Benefits and risks of drug combination therapy for diabetes mellitus and its complications: a comprehensive review

Diabetes is a chronic metabolic disease, and its therapeutic goals focus on the effective management of blood glucose and various complications. Drug combination therapy has emerged as a comprehensive treatment approach for diabetes. An increasing number of studies have shown that, compared with monotherapy, combination therapy can bring significant clinical benefits while controlling blood glucose, weight, and blood pressure, as well as mitigating damage from certain complications and delaying their progression in diabetes, including both type 1 diabetes (T1D), type 2 diabetes (T2D) and related complications. This evidence provides strong support for the recommendation of combination therapy for diabetes and highlights the importance of combined treatment. In this review, we first provided a brief overview of the phenotype and pathogenesis of diabetes and discussed several conventional anti-diabetic medications currently used for the treatment of diabetes. We then reviewed several clinical trials and pre-clinical animal experiments on T1D, T2D, and their common complications to evaluate the efficacy and safety of different classes of drug combinations. In general, combination therapy plays a pivotal role in the management of diabetes. Integrating the effectiveness of multiple drugs enables more comprehensive and effective control of blood glucose without increasing the risk of hypoglycemia or other serious adverse events. However, specific treatment regimens should be tailored to individual patients and implemented under the guidance of healthcare professionals.

Association of Glucagon-like Peptide 1 Analogs and Agonists Administered for Obesity with Weight Loss and Adverse Events: A Systematic Review and Network Meta-analysis

BACKGROUND

Comparative effectiveness of 7 glucagon-like peptide 1 (GLP-1) agents on weight loss (WL) in obesity remains unknown.

METHODS

We performed a systematic review, network meta-analysis (NMA) utilizing the following data sources: MEDLINE, EMBASE, Scopus, Cochrane Central and clinical trial registries, from inception to March 2, 2021. The prespecified criteria for study inclusion were randomized clinical trials (RCTs) of ≥12 weeks' duration. The data appraisal and extraction were performed by two investigators independently, using the published reports. The main outcomes and statistical methods were weight loss over placebo (WLOP) and adverse events (AEs) among GLP-1 agents using random-effects NMA (frequentist approach); relative ranking using surface under the cumulative ranking (SUCRA) method and certainty of evidence using grading of recommendations, assessment, development and evaluations (GRADE).

FINDINGS

64 RCTs (from 2004 to 2021) included 27018 patients (median of age, 55.1 years old; 57.4% women; baseline weight 94.8kg and BMI 33.0kg/m²; trial duration 26 weeks). Direct meta-analysis showed significant WLOP with: -1.44kg (95% CI, -2.14 to -0.74) with dulaglutide ≥1.5 mg; -1.82kg (-2.42 to -1.23) with exenatide immediate release (IR); -2.20kg (-4.31 to -0.08) with exenatide extended release (ER); -3.20kg (-6.53 to 0.15) with efpeglenatide; -2.72kg (-3.35 to -2.09) with liraglutide ≤1.8mg; -4.49kg (-5.26 to -3.72) with liraglutide >1.8mg; -0.62kg (-1.22 to -0.02) with lixisenatide; -4.33kg (-5.71 to -3.00) with semaglutide SQ <2.4mg; -9.88kg (-13.17 to -6.59) with semaglutide SQ 2.4mg; -2.73kg (-4.81 to -0.65) with semaglutide oral; and -1.71kg (-2.64 to -0.78) with taspoglutide. Highest WLOP were with semaglutide SQ 2.4mg and <2.4mg, and liraglutide >1.8mg (SUCRAs 100, 86.1, 82.8 respectively). Highest SUCRAs for discontinuation due to AEs were with taspoglutide and liraglutide >1.8mg. Risk of bias was high or unclear for random sequence generation (29.7%), allocation concealment (26.6%), and incomplete outcome data (26.6%). Heterogeneity (I² >50%) in WL and AEs reflected magnitude, not direction of effect.

