Overview of metformin: special focus on metformin extended release

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.

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.

Versatile Solid Modifications of Multicomponent Pharmaceutical Salts: Novel Metformin-Rhein Salts Based on Advantage Complementary Strategy Design

This study aimed to develop an effective treatment for diabetes and diabetic complications, based on the advantage complementary strategy of drug-drug salt, by designing and synthesizing the multicomponent molecular salts containing metformin (MET) and rhein (RHE). Finally, the salts of MET-RHE (1:1), MET-RHE-H₂O (1:1:1), MET-RHE-ethanol-H₂O (1:1:1:1), and MET-RHE-acetonitrile (2:2:1) were obtained, indicating the polymorphism of salts formed by MET and RHE. The structures were analyzed by the combination of characterization experiments and theoretical calculation, and the formation mechanism of polymorphism was discussed. The obtained results of in vitro evaluation showed that MET-RHE had a similar hygroscopicity with metformin hydrochloride (MET·HCl), and the solubility of the component of RHE increased by approximately 93 times, which laid a foundation for improving the bioavailability of MET and RHE in vivo. The evaluation of hypoglycemic activity in mice (C57BL/6N) indicated that MET-RHE exhibited better hypoglycemic activity than the parent drugs and the physical mixtures of MET and RHE. The above findings demonstrate that this study achieved the complementary advantages of MET and RHE through the multicomponent pharmaceutical salification technique, and provides new possibilities for the treatment of diabetic complications.

Post-pancreatitis diabetes mellitus: insight on optimal management with nutrition and lifestyle approaches

Pancreatitis is the leading gastrointestinal cause of hospitalizations. There are multiple short- and long-term complications associated with pancreatitis. Post-pancreatitis diabetes mellitus (PPDM) is one of the less explored complications of pancreatitis. Nonetheless, it has attracted considerable attention during the last decade. PPDM is now the second most common cause of new-onset diabetes mellitus (DM) in adults after type II DM surpassing type 1 DM. However, there exists a knowledge gap amongst practitioners regarding diagnosis, complications, and management of PPDM. In this narrative, we aim to provide a brief review regarding risks, diagnosis and management of PPDM with a special focus on dietary and lifestyle management strategies.KEY MESSAGESPost-pancreatitis diabetes mellitus (PPDM) is now the second most common cause of new-onset diabetes mellitus (DM) in adults after type II DM surpassing type 1 DM.New-onset diabetes in patients with pancreatitis could also be an early marker of occult pancreatic malignancy.Management of PPDM is complex and requires a team-based approach including gastroenterologists, endocrinologists, primary care physicians, nutritionists, and behavioural health specialists.

Instituting a Successful Discharge Plan for Patients With Type 2 Diabetes: Challenges and Solutions

Achieving target inpatient glycemic management outcomes has been shown to influence important clinical outcomes such as hospital length of stay and readmission rates. However, arguably the most profound, lasting impact of inpatient diabetes management is achieved at the time of discharge-namely reconciling and prescribing the right medications and making referrals for follow-up. Discharge planning offers a unique opportunity to break through therapeutic inertia, offer diabetes self-management education, and institute an individualized treatment plan that prepares the patient for discharge and promotes self-care and engagement. However, the path to a successful discharge plan can be fraught with potential pitfalls for clinicians, including lack of knowledge and experience with newer diabetes medications, costs, concerns over insurance coverage, and lack of time and resources. This article presents an algorithm to assist clinicians in selecting discharge regimens that maximize benefits and reduce barriers to self-care for patients and a framework for creating an interdisciplinary hospital diabetes discharge program.

Detección de Nuevas Tecnologías Sanitarias Para Mejorar el Control Metabólico de Pacientes Con Diabetes Tipo 2 Atendidos en el Programa de Salud Cardiovascular de Chile

OBJECTIVES

In Chile, > 900,000 people with type 2 diabetes mellitus (DM2) are controlled in the Cardiovascular Health Program (PSCV). Even though the PSCV includes a set of interventions for the control of patients with DM2, the results are still insufficient, generating a high human, economic, and social cost. This study aimed to identify and select new health technologies for the control of patients with DM2 not currently incorporated into the PSCV to be proposed as candidates for an economic evaluation in the Chilean context.

METHODS

For the identification of new health technologies, consultations with key informants and an umbrella review of updated scientific evidence were used as sources of information. In a second step, selection among those technologies was conducted based on the effectiveness of the intervention, target population, nature of the intervention, and international evidence of cost-effectiveness antecedents.

RESULTS

Key informants identified 12 candidate health technologies not currently incorporated into the PSCV. From the umbrella review, an additional 9 health technologies were identified that were not identified by the key informants. Of the 21 new health technologies identified, finally 8 health technologies were selected (structured group education, pedometer use, periodontal treatment, cognitive-behavioral therapy, telemonitoring, sitagliptin, canagliflozin, and insulin degludec).

CONCLUSIONS

The health technologies detected have a high potential to be studied through economic evaluations that allow guiding decision making around improving the health outcomes of patients with DM2 in Chile.

Biguanide Pharmaceutical Formulations and the Applications of Bile Acid-Based Nano Delivery in Chronic Medical Conditions

Biguanides, particularly the widely prescribed drug metformin, have been marketed for many decades and have well-established absorption profiles. They are commonly administered via the oral route and, despite variation in oral uptake, remain commonly prescribed for diabetes mellitus, typically type 2. Studies over the last decade have focused on the design and development of advanced oral delivery dosage forms using bio nano technologies and novel drug carrier systems. Such studies have demonstrated significantly enhanced delivery and safety of biguanides using nanocapsules. Enhanced delivery and safety have widened the potential applications of biguanides not only in diabetes but also in other disorders. Hence, this review aimed to explore biguanides’ pharmacokinetics, pharmacodynamics, and pharmaceutical applications in diabetes, as well as in other disorders.

