Long-Acting Metformin Vs. Metformin Immediate Release in Patients With Type 2 Diabetes: A Systematic Review

Use of adjunctive glycaemic agents with vascular protective properties in individuals with type 1 diabetes: Potential benefits and risks

Glycaemic therapy in type 1 diabetes (T1D) is focused on insulin, with the majority of studies investigating different insulin preparations, delivery devices and dosing accuracy methods. While insulin deficiency is the key mechanism for hyperglycaemia in T1D, individuals with this condition can also develop insulin resistance (IR), making optimisation of glycaemia more challenging. Importantly, IR in T1D increases the risk of both microvascular and macrovascular complications; yet, it is rarely targeted in routine clinical care. In this narrative review, we briefly discuss the mechanistic pathways for diabetes complications in individuals with T1D, emphasising the adverse role of IR. We subsequently cover the use of adjunctive glycaemic therapies for improving the metabolic profile in T1D, focusing on therapies that have possible or definite cardiovascular or renal protective properties in individuals with type 2 diabetes. These include metformin and agents in the thiazolidinedione, Sodium-Glucose Cotransporter-2 inhibitor (SGLT2i) and Glucagon-Like Peptide-1 Receptor Agonists (GLP-1RA) groups. In addition to reviewing the role of these agents in improving metabolic parameters, we address their potential vascular and renal protective effects in individuals with T1D. We suggest a pragmatic approach for using these agents in T1D, based on current knowledge of their benefits and risks, while also highlighting gaps in knowledge and areas that require further research. It is hoped that the review raises awareness of the role of adjunctive therapies in T1D and offers healthcare professionals simple guidance on using such agents for the management of high-risk individuals with T1D.

Solidified ionic liquid-based formulations of metformin with enhanced GI epithelial permeability

Active Pharmaceutical Ingredient-Ionic Liquids (API-ILs) can enhance intestinal epithelial membrane permeability of poorly bioavailable APIs, improving bioavailability. However, clinical and commercial application is to date limited due to challenging physical handling properties. Lipid-based formulations (LBFs) are commonly used to enhance intestinal drug absorption but face challenges including low drug-loading capacity and limited stability. To address these issues, a method for transforming liquid API-ILs and LBFs into high-loading solid forms via spray-encapsulation with polymers was developed. Here the method was applied to a lipophilic API-IL of BCS Class III, namely metformin, and multi-component API-IL solutions containing known intestinal permeation enhancers (Labrasol®, docusate). The spray-encapsulated solid formulations exhibited improved handling, self-emulsified in both phosphate buffer (pH 6.8) and fasted state simulated intestinal fluid (FaSSIF), while exhibiting superior in vitro release profiles compared to the liquid formulations. Ex vivo permeability studies on metformin docusate formulations using rat intestinal mucosae in Ussing chambers demonstrated a 2.3- to 6.3-fold increase in permeability (Papp) for solidified formulations, with metformin hydrochloride as the control. Further studies revealed a correlation between docusate concentration and permeability enhancement. These findings highlight the potential of solidified docusate-based lipophilic API-IL formulations to improve membrane permeability of poorly bioavailable APIs.

Gene Expression Analysis in T2DM and Its Associated Microvascular Diabetic Complications: Focus on Risk Factor and RAAS Pathway

Prolonged hyperglycemic conditions in type 2 diabetes mellitus (T2DM) cause pathological and functional damage to many organs and tissues, including the kidneys, retina, skin, and neuronal tissues, resulting in the development of microvascular diabetic complications. The altered renin angiotensin aldosterone system (RAAS) pathway has been reported to play an important role in the development of insulin resistance in T2DM and associated complications. The current study was carried out to evaluate the association of risk factors and altered expression of RAAS genes in T2DM patients without complications and T2DM patients with complications (retinopathy, nephropathy, and neuropathy). Four hundred and twenty subjects including 140 healthy controls, 140 T2DM patients with diabetic complications, and 140 T2DM patients without diabetic complications were included in the study. Risk factors associated with the development of T2DM and diabetic complications were evaluated. Further, expression analysis of RAAS genes (AGT, ACE, ACE2, and AGT1R) was carried out using qRTPCR in healthy controls, T2DM patients with complications, and T2DM patients without complications. Various risk factors like urban background, higher BMI, alcoholism, smoking, and family history of diabetes among others were found to be associated with the development of T2DM as well as diabetic complications. The expression level of AGT, ACE, and AGT1R was found to be upregulated whereas ACE2 was found to be downregulated in T2DM patients with complications and T2DM patients without complications as compared to controls. Altered expression of the studied genes of RAAS pathway is associated with the development of microvascular diabetic complications.