Exenatide, Metformin, or Both for Prediabetes in PCOS: A Randomized, Open-label, Parallel-group Controlled Study

CONTEXT

Up to 40% of patients with polycystic ovary syndrome (PCOS) have prediabetes; an optimal pharmacotherapy regimen for diabetes prevention in PCOS is yet to be established.

OBJECTIVE

To evaluate clinical efficacy of exenatide (EX), metformin (MET), or combination (COM) for prediabetes in PCOS.

DESIGN

Randomized, open-label, parallel-group controlled trial.

SETTING

Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine.

PATIENTS

PCOS with prediabetes (fasting plasma glucose 5.6-6.9 mmol/L and/or 2 hour post glucose 7.8-11.0 mmol/L on oral glucose tolerance test [OGTT]). A total of 150 out of 183 eligible enrollees completed the study.

INTERVENTION

EX (10-20μg daily), MET (1500-2000 mg daily), or COM (EX plus MET) for 12 weeks.

MAIN OUTCOME MEASURES

Sustained remission rate of prediabetes (primary endpoint, a normal OGTT after 12 weeks of treatment followed by 12 weeks of washout on no drug treatment) along with anthropometric, hormonal, metabolic, and pancreatic β-cell function parameters (secondary endpoints) and potential mechanisms were assessed.

RESULTS

Impaired glucose tolerance was found the dominant prediabetes phenotype. Overall sustained prediabetes remission rate was 50.7%. Remission rate of COM group (64%, 32/50) or EX group (56%, 28/50) was significantly higher than that of the MET group (32%, 16/50) (P = .003 and .027, respectively). EX was associated with superior suppression of 2-hour glucose increment in OGTT. A 2-step hyperglycemic clamp study revealed that EX had led to higher postprandial insulin secretion than MET, potentially explaining the higher remission rate.

CONCLUSIONS

Compared with MET monotherapy, EX or COM achieved higher rate of remission of prediabetes among PCOS patients by improving postprandial insulin secretion.

Risk of any hypoglycaemia with newer antihyperglycaemic agents in patients with type 2 diabetes: A systematic review and meta-analysis

OBJECTIVES

For patients with type 2 diabetes, newer antihyperglycaemic agents (AHA), including the dipeptidyl peptidase IV inhibitors (DPP4i), glucagon-like peptide-1 receptor agonists (GLP1RA) and sodium glucose co-transporter 2 inhibitors (SGLT2i) offer a lower risk of hypoglycaemia relative to sulfonylurea or insulin. However, it is not clear how AHA compare to placebo on risk of any hypoglycaemia. This study evaluates the risk of any and severe hypoglycaemia with AHA and metformin relative to placebo.

DESIGN

A systematic review and meta-analysis was conducted of randomized, placebo-controlled trials ≥12 weeks in duration. MEDLINE, Embase and the Cochrane Library were searched up to April 16, 2019. Studies allowing use of other diabetes medications were excluded. Mantel-Haenszel risk ratio with 95% confidence intervals were used to pool estimates based on class of AHA and number of concomitant therapies used.

PATIENTS

Eligible studies enrolled patients with type 2 diabetes ≥18 years of age.

RESULTS

144 studies met our inclusion criteria. Any hypoglycaemia was not increased with AHA when used as monotherapy (DPP4i (RR 1.12; 95% CI 0.81-1.56), GLP1RA (1.77; 0.91-3.46), SGLT2i (1.34; 0.83-2.15)), or as add-on to metformin (DPP4i (0.95; 0.67-1.35), GLP1RA (1.24; 0.80-1.91), SGLT2i (1.29; 0.91-1.83)) or as triple therapy (1.13; 0.67-1.91). However, metformin monotherapy (1.73; 1.02-2.94) and dual therapy initiation (3.56; 1.79-7.10) was associated with an increased risk of any hypoglycaemia. Severe hypoglycaemia was rare not increased for any comparisons.

CONCLUSIONS

Metformin and the simultaneous initiation of dual therapy, but not AHA used alone or as single add-on combination therapy, was associated with an increased risk of any hypoglycaemia relative to placebo.

