbA1c (adjusted OR: 1.45, 95% CI: 1.05, 2.1, p = 0.04) and lower baseline weight (adjusted OR: 0.97, 95% CI: 0.94, 0.99, p = 0.01) were associated with better glycemic response to liraglutide, while higher baseline weight was associated with worse weight response (adjusted OR: 0.97, 95% CI: 0.95, 0.99, p = 0.02). Conclusions: Specific patient features can predict glycemic and weight loss response to liraglutide in individuals with T2DM.

Mini Review: Effect of GLP-1 Receptor Agonists and SGLT-2 Inhibitors on the Growth Hormone/IGF Axis

Accumulating evidence supports the early use of glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium glucose transporter-2 inhibitors (SGLT-2is) for the treatment of type 2 diabetes. Indeed, these compounds exert numerous pleiotropic actions that favorably affect metabolism and diabetes comorbidities, showing an additional effect beyond glucose control. Although a substantial amount of knowledge has been generated regarding the mechanism of action of both drug classes, much remains to be understood. Growth hormone (GH) is an important driver for multiple endocrine responses involving changes in glucose and lipid metabolism, and affects several tissues and organs (e.g., bone, heart). It acts directly on several target tissues, including skeletal muscle and bone, but several effects are mediated indirectly by circulating (liver-derived) or locally produced IGF-1. In consideration of the multiple metabolic and cardiovascular effects seen in subjects treated with GLP-1RAs and SGLT-2is (e.g., reduction of hyperglycemia, weight loss, free/fat mass and bone remodeling, anti-atherosclerosis, natriuresis), it is reasonable to speculate that GH and IGF-1 may play a about a relevant role in this context. This narrative mini-review aims to describe the involvement of the GH/IGF-1/IGF-1R axis in either mediating or responding to the effects of each of the two drug classes.

Role of Glucose-Lowering Medications in Erectile Dysfunction

Erectile dysfunction (ED) is a long-term complication of type 2 diabetes (T2D) widely known to affect the quality of life. Several aspects of altered metabolism in individuals with T2D may help to compromise the penile vasculature structure and functions, thus exacerbating the imbalance between smooth muscle contractility and relaxation. Among these, advanced glycation end-products and reactive oxygen species derived from a hyperglycaemic state are known to accelerate endothelial dysfunction by lowering nitric oxide bioavailability, the essential stimulus of relaxation. Although several studies have explained the pathogenetic mechanisms involved in the generation of erectile failure, few studies to date have described the efficacy of glucose-lowering medications in the restoration of normal sexual activity. Herein, we will present current knowledge about the main starters of the pathophysiology of diabetic ED and explore the role of different anti-diabetes therapies in the potential remission of ED, highlighting specific pathways whose activation or inhibition could be fundamental for sexual care in a diabetes setting.

Safety, Tolerability and Pharmacokinetics of Single Dose Polyethylene Glycolated Exenatide Injection (PB-119) in Healthy Volunteers

BACKGROUND AND OBJECTIVE

Exenatide promotes insulin secretion and inhibits postprandial glucagon secretion. Polyethylene glycolated exenatide injection (PB-119), a derivative obtained by modification of exenatide, is more stable in metabolic behavior than exenatide in vivo. Our study aimed to evaluate the safety, tolerability and pharmacokinetic characteristics of polyethylene glycolated exenatide as a single subcutaneous injection in healthy volunteers.

METHODS

Seventy subjects were randomly assigned to 8 incremental dosage groups (2, 5, 10, 25, 50, 100, 200 and 400 µg). The 2- to 50-µg groups had 8 subjects in each group (the ratio of test preparation to placebo was 3:1), and the 100- to 400-µg groups had 10 subjects in each group (the ratio of test preparation to placebo was 4:1). All the subjects received a single subcutaneous injection of polyethylene glycolated exenatide and placebo according to the dosage groups. The tolerability test was conducted in the 2- to 10-µg groups. The pharmacokinetic test was carried out in the 25- to 400-µg groups, and plasma samples were collected to determine the pharmacokinetics of polyethylene glycolated exenatide. After medication, the vital signs of the subjects were monitored, and laboratory tests and electrocardiogram tests were carried out regularly in all the subjects.