Gastrointestinal adverse events of metformin treatment in patients with type 2 diabetes mellitus: a systematic review and meta-analysis with meta-regression of observational studies

INTRODUCTION

Metformin is the most prescribed medication for type 2 diabetes mellitus (T2DM); there is a well-established link with the elevated incidence of gastrointestinal (GI) adverse events (AE) limiting its administration or intensification.

OBJECTIVES

The objective of this systematic review and meta-analysis of observational studies was to evaluate the pooled incidence of GI AE related to metformin use in patients with T2DM.

MATERIALS AND METHODS

PUB MED/CINAHL/Web of Science/Scopus were searched from database inception until 29.07.2024 for observational studies in English describing the frequency of GI AE in patients with T2DM treated with metformin. Random-effects meta-analyses were used to derive effect sizes: event rates.

RESULTS

From 7019 publications, we identified 211 potentially eligible full-text articles. Ultimately, 21 observational studies were included in the meta-analysis. The prevalence of GI AE was as follows: diarrhea 6.9% (95% CI: 0.038-0.123), bloating 6,2% (95% CI: 0.020-0.177), abdominal pain 5,3% (95% CI: 0.003-0.529), vomiting 2.4% (95%: CI 0.007-0.075), constipation 1.1% (95%: CI 0.001-0.100). The incidence of bloating (coefficient -4.46; p < 0.001), diarrhea (coefficient -1.17; p = 0.0951) abdominal pain (coefficient -2.80; p = 0.001), constipation (coefficient -5.78; p = 0.0014) and vomiting (coefficient -2.47; p < 0.001) were lower for extended release (XR) metformin than metformin immediate release (IR) formulation.

CONCLUSIONS

This study highlights the prevalence of GI AE in patients receiving metformin, with a diarrhea predominance, followed by bloating, diarrhea, abdominal pain, constipation, and vomiting. The incidence is lower in patients administered with XR metformin.

TRIAL REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021289975 , identifier CRD42021289975.

Metformin-Associated Gastrointestinal Adverse Events Are Reduced by Probiotics: A Meta-Analysis

Metformin, one of the most frequently used oral glucose-lowering drugs (GLDs), is associated with the occurrence of gastrointestinal (GI) adverse events in approximately 20% of users. These unwanted actions result in non-compliance or even discontinuation of metformin therapy. The aim of the presented meta-analysis was to determine whether adding a drug from the group of sulfonylureas, glitazones, DPP-IV inhibitors, or probiotics to metformin monotherapy may affect the risk of GI side effects. The material for this meta-analysis comprised data from 26 randomized controlled clinical trials (RCTs) published in English. This meta-analysis included 41,048 patients. The PubMed, Cochrane Library, and Clinical Trials databases were thoroughly searched to find relevant RCTs. The Population, Intervention, Comparison, Outcomes, and Study Type (PICOT) structure was used to formulate study selection criteria and the research question. Cochrane Review Manager Software 5.4 was used to carry out analysis of collected data. The results were presented as relative risk (RR) and 95% confidence interval (95% CI) for each group, and p < 0.05 was considered as statistically significant. As expected from clinical practice, metformin was associated with a markedly increased risk of abdominal pain, nausea, and vomiting compared to placebo. In comparison to other GLDs, taking metformin was related to an elevated risk of diarrhea and abdominal pain and to a lowered risk of vomiting and bloating. In turn, adding other GLDs to metformin treatment was associated with an elevated risk of nausea and vomiting than treatment with metformin in monotherapy. However, adding probiotics to metformin therapy was related to a decreased risk of diarrhea, bloating, and constipation. The obtained results demonstrate that the combination of metformin with other GLDs may elevate the risk of nausea and vomiting, whereas combination with probiotics decreases the risk of diarrhea, bloating, and constipation. Thus, the results of our meta-analysis suggest that probiotics may reduce the risk of some GI side effects in people with type 2 diabetes mellitus (T2DM) who started treatment with metformin.