New Insights into Adipokines as Potential Biomarkers for Type-2 Diabetes Mellitus

A large number of studies have been focused on investigating serum biomarkers associated with risk or diagnosis of type-2 diabetes mellitus. In the last decade, promising studies have shown that circulating levels of adipokines could be used as a relevant biomarker for diabetes mellitus progression as well as therapeutic future targets. Here, we discuss the possible use of recently described adipokines, including apelin, omentin-1, resistin, FGF-21, neuregulin-4 and visfatin, as early biomarkers for diabetes. In addition, we also include recent findings of other well known adipokines such as leptin and adiponectin. In conclusion, further studies are needed to clarify the pathophysiological significance and clinical value of these biological factors as potential biomarkers in type-2 diabetes and related dysfunctions.

Time-Dependent Change in Omentin-1 Level Correlated with Early Improvement of Myocardial Function in Patients with First Anterior ST-Segment Elevation Myocardial Infarction After Primary Percutaneous Coronary Intervention

Aim: Omentin-1, as a novel adipocytokine, ameliorates obesity-associated disorders and suppresses the development of atherosclerotic lesions. The present research investigated the correlation between serum omentin-1 and post-infarction myocardial function.

Methods: A total of 52 patients with first anterior ST-segment elevation myocardial infarction (STEMI) were recruited into this study. Participants were divided into two subgroups according to median admission omentin-1 concentration. δ1 was defined as (admission omentin-1 level) - (serum omentin-1 at 24 hours after admission) and δ2 was defined as (admission omentin-1 level) - (serum omentin-1 at 72 hours after admission). The change in left ventricular ejection fraction (LVEF) was regarded as (LVEF at 3 months post-STEMI) – (LVEF at 2 days post-STEMI).

Results: Admission omentin-1 level was the highest, while omentin-1 decreased over the following 3 days. The high admission omentin-1 group had lower peak muscle brain fraction of creatine kinase (CK–MB). Additionally, the change in LVEF and the global LVEF at 3 months post-STEMI all ameliorated significantly in the high admission omentin-1 group. For the time-dependent change in omentin-1, there were negative associations among δ1, δ2, and peak CK–MB. δ1 and δ2 also correlated positively with LVEF at 3 months post-STEMI. Most importantly, δ1 (r = 0.346, p = 0.012) and δ2 (r = 0.439, p = 0.001) also correlated positively with the change in LVEF. After multivariate linear regression analysis, δ1 (Beta = 0.026, 95% CI 0.011 to 0.041, p = 0.001) and δ2 (Beta = 0.024, 95% CI 0.009 to 0.038, p = 0.003) also remained associated with the change in LVEF.

Conclusions: The admission omentin-1 and time-dependent change in omentin-1 level all have a significant correlation with the early improvement of post-infarction myocardial function. While only the time-dependent change in omentin-1 (δ1 and δ2) remained associated with the early improvement of post-infarction myocardial function after multivariate linear regression analysis. The present research indicated that omentin-1 represents a promising adipocytokine to retard negative cardiac remodeling after STEMI.

The Effects of Novel Antidiabetic Drugs on Albuminuria in Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND AND OBJECTIVE

The effects of novel antidiabetic drugs, including sodium-glucose cotransporter 2 (SGLT-2) inhibitors, glucagon-like peptide 1 (GLP-1) receptor agonists, and dipeptidyl peptidase 4 (DPP-4) inhibitors, on albuminuria in patients with type 2 diabetes mellitus (T2DM) are still controversial. Therefore, we performed a meta-analysis to evaluate the effects of novel antidiabetic drugs on albuminuria in patients with T2DM.

METHODS

We conducted a random-effects meta-analysis of randomized controlled trials (RCTs) by searching the MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials databases up to 16 August 2018. The effects of novel antidiabetic drugs on albuminuria were evaluated as percent changes from baseline to follow-up urinary albumin excretion/urinary albumin to creatinine ratio (UAE/UACR) levels in both the intervention and control groups. Data regarding percent changes were used to generate weighted mean differences (WMDs) and 95% confidence intervals (CIs).

