Metformin reduces weight, centripetal obesity, insulin, leptin, and low-density lipoprotein cholesterol in nondiabetic, morbidly obese subjects with body mass index greater than 30

Metformin attenuates high-carbohydrate diet-induced redox imbalance, inflammation, and mitochondrial dysfunction in Megalobrama amblycephala

This study aimed to investigate the effects of dietary metformin supplementation on the redox balance, inflammation, mitochondrial biogenesis, and function in blunt snout bream fed a high-carbohydrate (HC) diet. Fish (45.12 ± 0.36 g) were randomly offered four diets, including a control diet (33% carbohydrate), an HC diet (45% carbohydrate), and the HC diet supplemented with 0.06% (HCM1) and 0.12% (HCM2) metformin respectively for 12 weeks. Compared with the control, feeding the HC diet significantly increased the hepatosomatic index (HSI), the mesenteric fat index, liver and muscle glycogen contents, liver and adipose tissue lipid contents, plasma glucose and glycation end products (AGES) levels and aspartate transaminase activity, plasma and liver malondialdehyde (MDA) contents, hepatic adenosine triphosphate (ATP) and adenosine monophosphate (AMP) contents, mitochondrial cytochrome c content, mitochondrial complex IV activity and ATP 6 transcription, but decreased plasma catalase (CAT) activity, muscle superoxide dismutase (SOD) activity, hepatic antioxidant enzymes activities, and the transcriptions of transforming growth factor β (tgfβ) and interleukin 10 (il10). Compared with the HC group, metformin treatment (especially the HCM2 group) significantly elevated tissue glycogen contents, muscle SOD activity, plasma and liver antioxidant enzymes activities, the transcriptions of tgfβ and il10, the sodium/potassium ATPase activity, the contents of mitochondrial protein and AMP, the level of p-AMP activated protein kinase (AMPK), and the p-AMPK/t-AMPK ratio, but lowered the HSI, tissue lipid contents, plasma levels of glucose, AGES and glycated serum protein, plasma, and liver MDA contents, the transcriptions of il1β, NADH dehydrogenase subunit 1 and ATP 6, the contents of ATP and cytochrome c, the ATP/AMP ratio, and the activities of complexes I and IV. In conclusion, metformin could attenuate the HC diet-induced redox imbalance, inflammation, and mitochondrial dysfunction in blunt snout bream.

Metabolic Dysfunction-Associated Steatotic Liver Disease: From Pathogenesis to Current Therapeutic Options

The epidemiological burden of liver steatosis associated with metabolic diseases is continuously growing worldwide and in all age classes. This condition generates possible progression of liver damage (i.e., inflammation, fibrosis, cirrhosis, hepatocellular carcinoma) but also independently increases the risk of cardio-metabolic diseases and cancer. In recent years, the terminological evolution from "nonalcoholic fatty liver disease" (NAFLD) to "metabolic dysfunction-associated fatty liver disease" (MAFLD) and, finally, "metabolic dysfunction-associated steatotic liver disease" (MASLD) has been paralleled by increased knowledge of mechanisms linking local (i.e., hepatic) and systemic pathogenic pathways. As a consequence, the need for an appropriate classification of individual phenotypes has been oriented to the investigation of innovative therapeutic tools. Besides the well-known role for lifestyle change, a number of pharmacological approaches have been explored, ranging from antidiabetic drugs to agonists acting on the gut-liver axis and at a systemic level (mainly farnesoid X receptor (FXR) agonists, PPAR agonists, thyroid hormone receptor agonists), anti-fibrotic and anti-inflammatory agents. The intrinsically complex pathophysiological history of MASLD makes the selection of a single effective treatment a major challenge, so far. In this evolving scenario, the cooperation between different stakeholders (including subjects at risk, health professionals, and pharmaceutical industries) could significantly improve the management of disease and the implementation of primary and secondary prevention measures. The high healthcare burden associated with MASLD makes the search for new, effective, and safe drugs a major pressing need, together with an accurate characterization of individual phenotypes. Recent and promising advances indicate that we may soon enter the era of precise and personalized therapy for MASLD/MASH.

The effect of metformin on adipokines levels: A systematic review and meta-analysis of randomized-controlled trials

BACKGROUND

Considering the role of adipokine on diseases related to metabolic syndrome and even chronic diseases, it seems necessary to investigate effective interventions on these factors. This study aimed to comprehensively investigate the effects of metformin on adipokines.

METHODS

A comprehensive search was conducted in five databases using established keywords. The purpose of this search was to uncover controlled studies that have examined the impact of metformin on adipokines, specifically leptin, adiponectin, and resistin. The random-effects model analysis was used to provide pooled weighted mean difference and 95% confidence intervals.

