The effect of metformin on the metabolic abnormalities associated with upper-body fat distribution. BIGPRO Study Group

Upregulation of cholesterol synthesis by lysosomal defects requires a functional mitochondrial respiratory chain

Mitochondria and lysosomes are two organelles that carry out both signaling and metabolic roles in cells. Recent evidence has shown that mitochondria and lysosomes are dependent on one another, as primary defects in one cause secondary defects in the other. Although there are functional impairments in both cases, the signaling consequences of primary mitochondrial dysfunction and lysosomal defects are dissimilar. Here, we used RNA sequencing to obtain transcriptomes from cells with primary mitochondrial or lysosomal defects to identify the global cellular consequences associated with mitochondrial or lysosomal dysfunction. We used these data to determine the pathways affected by defects in both organelles, which revealed a prominent role for the cholesterol synthesis pathway. We observed a transcriptional upregulation of this pathway in cellular and murine models of lysosomal defects, while it is transcriptionally downregulated in cellular and murine models of mitochondrial defects. We identified a role for the posttranscriptional regulation of transcription factor SREBF1, a master regulator of cholesterol and lipid biosynthesis, in models of mitochondrial respiratory chain deficiency. Furthermore, we found that retention of Ca2+ in lysosomes of cells with mitochondrial respiratory chain defects contributes to the differential regulation of the cholesterol synthesis pathway in the mitochondrial and lysosomal defects tested. Finally, we verified in vivo, using a model of mitochondria-associated disease in Caenorhabditis elegans that normalization of lysosomal Ca2+ levels results in partial rescue of the developmental delay induced by the respiratory chain deficiency.

Metformin Monotherapy With and Without Lifestyle Changes Affects Anthropometric Parameters, Blood Pressure, Blood Glucose, and Lipid Profile in Indian Patients With Newly Diagnosed Type 2 Diabetes

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is a consequence of insulin resistance, insulin deficiency, or both. It is usually seen in adults and is a consequence of genetic (polygenic inheritance), endogenous (obesity and or hormonal factors), and environmental factors (e.g., obesogenic environment, endocrine disrupting chemicals, stress, and medicines). The prevalence of T2DM has increased over the past few decades. South Asians, including Indians, are more prone to central adiposity and develop lifestyle diseases like T2DM at body mass index values lower than those considered normal for the Western population. Generally, the first line of treatment is metformin monotherapy with lifestyle changes in patients with T2DM. Most of the research conducted on this drug is on Western subjects. Since the Indian population has genetic differences in the site of deposition of adipose and is more prone to develop lifestyle diseases, the effect of metformin may be different in Indians.

METHODS

Seventy-one (34 female, non-pregnant, non-lactating) adults with newly diagnosed T2DM were recruited in this short-duration pilot study after obtaining written informed consent. Patients regularly taking any drug were excluded, as were patients with chronic comorbidities. Treatment was initiated with metformin 500 mg OD. Lifestyle changes were recommended according to the age and physical condition of the patients. Anthropometric parameters (age, weight, height, BMI, waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR)), blood pressure, glycemic status (fasting and 2 h PP glucose and HbA1c), and lipid profile of the subjects were recorded before initiating and six months after initiating metformin monotherapy with lifestyle changes.

RESULTS

Small but statistically significant improvements were observed in the WHR,WHtR, blood pressure, blood glucose, and glycated hemoglobin. Although improvement was also observed in weight and lipid profile, these changes were not statistically significant.

CONCLUSION

This study shows that metformin monotherapy with lifestyle changes is suitable for patients of Indian origin and results in improvement in the WHR, WHtR, blood pressure, plasma glucose, and glycated hemoglobin.

The impact of metformin on weight and metabolic parameters in patients with obesity: A systematic review and meta-analysis of randomized controlled trials

There are conflicting data on the weight-reducing potential of metformin (MTF) in nondiabetic patients with obesity. The purpose of this systematic review and meta-analysis was to evaluate the effect of MTF on weight and cardiometabolic parameters in adults with overweight/obesity with or without nonalcoholic fatty liver disease (NAFLD) (CRD42018085512). We included randomized controlled trials (RCTs) in adults without diabetes mellitus, with mean body mass index (BMI) ≥ 25 kg/m2, with or without NAFLD, comparing MTF to placebo/control, lifestyle modification (LSM) or a US Food and Drug Administration-approved anti-obesity drug, reporting on weight or metabolic parameters, and extending over at least 3 months. We conducted a systematic search in MEDLINE, EMBASE, PubMed and the Cochrane Library without time limitation (until March 2022). We screened and selected eligible articles, abstracted relevant data, and assessed the risk of bias. All steps were in duplicate and independently. We conducted a random-effects model meta-analysis using Review Manager version 5.3, with prespecified subgroup analyses in case of heterogeneity. We identified 2650 citations and included 49 trials (55 publications). Compared to placebo, MTF was associated with a significant reduction in BMI (mean difference [MD] -0.56 [-0.74, -0.37] kg/m2; p < 0.0001), at doses ranging from 500 to 2550 mg/day, and with a significant percentage change in BMI of -2.53% (-2.90, -2.17) at the dose 1700 mg/day. There was no interaction by baseline BMI, MTF dose or duration, nor presence or absence of NAFLD. There was no significant difference between MTF and LSM. Orlistat was more effective than MTF (at doses of 1000-1700 mg/day) in terms of weight loss, with an MD in BMI of -3.17 (-5.88; -0.47) kg/m2, favouring the former. Compared to placebo/control, MTF improved insulin parameters, while no effect was detected when compared to LSM. A few small trials showed heterogenous effects on liver parameters in patients with NAFLD treated with MTF compared to placebo/control. There was a large variability in the expression of outcome measures and RCTs were of low quality. In conclusion, MTF was associated with a modest weight reduction in obese nondiabetic patients. Further high-quality and better powered studies are needed to examine the impact of MTF in patients with insulin resistance and NAFLD.

Up-regulation of cholesterol synthesis by lysosomal defects requires a functional mitochondrial respiratory chain

Mitochondria and lysosomes are two organelles that carry out both signaling and metabolic roles in the cells. Recent evidence has shown that mitochondria and lysosomes are dependent on one another, as primary defects in one cause secondary defects in the other. Nevertheless, the signaling consequences of primary mitochondrial malfunction and of primary lysosomal defects are not similar, despite in both cases there are impairments of mitochondria and of lysosomes. Here, we used RNA sequencing to obtain transcriptomes from cells with primary mitochondrial or lysosomal defects, to identify what are the global cellular consequences that are associated with malfunction of mitochondria or lysosomes. We used these data to determine what are the pathways that are affected by defects in both organelles, which revealed a prominent role for the cholesterol synthesis pathway. This pathway is transcriptionally up-regulated in cellular and mouse models of lysosomal defects and is transcriptionally down-regulated in cellular and mouse models of mitochondrial defects. We identified a role for post-transcriptional regulation of the transcription factor SREBF1, a master regulator of cholesterol and lipid biosynthesis, in models of mitochondrial respiratory chain deficiency. Furthermore, the retention of Ca 2+ in the lysosomes of cells with mitochondrial respiratory chain defects contributes to the differential regulation of the cholesterol synthesis pathway in the mitochondrial and lysosomal defects tested. Finally, we verified in vivo , using models of mitochondria-associated diseases in C. elegans , that normalization of lysosomal Ca 2+ levels results in partial rescue of the developmental arrest induced by the respiratory chain deficiency.

Body mass index-based predictions and personalized clinical strategies for colorectal cancer in the context of PPPM

Currently colorectal cancer (CRC) is the third most prevalent cancer worldwide. Body mass index (BMI) is frequently used in CRC screening and risk assessment to quantitatively evaluate weight. However, the impact of BMI on clinical strategies for CRC has received little attention. Within the framework of the predictive, preventive, and personalized medicine (3PM/PPPM), we hypothesized that BMI stratification would affect the primary, secondary, and tertiary care options for CRC and we conducted a critical evidence-based review. BMI dynamically influences CRC outcomes, which helps avoiding adverse treatment effects. The outcome of surgical and radiation treatment is adversely affected by overweight (BMI ≥ 30) or underweight (BMI < 20). A number of interventions, such as enhanced recovery after surgery and robotic surgery, can be applied to CRC at all levels of BMI. BMI-controlling modalities such as exercise, diet control, nutritional therapy, and medications may be potentially beneficial for patients with CRC. Patients with overweight are advised to lose weight through diet, medication, and physical activity while patients suffering of underweight require more focus on nutrition. BMI assists patients with CRC in better managing their weight, which decreases the incidence of adverse prognostic events during treatment. BMI is accessible, noninvasive, and highly predictive of clinical outcomes in CRC. The cost-benefit of the PPPM paradigm in developing countries can be advanced, and the clinical benefit for patients can be improved with the promotion of BMI-based clinical strategy models for CRC.

