Efficacy of metformin in type II diabetes: results of a double-blind, placebo-controlled, dose-response trial

Ovarian Hyperthecosis Presenting With Postmenopausal Virilization and New-Onset Type 2 Diabetes

Postmenopausal virilization accompanied by insulin resistance is rare and may present as a diagnostic challenge. Ovarian hyperthecosis is characterized by ovarian stromal cell proliferation, leading to androgen excess and associated insulin resistance. Here, we present a case of a 58-year-old postmenopausal woman with new onset virilization and associated type 2 diabetes due to ovarian hyperthecosis, who was successfully treated with bilateral oophorectomy, resulting in normalization of hyperandrogenism and improvement in glycemic control along with metformin and lifestyle advice. This case underscores the importance of recognizing ovarian hyperthecosis as a differential diagnosis when assessing new onset virilization and metabolic disturbance in postmenopausal women.

Recent advances in targeting obesity, with a focus on TGF-β signaling and vagus nerve innervation

Over a third of the global population is affected by obesity, fatty liver disease (Metabolic Dysfunction-Associated Steatotic Liver Disease, MASLD), and its severe form, MASH (Metabolic Dysfunction-Associated Steatohepatitis), which can ultimately progress to hepatocellular carcinoma (HCC). Recent advancements include therapeutics such as glucagon-like peptide 1 (GLP-1) agonists and neural/vagal modulation strategies for these disorders. Among the many pathways regulating these conditions, emerging insights into transforming growth factor-β (TGF-β) signaling highlight potential future targets through its role in pathophysiological processes such as adipogenesis, inflammation, and fibrosis. Vagus nerve innervation in the gastrointestinal tract is involved in satiety regulation and energy homeostasis, and vagus nerve stimulation has been applied in weight loss and diabetes. This review explores clinical trials in obesity, novel therapeutic targets, and the role of TGF-β signaling and vagus nerve modulation in obesity-related liver diseases and HCC.

Repurposing Atorvastatin, HMGCO-A Reductase Inhibitor, in Patients with Ulcerative Colitis: A Randomized Controlled Study

Background/Objective: Among the inflammatory bowel illnesses, ulcerative colitis (UC) affects 5 million people worldwide. UC manifests as weight loss, rectal bleeding, persistent diarrhea, and abdominal pain. Experimental research focused into the potential benefits of atorvastatin for colitis, although the literature only has a small amount of clinical evidence. To examine atorvastatin's protective effect in UC patients by assessing its impact on fecal myeloperoxidase, zonulin, and disease activity index (DAI). Methods: Two groups of patients with mild to moderate UC were randomly assigned. Over a six-month period, the control group (placebo group) received a placebo alongside mesalamine (1 g, three times daily [t.i.d.]). The atorvastatin group received atorvastatin (80 mg once daily) in addition to mesalamine (1 g t.i.d.). Disease severity was assessed by a gastroenterologist using the Disease Activity Index (DAI). Serum zonulin and fecal myeloperoxidase levels were measured before and after treatment to assess the biological efficacy of the interventions. Outcomes: Reduction in DAI and biomarker levels. Results: Both groups showed a significant decrease in DAI, zonulin, and fecal myeloperoxidase levels. However, the atorvastatin group (n = 23) demonstrated a significantly greater decrease in zonulin (p = 0.04), fecal myeloperoxidase (p = 0.03), and DAI (p = 0.001) compared to the placebo group (n = 24). In atorvastatin group, a significant correlation was observed between DAI and zonulin (p = 0.007, r = 0.4) and myeloperoxidase (p = 0.02, r = 0.36). Conclusions: The co-administration of atorvastatin may serve as a potential adjunct therapy for patients with UC.

Gastrointestinal symptoms in patients receiving imeglimin in combination with metformin: A post-hoc analysis of imeglimin clinical trial data

INTRODUCTION

An increased rate of gastrointestinal (GI) symptoms is reported in patients with type 2 diabetes receiving imeglimin plus metformin vs monotherapy or in combination with other antidiabetic drugs. This post-hoc analysis explored GI symptom incidence, risk factors for their occurrence, and the impact on therapeutic efficacy during imeglimin and metformin combination therapy.

MATERIALS AND METHODS

Data were derived from the 52-week, open-label, phase 3 TIMES-2 trial in Japanese type 2 diabetes patients. Patients in the imeglimin plus metformin group were divided into two subgroups based on the presence of GI symptoms and diarrhea, with efficacy and safety assessed. Factors associated with their occurrence were explored using multivariate logistic regression analysis.

RESULTS

Of 64 patients analyzed, GI symptoms and diarrhea occurred in 40.6% (n = 26) and 17.2% (n = 11) of patients, respectively. Metformin dose and patient age did not significantly affect their incidence. Events occurred more frequently within the first 4 months of treatment. Approximately half resolved within 1 week, and most were mild. Type 2 diabetes duration <5 years was significantly associated with diarrhea (odds ratio = 5.979; P = 0.039). Significant hypoglycemic effects were observed from baseline, irrespective of GI symptoms or diarrhea. However, the degree of HbA1c improvement tended to be greater in patients with GI symptoms and diarrhea.

CONCLUSIONS

Increased awareness regarding the potential for GI symptoms, including diarrhea, during imeglimin plus metformin combination therapy is warranted. This data will provide clinicians with useful information regarding symptomatic treatment when it occurs and help determine whether to continue treatment administration and is expected to improve patient adherence.

The adjunctive role of metformin in patients with mild to moderate ulcerative colitis: a randomized controlled study

Background

Metformin, hypoglycemic medication, is recognized for its diverse properties and its capacity to influence the inflammatory pathways. Medications with anti-inflammatory and anti-oxidative characteristics have been demonstrated to be able to elicit and sustain remission in ulcerative colitis (UC), chronic inflammatory disorder of the bowel. Studies in both preclinical and clinical settings have looked into the several metabolic pathways via which metformin protects against UC.

Aim

To assess efficacy of metformin as adjunctive therapy in patients with mild to moderate UC.

Methods

This clinical research was double-blinded, randomized, controlled, and involved 60 patients with mild to moderate UC. The participants were randomly assigned to one of two groups (n = 30). The control group was given 1 g of mesalamine three times a day (t.i.d.) for a period of 6 months (mesalamine group). The metformin group was given 500 mg of metformin twice daily and 1 g of mesalamine t. i.d. For a period of 6 months. Patients with UC were assessed by a gastroenterologist using the disease activity index (DAI) both at the beginning of treatment and 6 months thereafter. To evaluate the drug's biological efficacy, measurements of fecal calprotectin, serum C-reactive protein (CRP), interleukin 10 (IL-10), and nitric oxide (NO) were taken both before and after treatment.

Study outcomes

Decrease in DAI and change in the level of measured serum and fecal markers.

Results

The metformin group displayed a statistical reduction in DAI (p = 0.0001), serum CRP (p = 0.019), NO (p = 0.04), and fecal calprotectin (p = 0.027), as well as a significant increase in IL-10 (p = 0.04) when compared to the mesalamine group. There was a significant direct correlation between DAI and calprotectin (p < 0.0001, r = 0.551), and between DAI and CRP (p < 0.0001, r = 0.794). There was a significant negative correlation between DAI and IL-10 (p = 0.0003, r = 0.371).

Conclusion

Metformin may be an effective adjunct drug in management of patients with mild to moderate UC by decreasing DAI and other inflammatory markers that were involved in the pathogenesis of UC.

Clinical Trial Registration

identifier NCT05553704.

The inflammatory bowel disease and gut microbiome are restored by employing metformin-loaded alginate-shelled microcapsules

Inflammatory bowel disease (IBD) is a chronic or recurrent inflammatory disorder affecting various parts of the gastrointestinal tract. Metformin, a widely prescribed hypoglycemic drug for type 2 diabetes, has shown potential in reducing IBD risk. However, its oral administration faces significant challenges due to the harsh gastrointestinal environment, requiring higher or more frequent doses to achieve therapeutic effects, which increases the risk of side effects. To address this, we developed alginate-shelled hydrogel microcapsules with a thin oil layer for targeted intestinal delivery of metformin. The oil layer protects metformin from gastric acid and ensures its release specifically in the intestines. In a dextran sulfate sodium-induced colitis mouse model, metformin-loaded hydrogel microcapsules (MHM) significantly reduced disease activity, intestinal epithelial damage, and macrophage infiltration linked to pro-inflammatory cytokine factors. Additionally, MHM improved dysbiosis of specific bacterial genera, including Bacteroides vulgatus, Lactobacillus (L.) gasseri, L. reuteri, and L. intestinalis, optimizing the abundance and composition of microorganisms. These findings indicate that encapsulating metformin within alginate shelled-microcapsules with a thin oil layer presents a potential delivery system for IBD treatment.