Efficacy and Side Effect Profile of Different Formulations of Metformin: A Systematic Review and Meta-Analysis

INTRODUCTION

Metformin is among the most frequently prescribed drugs worldwide for a variety of indications. Although metformin has several important advantages, for example being easy to store and administer, it is associated with a high incidence of gastrointestinal side effects. Slower-release formulations of metformin may reduce the incidence of side effects while maintaining efficacy; however, there is a lack of systematic evidence available to guide head-to-head comparisons between different metformin formulations.

METHODS

PubMed, Web of Science, OVID EMBASE, MEDLINE, The Cochrane database and Clinicaltrials.gov were systematically searched (from inception to 25 January 2021). Trials that randomized adult participants to extended-release formulation of metformin (met-XR), delayed-release (met-DR) or immediate-release metformin (met-IR) were included. Two reviewers independently assessed articles for eligibility and risk-of-bias, with conflicts resolved by a third reviewer. Outcome measures were change in fasting plasma glucose (FPG), glycated haemoglobin (HbA1c), body weight, BMI, lipid profile and side effects. Meta-analyses were conducted using random-effects models.

RESULTS

Fifteen studies (n = 3765) met eligibility criteria. There was no significant difference between the efficacy of met-IR, met-XR or met-DR in changing FPG (p = 0.93). A non-significant reduction in mean body weight was observed in individuals randomized to met-XR vs. met-IR (- 1.03 kg, 95% CI - 2.12 to 0.05, p = 0.06). Individuals randomized to met-XR vs. met-IR had lower low-density lipoprotein (LDL) cholesterol levels (- 5.73 mg/dl, 95% CI - 7.91 to - 3.56, p < 0.00001). Gastrointestinal (GI) side effects were markedly reduced in patients randomised to met-DR vs. met-IR (OR 0.45, 95% CI 0.26-0.80, p = 0.006).

CONCLUSION

Our results demonstrate equal efficacy of longer-acting formulations (met-XR, met-DR) versus immediate-release metformin formulations in terms of glycaemic control. There were insufficient studies available to compare the efficacy of different metformin formulations outside of diabetes care. However met-XR was associated with reduced serum LDL cholesterol concentrations, while met-DR was strongly associated with reduced GI side effects, which could improve drug compliance.

Comparison of Metformin and Repaglinide Monotherapy in the Treatment of New-Onset Type 2 Diabetes Mellitus

Objectives We intend to investigate the feasibility of using repaglinide as initial therapy in patients with newly diagnosed type 2 diabetes mellitus naive to the oral anti-hyperglycemic agents by validating the effects of repaglinide on glycemic control (HbA1c) in comparison with metformin monotherapy. Methodology This parallel-controlled, randomized study was carried at the outpatient department of a tertiary care hospital. Two-hundred patients of both genders with newly diagnosed type 2 diabetes mellitus were included. After taking relevant history and physical examination, we drew venous blood samples of each patient and sent them to the institutional laboratory for analysis of fasting blood sugar (FBS) levels, HbA1c, and lipid profile. We divided the patients into two subgroups based on the lottery method. Group A was prescribed metformin, and group B was prescribed repaglinide, while the dosages were adjusted according to the blood sugar levels. All data were analyzed using SPSS Software 25.0 (SPSS Inc., Chicago, USA). We reported the data as means along with the standard error. Results All patients completed the study. There was a decline in fasting blood glucose levels after three months of therapy, both in the metformin (135 mg/dl ± 6 mg/dl versus 115 mg/dl ± 7 mg/dl, p < 0.01) and repaglinide groups (145 ± 6 mg/dl versus 122 ± 6 mg/dl, p < 0.01). Similarly, significant reductions in HbA1c were seen in both metformin (7.12 ± 0.15% versus 6.67 ± 0.06%, p < 0.01) and repaglinide treatment groups (7.83 ± 0.67% versus 6.81 ± 0.07%, p < 0.01). After three months of treatment, body mass index (BMI) was significantly decreased in the metformin group (26.87±1.1 kg/m² versus 25.11 ± 0.44 kg/m², p < 0.05). However, the patients in repaglinide group demonstrated a very slight decrease in BMI (27.11 ± 1.6 kg/m² versus 26.47 ± 0.40 kg/m²). On follow-up, we found a significant decrease in triglyceride levels in both groups (p < 0.01 and p < 0.05. respectively). We also found that only the patients in metformin group showed some improvements in total cholesterol and low-density lipoprotein (LDL) levels (p < 0.05). Conclusion Our study concluded that both metformin and repaglinide have similar anti-hyperglycemic effects. Repaglinide can be prescribed as an alternative drug to metformin in patients with new-onset diabetes mellitus.

Economic evaluation of dapagliflozin versus metformin in Chinese patients whose diabetes is inadequately controlled with diet and exercise

Background

To investigate the long-term economic outcome of dapagliflozin versus metformin in Chinese patients with type 2 diabetes mellitus (T2DM) whose diet and exercise have not provided sufficient glycemic control.

Methods

An economic analysis of dapagliflozin versus metformin was conducted by using the Chinese Outcomes Model for T2DM with a time horizon of lifetime, which was developed and validated based on the Chinese population. The efficacy data of lowering HbA1c of dapagliflozin and metformin was derived from a network meta-analysis. Other clinical, cost and utility inputs were obtained from published sources. Lifetime discounted quality-adjusted life-years, cost, and incremental cost-effectiveness ratio were measured. The uncertainty was facilitated by one-way and probabilistic sensitivity analyses.