RESULTS

In this meta-analysis, 26 RCTs involving 14,929 patients were included. Pooled analysis suggested that SGLT-2 inhibitors (WMD - 26.23%, 95% CI - 35.90 to - 16.56; p < 0.00001) and GLP-1 receptor agonists (WMD - 13.85%, 95% CI - 15.96 to - 11.74; p < 0.00001) were associated with a significant reduction in albuminuria compared with other conventional therapies or placebo. DPP-4 inhibitors (WMD - 6.19%, 95% CI - 14.03 to 1.66; p = 0.12) were not significantly associated with lower albuminuria than other conventional therapies or placebo.

CONCLUSION

This meta-analysis indicates that SGLT-2 inhibitors and GLP-1 receptor agonists were associated with a reduction in albuminuria compared with other conventional therapies or placebo, while DPP-4 inhibitors were not associated with albuminuria-reducing effects compared with other conventional therapies or placebo.

The Effects of Exenatide Once Weekly (EXQW) and Exenatide Twice a Day (EXBID) on Beta-Cell Function in Type 2 Diabetes: A Systematic Review and Network Meta-Analysis

BACKGROUND

In patients with type 2 diabetes mellitus (T2DM) and poor glycemic control receiving metformin (MET), glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are recommended as the adjunctive therapy. However, there are only a few studies involving the comparative effects of exenatide twice a day (EXBID) and exenatide once weekly (EXQW) on HOMA-β. This meta assessed the comparative effects of EXQW and EXBID on HOMA-β among T2DM patients.

MATERIALS AND METHODS

PubMed, Cochrane Library, and Embase databases were searched to collect randomized controlled trials (RCTs). Network meta-analysis was performed, and network diagrams were constructed to evaluate the effects. The primary outcome is HOMA-β, and the secondary outcomes are fasting blood glycose (FBG), glycated hemoglobin (HbA1c), and weight loss.

RESULTS

A total of 8 studies with 3506 subjects were included. Compared with other antidiabetic agents, EXQW has a greater improvement in HOMA-β than EXBID (weight mean difference (WMD) = -0.46, 95% confidence interval (CI) [-0.64, -0.28], P = 0.001). The effect of EXQW on HbA1c is superior to that of sitagliptin (SITA) (WMD = 0.51, 95% CI [0.03, 0.99], P = 0.037). The significant reduction of weight was detected for EXBID in comparison with EXQW (WMD = -0.73, 95% CI [-1.13, -0.33], P = 0.001), and no significant difference was found between EXQW and MET.

CONCLUSIONS

EXQW shows a greater improvement in HOMA-β than EXBID. Moreover, the efficacy of EXQW on glycemic control is similar to other antidiabetic agents including EXBID. It is an advisable treatment for diabetic patients to improve HOMA-β and has an advantage of fewer number of injections compared with EXBID, to increase patients' adherence and quality of life.

Glucagon-like peptide-1 exerts anti-inflammatory effects on mouse colon smooth muscle cells through the cyclic adenosine monophosphate/nuclear factor-κB pathway in vitro

Background

Intestinal smooth muscle cells (SMCs) undergo substantial morphological, phenotypic, and contractile changes during inflammatory bowel disease (IBD). SMCs act as a source and target for different inflammatory mediators, however their role in IBD pathogenesis is usually overlooked. Glucagon-like peptide-1 (GLP-1) is an incretin hormone reported to exert multiple anti-inflammatory effects in different tissues including the gastrointestinal tract through various mechanisms.

Aim

The aim of this research is to explore the effect of GLP-1 analog exendin-4 on the expression and secretion of inflammatory markers from mouse colon smooth muscle cells (CSMCs) after stimulation with lipopolysaccharide (LPS).

Materials and methods

Freshly isolated CSMCs from male BALB/c mice were cultured in DMEM and treated with vehicle, LPS (1 μg/mL), LPS+exendin-4 (50 nM), or LPS+exendin-4 (100 nM) for 24 h. Expression of inflammatory cytokines was then evaluated by antibody array membrane.