Non-Linear Dose-Response Relationship for Metformin in Japanese Patients With Type 2 Diabetes: Analysis of Irregular Longitudinal Data by Interpretable Machine Learning Models

The dose-response relationship between metformin and change in hemoglobin A1c (HbA1c) shows a maximum at 1500-2000 mg/day in patients with type 2 diabetes (T2D) in the U.S. In Japan, there is little evidence on the HbA1c-lowering effect of high-dose metformin because the maintenance and maximum doses of metformin were raised in 2010. The aim of this study was to investigate whether there is saturation of the dose-response relationship for metformin in Japanese T2D patients. Longitudinal clinical information of T2D patients was extracted from electronic medical records. Supervised machine learning models with random effect were constructed to predict change in HbA1c: generalized linear mixed-effects models (GLMM) with/without a feature selection and combining tree-boosting with Gaussian process and mixed-effects models (GPBoost). GPBoost was interpreted by SHapley Additive exPlanations (SHAP) and partial dependence. GPBoost had better predictive performance than GLMM with/without feature selection: root mean square error was 0.602 (95%CI 0.523-0.684), 0.698 (0.629-0.774) and 0.678 (0.609-0.753), respectively. Interpretation of GPBoost by SHAP and partial dependence suggested that the relationship between the daily dose of metformin and change in HbA1c is non-linear rather than linear, and the HbA1c-lowering effect of metformin reaches a maximum at 1500 mg/day. Interpretation of GPBoost, a non-linear supervised machine-learning algorithm, suggests that there is saturation of the dose-response relationship of metformin in Japanese patients with T2D. This finding may be useful for decision-making in pharmacotherapy for T2D.

Effect of a high dose atorvastatin as adjuvant therapy to mesalamine in attenuating inflammation and symptoms in patients with ulcerative colitis: a randomized controlled pilot study

Background

Ulcerative colitis (UC) is a chronic inflammatory disorder of the colon. Several preclinical studies investigated the beneficial effects of atorvastatin in colitis. Activation of sphingosine 1 phosphate (S1P)/ tumor necrosis factor-alpha (TNF-α)/ interleukin-6 (IL-6) pathways has been confirmed in the pathogenesis of UC and preclinical studies proved the efficacy of atorvastatin on these pathways.

Aim

To investigate the role of atorvastatin on S1P/TNF-α/IL-6 pathway in UC.

Methods

Patients with mild to moderate UC were allocated into two groups in this pilot study. For 6 months, Group 1 (placebo group) received both a placebo and 1 g of mesalamine three times daily (t.i.d.). Group 2, (the atorvastatin group) received atorvastatin 80 mg once daily and 1 g of mesalamine t.i.d. A gastroenterologist evaluated the patients' colitis severity by partial Mayo score index (PMS). Serum IL-6, S1P, TNF-α, nitric oxide (NO), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and fecal calprotectin were measured before and after treatment. Short Form 36 questionnaire (SF-36) was also assessed. A clinical response was defined as a decline in the rectal bleeding sub score of at least one point, and a decrease in PMS of at least two points. Clinical remission was defined as a PMS of less than 2 and the absence of any single sub score greater than 1.

Primary outcome

Decreased PMS and improved quality of life.

Secondary outcome

Change in the level of measured biomarkers.

Results

Compared to the placebo group (n = 24), the atorvastatin group (n = 23) exhibited a significant decrease in the level of IL-6 (p = 0.001), S1P (p = 0.0001), TNF-α (p = 0.003), NO (p = 0.0001), CRP (p = 0.015), ESR (p = 0.012), PMS (p = 0.013), and fecal calprotectin (p = 0.0003), and improved SF-36 (p = 0.006). In placebo group, the response rate was 83.33% (n = 20/24) for PMS, and the remission rate was 45.83% (n = 11/24). In the atorvastatin group, the response rate was 91.3% (n = 21/23), and the remission rate was 60.8% (n = 14/23) for PMS.

Conclusion

Atorvastatin could be an adjunctive therapy for patients with UC.

Clinical trial registration

https://www.clinicaltrials.gov/, Identifier NCT05561062.

Long Non-Coding RNAs in Diabetic Cardiomyopathy: Potential Function as Biomarkers and Therapeutic Targets of Exercise Training

Recent studies emphasize the beneficial effects of exercise on diabetic cardiomyopathy (DCM), adding to the growing body of evidence that underscores the role of exercise in improving health outcomes. Despite this, a notable gap persists in the number of healthcare providers who actively prescribe exercise as a therapeutic intervention for DCM management. In addition, exercise modulates the expression of lncRNAs, which play a pivotal role in DCM progression. Further investigation into this relationship may facilitate the identification of novel biomarkers and therapeutic targets for DCM. This review consolidates recent advances in identifying lncRNAs biomarkers in DCM, summarizing the current knowledge on dysregulated lncRNAs and their molecular mechanisms. Additionally, it offers new insights into the mechanistic roles of lncRNAs, highlighting their potential as biomarkers and therapeutic targets for DCM. Overall, this review aims to inform future research and reinforce the significance of addressing diabetes-related cardiovascular diseases to potentially improve clinical outcomes.

Common mistakes concerning diabetes management in daily clinical practice

Diabetes mellitus is a chronic metabolic disease, potentially leading to dire complications. Although there are numerous pharmaceutical treatments available, management of the disease is frequently not optimal. Managing diabetes in daily clinical practice can be challenging, and several common mistakes may occur. Healthcare providers must be aware of these errors to provide adequate patient care. In this review, some frequent mistakes in diabetes management are analyzed, focusing on factors such as medication management, blood glucose level monitoring, inadequate addressing of complications and comorbidities, lifestyle choices, patient education, and overall health counselling.

Advancing Longevity: Exploring Antiaging Pharmaceuticals in Contemporary Clinical Trials Amid Aging Dynamics

Aging is an inevitable biological process that significantly impacts human health, leading to a decline in cellular function and an increase in cellular damage. This study elucidates the burgeoning potential of antiaging pharmaceuticals in mitigating the thriving burden of chronic conditions linked to advancing age. It underscores the pivotal role of these pharmacotherapeutic agents in fostering longevity free from debilitating age-related afflictions, notably cardiovascular disorders, neoplastic processes, and neurodegenerative pathologies. While commendable strides have been made evident in preclinical models, it is crucial to thoroughly investigate their effectiveness and safety in human groups. In addition, ethical concerns about fair access, societal impacts, and careful resource distribution are significant in discussions about developing and using antiaging medications. By approaching the development and utilization of antiaging medications with diligence and foresight, we can strive toward a future where individuals can enjoy extended lifespans free from the debilitating effects of age-related ailments.

Repurposing metformin as adjuvant therapy in patients with ulcerative colitis treated with mesalamine: A randomized controlled double-blinded study

BACKGROUND

Ulcerative colitis (UC) is a type of inflammatory bowel disease associated with persistent inflammation. Animal studies proved the efficacy of metformin in UC.

AIM

To investigate the potential role of metformin and its protective pathways in patients with UC.

METHODS

This is a randomized, controlled, and double-blinded clinical trial that included 60 participants with mild to moderate UC and was divided randomly into two groups (n = 30). For 6 months, the mesalamine group received 1 g of mesalamine three times daily (t.i.d.). For six months, the metformin group received mesalamine 1 g t.i.d. and metformin 500 mg twice daily. A gastroenterologist evaluated patients at baseline and 6 months after starting the treatment in order to measure serum levels of zonulin, sphingosine 1 phosphate (S1P), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). Biopsies from the colon were used to measure gene expression of zonula occuldin-1 (ZO-1), signal transducer and activator of factor-3 (STAT-3), and intracellular adhesion molecule-1 (ICAM-1). The numeric pain rating scale (NRS) and partial Mayo score were also assessed for each patient.

RESULTS

When compared to the mesalamine group, the metformin group demonstrated a statistical decrease in serum IL-6, zonulin, TNF-α, SIP, gene expression of ICAM-1 and STAT-3, and a significant increase in colonic ZO-1 when compared to the mesalamine group. The metformin group also showed a significant decrease in NRS and partial Mayo score index in comparison with the mesalamine group.

CONCLUSION

Metformin may be a promising additional therapy for UC patients. Trial registration identifier: NCT05553704.