Results

The comparison of metformin and dapagliflozin in Chinese patients with insufficient glycemic control by diet and exercise showed that dapagliflozin was more costly and produced fewer health benefits in our simulated cohort. The sensitivity analyses indicated that the results were robust.

Conclusions

Dapagliflozin is not likely to be cost-effective compared with metformin for Chinese patients with T2DM inadequately controlled with diet and exercise.

Dose distribution and up-titration patterns of metformin monotherapy in patients with type 2 diabetes

AIMS

To assess the dose distribution among users of metformin monotherapy as well as the patterns of up-titration following initiation of therapy in people with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

This was a retrospective cohort study of adults with T2DM in the United Kingdom (UK). Metformin dose distribution was assessed at 0, 6 and 12 months in people initiating metformin monotherapy (new users) and cross-sectionally in people with ongoing metformin monotherapy (prevalent users). Patterns and predictors of up-titration were also analysed in new users. Dose distributions and treatment patterns were assessed descriptively; predictors of up-titration were determined using multivariable logistic regressions.

RESULTS

Totals of 6174 new users and 8733 prevalent users were included. New users initiated metformin at >0 mg to ≤500 mg (25%), >500 mg to ≤1000 mg (47%), >1000 mg to ≤1500 mg (17%) or >1500 mg to ≤2000 mg (12%) daily. This distribution did not vary over time. Prevalent users of metformin received doses of >0 mg to ≤500 mg (14%), >500 mg to ≤1000 mg (40%), >1000 mg to ≤1500 mg (15%), >1500 mg to ≤2000 mg (29%) or >2000 mg (1%) daily. Among new users of metformin, 6.7% and 10.8% had been up-titrated at 6 and 12 months, respectively, despite the majority having glycated haemoglobin >53 mmol/mol. Predictors of up-titration included younger age and higher HbA1c.

CONCLUSIONS

A majority of T2DM patients taking metformin received a dose ≤1000 mg/day. Up-titration of metformin is infrequent in the first year postinitiation.

[Metformin inhibits aortic atherosclerosis in mice by regulating actin skeleton in vascular smooth muscle cells]

ObjectiveInvestigate the effect and mechanism of metformin on the development of metabolic syndrome related atherosclerosis.MethodTransfecting EGFP-CLIP170 or EGFP-Pdlim5 plasmid to the mouse aortic smooth muscle cell line, to test the expression of p-AMPK, pCLIP-170 and pPdlim5, and observe the microtubule or the actin skeleton system by immunofluorescence staining. Scratch the cells to perform wound healing experiment, stimulating the cells with gradient metformin (0, 0.5, 1 mmol/L) for 8 h, and observe the change of the scratch size and the dynamic change of cell skeleton and migration in vitro. ApoE-/- mice were injected with streptozotocin and followed by 8 weeks of high fat diet to induce metabolic syndrome model. In the therapeutic group, mice were treated metformin (Met) instead of saline in control group (Control, CTL group). In the end, the whole aorta and its root were isolated and performed oil red O staining and immol/Lunostaining of α-SMA to evaluate the migration of smooth muscle cells and the accumulation of lipids in the aorta.ResultsMouse aortic smooth muscle cells showed an enhanced stress fiber and focal adhesion which representing the dynamic change of actin skeleton after Met stimulation, while the tubulin system rarely showed any change to Met. In animal model, The staining of α-SMA showed smooth muscle cells migrated to the intima or even to the lipid area from the media of aorta in CTL group compared to the Met group. Oil red O staining showed a reduced accumulation of lipids in the Met group than the controls (P < 0.05).ConclusionMetformin reduces the formation of atherosclerosis by inhibiting the migration of smooth muscle cells through modulating cellular actin skeleton system in mice.

Reduction in HbA1c with Exercise videogames among participants with elevated HbA1c: Secondary analysis of the Wii Heart Fitness trial

AIMS

Physical activity plays an important role in blood glucose management, yet most adults with elevated blood glucose do not engage in regular physical activity. Exercise videogames (EVGs) may be an attractive alternative for persons who have not found standard exercise modalities appealing.

METHODS

This sub-study within a larger trial examined the effects of 12 weeks of EVGs versus standard exercise (e.g., treadmill, cycling) and a control condition among individuals with elevated HbA1c (100% prediabetic). This study was conducted at a university research lab. Outcomes included HbA1c and weekly minutes of moderate to vigorous physical activity (MVPA) assessed using self-report and accelerometer.Other health risk indices (e.g., lipids) and psychosocial constructs shown to influence exercise participation (e.g., intrinsic motivation) were assessed.

RESULTS

Participants (n = 84), averaged age 51.4 years (range 20-79), 80% were female, and 77.4% were non-Hispanic. Baseline HbA1c ranged from 5.7% to 6.4% (39-49 mmol/mol). At week 12, EVG participants demonstrated an average 2% reduction in HbA1c compared to a 0.6% reduction in Standard and Control groups (p's = 0.04 and 0.03). EVG participants engaged in significantly more MVPA than Standard (+17 min/week) and Controls (+54 min/week) (p's < 0.05), had reduced LDL cholesterol (p = 0.05) and trends suggesting reduced body fat (p = 0.10). EVG participants reported higher exercise enjoyment and motivation compared to other participants.

CONCLUSIONS

EVGs may be an attractive and effective tool to improve management of blood glucose that might contribute toward preventing the onset of type 2 diabetes among those with prediabetes.

Actions of metformin and statins on lipid and glucose metabolism and possible benefit of combination therapy

Patients with diabetes type 2 have an increased risk for cardiovascular disease and commonly use combination therapy consisting of the anti-diabetic drug metformin and a cholesterol-lowering statin. However, both drugs act on glucose and lipid metabolism which could lead to adverse effects when used in combination as compared to monotherapy. In this review, the proposed molecular mechanisms of action of statin and metformin therapy in patients with diabetes and dyslipidemia are critically assessed, and a hypothesis for mechanisms underlying interactions between these drugs in combination therapy is developed.