Approved and Commercialized Antidiabetic Medicines (Excluding Insulin) in Seven European Countries-A Cross-Sectional Comparison

Diabetes mellitus is a complex, multifactorial, progressive condition with a variety of approved therapeutic options. The purpose of this study was to offer an overview of the authorized antidiabetic medicines (excluding insulin) compared with marketed products in seven European countries. Data were obtained from primary sources, including the websites of national authorities and directly from specialists in the countries of interest. The range of marketed medicines compared with the authorized group was assessed in terms of active pharmaceutical ingredients (>60% in Bulgaria, France, Serbia), brand names (>70% in Bulgaria, the Czech Republic, Romania, Serbia, Spain), pharmaceutical forms (>60% in all countries), strengths (>60% in Bulgaria, the Czech Republic, Romania, Serbia, Spain), marketing authorization holder (≥50% in all countries) and the status of medicine. Spain was found to have the highest number of products based on most of these attributes. Over 90% of authorized medicines had a pharmacy price in Serbia. Regarding the newer class of GLP-1 receptor agonists, a retail price for all approved substances was available in Bulgaria, Romania, Serbia, and Spain. Only one brand name with one concentration was found available for some agents, being susceptible to drug shortages: glibenclamide (Romania, Serbia, Spain), glipizide (the Czech Republic, Poland, Romania, Spain), glisentide (Spain), acarbose (the Czech Republic), sitagliptin (Bulgaria, Poland), vildagliptin (the Czech Republic, Poland) and saxagliptin (the Czech Republic, France, Romania, Serbia). An overview of the national and international therapeutic options may allow competent authorities and health professionals to take rapid measures in case of supply problems or health crises.

Effect of metformin (vs. placebo or sulfonylurea) on all-cause and cardiovascular mortality and incident cardiovascular events in patients with diabetes: an umbrella review of systematic reviews with meta-analysis

Purpose

The current umbrella review aimed to evaluate the effect of metformin on all-cause mortality (ACM), cardiovascular mortality, and cardiovascular disease (CVD) incidence in DM patients.

Methods

PubMed, Scopus, Cochrane, Google Scholar, and Web of Science databases were searched with special keywords. Related studies were included after screening by two independent investigators based on title and full texts. The AMSTAR2 checklist was used to assess the quality of studies, and Cochran tests were used to assess the heterogeneity between studies. Overall, seventeen systematic reviews and meta-analysis studies were included. The results revealed that the risk of ACM in patients who received metformin was lower than in patients who did not receive metformin. (OR: 0.80, 95% CI:0.744,0.855); also, the risk of CVD mortality in metformin patients was lower than in the other two groups (placebo and other anti-diabetic drugs) (OR: 0.771, 95% CI:0.688,0.853, P:0.001). The risk of CVD in metformin users was also lower than in the other two groups (OR: 0.828, 95% CI:0.781,0.785).

Summary

This comprehensive review showed that the risk of ACM, death due to CVD, and incidents of CVD in DM who use metformin was lower than the patients who received a placebo only or other diabetic drugs, which can guide clinicians in medical decision-making.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01309-y.

View on Metformin: Antidiabetic and Pleiotropic Effects, Pharmacokinetics, Side Effects, and Sex-Related Differences