RESULTS

All 70 subjects completed the experiment. Except for the 5-µg and 10-µg groups, the safety and tolerability tests showed no adverse reactions in the 2-µg to 50-µg groups. Several subjects in the 100-µg and 200-µg groups had tolerable gastrointestinal tract reactions, and all subjects in the 400-µg group experienced adverse reactions, mainly gastrointestinal tract reactions and liver dysfunction. The pharmacokinetics of polyethylene glycolated exenatide was studied in 36 subjects, which showed slow absorption, a mean peak time of 20-40 h, and a mean elimination half-life of 51-64 h.

CONCLUSION

The administration of polyethylene glycolated exenatide injection at a single dose of 2-200 µg is safe and tolerable for healthy volunteers. Once-weekly polyethylene glycolated exenatide injection can be recommended.

CLINICAL TRIALS REGISTRATION

The study was registered at clinicaltrials.gov (No. NCT02084251).

Safety, Pharmacokinetics and Pharmacodynamics of Multiple Escalating Doses of PEGylated Exenatide (PB-119) in Healthy Volunteers

BACKGROUND AND OBJECTIVE

At present, the deficiency of β-cell function is progressive in patients with type 2 diabetes mellitus. Exenatide cannot only control blood glucose well, but also promotes the regeneration and proliferation of islet β-cells and improves the function of β cells. However, it needs to be given twice a day, and there are many adverse reactions such as nausea. PEGylated exenatide (study code: PB-119) needs to be administered only once a week. The purpose of this experiment was to evaluate the safety, pharmacokinetics and pharmacodynamics of an escalating dose regimen of subcutaneous PEGylated exenatide injections in healthy subjects.

METHODS

Twelve healthy young adult subjects in each group received once-weekly subcutaneous injections of 165 μg, 330 μg, and 660 μg PEGylated exenatide for 6 weeks. Plasma drug concentration was determined in venous blood collected across selected time points. Safety and tolerability were evaluated by monitoring adverse events, laboratory parameters, and electrocardiogram. Blood glucose, insulin,  glucagon and C peptide were monitored at different time points to evaluate the pharmacodynamics of PEGylated exenatide.

RESULTS

A total of 11, 10, and 12 subjects completed the study in 165 µg, 330 µg, and 660 µg dose groups, respectively. After 6 consecutive weeks of administration, the t_1/2 in the 165 μg, 330 μg, and 660 µg dose groups was 55.67 ± 11.03 h, 56.99 ± 21.37 h, and 54.81 ± 13.87 h, respectively. The C_avg was 4.22 ± 0.78 ng/ml, 6.03 ± 1.43 ng/ml, and 10.50 ± 3.06 ng/ml, respectively. AUCss was 708.59 ± 131.87 h•ng/ml, 1012.63 ± 240.79 h•ng/ml, and 1763.81 ± 514.50 h•ng/ml, respectively. The accumulation index was 1.15 ± 0.07, 1.17 ± 0.11, and 1.14 ± 0.07. The CLss/F was 241.25 ± 51.13 ml/h, 341.53 ± 73.62 ml/h, and 450.06 ± 313.76 ml/h, respectively. A total of 10 of 36 (27.78%) subjects in the three dose groups developed specific antibodies after consecutive subcutaneous injections of PEGylated exenatide. The C_avg and C_max were higher than those of antibody-negative subjects. Furthermore, in antibody-positive subjects, CLss/F, t_1/2, AUC_τ, accumulation index, MRT_(0-inf) and other parameters were lower than those of antibody-negative subjects. In the 165 μg dose group, two subjects (16.67%) experienced 4 adverse events. In the 330 μg dose group, no subjects reported adverse events. In the 660 μg dose group, 8 subjects (66.67%) reported 16 adverse events, which were mostly gastrointestinal. There were no significant changes in the pharmacodynamic parameters except the glucagon level at day 36 in the 660 µg dose group, the 2h postprandial insulin and C peptide levels at day 36 and day 50 in the 165 μg dose group compared with baseline (- 1 day).