Dihydromyricetin prevents obesity via regulating bile acid metabolism associated with the farnesoid X receptor in ob/ob mice

With the high incidence of obesity around the globe, the potential role of bile acid metabolism and gut microbiota in modulating obesity aroused great enthusiasm. Here we studied the anti-obesity effect of dihydromyricetin (DHM), the main biologically active component in Ampelopsis grossedentata, which was applied for thousands of years in the form of tea beverages. A 12-week treatment of DHM significantly reduced body weight gain of the ob/ob mice. Meanwhile, serum parameters that are closely associated with obesity, including levels of total cholesterol, triglyceride, low density lipoprotein, nonestesterified fatty acid, and activity of alanine amino transferase and aspartate aminotransferase were all lower than the non-treated ob/ob mice. Using LC-MS/MS technology, we determined that DHM could enhance the bile acid (BA) conjugation, BA transport in the liver and inhibit the reabsorption of BAs in the ileum mediated by farnesoid X receptor (FXR)-related signalling pathways. Key genes in regulating enterohepatic circulation of BAs were verified by qPCR, and regulators related to FXR pathway were verified by western-blot. We also found that DHM could effectively inhibit the de novo lipogenesis through FXR-SREBP-1C pathway in the liver. In addition, metagenome analysis of the microbiota showed that DHM may affect the activity of bile salt hydrolase by inhibiting the level of Lactobacillus. In summary, the anti-obesity effect of DHM may be attributed to its positive effects on BA metabolism associated with FXR activation.

Pharmacogenomics of Medication-Induced Weight Gain and Antiobesity Medications

Obesity is a chronic, multifactorial disease associated with a large number of comorbidities. The clinical management of obesity involves a stepwise integrated approach, beginning with behavioral and lifestyle modification, followed by antiobesity medications, endobariatric procedures, and bariatric surgery. Weight gain and subsequent obesity are common side effects of medications, such as prednisone or antipsychotics. In this era of precision medicine, it is essential to identify patients at the highest risk of weight gain as a result of medication use. Pharmacogenomics could play an important role in obesity management by optimizing use of antiobesity medications as well as minimizing adverse weight gain. This review aims to provide a comprehensive analysis of the current literature on the role of pharmacogenomics in obesity and medication-induced weight gain. In summary, there are more robust studies of medication associated with weight gain and pharmacogenomics, and more studies are needed to understand the role of pharmacogenomics in antiobesity medications.

Weight-centric pharmacological management of type 2 diabetes mellitus - An essential component of cardiovascular disease prevention

Obesity and overweight are contributing factors for diseases such as type 2 diabetes mellitus (T2DM), hypertension, hyperlipidemia, and ultimately, cardiovascular (CV) disease. Obesity is imposing an increasing health burden in rich and poor nations, with almost 30% of people globally now either obese or overweight - a staggering 2.1 billion. The link between obesity and T2DM is widely held to involve two adverse effects: obesity-induced insulin resistance and β-cell failure. This "unified field theory" raises questions about whether defects favoring progressive weight gain and metabolic impairment also contribute to β-cell decompensation. The concept of weight-centric management of T2DM is considered justified because of the strong negative impact of obesity on the effects of treatment of diabetes. Two pharmacotherapy options are considered: drugs developed primarily for blood glucose control that also exert a favorable effect on body weight and drugs developed primarily to induce weight loss that also have a favorable effect on glycemia. Treating hunger counter-regulatory mechanisms will have an additional effect on glucose control in T2DM. This narrative review addresses advances in pharmacotherapy for the management of obesity and obesity-related co-morbidities, with a focus on T2DM. It is also important to identify the correct balance between weight-centric and glucose-centric management of T2DM.

Manipulation of Metabolic Pathways and Its Consequences for Anti-Tumor Immunity: A Clinical Perspective

In the relatively short history of anti-tumor treatment, numerous medications have been developed against a variety of targets. Intriguingly, although many anti-tumor strategies have failed in their clinical trials, metformin, an anti-diabetic medication, demonstrated anti-tumor effects in observational studies and even showed its synergistic potential with immune checkpoint inhibitors (ICIs) in subsequent clinical studies. Looking back from bedside-to-bench, it may not be surprising that the anti-tumor effect of metformin derives largely from its ability to rewire aberrant metabolic pathways within the tumor microenvironment. As one of the most promising breakthroughs in oncology, ICIs were also found to exert their immune-stimulatory effects at least partly via rewiring metabolic pathways. These findings underscore the importance of correcting metabolic pathways to achieve sufficient anti-tumor immunity. Herein, we start by introducing the tumor microenvironment, and then we review the implications of metabolic syndrome and treatments for targeting metabolic pathways in anti-tumor therapies. We further summarize the close associations of certain aberrant metabolic pathways with impaired anti-tumor immunity and introduce the therapeutic effects of targeting these routes. Lastly, we go through the metabolic effects of ICIs and conclude an overall direction to manipulate metabolic pathways in favor of anti-tumor responses.

A randomized trial of dapagliflozin and metformin, alone and combined, in overweight women after gestational diabetes mellitus

BACKGROUND

Women with a history of gestational diabetes mellitus are at a substantially increased risk of gestational diabetes mellitus recurrence and type 2 diabetes. Weight gain, particularly increased central adiposity after delivery, is strongly associated with deterioration of pancreatic beta cell compensation for insulin resistance. Weight management after gestational diabetes mellitus could have a significant benefit in these women who are at a high risk of developing type 2 diabetes.

OBJECTIVE

This study aimed to evaluate the treatment efficacy of dapagliflozin and metformin, alone and in combination, on body weight and anthropometric, cardiovascular, and metabolic parameters in overweight women with a recent history of gestational diabetes mellitus.

STUDY DESIGN

This was a prospective, single-blind, randomized, outpatient clinical trial with 3 parallel treatment groups. Overweight or obese (body mass index>25) females (n=66; ≥18-45 years) with gestational diabetes mellitus in pregnancy in the past 12 months were randomized in a single-blind manner to dapagliflozin, metformin, or dapagliflozin-metformin for 24 weeks. Body weight, height, body mass index, waist circumference, waist-to-height ratio, and blood pressure were determined at baseline and trial completion. Oral glucose tolerance tests were performed at baseline and 24 weeks to assess glycemia and mean blood glucose and calculate insulin sensitivity and secretion measures. Plasma lipid fractions, thyroid-stimulating hormone, and liver enzymes were also assessed in the fasting sample at the beginning and completion of the study trial.

RESULTS

The study was completed by 49 participants (74%). Significant reduction of weight, waist circumference, and waist-to-height ratio and improved glycemia and insulin sensitivity index derived from oral glucose tolerance test were found with dapagliflozin-metformin vs metformin monotherapy. Both dapagliflozin and dapagliflozin-metformin therapy were superior to metformin in increasing high-density lipoprotein levels, reducing triglyceride concentrations, lowering the triglyceride-to-high-density lipoprotein cholesterol ratio, and improving glucose excursion after an oral glucose tolerance test. The early insulin response to a glucose challenge significantly improved with only dapagliflozin-metformin compared with single-drug treatments.

CONCLUSION

This is the first report comparing the efficacy of a sodium-glucose cotransporter 2 inhibitor alone and in combination with metformin in this patient population. We found that combination dapagliflozin-metformin treatment over a 24-week period had a greater positive effect on body weight, waist circumference, and glycemic, cardiovascular, and metabolic parameters than metformin monotherapy in overweight or obese at-risk women with a recent history of gestational diabetes mellitus.

Postpartum treatment with liraglutide in combination with metformin versus metformin monotherapy to improve metabolic status and reduce body weight in overweight/obese women with recent gestational diabetes: A double-blind, randomized, placebo-controlled study

BACKGROUND

Gestational diabetes (GDM) imparts a high risk of developing diabetes postpartum. Insulin resistance appears to be the major contributor. Liraglutide, a glucagon-like peptide-1 analogue, improves peripheral glucose disposal and reduces body weight. We evaluated whether liraglutide in combination with metformin (MET-LIRA) is more effective than metformin monotherapy (MET-P) in improving insulin action and reducing body weight in overweight prior GDM (pGDM) women.

METHODS

Women (n = 153; body mass index (BMI) ≥25 kg/m²; 18-45 y; GDM within 12 months) with metabolic abnormalities were randomized to MET-LIRA (MET-2000 mg, LIRA 1.8 mg SC QD) or MET-P (MET-2000 mg, Placebo QD). Study visits at baseline, 36-40, 56-60 and 80-84 weeks included body weight (BW), BMI, waist circumference and waist-to-height ratio measures. Oral glucose tolerance tests (OGTTs) were performed to assess glycemia, mean blood glucose (MBG), lipids, and compute insulin sensitivity and secretion measures.

FINDINGS

Seventy-two (47%) participants completed the study. MET-LIRA therapy was significantly better in improving MBG and insulin sensitivity indices [SI_OGTT MET-LIRA from 4.6 (3.2) to 5.9 (2.9) vs. MET-P 5.5 (3.0) to 5.4 (3.2)] and reducing BW and central adiposity [BMI MET-LIRA from 37.2 (8.3) to 33.8 (5.2) vs MET-P 33.8(5.2) to 32.8(6)]. MET-LIRA therapy but not MET-P decreased triglycerides (TRG) and TRG/high density lipoprotein cholesterol (HDL-C) ratios.