Metformin: Therapeutic profile in the treatment of type 2 diabetes

Metformin (dimethyl-biguanide) can claim its origins in the use of Galega officinalis as a plant treatment for symptoms ascribed to diabetes. Since the first clinical use of metformin as a glucose-lowering agent in 1957, this medicine has emerged as a first-line pharmacological option to support lifestyle interventions in the management of type 2 diabetes (T2D). It acts through multiple cellular pathways, principally in the gut, liver and muscle, to counter insulin resistance and lower blood glucose without weight gain or risk of overt hypoglycaemia. Other effects include improvements in lipid metabolism, decreased inflammation and lower long-term cardiovascular risk. Metformin is conveniently combined with other diabetes medications, can be prescribed in prediabetes to reduce the risk of progression to T2D, and is used in some regions to assist glycaemic control in pregnancy. Consistent with its diversity of actions, established safety profile and cost-effectiveness, metformin is being assessed for further possible clinical applications. The use of metformin requires adequate renal function for drug elimination, and may cause initial gastrointestinal side effects, which can be moderated by taking with meals or using an extended-release formulation. Thus, metformin serves as a valuable therapeutic resource for use throughout the natural history of T2D.

Metformin's role in lowering colorectal cancer risk among individuals with diabetes from the Southern Community Cohort Study

BACKGROUND

Metformin, utilized to manage hyperglycemia, has been linked to a reduced risk of colorectal cancer (CRC) among individuals with diabetes. However, evidence is lacking for non-Hispanic Black individuals and those with lower socioeconomic status (SES), who face elevated risk for both diabetes and CRC. In this study, we investigated the association between metformin use and incident CRC risk within the Southern Community Cohort Study (SCCS), a racially- and SES-diverse prospective cohort.

METHODS

Participants reported their diabetes diagnosis and medications, including metformin, upon enrollment (2002-2009) and during follow-up surveys approximately every five years. Incident cases of CRC were identified through state cancer registries and the National Death Index. Proportional hazards models were employed to explore the relationship between metformin use and CRC risk, adjusted for cancer risk factors.

RESULTS

A total of 25,992 participants with diabetes were included in the analysis, among whom 10,095 were taking metformin. Of these participants, 76% identified as non-Hispanic Black, and 60% reported household incomes <$15,000/year. Metformin use was associated with a significantly lower CRC risk (HR [95% CI]: 0.71 [0.55-0.93]), with consistent results for both colon (0.80 [0.59-1.07]) and rectal cancers (0.49 [0.28-0.86]). The protective association appeared to be stronger among non-Hispanic White individuals (0.51 [0.31-0.85]) compared to non-Hispanic Black participants (0.80 [0.59-1.08], p-interaction =.13). Additionally, a protective association was observed among obese individuals (BMI ≥30 kg/m2, 0.59 [0.43-0.82] but not among non-obese participants (0.99 [0.65-1.51], p-interaction =.05) CONCLUSION: Our findings indicate that metformin use is associated with a reduced risk of CRC in individuals with diabetes, including among those from predominantly low SES backgrounds. These results support previous epidemiological findings, and demonstrate that the protective association for metformin in relation to incident CRC likely generalizes to populations with higher underlying risk.

Metformin: Past, Present, and Future

PURPOSE OF REVIEW

This review provides the most recent update of metformin, a biguanide oral antihyperglycemic drug used as a first-line treatment in type 2 diabetes mellitus.

RECENT FINDINGS

Metformin continues to dominate in the world of antidiabetics, and its use will continue to rise because of its high efficiency and easy availability. Apart from type 2 diabetes, research is exploring its potential in other conditions such as cancer, memory loss, bone disorders, immunological diseases, and aging. Metformin is the most prescribed oral antidiabetic worldwide. It has been in practical use for the last six decades and continues to be the preferred drug for newly diagnosed type 2 diabetes mellitus. It reduces glucose levels by decreasing hepatic glucose production, reducing intestinal glucose absorption, and increasing insulin sensitivity. It can be used as monotherapy or combined with other antidiabetics like sulfonylureas, DPP-4 inhibitors, SGLT-2 inhibitors, or insulin, improving its efficacy. Metformin can be used once or twice daily, depending on requirements. Prolonged usage of metformin may lead to abdominal discomfort, deficiency of Vitamin B12, or lactic acidosis. It should be used carefully in patients with renal impairment. Recent studies have explored additional benefits of metformin in polycystic ovarian disease, gestational diabetes mellitus, cognitive disorders, and immunological diseases. However, more extensive studies are needed to confirm these additional benefits.

Associations among diabetes medication use, serum magnesium, and insulin resistance in a cohort of older Puerto Rican adults

BACKGROUND

Hypomagnesemia is commonly observed in individuals with diabetes, but how diabetes medications alter magnesium (Mg) status remains unclear.

OBJECTIVES

We aimed to examine the association between diabetes medication and hypomagnesemia and evaluate whether serum Mg mediates the association between diabetes medication and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) in a prospective cohort.

METHODS

Adults from the Boston Puerto Rican Health Study were included (n = 1106). Multivariable logistic regression models were used to estimate odds ratio (OR) and 95% confidence interval (CI) for cross-sectional association between diabetes medication and hypomagnesemia (serum Mg <0.75 mmol/L). Longitudinal mediation analysis was performed to evaluate the direct and indirect (via serum Mg) associations between diabetes medication and 4-y HOMA-IR in 341 participants with baseline hemoglobin A1c (HbA1c) of ≥6.5%.

RESULTS

Mean age at baseline was 59.0 ± 7.6 y, with 28.0% male and 45.8% with hypomagnesemia. Use of metformin [OR (95% CI) = 3.72 (2.53, 5.48)], sulfonylureas [OR (95% CI) = 1.68 (1.00, 2.83)], and glitazones [OR (95% CI) = 2.09 (1.10, 3.95)], but not insulin, was associated with higher odds of hypomagnesemia. Use of multiple diabetes medications and longer duration of use were associated with higher odds of hypomagnesemia. Serum Mg partially mediated the association between metformin and HOMA-IR [indirect association: β (95% CI) = 1.11 (0.15, 2.07)], which weakened the direct association [β (95% CI) = -5.16 (-9.02, -1.30)] by 22% [total association: β (95% CI) = -4.05 (-7.59, -0.51)]. Similarly, serum Mg mediated 17% of the association between sulfonylureas and elevated HOMA-IR. However, the mediation by serum Mg was weak for insulin and glitazones.

CONCLUSIONS

Diabetes medication, especially metformin, was associated with elevated odds of hypomagnesemia, which may weaken the association between metformin and lowering of HOMA-IR. The causal inference needs to be confirmed in further studies.

METformin for the MINimization of Geographic Atrophy Progression (METforMIN): A Randomized Trial

Purpose

Metformin use has been associated with a decreased risk of age-related macular degeneration (AMD) progression in observational studies. We aimed to evaluate the efficacy of oral metformin for slowing geographic atrophy (GA) progression.

Design

Parallel-group, multicenter, randomized phase II clinical trial.

Participants

Participants aged ≥ 55 years without diabetes who had GA from atrophic AMD in ≥ 1 eye.

Methods

We enrolled participants across 12 clinical centers and randomized participants in a 1:1 ratio to receive oral metformin (2000 mg daily) or observation for 18 months. Fundus autofluorescence imaging was obtained at baseline and every 6 months.

Main Outcome Measures

The primary efficacy endpoint was the annualized enlargement rate of the square root-transformed GA area. Secondary endpoints included best-corrected visual acuity (BCVA) and low luminance visual acuity (LLVA) at each visit.

Results

Of 66 enrolled participants, 34 (57 eyes) were randomized to the observation group and 32 (53 eyes) were randomized to the treatment group. The median follow-up duration was 13.9 and 12.6 months in the observation and metformin groups, respectively. The mean ± standard error annualized enlargement rate of square root transformed GA area was 0.35 ± 0.04 mm/year in the observation group and 0.42 ± 0.04 mm/year in the treatment group (risk difference = 0.07 mm/year, 95% confidence interval = -0.05 to 0.18 mm/year; P = 0.26). The mean ± standard error decline in BCVA was 4.8 ± 1.7 letters/year in the observation group and 3.4 ± 1.1 letters/year in the treatment group (P = 0.56). The mean ± standard error decline in LLVA was 7.3 ± 2.5 letters/year in the observation group and 0.8 ± 2.2 letters/year in the treatment group (P = 0.06). Fourteen participants in the metformin group experienced nonserious adverse events related to metformin, with gastrointestinal side effects as the most common. No serious adverse events were attributed to metformin.