Is It Time to Change the Type 2 Diabetes Treatment Paradigm? No! Metformin Should Remain the Foundation Therapy for Type 2 Diabetes

Most treatment guidelines, including those from the American Diabetes Association/European Association for the Study of Diabetes and the International Diabetes Federation, suggest metformin be used as the first-line therapy after diet and exercise. This recommendation is based on the considerable body of evidence that has accumulated over the last 30 years, but it is also supported on clinical grounds based on metformin's affordability and tolerability. As such, metformin is the most commonly used oral antihyperglycemic agent in the U.S. However, based on the release of newer agents over the recent past, some have suggested that the modern approach to disease management should be based upon identification of its etiology and correcting the underlying biological disturbances. That is, we should use interventions that normalize or at least ameliorate the recognized derangements in physiology that drive the clinical manifestation of disease, in this circumstance, hyperglycemia. Thus, it is argued that therapeutic interventions that target glycemia but do not correct the underlying pathogenic disturbances are unlikely to result in a sustained benefit on the disease process. In our field, there is an evolving debate regarding the suggested first step in diabetes management and a call for a new paradigm. Given the current controversy, we provide a Point-Counterpoint debate on this issue. In the point narrative that precedes the counterpoint narrative below, Drs. Abdul-Ghani and DeFronzo provide their argument that a treatment approach for type 2 diabetes based upon correcting the underlying pathophysiological abnormalities responsible for the development of hyperglycemia provides the best therapeutic strategy. Such an approach requires a change in the recommendation for first-line therapy from metformin to a GLP-1 receptor agonist. In the counterpoint narrative below, Dr. Inzucchi argues that based on the medical community's extensive experience and the drug's demonstrated efficacy, safety, low cost, and cardiovascular benefits, metformin should remain the "foundation therapy" for all patients with type 2 diabetes, barring contraindications.-William T. CefaluChief Scientific, Medical & Mission Officer, American Diabetes Association.

Effects of metformin extended release compared to immediate release formula on glycemic control and glycemic variability in patients with type 2 diabetes

PURPOSE

The purpose of this study is to evaluate, in a randomized clinical trial, the effects of metformin immediate release (IR) compared with metformin extended release (XR) on the gastrointestinal tolerability and glycemic control.

MATERIALS AND METHODS

We enrolled 253 Caucasian patients with type 2 diabetes not well controlled by diet (glycated hemoglobin [HbA_1c] >7.0% and <8.5%). Patients were randomized to metformin IR or metformin XR for a period of 6 months at the maximum tolerated dose. The average dose of metformin IR used was 2,000±1,000 mg/day, while that of metformin XR was 1,000±500 mg/day. We evaluated body weight, HbA_1c, fasting and postprandial glucose, fasting plasma insulin (FPI) and homeostasis model assessment insulin resistance (HOMA-IR), lipid profile, and levels of some adipocytokines, including tumor necrosis factor-α (TNF-α), high-sensitivity C-reactive protein (hs-CRP), visfatin, and vaspin. Moreover, at the baseline and after 6 months, we administered patients some validated questionnaires to assess patients' satisfaction toward treatments.

RESULTS

After 6 months, both formulations gave a similar reduction in body weight and body mass index (BMI); however, metformin XR gave a greater improvement in glycemic control, FPI, and HOMA-IR, compared with both baseline and metformin IR. A reduction in total cholesterol (TC) and low-density lipoprotein (LDL) cholesterol was observed with metformin XR compared with IR. Levels of TNF-α, hs-CRP, and vaspin were reduced by metformin XR but not by the IR formulation. Metformin XR also raised the levels of visfatin.

CONCLUSION

Metformin XR formulation seems to be more effective than metformin IR in improving glyco-metabolic control, lipid profile, and levels of some adipocytokines in patients with type 2 diabetes mellitus.

New insights into the anti-diabetic actions of metformin: from the liver to the gut

Metformin is established as the first-line therapy for type 2 diabetes (T2DM), but its mode of action remains elusive. Elucidation of the mechanisms underlying the anti-diabetic action of metformin may have the potential to optimise its glucose-lowering efficacy and lead to the development of agents acting on novel targets for the management of type 2 diabetes. Areas covered: This review highlights key pharmacokinetic features of metformin, summarises recent insights into its hepatic and gastrointestinal actions relevant to blood glucose homeostasis, and discusses the common gastrointestinal side effects of metformin. Literature concerning these areas was reviewed on PubMed. Expert commentary: The mechanisms by which metformin improves glycaemic control in type 2 diabetes are complex. Although novel hepatic pathways continue to be reported in preclinical studies, there is a lack of human evidence for most of these. Considering the fundamental role of the gastrointestinal tract in the regulation of blood glucose homeostasis and pleiotropic actions of metformin on several gastrointestinal targets relevant to glycaemic control, the gut is likely to represent at least as important a site of metformin action as the liver in the management of type 2 diabetes.

Long-term treatment with metformin in obese, insulin-resistant adolescents: results of a randomized double-blinded placebo-controlled trial

Background:

As adolescents with obesity and insulin resistance may be refractory to lifestyle intervention therapy alone, additional off-label metformin therapy is often used. In this study, the long-term efficacy and safety of metformin versus placebo in adolescents with obesity and insulin resistance is studied.