INTERPRETATION

MET-LIRA treatment demonstrated superior efficacy in correcting the metabolic status of pGDM women over 84 weeks of therapy. The addition of liraglutide to metformin therapy resulted in a more dramatic decrease in BW and central adiposity than metformin alone.

FUNDATION

Supported by an unrestricted investigator initiated grant from Novo Nordisk, Inc. awarded to K.E.H.

MEETING PRESENTATION

The results from preliminary analyses of this study were presented at 76th meeting of the American Diabetes Association, June 10-14, 2016 New Orleans, LA, and 77th meeting of the American Diabetes Association, June 9-12, 2017San Diego, CA.

Effects of metformin on blood lipid profiles in nondiabetic adults: a meta-analysis of randomized controlled trials

PURPOSE

To evaluate the effects of metformin on serum lipid profiles in nondiabetic adults through a comprehensive meta-analysis.

METHODS

In the present meta-analysis, randomized and controlled trials were collected by searching PubMed, Embase, and Cochrane Libraries from inception to April 2019. Compared with placebos, the effects of metformin treatment on lipid profiles in nondiabetic adults were evaluated.

RESULTS

Forty-seven studies from 45 articles including 5731 participants were enrolled. Pooled results showed that metformin had significant effects on total cholesterol (mean change -6.57 mg/dl; 95% CI -9.66, -3.47; P = 0.000) and LDL-c (mean change -4.69 mg/dl; 95% CI -7.38, -2.00; P = 0.001), but insignificant effects on HDL-c (mean change -4.33 mg/dl; 95% CI -9.62, 0.96; P = 0.109) and triglyceride (mean change -0.85 mg/dl; 95% CI -0.36, 2.06; P = 0.169). Significant heterogeneities were found for all lipid profiles (HDL-c = 85.5%; LDL-c = 59.9%; total cholesterol = 75.3% and triglyceride = 67.1%). Different from the pooled data, in a subgroup analysis, the effect of metformin on triglyceride in patients with polycystic ovarian syndrome (PCOS) was significant with a mean reduction of 8.15 mg/dl. In addition, sensitivity analysis showed that the pooled effects of metformin on serum lipid profiles were stable. Publication bias derived from funnel plots or Begg's tests (P = 0.933, 0.860, 0.904, and 0.567 for HDL-c, LDL-c, total cholesterol, and triglyceride, respectively) was not significant.

CONCLUSION

This meta-analysis revealed that metformin could reduce total cholesterol and LDL-c in nondiabetic adults. In addition, metformin might exert a triglyceride-lowering effect in nondiabetics with PCOS status.

Metformin for prevention or delay of type 2 diabetes mellitus and its associated complications in persons at increased risk for the development of type 2 diabetes mellitus

BACKGROUND

The projected rise in the incidence of type 2 diabetes mellitus (T2DM) could develop into a substantial health problem worldwide. Whether metformin can prevent or delay T2DM and its complications in people with increased risk of developing T2DM is unknown.

OBJECTIVES

To assess the effects of metformin for the prevention or delay of T2DM and its associated complications in persons at increased risk for the T2DM.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Scopus, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform and the reference lists of systematic reviews, articles and health technology assessment reports. We asked investigators of the included trials for information about additional trials. The date of the last search of all databases was March 2019.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with a duration of one year or more comparing metformin with any pharmacological glucose-lowering intervention, behaviour-changing intervention, placebo or standard care in people with impaired glucose tolerance, impaired fasting glucose, moderately elevated glycosylated haemoglobin A1c (HbA1c) or combinations of these.

DATA COLLECTION AND ANALYSIS

Two review authors read all abstracts and full-text articles and records, assessed risk of bias and extracted outcome data independently. We used a random-effects model to perform meta-analysis and calculated risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 20 RCTs randomising 6774 participants. One trial contributed 48% of all participants. The duration of intervention in the trials varied from one to five years. We judged none of the trials to be at low risk of bias in all 'Risk of bias' domains. Our main outcome measures were all-cause mortality, incidence of T2DM, serious adverse events (SAEs), cardiovascular mortality, non-fatal myocardial infarction or stroke, health-related quality of life and socioeconomic effects.The following comparisons mostly reported only a fraction of our main outcome set. Fifteen RCTs compared metformin with diet and exercise with or without placebo: all-cause mortality was 7/1353 versus 7/1480 (RR 1.11, 95% CI 0.41 to 3.01; P = 0.83; 2833 participants, 5 trials; very low-quality evidence); incidence of T2DM was 324/1751 versus 529/1881 participants (RR 0.50, 95% CI 0.38 to 0.65; P < 0.001; 3632 participants, 12 trials; moderate-quality evidence); the reporting of SAEs was insufficient and diverse and meta-analysis could not be performed (reported numbers were 4/118 versus 2/191; 309 participants; 4 trials; very low-quality evidence); cardiovascular mortality was 1/1073 versus 4/1082 (2416 participants; 2 trials; very low-quality evidence). One trial reported no clear difference in health-related quality of life after 3.2 years of follow-up (very low-quality evidence). Two trials estimated the direct medical costs (DMC) per participant for metformin varying from $220 to $1177 versus $61 to $184 in the comparator group (2416 participants; 2 trials; low-quality evidence). Eight RCTs compared metformin with intensive diet and exercise: all-cause mortality was 7/1278 versus 4/1272 (RR 1.61, 95% CI 0.50 to 5.23; P = 0.43; 2550 participants, 4 trials; very low-quality evidence); incidence of T2DM was 304/1455 versus 251/1505 (RR 0.80, 95% CI 0.47 to 1.37; P = 0.42; 2960 participants, 7 trials; moderate-quality evidence); the reporting of SAEs was sparse and meta-analysis could not be performed (one trial reported 1/44 in the metformin group versus 0/36 in the intensive exercise and diet group with SAEs). One trial reported that 1/1073 participants in the metformin group compared with 2/1079 participants in the comparator group died from cardiovascular causes. One trial reported that no participant died due to cardiovascular causes (very low-quality evidence). Two trials estimated the DMC per participant for metformin varying from $220 to $1177 versus $225 to $3628 in the comparator group (2400 participants; 2 trials; very low-quality evidence). Three RCTs compared metformin with acarbose: all-cause mortality was 1/44 versus 0/45 (89 participants; 1 trial; very low-quality evidence); incidence of T2DM was 12/147 versus 7/148 (RR 1.72, 95% CI 0.72 to 4.14; P = 0.22; 295 participants; 3 trials; low-quality evidence); SAEs were 1/51 versus 2/50 (101 participants; 1 trial; very low-quality evidence). Three RCTs compared metformin with thiazolidinediones: incidence of T2DM was 9/161 versus 9/159 (RR 0.99, 95% CI 0.41 to 2.40; P = 0.98; 320 participants; 3 trials; low-quality evidence). SAEs were 3/45 versus 0/41 (86 participants; 1 trial; very low-quality evidence). Three RCTs compared metformin plus intensive diet and exercise with identical intensive diet and exercise: all-cause mortality was 1/121 versus 1/120 participants (450 participants; 2 trials; very low-quality evidence); incidence of T2DM was 48/166 versus 53/166 (RR 0.55, 95% CI 0.10 to 2.92; P = 0.49; 332 participants; 2 trials; very low-quality evidence). One trial estimated the DMC of metformin plus intensive diet and exercise to be $270 per participant compared with $225 in the comparator group (94 participants; 1 trial; very-low quality evidence). One trial in 45 participants compared metformin with a sulphonylurea. The trial reported no patient-important outcomes. For all comparisons there were no data on non-fatal myocardial infarction, non-fatal stroke or microvascular complications. We identified 11 ongoing trials which potentially could provide data of interest for this review. These trials will add a total of 17,853 participants in future updates of this review.

AUTHORS' CONCLUSIONS

Metformin compared with placebo or diet and exercise reduced or delayed the risk of T2DM in people at increased risk for the development of T2DM (moderate-quality evidence). However, metformin compared to intensive diet and exercise did not reduce or delay the risk of T2DM (moderate-quality evidence). Likewise, the combination of metformin and intensive diet and exercise compared to intensive diet and exercise only neither showed an advantage or disadvantage regarding the development of T2DM (very low-quality evidence). Data on patient-important outcomes such as mortality, macrovascular and microvascular diabetic complications and health-related quality of life were sparse or missing.

BARI 2D: A Reanalysis Focusing on Cardiovascular Events

OBJECTIVE

To reanalyze the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial using a new composite cardiovascular disease (CVD) outcome to determine how best to treat patients with type 2 diabetes mellitus and stable coronary artery disease.