Metformin is a synthetic biguanide used as an antidiabetic drug in type 2 diabetes mellitus, achieved by studying the bioactive metabolites of Galega officinalis L. It is also used off-label for various other diseases, such as subclinical diabetes, obesity, polycystic ovary syndrome, etc. In addition, metformin is proposed as an add-on therapy for several conditions, including autoimmune diseases, neurodegenerative diseases, and cancer. Although metformin has been used for many decades, it is still the subject of many pharmacodynamic and pharmacokinetic studies in light of its extensive use. Metformin acts at the mitochondrial level by inhibiting the respiratory chain, thus increasing the AMP/ATP ratio and, subsequently, activating the AMP-activated protein kinase. However, several other mechanisms have been proposed, including binding to presenilin enhancer 2, increasing GLP1 release, and modification of microRNA expression. Regarding its pharmacokinetics, after oral administration, metformin is absorbed, distributed, and eliminated, mainly through the renal route, using transporters for cationic solutes, since it exists as an ionic molecule at physiological pH. In this review, particular consideration has been paid to literature data from the last 10 years, deepening the study of clinical trials inherent to new uses of metformin, the differences in effectiveness and safety observed between the sexes, and the unwanted side effects. For this last objective, metformin safety was also evaluated using both VigiBase and EudraVigilance, respectively, the WHO and European databases of the reported adverse drug reactions, to assess the extent of metformin side effects in real-life use.

Improving Type 2 Diabetes Care with Extended-Release Metformin: Real-Life Insights from a Physician Educational Program

BACKGROUND

Compared to Immediate-Release (IR) metformin, Extended-Release (ER) metformin reduces side effects and pill burden while improving adherence; however, there is little real-life data on patient satisfaction with this innovative formulation to guide physicians toward a more holistic approach.

OBJECTIVE

Our goal is to train general practitioners on holistic patient management, with the aim of increasing patient satisfaction and treatment adherence, reducing side effects, and improving quality of life in patients with poor tolerance to metformin-IR.

MATERIALS AND METHODS

We designed an educational program for physicians called SlowDiab, aimed at establishing a holistic patient approach. In this context, adult patients with T2DM who experienced gastrointestinal discomfort with metformin-IR were enrolled and switched to metformin- ER. Data on glycemic control were collected at baseline and 2 months after switching. A survey was carried out on patients to assess their level of satisfaction.

RESULTS

In 69 enrolled patients (mean (min-max) age, 68.2 (41-90)), side effects decreased after switching from 61.8% to 16.2% (p < 0.01), and the mean perceived burden of adverse events on a scale of 1 to 10 also decreased (6.17 vs. 3.82; p < 0.05). Among patients previously intolerant to metformin-IR, 74.3% reported no longer experiencing any side effects after the switch. The mean number of tablets taken daily (2.28 vs. 1.66; p < 0.01) and mean plasma glycated hemoglobin (HbA1c) values (7.0% vs. 6.7%; p < 0.05) decreased, while 93.8% of patients were satisfied with the treatment change. Moreover, 84.2% reported an improvement in glycemic control after the switch.

CONCLUSION

In a real-life setting, an educational program for general practitioners confirmed that metformin ER reduces side effects and improves pill burden, therapeutic adherence, and patient satisfaction compared to metformin IR.

Insights Into Metformin XR Pharmacotherapy Knowledge Among Community Pharmacists: A Cross-Sectional Study

BACKGROUND

There is a little knowledge on the extent to which healthcare providers understand and accept the professional recommendations and appropriate dosing strategy regarding metformin XR.

OBJECTIVES

To evaluate UAE community pharmacists' knowledge, attitude, and practices (KAP) concerning metformin XR.

METHODS

This is a cross-sectional research study conducted amongst licensed community pharmacists. The survey took place via a questionnaire and physical interviews were held. The survey used in this study included questions on demographics and questions on the participants' attitudes, knowledge and practices concerning metformin XR. The factors influencing KAP regarding metformin XR were examined via simple logistic regression analysis.

RESULTS

Threehundred fifty-three (n = 353) participants were recruited in the study. Independent pharmacies constituted 57.5% of this study sample and 42.5% were chain pharmacies. The average knowledge score about metformin XR tablets was 42.5% with a confidence interval (CI) of 95% [37.3%, 47.4]. Better knowledge scores on metformin XR tablets was observed in respondents aged ⩾40 years (OR 2.97, 95% CI 1.63-5.4), having greater than 10 years in terms of experience (OR 2.28; 95% CI 1.25-4.16) and pharmacist graduated from Regional or international universities (OR 2.08; 95% CI 1.34-3.24). About 78% (n = 275) of the participants believed that metformin XR tablets have better efficacy and 63.2% (n = 233) indicated that metformin IR was associated with greater adverse effects.