Methods:

In a randomized placebo-controlled double-blinded trial, 62 adolescents with obesity aged 10–16 years old with insulin resistance received 2000 mg of metformin or placebo daily and physical training twice weekly over 18 months. Primary end points were change in body mass index (BMI) and insulin resistance measured by the Homeostasis Model Assessment for Insulin Resistance (HOMA-IR). Secondary end points were safety and tolerability of metformin. Other end points were body fat percentage and HbA1c.

Results:

Forty-two participants completed the 18-month study (66% girls, median age 13 (12–15) years, BMI 30.0 (28.3 to 35.0) kg m⁻² and HOMA-IR 4.08 (2.40 to 5.88)). Median ΔBMI was +0.2 (−2.9 to 1.3) kg m⁻² (metformin) versus +1.2 (−0.3 to 2.4) kg m⁻² (placebo) (P=0.015). No significant difference was observed for HOMA-IR. No serious adverse events were reported. Median change in fat percentage was −3.1 (−4.8 to 0.3) versus −0.8 (−3.2 to 1.6)% (P=0.150), in fat mass −0.2 (−5.2 to 2.1) versus +2.0 (1.2–6.4) kg (P=0.007), in fat-free mass +2.0 (−0.1 to 4.0) versus +4.5 (1.3 to 11.6) kg (P=0.047) and in ΔHbA1c +1.0 (−1.0 to 2.3) versus +3.0 (0.0 to 5.0) mmol mol⁻¹ (P=0.020) (metformin versus placebo).

Conclusions:

Long-term treatment with metformin in adolescents with obesity and insulin resistance results in stabilization of BMI and improved body composition compared with placebo. Therefore, metformin may be useful as an additional therapy in combination with lifestyle intervention in adolescents with obesity and insulin resistance.

The Effect of Metformin Use on Left Ventricular Ejection Fraction and Mortality Post-Myocardial Infarction

BACKGROUND

Animal studies showed that the use of metformin after myocardial infarction (MI) resulted in a protective effect on cardiac myocytes. In this study, we examined the effect of metformin in patients with diabetes mellitus (DM) on left ventricular ejection fraction (LVEF) and post-MI mortality.

METHODS

We reviewed charts of patients with MI admitted to the UAMS medical center. Baseline characteristics and 12-month follow up data were collected. Patients were classified into three groups: Control group- no DM (n = 464), Metformin group- DM + MI (n = 88) and No-Metformin group- DM + MI (n = 168). First, we compared Metformin and No-Metformin groups to the Control group. Second, we performed propensity-score matching in patients with DM, and compared Metformin to No-Metformin groups.

RESULTS

All-cause 30-day and 12-month mortality was significantly higher in the No-Metformin group compared to controls (13.5 vs 9.3% p = 0.03 at 30 days, 23.7 vs 15.9 % p = 0.03 at 12 months). However, all-cause 30-day and 12-month mortality were similar in the Controls and Metformin group (9.3 vs 6.8 % p = 0.93 at 30 days, 15.9 vs 11.4 % p = 0.97 at 12 months). Mean LVEF on presentation (45 % in the three groups) and at follow up (47.84, 46.38 and 43.62 % in Control, Metformin, and No-Metformin groups, respectively) were not statistically different. There were no significant differences in regard to re-hospitalization, re-intervention, new stroke, CHF development, new MI, or identifiable arrhythmias. Metformin was an independent predictor of lower 30-day and 12-month all-cause mortality in patients with DM (HR 0.25, p = 0.02 and HR 0.32, p = 0.01, respectively). In the matched analysis, 30-day all-cause mortality was significantly higher in the No-Metformin compared to the Metformin group (21.1 vs 8.8 %, p = 0.05). However the difference in 12-month all-cause mortality did not reach statistical significance (24.6 vs 15.8 %, p = 0.15).

CONCLUSION

This proof-of-concept study shows that use of metformin in patients with DM is associated with lower 30-day all-cause mortality and tendency for a lower 12-month all-cause mortality following MI without discernible improvement in LVEF.

Metformin in Amnestic Mild Cognitive Impairment: Results of a Pilot Randomized Placebo Controlled Clinical Trial

Diabetes and hyperinsulinemia may be risk factors for Alzheimer's disease (AD). We conducted a pilot study of metformin, a medication efficacious in treating and preventing diabetes while reducing hyperinsulinemia, among persons with amnestic mild cognitive impairment (aMCI) with the goal of collecting preliminary data on feasibility, safety, and efficacy. Participants were 80 men and women aged 55 to 90 years with aMCI, overweight or obese, without treated diabetes. We randomized participants to metformin 1000 mg twice a day or matching placebo for 12 months. The co-primary clinical outcomes were changes from baseline to 12 months in total recall of the Selective Reminding Test (SRT) and the score of the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog). The secondary outcome was change in relative glucose uptake in the posterior cingulate-precuneus in brain fluorodeoxyglucose positron emission tomography. Change in plasma Aβ42 was an exploratory outcome. The mean age of participants was 65 years. Fifty percent of participants were women. The only baseline variable that was different between the arms was the ADAS-Cog. Metformin could not be tolerated by 7.5% of participants; 15% tolerated 500 mg/day, 35% tolerated 1000 mg/day, 32.5% tolerated 1500 mg/day, and only 10% tolerated the maximum dose. There were no serious adverse events related to metformin. The 7.5% of persons who did not tolerate metformin reported gastrointestinal symptoms. After adjusting for baseline ADAS-cog, changes in total recall of the SRT favored the metformin group (9.7±8.5 versus 5.3±8.5; p = 0.02). Differences for other outcomes were not significant. A larger trial seems warranted to evaluate the efficacy and cognitive safety of metformin in prodromal AD.