PATIENTS AND METHODS

From January 1, 2001, to November 30, 2008, 2368 patients with type 2 diabetes mellitus and angiographically proven coronary artery disease were randomly assigned to insulin-sensitizing (IS) or insulin-providing (IP) therapy and simultaneously to coronary revascularization (REV) or no or delayed REV (intensive medical therapy [MED]), with all patients receiving intensive medical treatment. The outcome of this analysis was a composite of 8 CVD events.

RESULTS

Four-year Kaplan-Meier rates for the composite CVD outcome were 35.8% (95% CI, 33.1%-38.5%) with IS therapy and 41.6% (95% CI, 38.7%-44.5%) with IP therapy (P=.004). Much of this difference was associated with lower in-trial levels of fibrinogen, C-reactive protein, and hemoglobin A1c with IS therapy. Four-year composite CVD rates were 32.7% (95% CI, 30.0%-35.4%) with REV and 44.7% (95% CI, 41.8%-47.6%) with MED (P<.001). A beneficial effect of IS vs IP therapy was present with REV (27.7%; 95% CI, 24.0%-31.4% vs 37.5%; 95% CI, 33.6%-41.4%; P<.001), but not with MED (43.6%; 95% CI, 39.5%-47.7% vs 45.7%; 95% CI, 41.6%-49.8%; P=.37) (homogeneity, P=.05). This interaction between IS therapy and REV was limited to participants preselected for coronary artery bypass grafting (CABG). The lowest composite CVD rates occurred in patients preselected for CABG and assigned to IS therapy and REV (17.3%; 95% CI, 11.8%-22.8%).

CONCLUSION

In the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial, the IS treatment strategy and the REV treatment strategy each reduces cardiovascular events. The combination of IS drugs and CABG results in the lowest risk of subsequent CVD events.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00006305.

Medications affecting the biochemical conversion to type 2 diabetes: A systematic review and meta-analysis

BACKGROUND

The extent to which some pharmacological interventions reduce or increase the risk of biochemical conversion to T2DM in at-risk individuals is unclear.

METHODS

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and Scopus through August 24, 2017, for randomized controlled trials evaluating the effect of drugs suspected to modify the risk of biochemical conversion to T2DM.

RESULTS

We included 43 trials with 192,156 subjects (mean age 60 years; 56% men; mean BMI 30.4 kg/m2). Alpha-glucosidase inhibitors, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, metformin, orlistat, phentermine-topiramate and pioglitazone significantly reduced the risk of biochemical conversion to T2DM, whereas statins and nateglinide increased the risk. There was insufficient direct evidence regarding the effects of sulfonylureas, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors and sodium-glucose cotransporter-2 inhibitors. Most trials were brief and evaluated this outcome during treatment without a withdrawal or washout period.

CONCLUSIONS

Several drugs modify the risk of biochemical conversation to T2DM, although whether this effect is persistent and clinically relevant is unclear. Future studies need to focus on cardiovascular disease prevention, mortality and patient-important outcomes instead of biochemical conversion to T2DM.

Efficacy of Metformin Treatment with Respect to Weight Reduction in Children and Adults with Obesity: A Systematic Review

BACKGROUND

Obesity and its related complications are increasing health issues. Since generally only minor weight loss is obtained with lifestyle intervention, additional pharmacological therapies such as metformin are often used.

OBJECTIVE

We conducted a systematic review to provide an overview of the efficacy of ≥ 6 months of metformin treatment in children and adults with respect to weight, insulin resistance, and progression toward type 2 diabetes mellitus (T2DM).

METHODS

In September 2018, we searched PubMed, Embase, and the Cochrane Library for studies published in English using the keywords metformin, obesity/overweight, and weight loss. Prospective studies reporting weight/body mass index (BMI) as a primary or secondary outcome in patients with overweight/obesity with ≥ 6 months' metformin treatment were included. Included subjects were children and adults with overweight/obesity who received ≥ 6 months of metformin and/or lifestyle intervention, and/or placebo and/or lifestyle intervention, and/or standard care. Studies were independently screened by two reviewers. Data were extracted by one and verified by the other reviewer, and both reviewers assessed the risk of bias using the Cochrane risk-of-bias tool.

RESULTS

Our review includes 15 pediatric and 14 adult studies. In children, after 6 months, more than half the studies reported a greater reduction in BMI with metformin versus controls. Only six studies had an intervention of > 6 months, and these studies found no further improvement in BMI in the metformin users, though their BMI was lower than that of controls. Three studies showed a significant improvement in insulin sensitivity in the metformin versus the control group. Adults using metformin experienced and maintained small decreases in weight irrespective of duration of intervention. In 11 of 14 studies, a greater reduction in weight/BMI was observed with metformin than with placebo. Progression toward T2DM was significantly reduced in adults using metformin, ranging from 7 to 31%. The safety and tolerability of metformin, withdrawal of participants, and comparison with other drugs were not taken into account.

CONCLUSIONS

The effects of metformin on weight/BMI vary, with smaller reductions in children than in adults. This could be because of differences in adherence, daily dosage, and insulin status. Metformin significantly reduced the progression toward T2DM in adults. Therefore, metformin should be considered as a treatment for obesity and its related complications.

Metformin: Mechanisms in Human Obesity and Weight Loss

PURPOSE OF REVIEW

Metformin has multiple benefits for health beyond its anti-hyperglycemic properties. The purpose of this manuscript is to review the mechanisms that underlie metformin's effects on obesity.

RECENT FINDINGS

Metformin is a first-line therapy for type 2 diabetes. Large cohort studies have shown weight loss benefits associated with metformin therapy. Metabolic consequences were traditionally thought to underlie this effect, including reduction in hepatic gluconeogenesis and reduction in insulin production. Emerging evidence suggests that metformin-associated weight loss is due to modulation of hypothalamic appetite regulatory centers, alteration in the gut microbiome, and reversal of consequences of aging. Metformin is also being explored in the management of obesity's sequelae such as hepatic steatosis, obstructive sleep apnea, and osteoarthritis. Multiple mechanisms underlie the weight loss-inducing and health-promoting effects of metformin. Further exploration of these pathways may be important in identifying new pharmacologic targets for obesity and other aging-associated metabolic diseases.

Metabolic Effects of Metformin in Humans

BACKGROUND

Both insulin deficiency and insulin resistance due to glucagon secretion cause fasting and postprandial hyperglycemia in patients with diabetes.

INTRODUCTION

Metformin enhances insulin sensitivity, being used to prevent and treat diabetes, although its mechanism of action remains elusive.

RESULTS

Patients with diabetes fail to store glucose as hepatic glycogen via the direct pathway (glycogen synthesis from dietary glucose during the post-prandial period) and via the indirect pathway (glycogen synthesis from "de novo" synthesized glucose) owing to insulin deficiency and glucagoninduced insulin resistance. Depletion of the hepatic glycogen deposit activates gluconeogenesis to replenish the storage via the indirect pathway. Unlike healthy subjects, patients with diabetes experience glycogen cycling due to enhanced gluconeogenesis and failure to store glucose as glycogen. These defects raise hepatic glucose output causing both fasting and post-prandial hyperglycemia. Metformin reduces post-prandial plasma glucose, suggesting that the drug facilitates glucose storage as hepatic glycogen after meals. Replenishment of glycogen store attenuates the accelerated rate of gluconeogenesis and reduces both glycogen cycling and hepatic glucose output. Metformin also reduces fasting hyperglycemia due to declining hepatic glucose production. In addition, metformin reduces plasma insulin concentration in subjects with impaired glucose tolerance and diabetes and decreases the amount of insulin required for metabolic control in patients with diabetes, reflecting improvement of insulin activity. Accordingly, metformin preserves β-cell function in patients with type 2 diabetes.

CONCLUSION

Several mechanisms have been proposed to explain the metabolic effects of metformin, but evidence is not conclusive and the molecular basis of metformin action remains unknown.

The effects of metformin on simple obesity: a meta-analysis

OBJECTIVE

To evaluate the efficacy of metformin versus a placebo in the treatment of patients with simple obesity without obesity related diseases.

METHODS

A search was done on Pub-Med, EMBASE, Cochrane, and Science Citation Index Expanded databases. The main inclusion criteria included the following:(1) randomized controlled trials. (2) patients diagnosed as being overweight or obese. (3) patients were randomly assigned to receive metformin or control. Exclusion criteria included the following: patients diagnosed with an obesity related disease, such as diabetes mellitus (DM) or polycystic ovary syndrome (PCOS).

RESULTS

Compared with the placebo, weighted mean difference (WMD) was 2.33 (95% CI 0.31, 4.35) kg higher with metformin (p = 0.02). Compared with the placebo, WMD was 0.57 (95% CI 0.35, 0.79) kg/m² higher with metformin(p < 0.00001). There was no significant difference in the reduction of waist circumference between the metformin group and the control group (p = 0.05). The fasting blood glucose levels were significantly lower in the metformin group than in the control group (p < 0.00001). However, no hypoglycemia was noted in the metformin group or the control group.

CONCLUSION

Metformin is effective in reducing body weight of simple obesity patients, and metformin does not induce hypoglycemia as a side effect.