Results

CSMCs showed basal expression of several cytokines which was enhanced with the induction of inflammation by LPS. However, exendin-4 (50 and 100 nM) significantly (p<0.05) reduced the expression of multiple cytokines including tumor necrosis factor-α (TNF-α), interleukin-1α (IL-1α), T cell activation gene-3 (TCA-3), stromal cell-derived factor-1 (SDF-1), and macrophage colony stimulating factor (M-CSF). To confirm these results, expression of these cytokines was further assessed by enzyme-linked immunosorbent assay and real-time polymerase chain reaction and similar results were also observed. Moreover, secretion of TNF-α and IL1-α into the conditioned media was significantly downregulated by exendin-4 when compared to LPS-treated cells. Furthermore, LPS increased NF-κB phosphorylation, while exendin-4 significantly reduced levels of NF-κB phosphorylation.

Conclusion

These data indicate that GLP-1 analogs can exert significant anti-inflammatory effects on CSMCs and can potentially be used as an adjunct treatment for inflammatory bowel conditions.

A network meta-analysis for efficacy and safety of seven regimens in the treatment of type II diabetes

The efficacy and safety of seven regimens based on metformin (placebo plus metformin, dapagliflozin plus metformin, vildagliptin plus metformin, saxagliptin plus metformin, empagliflozin plus metformin, exenatide plus metformin and sitagliptin plus metformin) on type 2 diabetes (T2D) were compared based on network meta-analysis. PubMed, Embase and Cochrane Library were applied in the computer-based retrieval process. Randomized controlled trials (RCTs) which were related with the above seven regimens based on metformin in the treatment of T2D were included in this study. Network meta-analysis merged the direct and indirect comparison evidence for the estimation of the weighted mean difference (WMD), odd ratios (ORs) and surface under the cumulative sequencing ranking curve (SUCRA) values. Eight eligible RCTs were applied in this network meta-analysis. The results demonstrated that: in terms of efficacy, the glycated hemoglobin (HbA1c) levels of T2D patients receiving vildagliptin plus metformin were relatively lower when compared with placebo plus metformin (WMD=-1.95, 95%CI=-3.70--0.23); in comparison with exenatide plus metformin, the triglyceride level in T2D patients taking vildagliptin plus metformin remained relatively lower (WMD=-1.36, 95%CI=-2.64--0.01). In terms of safety, the rate of adverse events in patients with T2D who received empagliflozin plus metformin was relatively lower when compared with saxagliptin plus metformin (OR=0.37, 95%CI=0.14-0.98). Furthermore, the SUCRA value of vildagliptin plus metformin was comparatively higher in efficacy, and that the SUCRA value of saxagliptin plus metformin was relatively lower in safety. The efficacy of vildagliptin plus metformin in patients with T2D is relatively better, while the safety of saxagliptin plus metformin in patients with T2D is relatively poorer.

The Use of Exenatide in Managing Markers of Cardiovascular Risk in Patients with Type 2 Diabetes: A Systematic Review

Objective: This review examines the use of exenatide twice daily in managing changes in markers of cardiovascular risk in patients with type 2 diabetes. Background: Type 2 diabetes is a progressive metabolic disorder, which results from defects in insulin secretion and/or insulin action leading to chronic hyperglycaemia and associated cardiovascular complications. Despite the use of diet, exercise, oral antihyperglycaemic agents and insulin, the progressive nature of the condition means that the levels of the preventive and treatment measures would have to be increased and/or new therapies have to be developed in order to address the long term impact of type 2 diabetes. The advent of exenatide, a glucagon-like peptide-1 receptor agonist provides a useful basis for managing type 2 diabetes and related cardiovascular complications without the side effects of regular diabetes therapies. However, exenatide twice daily is often used in combination with other therapies, although the mechanism of exenatide in managing diabetes and and associated cardiovascular risks and complications remain complex and still evolving. Method: A range of databases including EBSCOhost online research database were used to access articles based on PICO (Population, Interventions, Comparative Interventions, Outcomes) framework and Boolean operators. Results: Eleven randomised controlled studies which met the inclusion criteria were selected for this review. Nine of the eleven studies showed significant decrease in body weight among participants in the exenatide group compared with placebo or control group while the other two studies did not report statistically significant differences in body weight. In adition, all the studies showed statistically significant decrease in glycated haemoglobin (HbA1c) in the exenatide group compared to controls except in one study. In the present review, the seven studies, which looked at the effect of exenatide twice daily on lipid profile, did not find any significant difference between the exenatide group and the control group except for High density lipoprotein-cholesterol in two of the studies. However, statistically significant decrease was observed between exenatide group and controls with respect to blood pressure (systolic and/or diastolic) in these studies. Discussion: It would appear that exenatide is more effective in reducing body weight in patients with type 2 diabetes when used in combination with metformin than when used alone or in combination with thiazolidinedione. The findings of this review would suggest that exenatide twice daily may be useful in managing cardiovascular risks and complications by reducing body weight, HbA1c and blood pressure.