Metformin-associated lactic acidosis

: Metformin is the most commonly prescribed oral antidiabetic agent. Despite a good safety profile in most patients with diabetes, the risk of metformin-associated lactic acidosis is real if safety guidelines are ignored. Experience with 3 cases of metformin-associated lactic acidosis is reported. Two cases were caused by inappropriate use of metformin in the presence of renal, cardiac and hepatic failure and 1 case followed an intentional overdose. The literature was reviewed on the clinical presentation, prevalence, pathogenesis, prognosis and management of metformin-associated lactic acidosis. This report highlights the importance of proper patient selection, clinical and laboratory monitoring and recommendation on when to stop the drug in ambulatory and hospitalized patients to prevent this unusual but potentially lethal complication.

Potential approaches to ameliorate hepatic fat accumulation seen with MTP inhibition

Microsomal triglyceride transfer protein (MTP) is one of the promising targets for the therapy of dyslipidemia and MTP inhibition can lead to robust plasma low-density lipoprotein cholesterol (LDL-C) reduction. Lomitapide, a small-molecule MTP inhibitor, was recently approved by the US FDA as an additional treatment for homozygous familial hypercholesterolemia (hoFH). However, liver-related side effects, including hepatic fat accumulation and transaminase elevations, are the main safety concerns associated with MTP inhibitors. Here, we review recent knowledge on the mechanisms underlying liver toxicity of MTP inhibitors. The contribution of altered levels of intracellular triglycerides, cholesteryl esters, and free cholesterols toward cellular dysfunction is specifically addressed. On this basis, therapies targeted to attenuate cellular lipid accumulation, to reduce risk factors for non-alcoholic fatty liver disease (NAFLD) (i.e., insulin resistance and oxidative stress) and to specifically inhibit intestinal MTP may be useful for ameliorating liver damage induced by MTP inhibitors. In particular, weight loss through lifestyle interventions is expected to be the most effective and safest way to minimize the undesirable side effects. Specific dietary supplementation might also have protective effects against hepatosteatosis. Despite that, to date, few clinical data support these therapeutic options in MTP inhibition-related liver damage, such proposed approaches may be further explored in the future for their use in preventing unwanted effects of MTP inhibitors.

Effects of a Comprehensive, Intensive Lifestyle Intervention Combined with Metformin Extended Release in Obese Adolescents

Objective. To assess a comprehensive, intensive lifestyle intervention in combination with metformin extended release (MXR) or placebo on body mass index (BMI) and risk factors for type 2 diabetes and cardiovascular disease in obese adolescents. Study Design. Sixty-nineobese adolescents (mean BMI 32.5) received a comprehensive lifestyle intervention with structured dietary, physical activity, and behavioral components for 24 months. Subjects were randomized to 1 of 4 groups: MXR (33) 2,000 mg daily or placebo, with either moderate or vigorous intensity exercise for the first 3 months. Subsequently the exercise intervention was the same for all 4 groups. Results. Anthropometry measurements did not differ with initial exercise intensity at any time. At 3 months % body fat decreased in all 4 groups (P < 0.006). BMI and % body fat decreased in the MXR groups, but not the placebo groups, at 6 (-0.88, -3.16) and 12 months (-0.56, -2.34) (P < 0.05). Insulin resistance, fasting blood glucose, and leptin improved in all groups at 6 and 12 months. A high subject attrition rate (58%) occurred by 24 months. Conclusion. A comprehensive, intensive lifestyle intervention combined with MXR led to a decline in BMI and % body fat at 1 year independent of initial exercise intensity. This trial is registered with ClinicalTrials.gov NCT00934570 .

Results from a dietary survey in an Indian T2DM population: a STARCH study

OBJECTIVE

To assess the dietary total and complex carbohydrate (CHO) contents in type-2 diabetes mellitus (T2DM) participants in India.

SETTING

We enrolled 796 participants in this cross-sectional, single-visit, multicentre, two-arm, single-country survey. Participants were enrolled from 10 specialty endocrinology/dialectology centres from five regions of India.

PARTICIPANTS

A total of 796 participants (Asian) were enrolled in this study (385, T2DM and 409, non-T2DM). Key inclusion criteria-male or female ≥18 years, diagnosed with T2DM ≥12 months (T2DM), and not on any diet plan (non-T2DM).

STUDY OUTCOME

Primary outcome was to find out the percentage of total energy intake as simple and complex CHO from total CHO. Secondary outcomes were to find the differences in percentage of total energy intake as simple CHO, complex CHO, proteins and fats between T2DM and non-T2DM groups. The percentage of T2DM participants adhering to diet plan and showing glycaemic controls were also examined.

RESULTS

The mean (SD) of total calorie intake per day (Kcal) was 1547 (610, 95% CI 1486 to 1608) and 2132 (1892, 95% CI 1948 to 2316), respectively, for T2DM and non-T2DM groups. In the T2DM group (n=385), the mean (SD) percentage of total energy intake as total CHO, complex CHO and simple CHO was 64.1±8.3 (95% CI 63.3 to 64.9), 57.0±11.0 (95% CI 55.9 to 58.1) and 7.1±10.8 (95% CI 6.0 to 8.2), respectively. The mean (SD) percentage of complex CHO intake from total CHO was 89.5±15.3 (95% CI 88.0 to 91.1). The mean (SD) total protein/fat intake per day (g) was 57.1 (74.0)/37.2 (18.6) and 57.9 (27.2)/55.3 (98.2) in T2DM and non-T2DM groups, respectively.

CONCLUSIONS

Our study shows that CHO constitutes 64.1% of total energy from diet in T2DM participants, higher than that recommended in India. However, our findings need to be confirmed in a larger epidemiological survey.

TRIAL REGISTRATION NUMBER

NCT01450592 & Clinical Trial Registry of India: CTRI/2012/02/002398.