Review of Metformin Use for Type 2 Diabetes Prevention

CONTEXT

Prediabetes is prevalent and significantly increases lifetime risk of progression to type 2 diabetes. This review summarizes the evidence surrounding metformin use for type 2 diabetes prevention.

EVIDENCE ACQUISITION

Articles published between 1998 and 2017 examining metformin use for the primary indication of diabetes prevention available on MEDLINE.

EVIDENCE SYNTHESIS

Forty articles met inclusion criteria and were summarized into four general categories: (1) RCTs of metformin use for diabetes prevention (n=7 and n=2 follow-up analyses); (2) observational analyses examining metformin use in heterogeneous subgroups of patients with prediabetes (n=9 from the Diabetes Prevention Program, n=1 from the biguanides and the prevention of the risk of obesity [BIGPRO] trial); (3) observational analyses examining cost effectiveness of metformin use for diabetes prevention (n=11 from the Diabetes Prevention Program, n=1 from the Indian Diabetes Prevention Program); and (4) real-world assessments of metformin eligibility or use for diabetes prevention (n=9). Metformin was associated with reduced relative risk of incident diabetes, with the strongest evidence for use in those at highest risk (i.e., aged <60 years, BMI ≥35, and women with histories of gestational diabetes). Metformin was also deemed cost effective in 11 economic analyses. Recent studies highlighted low rates of metformin use for diabetes prevention in real-world settings.

CONCLUSIONS

Two decades of evidence support metformin use for diabetes prevention among higher-risk patients. However, metformin is not widely used in real-world practice, and enhancing the translation of this evidence to real-world practice has important implications for patients, providers, and payers.

Metformin Use in Children and Adolescents with Prediabetes

With the increasing incidence of childhood obesity, clinicians need to understand its comorbidities and their management. The American Diabetes Association recommends pediatricians screen high-risk overweight and obese children. Identifying and treating prediabetic children and adolescents can help to reduce the burden of type 2 diabetes. Lifestyle interventions are pivotal. Metformin is the only oral medication approved for diabetes treatment in children. It has been studied in clinical trials in nondiabetic children and has been shown to have beneficial effects on body weight. Effects on diabetes prevention have not been studied and long-term data are limited in the pediatric population.

Effects of metformin on blood pressure in nondiabetic patients: a meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the effects of metformin on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in nondiabetic patients.

METHODS

In this meta-analysis, we systematically searched PubMed, Embase, and the Cochrane Library through March 2016, and randomized controlled trials assessing the effects of metformin treatment compared with placebo were included. Random-effects models were used to estimate pooled mean differences in SBP and DBP.

RESULTS

Twenty-eight studies from 26 articles consisting of 4113 participants were included. Pooled results showed that metformin had a significant effect on SBP (mean difference -1.98 mmHg; 95% confidence interval -3.61, -0.35; P = 0.02), but not on DBP (mean difference -0.67 mmHg; 95% confidence interval -1.74, 0.41; P = 0.22). In subgroup analysis, we found that the effect of metformin on SBP was significant in patients with impaired glucose tolerance or obesity (BMI ≥30 kg/m), with a mean reduction of 5.03 and 3.00 mmHg, respectively. Significant heterogeneity was found for both SBP (I = 60.0%) and DBP (I = 45.4%). A sensitivity analysis indicated that the pooled effects of metformin on SBP and DBP were robust to systematically dropping each trial. Furthermore, no evidence of significant publication bias from funnel plots or Egger's tests (P = 0.51 and 0.21 for SBP and DBP, respectively) was found.

CONCLUSION

This meta-analysis suggested that metformin could effectively lower SBP in nondiabetic patients, especially in those with impaired glucose tolerance or obesity.

Metformin for Obesity in Prepubertal and Pubertal Children: A Randomized Controlled Trial

OBJECTIVES

Metformin has shown its effectiveness in treating obesity in adults. However, little research has been conducted in children, with a lack of attention on pubertal status. The objectives were to determine whether oral metformin treatment reduces BMI z score, cardiovascular risk, and inflammation biomarkers in children who are obese depending on pubertal stage and sex.

METHODS

This was a randomized, prospective, double-blind, placebo-controlled, multicenter trial, stratified according to pubertal stage and sex, conducted at 4 Spanish clinical hospitals. Eighty prepubertal and 80 pubertal nondiabetic children who were obese aged 7 to 14 years with a BMI >95th percentiles were recruited. The intervention included 1 g/d of metformin versus placebo for 6 months. The primary outcome was a reduction in BMI z score. Secondary outcomes comprised insulin resistance, cardiovascular risk, and inflammation biomarkers.

RESULTS

A total of 140 children completed the study (72 boys). Metformin decreased the BMI z score versus placebo in the prepubertal group (-0.8 and -0.6, respectively; difference, 0.2; P = .04). Significant increments were observed in prepubertal children treated with metformin versus placebo recipients in the quantitative insulin sensitivity check index (0.010 and -0.007; difference, 0.017; P = .01) and the adiponectin-leptin ratio (0.96 and 0.15; difference, 0.81; P = .01) and declines in interferon-γ (-5.6 and 0; difference, 5.6; P = .02) and total plasminogen activator inhibitor-1 (-1.7 and 2.4; difference, 4.1; P = .04). No serious adverse effects were reported.

CONCLUSIONS

“Metformin decreased the BMI z score and improved inflammatory and cardiovascular-related obesity parameters only in prepubertal children, but a differential effect of metformin was not observed in prepubertal compared to pubertal children. Nevertheless, the doses per kilogram of weight administrated may have had an impact on the metformin effect. Further investigations are necessary.”

Effects of metformin on endothelial health and erectile dysfunction

Erectile dysfunction (ED) affects approximately 18 million American men. ED may be attributed to several etiologies, including arteriogenic, psychogenic, neurogenic, hormonal, drug-induced, and systemic disease or aging related factors. Specific to arteriogenic ED, three major mechanisms have been identified: (I) endothelium-dependent vasodilatory impairment; (II) sympathetic nerve activity elevation; (III) atherosclerotic luminal narrowing. Additionally, these insults have been linked to the insulin resistant state, which in turn is comorbid with obesity, dyslipidemia, diabetes, and hypertension. In this review, we summarize the evidence regarding the impact of metformin—an insulin sensitizer—on the three mechanisms of arteriogenic ED. We report that metformin treatment positively affects two of three pathways, specifically through enhanced endothelium-dependent vasodilation and sympathetic nerve activity attenuation, but does not seem to have a significant impact on hypertension regulation. Given the encouraging data found in both animal and clinical studies, we advocate for further studies on metformin use in ED.

A story of metformin-butyrate synergism to control various pathological conditions as a consequence of gut microbiome modification: Genesis of a wonder drug?

The most widely prescribed oral anti-diabetic agent today in the world today is a member of the biguanide class of drugs called metformin. Apart from its use in diabetes, it is currently being investigated for its potential use in many diseases such as cancer, cardiovascular diseases, Alzheimer's disease, obesity, comorbidities of diabetes such as retinopathy, nephropathy to name a few. Numerous in-vitro and in-vivo studies as well as clinical trials have been and are being conducted with a vast amount of literature being published every day. Numerous mechanisms for this drug have been proposed, but they have been unable to explain all the actions observed clinically. It is of interest that insulin has a stimulatory effect on cellular growth. Metformin sensitizes the insulin action but believed to be beneficial in cancer. Like -wise metformin is shown to have beneficial effects in opposite sets of pathological scenario looking from insulin sensitization point of view. This requires a comprehensive review of the disease conditions which are claimed to be affected by metformin therapy. Such a comprehensive review is presently lacking. In this review, we begin by examining the history of metformin before it became the most popular anti-diabetic medication today followed by a review of its relevant molecular mechanisms and important clinical trials in all areas where metformin has been studied and investigated till today. We also review novel mechanistic insight in metformin action in relation to microbiome and elaborate implications of such aspect in various disease states. Finally, we highlight the quandaries and suggest potential solutions which will help the researchers and physicians to channel their research and put this drug to better use.

Metformin, beyond an insulin sensitizer, targeting heart and pancreatic β cells

Metformin, a biguanide derivate, is known as the first-line antidiabetic agent for type 2 diabetes mellitus (T2DM) treatment. It reduces insulin resistance and decreases blood glucose concentration by inhibiting gluconeogenesis and suppressing hepatic glucose production with improved peripheral tissue insulin sensitivity. As an insulin sensitizer, metformin takes pleiotropic actions and exerts protective effects on multiple organs mainly in insulin-targeted tissues such as liver, muscle, and adipose tissues. Recent studies discover that metformin also plays essential roles in heart and pancreatic β cells - two important organs in metabolic regulation. Metformin not only protects T2DM patients from cardiovascular diseases and heart failure, but also restores insulin secretion activities and protects pancreatic β cells from lipotoxicity or glucotoxicity. Although accumulated evidence shed light on the metformin action, the precise mechanism of metformin is still under investigation. Further laboratory investigations and clinical trials are needed to pinpoint a map of metformin action. Based on recent findings, this review characterizes the beneficial role of metformin in cardiovascular diseases and pancreatic β cells.