Conclusions

The results of this trial as conducted do not support oral metformin having effects on reducing the progression of GA. Additional placebo-controlled trials are needed to explore the role of metformin for AMD, especially for earlier stages of the disease.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

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.

Cancer Precision-Prevention trial of Metformin in adults with Li Fraumeni syndrome (MILI) undergoing yearly MRI surveillance: a randomised controlled trial protocol

BACKGROUND

Li-Fraumeni syndrome (LFS) is a rare autosomal dominant disease caused by inherited or de novo germline pathogenic variants in TP53. Individuals with LFS have a 70-100% lifetime risk of developing cancer. The current standard of care involves annual surveillance with whole-body and brain MRI (WB-MRI) and clinical review; however, there are no chemoprevention agents licensed for individuals with LFS. Preclinical studies in LFS murine models show that the anti-diabetic drug metformin is chemopreventive and, in a pilot intervention trial, short-term use of metformin was well-tolerated in adults with LFS. However, metformin's mechanism of anticancer activity in this context is unclear.

METHODS

Metformin in adults with Li-Fraumeni syndrome (MILI) is a Precision-Prevention phase II open-labelled unblinded randomised clinical trial in which 224 adults aged ≥ 16 years with LFS are randomised 1:1 to oral metformin (up to 2 mg daily) plus annual MRI surveillance or annual MRI surveillance alone for up to 5 years. The primary endpoint is to compare cumulative cancer-free survival up to 5 years (60 months) from randomisation between the intervention (metformin) and control (no metformin) arms. Secondary endpoints include a comparison of cumulative tumour-free survival at 5 years, overall survival at 5 years and clinical characteristics of emerging cancers between trial arms. Safety, toxicity and acceptability of metformin; impact of metformin on quality of life; and impact of baseline lifestyle risk factors on cancer incidence will be assessed. Exploratory end-points will evaluate the mechanism of action of metformin as a cancer preventative, identify biomarkers of response or carcinogenesis and assess WB-MRI performance as a diagnostic tool for detecting cancers in participants with LFS by assessing yield and diagnostic accuracy of WB-MRI.

DISCUSSION

Alongside a parallel MILI study being conducted by collaborators at the National Cancer Institute (NCI), MILI is the first prevention trial to be conducted in this high-risk group. The MILI study provides a unique opportunity to evaluate the efficacy of metformin as a chemopreventive alongside exploring its mechanism of anticancer action and the biological process of mutated P53-driven tumourigenesis.

TRIAL REGISTRATION

ISRCTN16699730. Registered on 28 November 2022. URL: https://www.isrctn.com/ EudraCT/CTIS number 2022-000165-41.

Development of a multi-component gastroretentive expandable drug delivery system (GREDDS) for personalized administration of metformin

OBJECTIVES

Efficacy and compliance of type II diabetes treatment would greatly benefit from dosage forms providing controlled release of metformin in the upper gastrointestinal tract. In this respect, the feasibility of a new system ensuring stomach-retention and personalized release of this drug at its absorption window for multiple days was investigated.

METHODS

The system proposed comprised of a drug-containing core and a viscoelastic umbrella-like skeleton, which were manufactured by melt-casting and 3D printing. Prototypes, alone or upon assembly and insertion into commercially-available capsules, were characterized for key parameters: thermo-mechanical properties, accelerated stability, degradation, drug release, deployment performance, and resistance to simulated gastric contractions.

RESULTS

Each part of the system was successfully manufactured using purposely-selected materials and the performance of final prototypes matched the desired one. This included: i) easy folding of the skeleton against the core in the collapsed administered shape, ii) rapid recovery of the cumbersome configuration at the target site, even upon storage, and iii) prolonged release of metformin.

CONCLUSIONS

Composition, geometry, and performance of the system developed in this work were deemed acceptable for stomach-retention and prolonged as well as customizable release of metformin in its absorption window, laying promising bases for further development steps.

Effects of Metformin Therapy on Thyroid Volume and Functions in Patients with Newly Diagnosed Type 2 Diabetes Mellitus: A Single-center Prospective Study

OBJECTIVE

Patients with impaired glucose metabolism have increased thyroid volume and a higher prevalence of nodules. Yet, some studies show that there is an improvement in these thyroid parameters after diabetes treatment. Our observational study aimed to reveal the effect of treatment on thyroid function, thyroid volume, and the presence of nodules in newly diagnosed type 2 diabetes mellitus (T2DM) patients who were started on metformin treatment.

METHODS

Euthyroid and subclinically hypothyroid patients with a serum TSH level of <10 mU/L, who were newly diagnosed with T2DM and started on metformin as an antidiabetic treatment and not used any thyroid medication previously, were included in our study. Patients' characteristics were recorded. Baseline and 6th-month serum thyroid function tests were scheduled. Baseline and 6th-month thyroid gland characteristics were examined by thyroid ultrasonography.

RESULTS

A total of 101 (37 males, 64 females) newly diagnosed T2DM patients with euthyroid (n=95) or subclinical hypothyroidism (n=6) were included in the study. The mean age of the patients was 53.02 ± 11.9 years, and the mean BMI was 29.60 ± 3.9 kg/m2. Fifty-two (52%) patients were classified as obese. Body weight, BMI, serum TSH, ALT, Anti-TPO levels, and thyroid volume decreased significantly in the 6th-month compared to baseline values (p = 0.000; p = 0.000; p = 0.011; p = 0.022; p = 0.000, respectively). Serum anti-Tg, fT4, fT3 levels, and thyroid nodule count did not change significantly. A high agreement was found between the baseline and 6thmonth nodule counts (gamma= 0.886; p < 0.001) and the presence of multi-nodularity in the thyroid (gamma= 0.941; p < 0.001), but no significant change was observed. Anti-TPO levels showed a significant decrease in both with and without obesity groups at the end of 6 months (p = 0.003, p = 0.009, respectively). Serum TSH level decreased significantly only in non-obese subjects (p = 0.004), and thyroid volume decreased significantly only in obese subjects (p = 0.000).

CONCLUSION

Our results suggest that metformin treatment significantly reduces body weight, BMI, thyroid volume, and serum TSH, ALT, and Anti-TPO levels in patients with newly diagnosed T2DM. Moreover, serum TSH levels showed a significant decrease in non-obese subjects, while thyroid volume showed a significant decrease in obese subjects.

Current status and frontier tracking of clinical trials on Metformin for cancer treatment

PURPOSE

Metformin has been used clinically for more than six decades. Over time, numerous remarkable effects of metformin beyond the clinic have been discovered and discussed. Metformin has been shown to have a favorable impact on cancer therapy in addition to its clinically recognized hypoglycemic effect. However, the antitumor efficacy of metformin in humans has not been clearly demonstrated yet. Hence, a systematic analysis of the existing trials is necessary.

METHODS

Here, we retrieved clinical trials from the Clinical Trials.gov database to overview the clinical development of metformin for the treatment of cancer, analyze existing clinical results, and summarize some promising applications for specific cancer therapies.

RESULTS

The potential application of metformin contains three directions: Firstly, improvement of metabolic factors associated with treatment effects, such as insulin resistance and peripheral neuropathy. Secondly, in combination with immune checkpoint blockade effects. Finally, use it for the endocrine treatment of hormone-dependent cancers.

CONCLUSION

Although the outcomes of metformin as a repurposed agent in some trials have been unsatisfactory, it still has the potential to be used in select cancer therapy settings.

The anti-diabetic effects of metformin are mediated by regulating long non-coding RNA

Type 2 diabetes (T2D) is a metabolic disease with complex etiology and mechanisms. Long non-coding ribonucleic acid (LncRNA) is a novel class of functional long RNA molecules that regulate multiple biological functions through various mechanisms. Studies in the past decade have shown that lncRNAs may play an important role in regulating insulin resistance and the progression of T2D. As a widely used biguanide drug, metformin has been used for glucose lowering effects in clinical practice for more than 60 years. For diabetic therapy, metformin reduces glucose absorption from the intestines, lowers hepatic gluconeogenesis, reduces inflammation, and improves insulin sensitivity. However, despite being widely used as the first-line oral antidiabetic drug, its mechanism of action remains largely elusive. Currently, an increasing number of studies have demonstrated that the anti-diabetic effects of metformin were mediated by the regulation of lncRNAs. Metformin-regulated lncRNAs have been shown to participate in the inhibition of gluconeogenesis, regulation of lipid metabolism, and be anti-inflammatory. Thus, this review focuses on the mechanisms of action of metformin in regulating lncRNAs in diabetes, including pathways altered by metformin via targeting lncRNAs, and the potential targets of metformin through modulation of lncRNAs. Knowledge of the mechanisms of lncRNA modulation by metformin in diabetes will aid the development of new therapeutic drugs for T2D in the future.