Selection of essential medicines for diabetes in low and middle income countries: a survey of 32 national essential medicines lists

AIM

Diabetes is a growing burden especially in low and middle income countries (LMICs). Inadequate access to diabetes care is of particular concern and selection of appropriate diabetes medicines on national essential medicines lists (NEMLs) is a first step in achieving adequate access. This selection was studied among LMICs and influences of various factors associated with selection decisions were assessed.

METHODS

Countries were studied if they employed NEMLs for reimbursement or procurement purposes. Presence and number of essential diabetes medicines from different classes, both insulins and oral blood glucose lowering medicines, were surveyed and calculated. Data were also analyzed by country income level, geographic region, year of last update of the NEML and purpose of NEML employment. The effect of prevalence and burden of disease on the number of essential diabetes medicines was also studied. Non parametric tests and univariate linear regression analysis were used.

RESULTS

Nearly all countries (n = 32) had chosen fast (97%) and intermediate acting insulin (93%), glibenclamide and metformin (100% both) as essential medicines. The median number of essential diabetes medicines was 6, equally divided between insulins and oral medicines. 20% of the countries had selected insulin analogues as essential medicines. Among all the studied factors, an increase in burden of diabetes and wealth of countries were associated with selection of higher numbers of essential diabetes medicines (p = 0.02 in both cases).

CONCLUSIONS

Nearly all the studied LMICs had included the minimum required medicines for diabetes management in their NEMLs. Selection can still be improved (e.g. exclusion of insulin analogues and replacement of glibenclamide by gliclazide). Nevertheless, the known suboptimal and inconsistent availability of essential diabetes medicines in LMICs cannot be explained by inadequate selection of essential medicines. Countries should therefore be encouraged to give precedence to implementation of NEMLs to make essential diabetes medicines more accessible.

Insulin resistance in Alzheimer's disease

Insulin is a key hormone regulating metabolism. Insulin binding to cell surface insulin receptors engages many signaling intermediates operating in parallel and in series to control glucose, energy, and lipids while also regulating mitogenesis and development. Perturbations in the function of any of these intermediates, which occur in a variety of diseases, cause reduced sensitivity to insulin and insulin resistance with consequent metabolic dysfunction. Chronic inflammation ensues which exacerbates compromised metabolic homeostasis. Since insulin has a key role in learning and memory as well as directly regulating ERK, a kinase required for the type of learning and memory compromised in early Alzheimer's disease (AD), insulin resistance has been identified as a major risk factor for the onset of AD. Animal models of AD or insulin resistance or both demonstrate that AD pathology and impaired insulin signaling form a reciprocal relationship. Of note are human and animal model studies geared toward improving insulin resistance that have led to the identification of the nuclear receptor and transcription factor, peroxisome proliferator-activated receptor gamma (PPARγ) as an intervention tool for early AD. Strategic targeting of alternate nodes within the insulin signaling network has revealed disease-stage therapeutic windows in animal models that coalesce with previous and ongoing clinical trial approaches. Thus, exploiting the connection between insulin resistance and AD provides powerful opportunities to delineate therapeutic interventions that slow or block the pathogenesis of AD.

A novel glycated hemoglobin A1c-lowering traditional Chinese medicinal formula, identified by translational medicine study

Diabetes is a chronic metabolic disorder that has a significant impact on the health care system. The reduction of glycated hemoglobin A1c is highly associated with the improvements of glycemic control and diabetic complications. In this study, we identified a traditional Chinese medicinal formula with a HbA1c-lowering potential from clinical evidences. By surveying 9,973 diabetic patients enrolled in Taiwan Diabetic Care Management Program, we found that Chu-Yeh-Shih-Kao-Tang (CYSKT) significantly reduced HbA1c values in diabetic patients. CYSKT reduced the levels of HbA1c and fasting blood glucose, and stimulated the blood glucose clearance in type 2 diabetic mice. CYSKT affected the expressions of genes associated with insulin signaling pathway, increased the amount of phosphorylated insulin receptor in cells and tissues, and stimulated the translocation of glucose transporter 4. Moreover, CYSKT affected the expressions of genes related to diabetic complications, improved the levels of renal function indexes, and increased the survival rate of diabetic mice. In conclusion, this was a translational medicine study that applied a “bedside-to-bench” approach to identify a novel HbA1c-lowering formula. Our findings suggested that oral administration of CYSKT affected insulin signaling pathway, decreased HbA1c and blood glucose levels, and consequently reduced mortality rate in type 2 diabetic mice.

Comparison of repaglinide and metformin monotherapy as an initial therapy in Chinese patients with newly diagnosed type 2 diabetes mellitus

BACKGROUND

We aimed to compare the effect of repaglinide and metformin monotherapy as an initial therapy in Chinese patients with newly diagnosed type 2 diabetes mellitus (T2DM).

PATIENTS AND METHODS

In this 15-week, open-labelled, parallel-controlled, randomised study, 60 Chinese drug-naive patients with newly diagnosed T2DM were randomised (2:1) to receive repaglinide or metformin monotherapy. Primary endpoint was change in HbA1c from baseline to the end of the trial. Secondary endpoints included changes in glycaemic variability, insulin sensitivity and β-cell function.

RESULTS

Patients in both repaglinide and metformin groups achieved significant reductions in HbA1c (-1.8 ± 1.5 vs -1.6 ± 1.5%), FPG (fasting blood glucose) (-1.7 ± 1.7 vs -2.1 ± 1.7  mmol/l) and 2-h PPG (post-prandial glucose) (-3.8 ± 3.1 vs -3.8 ± 3.6  mmol/l), with no statistical differences between the groups. Glycaemic variability, glucose infusion rate and β-cell function were all significantly improved from baseline in the two groups (all P<0.05), without any statistical differences in the improvement between the groups.