Metformin: an Old Therapy that Deserves a New Indication for the Treatment of Obesity

Metformin is not currently used for weight loss or diabetes prevention because it lacks an FDA indication for obesity and/or pre-diabetes treatment. Based on the evidence, metformin has been shown to decrease the incidence of type 2 diabetes, and compares favorably to other weight-loss medications in terms of efficacy as well as safety. Thus, metformin should be considered for a treatment indication in patients with these conditions.

BAP guidelines on the management of weight gain, metabolic disturbances and cardiovascular risk associated with psychosis and antipsychotic drug treatment

Excess deaths from cardiovascular disease are a major contributor to the significant reduction in life expectancy experienced by people with schizophrenia. Important risk factors in this are smoking, alcohol misuse, excessive weight gain and diabetes. Weight gain also reinforces service users' negative views of themselves and is a factor in poor adherence with treatment. Monitoring of relevant physical health risk factors is frequently inadequate, as is provision of interventions to modify these. These guidelines review issues surrounding monitoring of physical health risk factors and make recommendations about an appropriate approach. Overweight and obesity, partly driven by antipsychotic drug treatment, are important factors contributing to the development of diabetes and cardiovascular disease in people with schizophrenia. There have been clinical trials of many interventions for people experiencing weight gain when taking antipsychotic medications but there is a lack of clear consensus regarding which may be appropriate in usual clinical practice. These guidelines review these trials and make recommendations regarding appropriate interventions. Interventions for smoking and alcohol misuse are reviewed, but more briefly as these are similar to those recommended for the general population. The management of impaired fasting glycaemia and impaired glucose tolerance ('pre-diabetes'), diabetes and other cardiovascular risks, such as dyslipidaemia, are also reviewed with respect to other currently available guidelines.These guidelines were compiled following a consensus meeting of experts involved in various aspects of these problems. They reviewed key areas of evidence and their clinical implications. Wider issues relating to primary care/secondary care interfaces are discussed but cannot be resolved within guidelines such as these.

Targeting AMPK signaling in combating ovarian cancers: opportunities and challenges

The development and strategic application of effective anticancer therapies have turned out to be one of the most critical approaches of managing human cancers. Nevertheless, drug resistance is the major obstacle for clinical management of these diseases especially ovarian cancer. In the past years, substantial studies have been carried out with the aim of exploring alternative therapeutic approaches to enhance efficacy of current chemotherapeutic regimes and reduce the side effects caused in order to produce significant advantages in overall survival and to improve patients' quality of life. Targeting cancer cell metabolism by the application of AMP-activated protein kinase (AMPK)-activating agents is believed to be one of the most plausible attempts. AMPK activators such as 5-aminoimidazole-4-carboxamide 1-β-d-ribofuranoside, A23187, metformin, and bitter melon extract not only prevent cancer progression and metastasis but can also be applied as a supplement to enhance the efficacy of cisplatin-based chemotherapy in human cancers such as ovarian cancer. However, because of the undesirable outcomes along with the frequent toxic side effects of most pharmaceutical AMPK activators that have been utilized in clinical trials, attentions of current studies have been aimed at the identification of replaceable reagents from nutraceuticals or traditional medicines. However, the underlying molecular mechanisms of many nutraceuticals in anticancer still remain obscure. Therefore, better understanding of the functional characterization and regulatory mechanism of natural AMPK activators would help pharmaceutical development in opening an area to intervene ovarian cancer and other human cancers.

The effect of sitagliptin on cardiovascular risk profile in Korean patients with type 2 diabetes mellitus: a retrospective cohort study

BACKGROUND

A 2013 postmarketing study suggested a possible link between saxagliptin use and hospital admission for heart failure. Cardiovascular (CV) effects of sitagliptin, the most commonly prescribed antidiabetic in the same class as saxagliptin, have not been evaluated much in Asian patients with type 2 diabetes. This study sought to ascertain the CV safety of sitagliptin in Korean patients.

METHODS

A retrospective cohort study of 4,860 patients who were classified into the sitagliptin and metformin groups was conducted using electronic patient data retrieved from a major tertiary care medical center in Korea. Primary composite end points included CV death, myocardial infarction, and ischemic stroke. Secondary composite end points included the aforementioned individual primary outcomes plus hospitalization due to unstable angina, heart failure, or coronary revascularization. A Cox proportional-hazards model was used to compare CV risk associated with drug exposure.

RESULTS

Following propensity score (PS) matching in a 1:2 ratio, 1,620 patients in the sitagliptin group and 3,240 patients in the metformin group were identified for cohort entry. The PS-matched hazard ratio (HR) and 95% confidence interval (CI) for sitagliptin relative to metformin were, respectively, 0.831 and 0.536-1.289 (P=0.408) for primary end point and 1.140 and 0.958-1.356 (P=0.139) for secondary end point. Heart failure hospitalization rates did not differ significantly between the two groups, with the PS-matched HR of 0.762 and 95% CI of 0.389-1.495 (P=0.430). When only those patients at high risk of ischemic heart disease were included for analysis, no excess CV risk was observed with sitagliptin compared with metformin. Overall, there were no substantial between-group differences in rates of adverse events, such as hypoglycemia and incident pancreatic disease.

CONCLUSION

Sitagliptin was not associated with elevated risk of CV complications including myocardial infarction, ischemic stroke, heart failure, and coronary revascularization, compared to metformin therapy among Korean patients with type 2 diabetes.

Cymene and Metformin treatment effect on biochemical parameters of male NMRI mice fed with high fat diet

Background

The increasing prevalence of obesity is considered a serious global health threat. Mainly due to change of diet and reduced physical activity, obesity is an important risk factor for chronic diseases. A higher level of cytokines and a general inflammatory state has also been associated with this condition. With this regard, potential anti-obesity compounds with anti-inflammatory properties could be beneficial in better control of the disease. p-Cymene is a natural aromatic compound that has been shown to have anti-inflammatory properties, while the antidiabetic drug metformin has been observed to be effective as an aid for weight loss. In this study, the effect of these comounds was compared in a high fat diet treated mice model.

Methods

48 adult NMRI mice were randomly divided into six groups: control group receiving a normal diet, high fat diet (HFD) fed control group, sham group receiving HFD and sunflower seed oil, Experimental group1 (E1) receiving HFD and 20 mg/kg metformin, Experimental group2 (E2) receiving 20 mg/kg metformin and 20 mg/kg p-cymene, Experimental group3 (E3) receiving 20 mg/kg p-cymene. Compounds were administered by intragastric gavage for 45 days.

Results

Non-fasting glucose serum levels, ALT, and ALP of E2 and E3 decreased significantly compared to HFD control group. In the E3 group, AST levels decrease was also significant. In E1, non-fasting glucose and TG serum levels decreased significantly compared to HFD control group. Histological observations on liver tissue showed an increase of lipid droplets in the HFD control group compared with the normal group, while upon treatment with the compounds, lipid droplets decreased and the cells appeared to be more ordered.

Conclusion

p-Cymene has a potential to ameliorate biochemical parameters in high fat diet treated mice, and its concurrent use with metformin was effective.

Effects of metformin on energy intake and satiety in obese children

AIMS

To investigate the effects of metformin on appetite and energy intake in obese children with hyperinsulinaemia.

METHODS

We conducted a 6-month randomized, double-blind, placebo-controlled trial to evaluate the effects of metformin 1000 mg twice daily on body weight and energy balance in 100 obese children with hyperinsulinaemia aged 6-12 years. The children ate ad libitum from standardized food arrays on two separate occasions before and after 6 months of study medication. The first test meal was consumed after an overnight fast. The second was preceded by a pre-meal load. For each test meal, energy intake was recorded, and the children completed scales of hunger, fullness and desire to eat.

RESULTS

Data from the meal studies at baseline and after treatment with study medication were available for 84 children (metformin-treated, n = 45; placebo-treated, n = 39). Compared with placebo, metformin treatment elicited significant reductions from baseline in adjusted mean ± standard error of the mean energy intake after the pre-meal load (metformin: -104.7 ± 83.8 kcal vs. placebo: +144.2 ± 96.9 kcal; p = 0.034) independently of changes in body composition. Metformin also significantly decreased ratings of hunger (-1.5 ± 5.6 vs. +18.6 ± 6.3; p = 0.013) and increased ratings of fullness (+10.1 ± 6.2 vs. -12.8 ± 7.0; p = 0.01) after the pre-meal load.

CONCLUSIONS

These data suggest that decreased perceived hunger resulting in diminished food intake are among the mechanisms by which metformin treatment reduces body weight in overweight children with hyperinsulinaemia.