Effects of three injectable antidiabetic agents on glycaemic control, weight change and drop-out in type 2 diabetes suboptimally controlled with metformin and/or a sulfonylurea: A network meta-analysis

AIMS

The objective of this review was to assess glucagon-like peptide-1 receptor agonists (GLP-1 RAs), basal insulin, and premixed insulin among participants with type 2 diabetes inadequately controlled with metformin and/or a sulfonylurea.

METHODS

We searched PubMed, EmBase, and the Cochrane Library to identify eligible randomized controlled trials (RCTs) for a network meta-analysis.

RESULTS

A total of 17 RCTs involving 5874 adult individuals were included. Compared with placebo, all three therapies showed a significant effect on achieving target glycated hemoglobin (HbA1c) (GLP-1 RAs: 31.7%, 95% CI, 24.7-38.6%; premixed insulin: 31.1%, 95% CI, 20.4-41.8%; basal insulin: 26.0%, 95% CI, 16.4-35.7%). However, there was no significant difference between the three therapies. A similar result was found in HbA1c reduction. The use of GLP-1 RAs resulted in significant body weight loss (-3.73 kg, 95% CI, -4.52 to -2.95 kg vs. basal insulin and -5.27 kg, 95% CI, -6.17 to -4.36 kg vs. premixed insulin) but there was a higher drop-out rate of participants. Premixed insulin seemed associated with more severe hypoglycemic episodes.

CONCLUSIONS

The three injectables had similar impact on glycemic control but other differentiating features relevant to the management of type 2 diabetes with GLP-1 RAs having the most favorable profile.

Exenatide twice daily: a review of its use in the management of patients with type 2 diabetes mellitus

Exenatide, administered subcutaneously twice daily (Byetta(®)), is a synthetic version of the natural peptide exendin-4, which is a glucagon-like peptide-1 (GLP-1) receptor agonist (incretin mimetic). Exenatide binds to the GLP-1 receptor with the same affinity as GLP-1, but has a much longer half-life, since it is not degraded by the enzyme dipeptidyl peptidase-4. Exenatide twice daily enhances glucose-dependent insulin secretion, suppresses inappropriately elevated glucagon secretion, slows gastric emptying and reduces caloric intake. In well-designed clinical trials, adjunctive subcutaneous exenatide 5 or 10 μg twice daily for 16-52 weeks significantly and dose-dependently improved glycaemic control and reduced mean body weight compared with placebo in patients with type 2 diabetes inadequately controlled with oral antihyperglycaemic drugs (OADs) and/or basal insulin. The improvements in glycaemic control and reductions in body weight were stably maintained during long-term therapy (up to 3.5 years). The efficacy of adjunctive exenatide twice daily was generally similar to that of basal, prandial or biphasic insulin, sulfonylureas, rosiglitazone and lixisenatide, and less than that of liraglutide, taspoglutide or exenatide once weekly with respect to reductions in glycated haemoglobin. Exenatide twice daily was generally well tolerated; mild to moderate nausea and vomiting, which decreased with time on therapy, were the most common adverse events. In patients not receiving concomitant sulfonylureas or insulin, the incidence of hypoglycaemia was low; when it did occur, it was generally mild in severity. Thus, adjunctive exenatide twice daily is a valuable option in the treatment of type 2 diabetes inadequately controlled with OADs and/or basal insulin.