CONCLUSIONS

Repaglinide and metformin achieved comparable efficacy in improving glycaemic control, reducing glycaemic variability, enhancing insulin sensitivity and ameliorating β-cell function. Therefore, repaglinide is an optional agent for initial therapy in Chinese patients with newly diagnosed T2DM.

Risk vs benefit in diabetes pharmacotherapy: a rational approach to choosing pharmacotherapy in type 2 diabetes

Type 2 diabetes now affects more than 1 in 10 US adults and is a leading cause of morbidity, mortality, and healthcare expense. There are increasing numbers of available pharmacotherapies, with established agents as well as newer drugs developed from hormones in the incretin pathway, among others. New data are accumulating continuously with respect to potential benefits of both long-standing and new agents, as well as risks identified through post-marketing surveillance. Here we review the commonly prescribed pharmacotherapy options with attention to recently published information and provide a rational approach to choice of therapy.

Demographic and clinico-pathological characteristics in patients with invasive breast cancer receiving metformin

There was a contradictory data with metformin use on breast cancer risk, but there is growing evidence that the use of metformin in diabetic patients was associated with lower risks of breast cancer mortality and incidence. The effect of metformin on clinical and pathological properties of breast cancer was not known exactly, and we aimed to investigate the demographic and clinico-pathological characteristics of patients with metformin users at the time of breast cancer diagnosis. Patients with breast cancer diagnosed from 2000 to 2012 in our clinic were retrospectively analyzed. Patient's demographics, including survival data and tumor characteristics were obtained from medical charts. Breast cancer patients who were taking metformin at the time of breast cancer diagnosis were enrolled as metformin users (n = 148), where the patients matched with the same age who were not taking metformin were included as a control group (n = 636). A total of 784 patients were included in this study. Median age of both metformin users and nonusers was 57 (23-87). There were no significant differences in baseline tumor size (P = 0.60), tumor stage (P = 0.76), and node positivity (P = 0.13) between the two groups. Metformin user patients compared to nonusers had significantly lower incidence of histological grade III tumor (P = 0.03). A similar significant trend for lower incidence of triple negative (P = 0.01) and higher incidence ER positivity (P = 0.008) and PR positivity (P = 0.01) was also seen in metformin users. In survival analysis, the estimated median disease-free survival was 118 months in metformin users, whereas 69 months in nonusers (P = 0.09). Median overall survival (OS) could not be obtained due to low events. In patients with metformin users, OS rate was 98.4, 97.1, and 93.8 %, and in nonusers was 99.6, 94.4, and 90.5 %, the first, third, and fifth years, respectively. The use of metformin at the time of breast cancer diagnosis was associated with better clinico-pathological properties and nonsignificantly improved disease-free survival in breast cancer patients.

Therapeutic approaches to non-alcoholic fatty liver disease: past achievements and future challenges

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver injury and mortality in Western countries and China. However, as to date, there is no direct and effective therapy for this disease. The aim of this review is to analyze the key progress and challenges of main current therapeutic approaches in NAFLD.

DATA SOURCE

We carried out a PubMed search of English-language articles relevant to NAFLD therapy.

RESULTS

There are two major therapeutic strategies for NAFLD treatment: (1) lifestyle interventions (including weight reduction, dietary modification and physical exercise) and (2) pharmaceutical therapies. Lifestyle interventions, particularly chronic and moderate intensity exercise, are the most effective and recognized clinical therapies for NAFLD. For pharmaceutical therapies, although their effects and mechanisms have been extensively investigated in laboratory studies, they still need further tests and investigations in clinical human trials.

CONCLUSION

Future advancement of NAFLD therapy should focus on the mechanistic studies on cell based and animal models and human clinical trials of exercise, as well as the combination of lifestyle intervention and pharmaceutical therapy specifically targeting main signaling pathways related to lipid metabolism, oxidative stress and inflammation.

Detection, evaluation and treatment of diabetes mellitus in chronic pancreatitis: recommendations from PancreasFest 2012

DESCRIPTION

Diabetes and glucose intolerance are common complications of chronic pancreatitis, yet clinical guidance on their detection, classification, and management is lacking.

METHODS

A working group reviewed the medical problems, diagnostic methods, and treatment options for chronic pancreatitis-associated diabetes for a consensus meeting at PancreasFest 2012.

RESULTS

Guidance Statement 1.1: Diabetes mellitus is common in chronic pancreatitis. While any patient with chronic pancreatitis should be monitored for development of diabetes, those with long-standing duration of disease, prior partial pancreatectomy, and early onset of calcific disease may be at higher risk. Those patients developing diabetes mellitus are likely to have co-existing pancreatic exocrine insufficiency. Guidance Statement 1.2: Diabetes occurring secondary to chronic pancreatitis should be recognized as pancreatogenic diabetes (type 3c diabetes). Guidance Statement 2.1: The initial evaluation should include fasting glucose and HbA1c. These tests should be repeated annually. Impairment in either fasting glucose or HbA1c requires further evaluation. Guidance Statement 2.2: Impairment in either fasting glucose or HbA1c should be further evaluated by a standard 75 g oral glucose tolerance test. Guidance Statement 2.3: An absent pancreatic polypeptide response to mixed-nutrient ingestion is a specific indicator of type 3c diabetes. Guidance Statement 2.4: Assessment of pancreatic endocrine reserve, and importantly that of functional beta-cell mass, should be performed as part of the evaluation and follow-up for total pancreatectomy with islet autotransplantation (TPIAT). Guidance Statement 3: Patients with pancreatic diabetes shall be treated with specifically tailored medical nutrition and pharmacologic therapies.

CONCLUSIONS

Physicians should evaluate and treat glucose intolerance in patients with pancreatitis.