A novel combination of metformin and resveratrol alleviates hepatic steatosis by activating autophagy through the cAMP/AMPK/SIRT1 signaling pathway

Nonalcoholic fatty liver disease (NAFLD) is a prevalent liver disorder that is associated with the accumulation of triglycerides (TG) in hepatocytes. Resveratrol (RSV), as a natural product, and metformin have been reported to have potential lipid-lowering effects for the treatment of NAFLD via autophagy, but the combined effects of both have not yet been studied. The current study aimed to investigate the role of autophagy in the lipid-lowering effects of RSV, alone and in combination with metformin, on the hepatic steatosis model of HepG2 cells and elucidate the mechanism of action. Triglyceride measurement and real-time PCR showed that RSV-metformin reduced lipid accumulation and the expression of lipogenic genes in palmitic acid (PA)-induced HepG2 cells. Additionally, the LDH release assay indicated that this combination protected HepG2 cells against PA-induced cell death through autophagy. The western blotting analysis revealed that RSV-metformin induced autophagy by reducing the expression of p62 and increasing LC3-I and LC3-II proteins. This combination also enhanced cAMP, phosphorylated AMP-activated protein kinase (p-AMPK), and Beclin-1 levels in HepG2 cells. Furthermore, SIRT1 inhibitor treatment inhibited autophagy induced by RSV-metformin, which indicated the autophagy induction is SIRT1-dependent. This study demonstrated for the first time that RSV-metformin reduced hepatic steatosis by triggering autophagy via the cAMP/AMPK/SIRT1 signaling pathway.

The Comparation of Renal Anti-Senescence Effects and Blood Metabolites between Dapagliflozin and Metformin in Non-Diabetes Environment

Delaying kidney senescence process will benefit renal physiologic conditions, and prompt the kidney recovering from different pathological states. The renal anti-senescence effects of sodium-glucose cotransporter-2 inhibitors (SGLT2i) and metformin have been proven in diabetic settings, but the roles of each one and combination of two drugs in natural kidney aging process remain undefined and deserve further research. Senescence-accelerated mouse prone 8 (SAMP8) were orally administered dapagliflozin, metformin, and a combination of them for 16 weeks. Dapagliflozin exhibits better effects than metformin in lowering senescence related markers, and the combination therapy shows the best results. In vitro experiments demonstrate the same results that the combination of dapagliflozin and metformin can exert a better anti-senescence effect. Blood metabolites detection in vivo shows dapagliflozin mainly leads to the change of blood metabolites enriched in choline metabolism, and metformin tends to induce change of blood metabolites enriched in purine metabolism. In conclusion, the results suggest dapagliflozin may have a better renal anti-senescence effect than metformin in non-diabetes environment, and the combination of the two drugs can strengthen the effect. The two drugs can lead to different blood metabolites alteration, which may lead to different systemic effects.

Metformin derivatives - Researchers' friends or foes?

Metformin has been used for ages to treat diabetes mellitus due to its safety profile and low cost. However, metformin has variable pharmacokinetics in patients, and due to its poor oral absorption, the therapeutic doses are relatively high, causing unpleasant gastrointestinal adverse effects. Therefore, novel derivatives of metformin have been synthesized during the past decades. Particularly, after the mid-2000 s, when organic cation transporters were identified as the main metformin carriers, metformin derivatives have been under intensive investigation. Nevertheless, due to the biguanide structure, derivatives of metformin have been challenging to synthesize. Moreover, the mechanisms of metformin's action are not fully understood to date, and since it has multifunctional properties, the interests have switched to re-purposing for other diseases. Indeed, metformin derivatives have been demonstrated in many cases to be more effective than metformin itself and have the potential to be used in different diseases, including several types of cancers and neurodegenerative diseases. On the other hand, the pleiotropic nature of metformin and its derivatives can also create challenges. Not all properties are fit for all diseases. In this review, the history of the development of metformin-like compounds is summarized, and insights into their potential for future drug discovery are discussed.

Metformin restrains ZIKV replication and alleviates virus-induced inflammatory responses in microglia

The re-emergence of Zika virus (ZIKV) remains a major public health threat that has raised worldwide attention. Accumulating evidence suggests that ZIKV can cause serious pathological changes to the human nervous system, including microcephaly in newborns. Recent studies suggest that metformin, an established treatment for diabetes may play a role in viral infection; however, little is known about the interactions between ZIKV infection and metformin administration. Using fluorescent ZIKV by flow cytometry and immunofluorescence imaging, we found that ZIKV can infect microglia in a dose-dependent manner. Metformin diminished ZIKV replication without the alteration of viral entry and phagocytosis. Our study demonstrated that metformin downregulated ZIKV-induced inflammatory response in microglia in a time- and dose-dependent manner. Our RNA-Seq and qRT-PCR analysis found that type I and III interferons (IFN), such as IFNα2, IFNβ1 and IFNλ3 were upregulated in ZIKV-infected cells by metformin treatment, accompanied with the downregulation of GBP4, OAS1, MX1 and ISG15. Together, our results suggest that metformin-mediated modulation in multiple pathways may attribute to restraining ZIKV infection in microglia, which may provide a potential tool to consider for use in unique clinical circumstances.

Analytical quality-by-design approach for development and validation of HPLC method for the simultaneous estimation of omarigliptin, metformin, and ezetimibe: application to human plasma and dosage forms

A simple, selective, and sensitive RP-HPLC method was proposed for the simultaneous determination of two co-administered antidiabetic drugs (omarigliptin and metformin) with an anti-hyperlipidemic drug (ezetimibe) in a medicinally-recommended ratio of 2.5:50:1, respectively. The proposed procedure was optimized by adopting a quality-by-design approach. The influence of different factors on chromatographic responses was optimized by applying the two-level full factorial design (2⁵). The optimum chromatographic separation was achieved using Hypersil BDS C18 column at 45 °C, and the mobile phase pumped isocratically composed of methanol: potassium dihydrogen phosphate buffer (6.6 mM; pH 7, 67:33% v/v) at a flow rate of 0.814 mL/min using 235 nm as a detection wavelength. The developed method was capable of separating this novel mixture in less than 8 min. The calibration plots of omarigliptin, metformin, and ezetimibe showed acceptable linearity over the ranges of 0.2-2.0, 0.5-25.0, and 0.1-2.0 µg/mL with quantitation limits of 0.06, 0.50, and 0.06 µg/mL, respectively. The proposed method was successfully applied to determine the studied drugs in their commercial tablets with high % recoveries (96.8-102.92%) and low % RSD values (less than 2%). The applicability of the method was extended to the in-vitro assay of the drugs in spiked human plasma samples with high % recoveries (94.3-105.7%). The suggested method was validated in accordance with ICH guidelines.

Exploring the Association between Citrus Nutraceutical Eriocitrin and Metformin for Improving Pre-Diabetes in a Dynamic Microbiome Model

Pre-diabetes is recognized as an altered metabolic state, which precedes type 2 diabetes, and it is associated with great dysfunction of the intestinal microbiota, known as dysbiosis. Natural compounds, capable of reducing blood glucose without side effects and with a beneficial effect on the microbiota, have been studied as substitutes or adjuvants to conventional hypoglycemic agents, such as metformin. In this work, the effect of the nutraceutical Eriomin®, a mixture of citrus flavonoids (eriocitrin, hesperidin, naringin, and didymin), which reduces glycemia and increases glucagon-like peptide-1 (GLP-1) in pre-diabetic patients, was tested in the Simulator of Human Intestinal Microbial Ecosystem (SHIME®), inoculated with pre-diabetic microbiota. After treatment with Eriomin® plus metformin, a significant increase in acetate and butyrate production was observed. Furthermore, sequencing of the 16S rRNA gene of the microorganisms showed that Eriomin® plus metformin stimulated the growth of Bacteroides and Subdoligranulum genera. Bacteroides are the largest fraction of the intestinal microbiota and are potential colonizers of the colon, with some species producing acetic and propionic fatty acids. In addition, Subdoligranulum species are associated with better host glycemic metabolism. In conclusion, Eriomin® associated with metformin improved the composition and metabolism of the intestinal microbiota, suggesting a potential use in pre-diabetes therapy.