The effect of metformin on cardiovascular risk profile in patients without diabetes presenting with acute myocardial infarction: data from the Glycometabolic Intervention as adjunct to Primary Coronary Intervention in ST Elevation Myocardial Infarction (GIPS-III) trial

OBJECTIVE

In patients with diabetes mellitus, metformin treatment is associated with reduced mortality and attenuation of cardiovascular risk. As a subanalysis of the Glycometabolic Intervention as adjunct to Primary Coronary Intervention in ST Elevation Myocardial Infarction (GIPS-III) study, we evaluated whether metformin treatment in patients with ST-segment elevation myocardial infarction (STEMI) without diabetes improves the cardiovascular risk profile.

METHODS

A total of 379 patients, without known diabetes, presenting with STEMI were randomly allocated to receive metformin 500 mg twice daily or placebo for 4 months.

RESULTS

After 4 months, the cardiovascular risk profile of patients receiving metformin (n=172) was improved compared with placebo (n=174); glycated hemoglobin (5.83% (95% CI 5.79% to 5.87%) vs 5.89% (95% CI 5.85% to 5.92%); 40.2 mmol/mol (95% CI 39.8 to 40.6) vs 40.9 mmol/mol (40.4 to 41.2), p=0.049); total cholesterol (3.85 mmol/L (95% CI 3.73 to 3.97) vs 4.02 mmol/L (95% CI 3.90 to 4.14), p=0.045); low-density lipoprotein cholesterol (2.10 mmol/L (95% CI 1.99 to 2.20) vs 2.3 mmol/L (95% CI 2.20 to 2.40), p=0.007); body weight (83.8 kg (95% CI 83.0 to 84.7) vs 85.2 kg (95% CI 84.4 to 86.1), p=0.024); body mass index (26.8 kg/m(2) (95% CI 26.5 to 27.0) vs 27.2 kg/m(2) (95% CI 27.0 to 27.5), p=0.014). Levels of fasting glucose, postchallenge glucose, insulin, high-density lipoprotein cholesterol, and blood pressure were similar in both groups.

CONCLUSIONS

Among patients with STEMI without diabetes, treatment with metformin for 4 months resulted in a modest improvement of the cardiovascular risk profile compared with placebo.

TRIAL REGISTER NUMBER

NCT01217307.

Treatment for overweight and obesity in adult populations: a systematic review and meta-analysis

BACKGROUND

Obesity is a major public health issue. This review updates the evidence on the effectiveness of behavioural and pharmacologic treatments for overweight and obesity in adults.

METHODS

We updated the search conducted in a previous review. Randomized trials of primary-care-relevant behavioural (diet, exercise and lifestyle) and pharmacologic (orlistat and metformin) with or without behavioural treatments in overweight and obese adults were included if 12-month, postbaseline data were provided for weight outcomes. Studies reporting harms were included regardless of design. Data were extracted and pooled wherever possible for 5 weight outcomes, 6 secondary health outcomes and 4 adverse events categories.

RESULTS

We identified 68 studies, most consisted of short-term (≤ 12 mo) treatments using diet (n = 8), exercise (n = 4), diet and exercise (n = 10), lifestyle (n = 19), orlistat (n = 25) or metformin (n = 4). Compared with the control groups, intervention participants had a greater weight loss of -3.02 kg (95% confidence interval [CI] -3.52 to -2.52), a greater reduction in waist circumference of -2.78 cm (95% CI -3.34 to -2.22) and a greater reduction in body mass index of -1.11 kg/m(2) (95% CI -1.39 to -0.84). The relative risk for loss of ≥ 5% body weight was 1.77 (95% CI 1.58-1.99, [number needed to treat 5, 95% CI 4-7]), and the relative risk for loss of ≥ 10% body weight was 1.91 (95% CI 1.69-2.16, [number needed to treat 9, 95% CI 7-12]). Incidence of type 2 diabetes was lower among pre-diabetic intervention participants (relative risk 0.62 [95% CI 0.50-0.77], number needed to treat 17 [95% CI 13-29]). With prevalence rates for type 2 diabetes on the rise, weight loss coupled with a reduction in the incidence of type 2 diabetes could potentially have a significant benefit on population health and a possible reduction in need for drug treatments for glycemic control.

INTERPRETATION

There is moderate quality evidence that behavioural and pharmacologic plus behvioural, treatments for overweight and obesity in adults lead to clinically important reductions in weight and incidence of type 2 diabetes in pre-diabetic populations.

REGISTRATION

PROSPERO no. CRD42012002753.

Blood levels of glucose and insulin and insulin resistance in patients with schizophrenia on clozapine monotherapy

OBJECTIVE

We tested the hypothesis that fasting blood glucose and insulin levels are higher in schizophrenic subjects on clozapine monotherapy compared with healthy controls and they correlate with anthropometric measurements, laboratory tests and body composition.

METHODS

Data for 24 subjects with schizophrenia treated with clozapine and 24 age- and sex-matched healthy volunteers was analyzed.

RESULTS

Patients taking clozapine had higher fasting levels of glucose (103.5±31.6 vs. 87.8±11.7mg/dL, z=-2.03, p=0.04), there was no difference for insulin concentrations and markers of insulin resistance. In the clozapine group glucose levels correlated with clozapine dose (R=-0.43, p=0.03), while insulin levels correlated with weight (R=0.66, p<0.001), body mass index (R=0.54, p=0.007), abdominal (R=0.53, p=0.007) and waist (R=0.43, p=0.04) circumference, total body fat (R=0.51, p=0.01), and uric acid levels (R=0.50, p=0.01). In the clozapine group insulin levels were lower in subjects with body mass index <25kg/m(2) (7.0±3.3 vs. 13.4±8.8μU/mL, p=0.04) and in subjects without abdominal obesity (6.3±2.4 vs. 13.3±8.6μU/mL, p=0.03).

CONCLUSIONS

We found higher blood glucose levels in subjects taking clozapine and no differences in blood insulin levels between subjects with schizophrenia and controls. Associations between blood insulin levels and abdominal/waist circumferences support the role of abdominal obesity as an important risk factor of insulin resistance.

MARCH2: comparative assessment of therapeutic effects of acarbose and metformin in newly diagnosed type 2 diabetes patients

Background

The data of MARCH (Metformin and AcaRbose in Chinese as the initial Hypoglycaemic treatment) trial demonstrated that acarbose and metformin have similar efficacy as initial therapy for hemoglobin A1c (HbA1c) reduction in Chinese patients with newly diagnosed type 2 diabetes. We investigated whether the therapeutic efficacy was diversified under different body mass index (BMI) status.

Methods

All 784 subjects were divided into normal-weight group (BMI<24 kg/m²), overweight group (BMI 24–28 kg/m²) and obese group (BMI≥28 kg/m²). Patients were assigned to 48 weeks of therapy with acarbose or metformin, respectively. The clinical trial registry number was ChiCTR-TRC-08000231.

Results

The reduction of HbA1c levels and the proportion of patients with HbA1c of 6.5% or less were similar in the three groups after acarbose and metformin treatment. In overweight group, fasting blood glucose (FBG) after metformin treatment showed greater decline compared to acarbose group at 48 weeks [−1.73 (−1.99 to −1.46) vs. −1.37 (−1.61 to −1.12), P<0.05), however the decrease of 2 h post-challenge blood glucose (PBG) after acarbose treatment at 48 weeks was bigger compared to metformin group [−3.34 (−3.83 to−2.84) vs. −2.35 (−2.85 to −1.85), P<0.01 ]. Both acarbose and metformin treatment resulted in a significant decrease in waist circumference, hip circumference, weight and BMI in the three groups (all P<0.05).

Conclusion

Acarbose and metformin decreased HbA1c levels similarly regardless of BMI status of Chinese type 2 diabetic patients. Acarbose and metformin resulted in a significant and modest improvement of anthropometric parametres in different BMI status. Thus, acarbose treatment may contribute a similar effect on plasma glucose control compared to metformin, even in obesity patients.

Trial Registration

ChiCTR.org ChiCTR-TRC-08000231

Metformin for non-diabetic patients with coronary heart disease (the CAMERA study): a randomised controlled trial

BACKGROUND

Metformin reduces cardiovascular risk in patients with type 2 diabetes seemingly independent of lowering blood glucose concentration. We assessed the cardiovascular effects of metformin in individuals without type 2 diabetes.

METHODS

We did a single-centre, double-blind, placebo-controlled trial at the Glasgow Clinical Research Facility (Glasgow, UK). We enrolled patients taking statins who did not have type 2 diabetes but who did have coronary heart disease and large waist circumferences. Participants were randomly assigned (1:1) by computer to either metformin (850 mg twice daily) or matching placebo in block sizes of four. Patients, investigators, trial staff, and statisticians were masked to treatment allocation. The primary endpoint was progression of mean distal carotid intima-media thickness (cIMT) over 18 months in the modified intention-to-treat population. Secondary endpoints were changes in carotid plaque score (in six regions), measures of glycaemia (HbA1c, fasting glucose, and insulin concentrations, and Homeostasis Model Assessment of Insulin Resistance [HOMA-IR]), and concentrations of lipids, high sensitivity C-reactive protein, and tissue plasminogen activator. The trial was registered at ClinicalTrials.gov, number NCT00723307.