CONCLUSION

This study demonstrated a distinct gap in knowledge, attitude and practice pertaining to metformin XR among community pharmacists in the UAE. The community pharmacists need to enhance their practice by receiving accurate and reliable data to support their decision-making on the prescribing of metformin XR. The implementation of novel guidelines and evidence dissemination strategies may help bridge this gap.

Preoperative considerations for patients with diabetes

INTRODUCTION

Patients undergoing surgery require a thorough assessment preoperatively. Hyperglycemia is associated with poor outcomes, and stability of glucose levels is an important factor in preoperative management. Diabetes presents a particular challenge since patients are often on multiple medications encompassing glycemic management and cardiovascular therapies.

AREAS COVERED

A PubMed search of published data and reviews on preoperative approaches in diabetes was conducted. Consensus opinion drives most of the guidelines and recommendations for management of diabetes in surgical patients. Pathophysiology is often complex with varying levels of glucose and surgical stress. Establishing well-controlled diabetes prior to surgical intervention should be standard practice in non-emergent procedures. We review the best practices for implementing preoperative assessment, with diabetes with a focus on diabetes medications.

EXPERT OPINION

The management of a patient preoperatively varies by region and country. Institutions differ in approaches to preoperative evaluation and the establishment of consistent approaches would provide a platform for monitoring patient outcomes. Multidisciplinary teams and pre-assessment clinics for preoperative evaluation can enhance patient care for those undergoing surgery.

Extended-release metformin improves cognitive impairment in frail older women with hypertension and diabetes: preliminary results from the LEOPARDESS Study

BACKGROUND

Women have a high risk of frailty independently of age and menopause state. Diabetes and hypertension increase the risk of frailty and cognitive impairment. Metformin has been employed in post-menopausal women and some reports have shown encouraging effects in terms of attenuated frailty. However, the impact on cognitive performance of a recently introduced extended-release formulation of metformin has never been explored.

METHODS

We studied consecutive frail hypertensive and diabetic older women presenting at the ASL (local health authority of the Italian Ministry of Health) Avellino, Italy, from June 2021 to August 2022, who were treated or not with extended-release metformin. We included a control group of frail older males with diabetes and hypertension treated with extended-release metformin and a control group of frail older women with diabetes and hypertension treated with regular metformin.

RESULTS

A total of 145 patients successfully completed the study. At the end of the 6-month follow-up, we observed a significantly different cognitive performance compared to baseline in the group of frail women treated with extended-release metformin (p: 0.007). Then, we compared the follow-up groups and we observed significant differences between frail women treated vs. untreated (p: 0.041), between treated frail women and treated frail men (p: 0.016), and between women treated with extended-release metformin vs. women treated with regular metformin (p: 0.048). We confirmed the crucial role of extended-release metformin applying a multivariable logistic analysis to adjust for potential confounders.

CONCLUSIONS

We evidenced, for the first time to the best of our knowledge, the favorable effects on cognitive impairment of extended-release metformin in frail women with diabetes and hypertension.

Clinical Application of Metformin Use in Anhui Province, China: A Cross-Sectional Study

Purpose

Given the importance of metformin, reasonable utilization is essential. We designed a cross-sectional survey on physicians' attitude and clinical application of metformin in Anhui Province, China.

Methods

The survey was distributed via an electronic questionnaire among endocrinologists and general practitioners. Seven representative questions were used to evaluate professional levels.

Results

Among the 477 valid responses, 72.75% of the respondents preferred to prescribe metformin extended-release, while only 34.38% of them would prescribe metformin extended-release at the correct frequency. More than half of the respondents thought that estimated glomerular filtration rate ˂ 45 mL/min/1.73 m² should be the contraindication of metformin prescription. Less than 10% of the physicians selected correct responses for two questions regarding metformin usage and contrast agent. Physicians with higher levels of hospital grades, education background and professional titles as well as working in general hospitals and in the Department of Endocrinology achieved high scores (P˂0.05). Logistic regression showed that department was an independent predictor for high scores.

Conclusion

Physicians, especially non-endocrinologists, are not at a professional level for prescribing metformin. Physicians should be highly vigilant in terms of standardized prescription for metformin. The guidelines or consensuses about diabetes care for physicians should be promoted.