In vitro to in vivo extrapolation and high-content imaging for simultaneous characterization of chemically induced liver steatosis and markers of hepatotoxicity

Chemically induced steatosis is characterized by lipid accumulation associated with mitochondrial dysfunction, oxidative stress and nucleus distortion. New approach methods integrating in vitro and in silico models are needed to identify chemicals that may induce these cellular events as potential risk factors for steatosis and associated hepatotoxicity. In this study we used high-content imaging for the simultaneous quantification of four cellular markers as sentinels for hepatotoxicity and steatosis in chemically exposed human liver cells in vitro. Furthermore, we evaluated the results with a computational model for the extrapolation of human oral equivalent doses (OED). First, we tested 16 reference chemicals with known capacities to induce cellular alterations in nuclear morphology, lipid accumulation, mitochondrial membrane potential and oxidative stress. Then, using physiologically based pharmacokinetic modeling and reverse dosimetry, OEDs were extrapolated from data of any stimulated individual sentinel response. The extrapolated OEDs were confirmed to be within biologically relevant exposure ranges for the reference chemicals. Next, we tested 14 chemicals found in food, selected from thousands of putative chemicals on the basis of structure-based prediction for nuclear receptor activation. Amongst these, orotic acid had an extrapolated OED overlapping with realistic exposure ranges. Thus, we were able to characterize known steatosis-inducing chemicals as well as data-scarce food-related chemicals, amongst which we confirmed orotic acid to induce hepatotoxicity. This strategy addresses needs of next generation risk assessment and can be used as a first chemical prioritization hazard screening step in a tiered approach to identify chemical risk factors for steatosis and hepatotoxicity-associated events.

Metformin regulates autophagy via LGMN to inhibit choriocarcinoma

Choriocarcinoma has the problem of chemotherapy insensitivity and recurrence. Metformin may be a promising candidate to restrict choriocarcinoma progress because of its indirect and direct beneficial role on inhabitations of cancer cells without severe adverse side effects. In this study, metformin pressed the proliferation and invasion of choriocarcinoma JAR cells in vitro and the growth of the JAR subcutaneous xenografts in vivo. The high throughput sequencing and bioinformatics technology identified the low expression of legumain (LGMN) in lysosomal pathway caused by metformin, which was upregulated in human choriocarcinoma tissues compared with the early pregnancy tissues. As elevating metformin concentration and treatment time, the mRNA and protein expression of LGMN both depressed in two choriocarcinoma cell lines (JAR and JEG-3). LGMN was involved in metformin-mediated inhibition of cell proliferation and invasion. Furthermore, metformin induced autophagy via inhibiting LGMN through AKT/mTOR/LC3II signaling pathway of choriocarcinoma. Autophagy inhibitor could depress metformin-induced autophagy and improve cell proliferation and invasion ability dropped by metformin, while autophagy inducer could partially reverse the change of cell proliferation and invasion modulated by combination of metformin and LGMN overexpression. These results indicated that metformin inhibited cell proliferation and invasion ability by inducing autophagy in a LGMN-dependent manner so as to play a role in the treatment of choriocarcinoma.

Hepatic Steatosis Alleviated by a Novel Metformin and Quercetin Combination Activating Autophagy Through the cAMP/AMPK/SIRT1 Pathway

Non-alcoholic fatty liver disease (NAFLD) incidence and prevalence are rapidly increasing globally. The combined effects of metformin and quercetin (Que) have yet to be investigated. However, both have demonstrated the potential to reduce triglyceride (TG) levels and treat NAFLD by promoting autophagy. The objective of the present study was to elucidate the mechanism of action and assess the role of autophagy in the lipid-lowering effects of Que, both individually and in combination with metformin, in a HepG2 cell model of hepatic steatosis. Triglyceride levels and lipogenic gene expression were reduced in HepG2 cells exposed to palmitic acid (PA) when treated with Que-metformin, as evidenced by triglyceride measurements and real-time PCR. The LDH release assay also showed that this combination induced autophagy to protect HepG2 cells from PA-induced cell death. According to the Western blot analysis outcomes, Que-metformin increased LC3-I and LC3-II protein levels while decreasing p62 expression to induce autophagy. In HepG2 cells, the co-administration of Que-metformin elevated cAMP, phosphorylated AMP-activated protein kinase (p-AMPK), and Beclin-1 levels. Additionally, the inhibition of SIRT1 reversed the autophagy induced by Que-metformin. The findings of this study demonstrated for the first time that Que-metformin reduced hepatosteatosis by stimulating autophagy through the cAMP/AMPK/SIRT1 signaling pathway and diminishing inflammatory cytokines.

Association of SLC22A1, SLC22A2, SLC47A1, and SLC47A2 Polymorphisms with Metformin Efficacy in Type 2 Diabetic Patients

Response to metformin, first-line therapy for type 2 diabetes mellitus (T2DM), exists interindividual variation. Considering that transporters belonging to the solute carrier (SLC) superfamily are determinants of metformin pharmacokinetics, we evaluated the effects of promoter variants in organic cation transporter 1 (OCT1) (SLC22A1 rs628031), OCT2 (SLC22A2 rs316019), multidrug and toxin extrusion protein 1 (MATE1) (SLC47A1 rs2289669), and MATE2 (SLC47A2 rs12943590) on the variation in metformin response. The glucose-lowering effects and improvement of insulin resistance of metformin were assessed in newly diagnosed, treatment-naive type 2 diabetic patients of Han nationality in Chaoshan China (n = 93) receiving metformin. Fasting plasma glucose (FPG), fasting insulin (FINS), glycated hemoglobin A1 (HbA1_C), homeostasis model assessment-insulin sensitivity (HOMA-IS), and homeostasis model assessment-insulin resistance (HOMA-IR) were the main metformin efficacy measurements. There were significant correlations between both SLC47A1 rs2289669 and SLC47A2 rs12943590 and the efficacy of metformin in individuals with T2DM. In normal weight T2DM patients, significant associations between the AA and GG genotypes of the rs2289669 variant of SLC47A1 and a greater reduction in FINS and HOMA-IR were detected. A significant correlation was observed between the AG genotype of the rs12943590 polymorphism of SLC47A2 and a greater reduction in HOMA-IR. Gene-environment interaction analysis showed that in the FINS interaction model, the second-order of dose30_g-SLC47A2 rs12943590 was statistically significant. The variants of SLC47A1 rs2289669 and SLC47A2 rs12943590 could be predictors of insulin resistance in type 2 diabetic patients treated with metformin. The second-order interaction of dose30_g-SLC47A2 rs12943590 may have a significant effect on FINS in patients with T2DM on metformin treatment. These findings suggest that promoter variants of SLC47A1 and SLC47A2 are important determinants of metformin transport and response in type 2 diabetes mellitus.

Metformin's Impact on the Microvascular Response to Insulin

Metformin improves insulin's action on whole-body glucose metabolism in various insulin-resistant populations. The detailed cellular mechanism(s) for its metabolic actions are multiple and still incompletely understood. Beyond metabolic actions, metformin also impacts microvascular function. However, the effects of metformin on microvascular function and microvascular insulin action specifically are poorly defined. In this mini-review, we summarize what is currently known about metformin's beneficial impact on both microvascular function and the microvascular response to insulin while highlighting methodologic issues in the literature that limit straightforward mechanistic understanding of these effects. We examine potential mechanisms for these effects based on pharmacologically dosed studies and propose that metformin may improve human microvascular insulin resistance by attenuating oxidative stress, inflammation, and endothelial dysfunction. Finally, we explore several important evidence gaps and discuss avenues for future investigation that may clarify whether metformin's ability to improve microvascular insulin sensitivity is linked to its positive impact on vascular outcomes.

A Phase II, Randomized, Double-Blind, Double-Dummy, Active-Controlled Clinical Trial to Investigate the Efficacy and Safety of NW Low-Glu® in Patients Newly Diagnosed with Type 2 Diabetes Mellitus

Background

Medicinal plants have long been used for the treatment of type 2 diabetes mellitus (T2DM). This study aimed to investigate the hypoglycemic efficacy and safety of NW Low-Glu® (contents of one capsule are 300 mg Mas Cotek + 100 mg Cinnamomum cassia L. + 250 mg Nigella sativa L. powdered extracts) in treatment-naïve, newly diagnosed T2DM patients.