FINDINGS

We screened 356 patients, of whom we enrolled 173 (86 in the metformin group, 87 in the placebo group). Average age was 63 years. At baseline, mean cIMT was 0·717 mm (SD 0·129) and mean carotid plaque score was 2·43 (SD 1·55). cIMT progression did not differ significantly between groups (slope difference 0·007 mm per year, 95% CI -0·006 to 0·020; p=0·29). Change of carotid plaque score did not differ significantly between groups (0·01 per year, 95% CI -0·23 to 0·26; p=0·92). Patients taking metformin had lower HbA1c, insulin, HOMA-IR, and tissue plasminogen activator compared with those taking placebo, but there were no significant differences for total cholesterol, HDL-cholesterol, non-HDL-cholesterol, triglycerides, high sensitivity C-reactive protein, or fasting glucose. 138 adverse events occurred in 64 patients in the metformin group versus 120 in 60 patients in the placebo group. Diarrhoea and nausea or vomiting were more common in the metformin group than in the placebo group (28 vs 5).

INTERPRETATION

Metformin had no effect on cIMT and little or no effect on several surrogate markers of cardiovascular disease in non-diabetic patients with high cardiovascular risk, taking statins. Further evidence is needed before metformin can be recommended for cardiovascular benefit in this population.

FUNDING

Chief Scientist Office (Scotland).

Body mass index and the risk for Crohn's disease and ulcerative colitis: data from a European Prospective Cohort Study (The IBD in EPIC Study)

OBJECTIVES

Obesity is associated with a proinflammatory state that may be involved in the etiology of inflammatory bowel disease (IBD), for which there are plausible biological mechanisms. Our aim was to perform the first prospective cohort study investigating if there is an association between obesity and the development of incident IBD.

METHODS

A total of 300,724 participants were recruited into the European Prospective Investigation into Cancer and Nutrition study. At recruitment, anthropometric measurements of height and weight plus physical activity and total energy intake from validated questionnaires were recorded. The cohort was monitored identifying participants who developed either Crohn's disease (CD) or ulcerative colitis (UC). Each case was matched with four controls and conditional logistic regression used to calculate odds ratios (ORs) for body mass index (BMI) adjusted for smoking, energy intake, and physical activity.

RESULTS

In the cohort, 177 participants developed incident UC and 75 participants developed incident CD. There were no associations with the four higher categories of BMI compared with a normal BMI for UC (Ptrend=0.36) or CD (Ptrend=0.83). The lack of associations was consistent when BMI was analyzed as a continuous or binary variable (BMI 18.5<25.0 vs. ≥25 kg/m(2)). Physical activity and total energy intake, factors that influence BMI, did not show any association with UC (physical activity, Ptrend=0.79; total energy intake, Ptrend=0.18) or CD (physical activity, Ptrend=0.42; total energy, Ptrend=0.11).

CONCLUSIONS

Obesity as measured by BMI is not associated with the development of incident UC or CD. Alternative measures of obesity are required to further investigate the role of obesity in the development of incident IBD.

Drug treatment of obesity in cardiovascular disease

Obesity is a significant health problem worldwide and is associated with a number of co-morbidities including type 2 diabetes mellitus, hypertension, dyslipidemia, obstructive sleep apnea, and cardiovascular disease. A number of different pathophysiologic mechanisms including increased inflammation, oxidative stress, and insulin resistance have been associated with initiation and progression of atherosclerotic disease in obese individuals. Lifestyle modifications have provided modest results in weight reduction and the focus of interest has now shifted towards drug development to treat severely obese individuals with a body mass index (BMI) >30 kg/m(2) or those with a BMI >27 kg/m(2) who have additional co-morbidities. Different regimens focusing on dietary absorption or acting centrally to control hunger and food intake have been developed. However, their weight loss effect is, in most cases, modest and this effect is lost once the medication is discontinued. In addition, long-term use of these drugs is limited by significant side effects and lack of long-term safety and efficacy data. Orlistat is the only US FDA-approved medication for long-term use. A number of new medications are currently under investigation in phase III trials with promising preliminary results. This review comments on available anti-obesity pharmacologic regimens, their weight-loss benefit, and their impact on cardiovascular risk factors.

Metformin for treatment of antipsychotic-induced weight gain: a randomized, placebo-controlled study

OBJECTIVES

To evaluate the efficacy of metformin for treatment of antipsychotic-induced weight gain.

METHODS

Seventy-two patients with first-episode schizophrenia who gained more than 7% of their predrug weight were randomly assigned to receive 1000 mg/d of metformin or placebo in addition to their ongoing treatment for 12 weeks using a double-blind study design. The primary outcome was change in body weight. The secondary outcomes included changes in body mass index, fasting glucose and insulin, and insulin resistance index.

RESULTS

Of the 72 patients who were randomly assigned, 66 (91.6%) completed treatments. The body weight, body mass index, fasting insulin and insulin resistance index decreased significantly in the metformin group, but increased in the placebo group during the 12-week follow-up period. Significantly more patients in the metformin group lost their baseline weight by more than 7%, which was the cutoff for clinically meaningful weight loss. Metformin was tolerated well by majority patients.

CONCLUSION

Metformin was effective and safe in attenuating antipsychotic-induced weight gain and insulin resistance in first-episode schizophrenia patients. Patients displayed good adherence to metformin.

Long-term safety, tolerability, and weight loss associated with metformin in the Diabetes Prevention Program Outcomes Study

OBJECTIVE

Metformin produced weight loss and delayed or prevented diabetes in the Diabetes Prevention Program (DPP). We examined its long-term safety and tolerability along with weight loss, and change in waist circumference during the DPP and its long-term follow-up.

RESEARCH DESIGN AND METHODS

The randomized double-blind clinical trial of metformin or placebo followed by a 7-8-year open-label extension and analysis of adverse events, tolerability, and the effect of adherence on change in weight and waist circumference.

RESULTS

No significant safety issues were identified. Gastrointestinal symptoms were more common in metformin than placebo participants and declined over time. During the DPP, average hemoglobin and hematocrit levels were slightly lower in the metformin group than in the placebo group. Decreases in hemoglobin and hematocrit in the metformin group occurred during the first year following randomization, with no further changes observed over time. During the DPP, metformin participants had reduced body weight and waist circumference compared with placebo (weight by 2.06 ± 5.65% vs. 0.02 ± 5.52%, P < 0.001, and waist circumference by 2.13 ± 7.06 cm vs. 0.79 ± 6.54 cm, P < 0.001 in metformin vs. placebo, respectively). The magnitude of weight loss during the 2-year double-blind period was directly related to adherence (P < 0.001). Throughout the unblinded follow-up, weight loss remained significantly greater in the metformin group than in the placebo group (2.0 vs. 0.2%, P < 0.001), and this was related to the degree of continuing metformin adherence (P < 0.001).

CONCLUSIONS

Metformin used for diabetes prevention is safe and well tolerated. Weight loss is related to adherence to metformin and is durable for at least 10 years of treatment.

A morbid obese Japanese woman with a body mass index of 83.2 kg/m2: before and after sleeve gastrectomy

A 34-year-old Japanese woman presented at our institution weighing 182.7 kg, 148.2 cm tall, and with a body mass index of 83.2 kg/m(2). She had been overweight since childhood, but no abnormality was found to explain her obesity. Treatments, including mazindol, bofu-tsusho-san, dietary restriction, and BioEnterics Intragastric Balloon, did not result in improvement of her obesity. Finally, we performed sleeve gastrectomy, and she has maintained her weight within 130-140 kg without rebounding for 2 and a half years. We followed the clinical changes before and after the operation. This case provides potentially interesting information regarding operative treatment for morbid obesity in Japanese.

Efficacy and safety of metformin for treatment of overweight and obesity in adolescents: an updated systematic review and meta-analysis

OBJECTIVE

To assess the efficacy and safety of using metformin in overweight and obese adolescents without related morbidity.

METHODS

We conducted a systematic review and meta-analysis of randomized clinical trials published until June 2011, comparing metformin to placebo or other interventions. Our primary variables were baseline BMI changes and development of adverse effects.

RESULTS

Nine studies (498 participants, mean age 14.2 years; mean BMI 36.4 kg/m² met the inclusion criteria. In all but one study, metformin was combined with lifestyle modification and was compared to placebo combined with changes in lifestyle. Analysis showed that metformin reduced mean BMI by 1.42 kg/m² (95% CI -2.18, 0.66), fasting insulin by 9.9 µU/ml (95% CI -13.8, -6.06) and the HOMA index by -1.78 (95% CI -3.32, -0.23). No changes in any other parameter were observed. No statistical differences were found in the rate of adverse events (33% metformin, 32% placebo).The withdrawal rates due to side effects in the metformin and placebo groups were 2.7% and 2.5%, respectively.

CONCLUSIONS

The available evidence indicates that, in the short term, administration of metformin in addition to lifestyle modification is relatively effective for reducing BMI and hyperinsulinemia among obese adolescents without related morbidity, and displays an acceptable safety pattern. Nevertheless, its long-term impact is unknown.