Comparison of the Efficacy and Safety of Metformin-Based Combination Therapy Versus Metformin Alone in Children and Adolescents With Type 2 Diabetes Mellitus: A Meta-Analysis

The aim of this meta-analysis is to synthesize and critically evaluate the available evidence on the comparison of the efficacy and safety of metformin-based combination therapy versus metformin alone in children and adolescents with type 2 diabetes mellitus (T2DM). We performed the present meta-analysis according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Eligible studies were identified using electronic searches for randomized controlled trials (RCTs) using PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), and clinicaltrial.gov from inception to 31 January 2023. The outcomes examined in this meta-analysis included change from baseline in glycated hemoglobin (HbA1C) (%), fasting plasma sugar (FPG) (mg/dl), and the number of individuals experiencing adverse events. Three studies met the criteria and were included in the meta-analysis. The reduction of HbA1C was significantly higher in metformin-based combination therapy (MD: -1.19, 95% CI: -2.05, -0.33, p-value: 0.007). No significant difference was reported between patients randomized in metformin-based combination therapy and metformin alone (MD: -18.67, 95% CI: -50.17, 12.84, p-value: 0.25). In conclusion, the present meta-analysis found that the reduction in HbA1C was significantly higher in patients receiving metformin-based combination therapy compared to metformin alone. No significant difference was found between the two groups in terms of the change in fasting plasma glucose (FPG) from the baseline. In relation to safety, no significant difference was found in the incidence of adverse events and serious adverse events between the two groups.

Comparative efficacy and safety of glucose-lowering drugs in children and adolescents with type 2 diabetes: A systematic review and network meta-analysis

OBJECTIVE

Type 2 diabetes is more common in adults, but is becoming the major concern in children and adolescent recently. This study aimed to provide additional pharmaceutical management for children and adolescents with type 2 diabetes by assessing the efficacy and safety of several glucose-lowering drugs.

METHODS

Searches were performed in PubMed, Medline, Ovid, Cochrane Controlled Register of Trials (CENTRAL), and ClinicalTrials.gov that reported the efficacy and safety of drugs for children and adolescents with type 2 diabetes. Pooled effects were calculated by frequentist fixed effects network meta-analyses and additive network meta-analyses.

RESULTS

A total of 12 trials assessing eight glucose-lowering drugs were included, which compose of seven trials with monotherapy and five trials with combination therapies. Network meta-analysis results showed compared to placebo, saxagliptin+metformin (mean difference (MD) -1.91% [-2.85%, -0.97%]), liraglutide+metformin (MD -1.45% [-1.65%, -1.26%]), and liraglutide (MD -0.90% [-1.35%, -0.45%]) were the top 3 drugs that significantly reduced hemoglobin A1c (HbA1c). Sitagliptin+metformin, dapagliflozin, exenatide-2mcg, linagliptin-5mg, metformin, exenatide-5/10mcg, glimepiride, and sitagliptin also showed significant reduction in HbA1c. There were no significant differences between treatments in the incidence of adverse events, except that liraglutide+metformin had significant adverse effect such as abdominal pain. In addition, dapagliflozin, sitagliptin+metformin, and saxagliptin+metformin showed better efficacy compared with FDA-approved drugs.

CONCLUSIONS

The top 10 treatments of type 2 diabetes in children and adolescents aged 10-17 years were saxagliptin+metformin, liraglutide+metformin, liraglutide, dapagliflozin, exenatide-2 mcg, sitagliptin+metformin, linagliptin-5 mg, linagliptin-1 mg, metformin, and exenatide-5/10 mcg.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=284897, identifier CRD42021284897.

Gastrointestinal adverse events of metformin treatment in patients with type 2 diabetes mellitus: A systematic review, meta-analysis and meta-regression of randomized controlled trials

INTRODUCTION

Metformin is the first choice drug in the treatment of type 2 diabetes mellitus but its administration may be linked to gastrointestinal adverse events limiting its use.

OBJECTIVES

The objective of this systematic review and meta-analysis was to assess the risk of gastrointestinal adverse events related to metformin use in patients with type 2 diabetes treated with metformin.