CONCLUSION

A once-weekly subcutaneous injection of 165 µg and 330 µg PEGylated exenatide is safe. No significant effects on blood glucose or pancreatic hormone levels were observed in the subjects within these dose groups. The pharmacokinetic parameters of PEGylated exenatide may be affected by immunogenicity.

CLINICAL TRIALS REGISTRATION

The study is registered at clinicaltrials.gov (No. NCT03062774).

Predictive factors associated with glycaemic response to exenatide in Chinese patients with type 2 diabetes mellitus

WHAT IS KNOWN AND OBJECTIVE

Exenatide is widely used in the treatment of type 2 diabetes mellitus (T2DM) because of its established effect on lowering glucose and promotion of weight loss. However, therapeutic response to exenatide varies considerably among patients with T2DM. The purpose of this study was to determine which variables can predict the response to exenatide and to individualize specific therapies for patients with T2DM who need treatment with exenatide.

METHODS

This is a retrospective cohort study of patients with T2DM who were treated with exenatide twice daily as a part of their diabetes care for at least 12 months. Patients were categorized into two cohorts based on glycaemic response to exenatide use: responders and non-responders.

RESULTS AND DISCUSSION

One hundred forty-eight patients met the inclusion criteria; among them, 92 responded with an HbA1C reduction ≥1.0% from baseline HbA1C and 56 did not respond to exenatide after 6 months of exenatide treatment. Binary logistic regression analysis revealed that baseline HbA1C and duration of diabetes were identified as predictors of HbA1C reduction ≥1% at 6 months (P < .05). Linear regression analysis further identified that patients with a higher baseline HbA1C (≥7.4%) and shorter duration of diabetes (≤15.0 years) were likely to respond to exenatide, whereas those with a lower baseline HbA1C (<7.4%) and longer duration of diabetes (>15.0 years) were not likely to respond to exenatide.

WHAT IS NEW AND CONCLUSION

Our data indicate that T2DM patients with a higher baseline HbA1C and a shorter duration of diabetes are more likely to have a glycaemic response to exenatide than those with a lower baseline HbA1C and a longer duration of diabetes. The identification of predictors of therapeutic response to exenatide can provide clinically useful information for characterizing the patients who could receive the greatest benefit from exenatide.

Effect of baseline body mass index on glycemic control and weight change with exenatide monotherapy in Chinese drug-naïve type 2 diabetic patients

BACKGROUND

The weight-reducing effect of exenatide has been proved, but too much weight loss in normal-weight patients may concern physicians. This study evaluated the effects of exenatide monotherapy on glycemic control and weight change in normal-weight, overweight, and obese patients with newly diagnosed type 2 diabetes (T2D).

METHODS

In this multicenter prospective study, 29 normal-weight, 54 overweight, and 27 obese newly diagnosed and drug-naïve patients with T2D were treated with exenatide for 48 weeks. The primary efficacy endpoint was the effect of baseline body mass index (BMI) on glycemic control, measured as the change in HbA1c from baseline to Week 48 compared among different BMI groups. Other endpoints included comparisons of the effects of exenatide on fasting plasma glucose (FPG), postprandial plasma glucose (PPG), body weight, and other metabolic indices.

RESULTS

After 48-week treatment, the estimated mean changes in HbA1c in normal-weight, overweight, and obese patients were -1.9%, -1.8%, and -1.5%, respectively (P = 0.290 among groups after adjustment for baseline values). There were similar declines in FPG and 0.5- and 2-hour PPG among groups. There were non-significant trends from normal-weight to overweight to obese patients for increased weight reduction (decreases of 2.2, 3.9, and 4.0 kg, respectively; P = 0.104) and changes in waist circumference (decreases of 2.2, 3.2, and 5.6 cm, respectively; P = 0.078).

CONCLUSIONS

Baseline BMI had no effect on glycemic control, weight change, or other metabolic indices with exenatide monotherapy. Normal-weight patients with T2D would benefit from exenatide as much as overweight or obese patients on glucose control, without increased risk of excess weight loss.