Methods

This was a 12-week, double-blind, double-dummy, randomized, phase 2 clinical trial. A total of 232 male and female patients aged ≥18 and ≤65 years who were newly diagnosed with T2DM and have not received any antidiabetic drugs before and were equally randomized to receive metformin (2000 mg per day), low-dose NW Low-Glu® (content of four capsules per day), or high-dose NW Low-Glu® (content of five capsules per day). Our primary objective was to measure the mean change in HbA1c between each of the experimental arms and the metformin arm.

Results

There was a significant reduction in mean HbA1c at 12 weeks compared to baseline in the low-dose (0.6 (1.4)%; p=0.002) and high-dose arms (0.8 (1.7)%; p=0.004). There was also a significant reduction in 2 hr PPG at 12 weeks in the low-dose (35.4 (74.9) mg/dL, p=0.001) and high-dose arms (24.7 (100.8) mg/dL, p=0.04). Weight reduction was significantly higher with both high-dose (1.1 (-1.7) Kg; p=0.005) and low-dose arms (0.9 (-1.5) Kg; p=0.023) compared to metformin (0.8 (-1.8) Kg). No serious AEs or deaths were reported.

Conclusions

After 3 months of treatment, NW Low-Glu® was noninferior to metformin in reducing HbA1c and 2 hr PPG, while leading to significantly higher weight reduction in newly diagnosed T2DM patients. It was also safe and well tolerated.

The effect of metformin on ameliorating neurological function deficits and tissue damage in rats following spinal cord injury: A systematic review and network meta-analysis

Spinal cord injury (SCI) is a devastating condition with few treatment options. Metformin, a classical antidiabetic and antioxidant, has extended its application to experimental SCI treatment. Here, we performed a systematic review to evaluate the neurobiological roles of metformin for treating SCI in rats, and to assess the potential for clinical translation. PubMed, Embase, China National Knowledge Infrastructure, WanFang data, SinoMed, and Vip Journal Integration Platform databases were searched from their inception dates to October 2021. Two reviewers independently selected controlled studies evaluating the neurobiological roles of metformin in rats following SCI, extracted data, and assessed the quality of methodology and evidence. Pairwise meta-analyses, subgroup analyses and network analysis were performed to assess the roles of metformin in neurological function and tissue damage in SCI rats. Twelve articles were included in this systematic review. Most of them were of moderate-to-high methodological quality, while the quality of evidence from those studies was not high. Generally, Basso, Beattie, and Bresnahan scores were increased in rats treated with metformin compared with controls, and the weighted mean differences (WMDs) between metformin and control groups exhibited a gradual upward trend from the 3rd (nine studies, n = 164, WMD = 0.42, 95% CI = −0.01 to 0.85, P = 0.06) to the 28th day after treatment (nine studies, n = 136, WMD = 3.48, 95% CI = 2.04 to 4.92, P < 0.00001). Metformin intervention was associated with improved inclined plane scores, tissue preservation ratio and number of anterior horn motor neurons. Subgroup analyses indicated an association between neuroprotection and metformin dose. Network meta-analysis showed that 50 mg/kg metformin exhibited greater protection than 10 and 100 mg/kg metformin. The action mechanisms behind metformin were associated with activating adenosine monophosphate-activated protein kinase signaling, regulating mitochondrial function and relieving endoplasmic reticulum stress. Collectively, this review indicates that metformin has a protective effect on SCI with satisfactory safety and we demonstrate a rational mechanism of action; therefore, metformin is a promising candidate for future clinical trials. However, given the limitations of animal experimental methodological and evidence quality, the findings of this pre-clinical review should be interpreted with caution.

Effectiveness and mechanism of metformin in animal models of pulmonary fibrosis: A preclinical systematic review and meta-analysis

Background: Pulmonary fibrosis (PF) is a lung disease with no curative drug, characterized by a progressive decrease in lung function. Metformin (MET) is a hypoglycemic agent with the advantages of high safety and low cost and has been used in several in vivo trials to treat fibrotic diseases.

Objective: This study aimed to explore the efficacy and safety of MET in treating PF and elaborate on its mechanism.

Methods: Eight databases were searched for in vivo animal trials of MET for PF from the time of database creation until 1 March 2022. The risk of bias quality assessment of the included studies was conducted using SYRCLE’s risk of bias assessment. Pulmonary inflammation and fibrosis scores were the primary outcomes of this study. Hydroxyproline (HYP), type I collagen (collagen I), α-smooth muscle actin (α-SMA), transforming growth factor-β (TGF-β), Smad, AMP-activated protein kinase (AMPK), and extracellular signal–regulated kinase (ERK) protein expression in lung tissues and animal mortality were secondary outcomes. Effect magnitudes were combined and calculated using Revman 5.3 and Stata 16.0 to assess the efficacy and safety of MET in animal models of PF. Inter-study heterogeneity was examined using the I² or Q test, and publication bias was assessed using funnel plots and Egger’s test.

Results: A total of 19 studies involving 368 animals were included, with a mean risk of bias of 5.9. The meta-analysis showed that MET significantly suppressed the level of inflammation and degree of PF in the lung tissue of the PF animal model. MET also reduced the content of HYP, collagen I, α-SMA, and TGF-β and phosphorylation levels of Smad2, Smad3, p-smad2/3/smad2/3, ERK1/2, and p-ERK1/2/ERK1/2 in lung tissues. MET also elevated AMPK/p-AMPK levels in lung tissues and significantly reduced animal mortality.

Conclusion: The results of this study suggest that MET has a protective effect on lung tissues in PF animal models and may be a potential therapeutic candidate for PF treatment.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=327285, identifier CRD42022327285.

From Diabetes to Atherosclerosis: Potential of Metformin for Management of Cardiovascular Disease

Atherosclerosis is a common cause of cardiovascular disease, which, in turn, is often fatal. Today, we know a lot about the pathogenesis of atherosclerosis. However, the main knowledge is that the disease is extremely complicated. The development of atherosclerosis is associated with more than one molecular mechanism, each making a significant contribution. These mechanisms include endothelial dysfunction, inflammation, mitochondrial dysfunction, oxidative stress, and lipid metabolism disorders. This complexity inevitably leads to difficulties in treatment and prevention. One of the possible therapeutic options for atherosclerosis and its consequences may be metformin, which has already proven itself in the treatment of diabetes. Both diabetes and atherosclerosis are complex metabolic diseases, the pathogenesis of which involves many different mechanisms, including those common to both diseases. This makes metformin a suitable candidate for investigating its efficacy in cardiovascular disease. In this review, we highlight aspects such as the mechanisms of action and targets of metformin, in addition to summarizing the available data from clinical trials on the effective reduction of cardiovascular risks.

Improving Diabetes Care: A Fijian Diabetes Service Improvement Study

Background. Achieving good outcomes in type 2 diabetes mellitus patients’ needs a decent integrated care service with access to resources. The Fiji Islands has one of the highest rates of diabetes disease burden and has available resources to alleviate the diabetic disease pandemic in its population, yet patient outcomes are getting worse. We hypothesize that a dysfunction in health-care delivery system may be accentuating the diabetic disease process; therefore, this service evaluation study was conducted to provide insight into the management of T2DM in a secondary care clinic setting. Methods. We conducted a retrospective chart review of patient records for the past three years (2015-2018). Random quota sampling was used to extract patient folders over a one-month period. A total of 113 patient charts were analyzed which met the inclusion criteria. Results. The overall glycemic levels were uncontrolled in every seven out of ten patients. Most of the patients were on combination drug therapy and at maximum dosing ranges. HbA1c tests, as a monitoring tool, were being inadequately used. Nonadherence to management was prominent in poor controlled patients, and physicians failed to provide appropriate interventions in this group. Nearly all the patients had not received eye assessments, foot risk assessment, and individualized dietetic counselling over three years. Macrovascular complications were more common than microvascular end organ damage. Conclusion. There is a high degree of uncontrolled glycemia and comorbidities in patients attending the service of study which is being perpetuated by poor integrated diabetes care. Strengthening educational initiatives, using validated strategic tools to streamline diabetic services and astute evidence-based resource allocation and management, is needed.