METHODS

PUB MED/CINAHL/Web of Science/Scopus were searched from database inception until 08.11.2020 for articles in English and randomized controlled trials related to patients with type 2 diabetes treated with metformin were included.

RESULTS

From 5315 publications, we identified 199 potentially eligible full-text articles. Finally, 71 randomized controlled trials were included in the meta-analysis. In these studies, metformin use was associated with higher risk of abdominal pain, diarrhea and nausea comparing to control. The risks of abdominal pain and nausea were highest comparing to placebo. Bloating risk was only elevated when metformin treatment was compared to DPP4i.

CONCLUSIONS

The risk of gastrointestinal adverse events such as abdominal pain, nausea and diarrhea is higher in type 2 diabetes patients treated with metformin compared to other antidiabetic drugs. There is a higher risk of bloating and diarrhea with metformin immediate-release than with metformin extended release formulation.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021289975, identifier CRD42021289975.

Metformin in Patients With COVID-19: A Systematic Review and Meta-Analysis

Importance/Background: The coronavirus disease (COVID-19) pandemic is a critical public health issue. Evidence has shown that metformin favorably influences COVID-19 outcomes. This study aimed to assess the benefits and risks of metformin in COVID-19 patients. Methods: We searched the PubMed, Embase, Cochrane Library, and Chinese Biomedical Literature Database from inception to February 18, 2021. Observational studies assessing the association between metformin use and the outcomes of COVID-19 patients were included. The primary outcome was mortality, and the secondary outcomes included intubation, deterioration, and hospitalization. Random-effects weighted models were used to pool the specific effect sizes. Subgroup analyses were conducted by stratifying the meta-analysis by region, diabetic status, the adoption of multivariate model, age, risk of bias, and timing for adding metformin. Results: We identified 28 studies with 2,910,462 participants. Meta-analysis of 19 studies showed that metformin is associated with 34% lower COVID-19 mortality [odds ratio (OR), 0.66; 95% confidence interval (CI), 0.56-0.78; I 2 = 67.9%] and 27% lower hospitalization rate (pooled OR, 0.73; 95% CI, 0.53-1.00; I 2 = 16.8%). However, we did not identify any subgroup effects. The meta-analysis did not identify statistically significant association between metformin and intubation and deterioration of COVID-19 (OR, 0.94; 95% CI, 0.77-1.16; I 2 = 0.0% for intubation and OR, 2.04; 95% CI, 0.65-6.34; I 2 = 79.4% for deterioration of COVID-19), respectively. Conclusions: Metformin use among COVID-19 patients was associated with a reduced risk of mortality and hospitalization. Our findings suggest a relative benefit for metformin use in nursing home and hospitalized COVID-19 patients. However, randomized controlled trials are warranted to confirm the association between metformin use and COVID-19 outcomes. Study Registration: The study was registered on the PROSPERO on Feb 23, 2021 (CRD42021238722).

Knowledge, Attitude, and Practice of Metformin Extended-Release Tablets Among Clinicians in China: A Cross-Sectional Survey

Background: Metformin extended-release (XR) is a once-daily alternative conventional immediate-release (IR) tablet for adults with type 2 diabetes. Aim: This study aimed to investigate the knowledge, attitude, and practice of the use of metformin XR tablets among clinicians. Methods: We conducted a cross-sectional online survey among endocrinologists, general practitioners, and internists, who are taking routine care of adults with type 2 diabetes in health institutes at all levels in Sichuan Province, China. We designed an online questionnaire including the demographic information, knowledge, attitude, and practice about metformin XR tablets. Results: We included 158 clinicians, 67.7% of whom were females and 63.9% were from tertiary hospitals. The median age was 39.6 years (ranging between 22 and 62 years). Only 8.2% of the clinicians correctly answered the knowledge questions, 82.3% and 62.0% of the responders assumed that metformin XR had superior efficacy and tolerability to the metformin IR, respectively. Only 46.8% of the clinicians prescribed the metformin XR based on the patient's preference for once daily frequency. Conclusion: The knowledge, attitude, and practice of metformin XR among Chinese clinicians need improving. Clinicians need credible information to support their clinical decision-making regarding metformin XR.