Metformin alleviates the depression-like behaviors of elderly apoE4 mice via improving glucose metabolism and mitochondrial biogenesis

Apolipoprotein E4 (apoE4) is closely related to late-onset depression (LOD). In addition, the benefits of metformin treatment of depression have been documented in a range of rodent studies and human trials, but few studies have probed into the effect of metformin on and the related mechanism in depressed elderly mice, especially in those APOE4 carriers. Here, we treated 13-month-old apoE3-targeted replacement (TR) and apoE4-TR mice with an intragastric administration of metformin (300 mg/kg/d) or normal saline for 5 months. We found that metformin exerted antidepressant effects on apoE4 mice, including reduced immobility time in TST and FST, and increased ratios of time and distance in the central area of OFT. Importantly, compared with apoE3 mice, apoE4 mice showed a higher expression of lactate dehydrogenase (LDH) and pyruvate dehydrogenase kinase (PDK1 and PDK4) in the hippocampus. The increased LDH level was rescued by metformin treatment. Moreover, the metformin administration increased the levels of transcriptional factor NRF-1 and TFAM, mtDNA, and most mitochondrial complex subunits in apoE-TR mice. Furthermore, it upregulated the expressions of antioxidant enzymes, such as MnSOD, GPX1, and GSR1/2. Interestingly, apoE4 blunted the hypoglycemic effect of metformin in aged mice. These data suggest that metformin ameliorates the depression-like behaviors probably by improving glucose metabolism and mitochondria biogenesis in the hippocampus of aged apoE4 mice. These findings imply that chronic metformin treatment can improve apoE4-mediated LOD, providing mechanistic insights for apoE4- and age-based depression prevention and therapy.

Effects of Hydrochlorothiazide and Metformin on Aquaresis and Nephroprotection by a Vasopressin V2 Receptor Antagonist in ADPKD: A Randomized Crossover Trial

BACKGROUND AND OBJECTIVES

The vasopressin V2 receptor antagonist tolvaptan is the only drug that has been proven to be nephroprotective in autosomal dominant polycystic kidney disease (ADPKD). Tolvaptan also causes polyuria, limiting tolerability. We hypothesized that cotreatment with hydrochlorothiazide or metformin may ameliorate this side effect.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a clinical study and an animal study. In a randomized, controlled, double-blind, crossover trial, we included 13 tolvaptan-treated patients with ADPKD. Patients were treated for three 2-week periods with hydrochlorothiazide, metformin, or placebo in random order. Primary outcome was change in 24-hour urine volume. We also measured GFR and a range of metabolic and kidney injury markers.

RESULTS

Patients (age 45±8 years, 54% women, measured GFR of 55±11 ml/min per 1.73 m2) had a baseline urine volume on tolvaptan of 6.9±1.4 L/24 h. Urine volume decreased to 5.1 L/24 h (P<0.001) with hydrochlorothiazide and to 5.4 L/24 h (P<0.001) on metformin. During hydrochlorothiazide treatment, plasma copeptin (surrogate for vasopressin) decreased, quality of life improved, and several markers of kidney damage and glucose metabolism improved. Metformin did not induce changes in these markers or in quality of life. Given these results, the effect of adding hydrochlorothiazide to tolvaptan was investigated on long-term kidney outcome in an animal experiment. Water intake in tolvaptan-hydrochlorothiazide cotreated mice was 35% lower than in mice treated with tolvaptan only. Combination treatment was superior to "no treatment" on markers of disease progression (kidney weight, P=0.003 and cystic index, P=0.04) and superior or equal to tolvaptan alone.

CONCLUSIONS

Both metformin and hydrochlorothiazide reduced tolvaptan-caused polyuria in a short-term study. Hydrochlorothiazide also reduced polyuria in a long-term animal model without negatively affecting nephroprotection.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2022_03_21_CJN11260821.mp3.

Barriers against the use of an optimal dose of metformin among patients with T2DM in Thi-Qar province, Iraq

Diabetes mellitus is a disease with a high burden and prevalence and serious complications. Glycemic control is vital in delaying or preventing complications. Although many people do not take optimal doses, metformin is a cornerstone in managing type 2 diabetes mellitus (T2DM) in all guidelines. This study determined the barriers interfering with optimal metformin dosage. A cross-sectional study was conducted in Thi-Qar Specialized, Diabetes, Endocrine and Metabolism Center (TDEMC) at Thi-Qar, southern Iraq, from January 2019 to January 2020. 475 patients (274 females and 201 males) were included, and examination and lab investigations were performed. Only 22 (4.6%) patients took the optimal dose with no differences between gender. Of those who took metformin, 255 (74%) took it as a regular pill, 79 (23%) as a combined form with sulfonylureas (SUs), while only 10 (0.3%) took combined pills with Dipeptidyl Peptidase-4 inhibitors (DPP4i). 188 patients (65%) took metformin with meals, 84 (29%) before meals, and 19 (6%) after meals. Ignorance caused poor adherence to optimal dose in 165 patients (38.6%), neglect in 75 (17.6%), the cost in 5 (1.2%), 11 patients (2.6%) thought they did not need metformin, 37(8.7%) and 12 (2.8%) blame side effects and shortage of supply from public health care clinics (PHCC) as a cause, respectively. The rest of the patients had more than one cause. The most common side effects were abdominal pain and bloating, 5.9% and 3.8%, respectively. Other side effects were diarrhea in 0.2%, and 7.8% of patients developed more than one side effect. Ignorance and neglect were major obstacles, so educating doctors and patients and supplying the patient with optimal doses through PHCC may overcome the problem.

Bioactive Peptides: From Basic Research to Clinical Trials and Commercialization

Chronic diseases, including metabolic diseases, have become a worldwide public health issue. Research regarding the use of bioactive peptides or protein hydrolysates derived from food, as the diet-based strategies for the prevention and mitigation of chronic diseases, has increased exponentially in the past decades. Numerous in vitro and in vivo studies report the efficacy and safety of food-derived bioactive peptides and protein hydrolysates as antihypertensive, anti-inflammatory, antidiabetic, and antioxidant agents. However, despite promising preclinical results, an inadequate understanding of their mechanisms of action and pharmacokinetics restrict their clinical translation. Commercialization of bioactive peptides can be further hindered due to scarce information regarding their efficacy, safety, bitter taste, as well as the lack of a cost-effective method of production. This review provides an overview of the current clinical evidence and challenges to commercial applications of food-derived bioactive peptides and protein hydrolysates for the prevention and alleviation of chronic diseases.

Association of SLC22A1 rs622342 and ATM rs11212617 polymorphisms with metformin efficacy in patients with type 2 diabetes

Metformin is the first-choice oral anti-hyperglycemic drug for type 2 diabetes mellitus (T2DM) patients. There are controversies about the association of SLC22A1 rs622342, which was not reported in the Chinese population, and ataxia-telangiectasia mutated (ATM) rs11212617 polymorphisms with metformin efficacy in T2DM. Our study was to investigate the effects of the two single nucleotide polymorphisms on the efficacy of metformin in T2DM of Han nationality in Chaoshan China. After enrollment, 82 newly diagnosed T2DM patients went on 2-month metformin monotherapy. According to BMI before treatment, the patients were divided into a normal weight group (≥18.5 and <25 kg/m2) and an overweight group (BMI ≥ 25 and <30 kg/m2). T-test, Pearson χ2 test, and regression analysis, which adjusted for age, BMI, sex, the dose of metformin, education, tea drink, smoking, and sweet, were used to evaluate the effects of rs622342 and rs11212617 on several variables, such as fasting plasma glucose (FPG). Compared with the AA or CC genotype, patients with AC genotype of rs622342 achieved greater reduction in Δ60FPG and Δ(60-30)FPG (P = 0.00820, 0.00089, respectively). For 11212617, the reduction in Δ30FPG and Δ60FPG was significantly different among patients with the AC genotype (P = 0.00026, 0.00820, respectively). Our results indicated that common variants of SLC22A1 rs622342 and ATM rs11212617 were associated with the efficacy of metformin in T2DM of Han nationality in Chaoshan China.

Metformin therapy in pediatric type 2 diabetes mellitus and its comorbidities: A review

Type 2 diabetes (T2D) rates in children and adolescents are rising globally. T2D is a complex and aggressive disease in children with several comorbidities, high treatment failure rates, and insulin needs within a few years from diagnosis. While myriads of pharmacotherapies are licensed to treat adults with T2D, treatments accessible to children and adolescents have been limited until recently. Metformin is an old drug with multiple beneficial metabolic health effects beyond glycemic control. This review discusses Metformin's origins, its mechanisms of action, and evidence for its use in the pediatric population to treat and prevent T2D. We also explore the evidence for its use as an obesity therapy, which is the primary driver of T2D, and T2D-driven comorbidities. While emerging therapies create new horizons for managing pediatric T2D, Metformin remains an inexpensive and safe part of the treatment plans of many T2D children globally for its beneficial metabolic effects.

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.