RESULTS

Forty-nine studies were included in this article. The pooled findings showed that that the administration of metformin significantly decreases leptin (WMD: -3.06 ng/ml, 95 % CI: -3.81, -2.30, P < 0.001) and resistin (WMD: -1.27 µg/mL, 95 % CI: -2.22, -0.31, P = 0.009) levels in different populations compared to the control group. However, no significant effect of this antidiabetic drug on adiponectin levels was reported. The results obtained from the subgroup results in the present study also showed that metformin in people with a BMI greater than 30 kg/m2 compared to a BMI ≤ 30 kg/m2 causes a significant decrease in leptin levels and an increase in adiponectin levels. Also, metformin in lower doses (≤1500 mg/day) and younger people (<30 years) causes a significant increase in adiponectin levels.

CONCLUSIONS

In general, considering the role of adipokines on metabolic disease and even chronic disease, this drug can be used as a potentially useful drug, especially in obese people, to improve these factors.

Effects of myo-inositol vs. metformin on hormonal and metabolic parameters in women with PCOS: a meta-analysis

OBJECTIVE

Polycystic Ovary Syndrome is the most prevalent hormonal disorder in females. Over the years, metformin (MET) has become the first-line choice of treatment; however, due to its gastrointestinal side effects, a more recent drug, myo-inositol (MI), has been introduced. We aim to conduct a systematic review and meta-analysis to compare the effects of MET and MI on hormonal and metabolic parameters.

MATERIALS AND METHODS

Authors extensively searched PubMed, Scopus, Cochrane Library, Google Scholar, and Web of Science for randomized clinical trials (RCTs) until August 2021. Eight (n = 8) articles were included, with a total sample size of 1088, of which 460 patients received MET, 436 received MI, and 192 received a combination of both. Standard mean differences (SMDs) and Confidence Intervals (CIs) were used for data synthesis, and forest plots were made using Review Manager 5.4 for Statistical Analysis using the random-effect model.

RESULTS

The meta-analysis indicates that there is no significant difference between MET and MI in terms of their effects on BMI (SMD = 0.16, 95% CI: - 0.11 to 0.43, p = 0.24), fasting insulin (SMD = 0.00, 95% CI: - 0.26 to 0.27, p = 0.97), fasting blood sugar (SMD = 0.11, 95% CI: - 0.31to 0.53, p = 0.60), HOMA index (SMD = 0.09, 95% CI: - 0.20 to 0.39, p = 0.50), and LH/FSH (SMD = 0.20, 95% CI: - 0.24 to 0.64, p = 0.37). BMI, fasting blood sugar, and LH/FSH ratio reported moderate heterogeneity because of the varying number of study participants.

CONCLUSION

Our meta-analysis comparing hormonal and metabolic parameters between MET and MI did not show much significant difference, indicating both drugs are equally beneficial in improving metabolic and hormonal parameters in patients with PCOS.

The development and benefits of metformin in various diseases

Metformin has been used for the treatment of type II diabetes mellitus for decades due to its safety, low cost, and outstanding hypoglycemic effect clinically. The mechanisms underlying these benefits are complex and still not fully understood. Inhibition of mitochondrial respiratory-chain complex I is the most described downstream mechanism of metformin, leading to reduced ATP production and activation of AMP-activated protein kinase (AMPK). Meanwhile, many novel targets of metformin have been gradually discovered. In recent years, multiple pre-clinical and clinical studies are committed to extend the indications of metformin in addition to diabetes. Herein, we summarized the benefits of metformin in four types of diseases, including metabolic associated diseases, cancer, aging and age-related diseases, neurological disorders. We comprehensively discussed the pharmacokinetic properties and the mechanisms of action, treatment strategies, the clinical application, the potential risk of metformin in various diseases. This review provides a brief summary of the benefits and concerns of metformin, aiming to interest scientists to consider and explore the common and specific mechanisms and guiding for the further research. Although there have been countless studies of metformin, longitudinal research in each field is still much warranted.

Pharmacogenetic impact of SLC22A1 gene variant rs628031 (G/A) in newly diagnosed Indian type 2 diabetes patients undergoing metformin monotherapy

OBJECTIVES

Type 2 diabetes (T2D) imposes an enormous burden all over the world in both developed and developing countries. Inter-individual differences are attributed to polymorphisms in candidate genes resulting in altered absorption, transportation, distribution, and metabolism of oral antidiabetic drugs (OADs). Hence, the present study was undertaken to evaluate the pharmacogenetic impact of SLC22A1 gene variant rs628031 (G/A) on metformin monotherapy in newly diagnosed untreated T2D patients.

METHODS

Newly diagnosed T2D patients ( n  = 500) were enrolled according to inclusion/exclusion criteria. Initially, enrolled subjects were prescribed metformin monotherapy and followed up for at least 12 weeks. Response to metformin was evaluated in 478 patients who revisited for follow-up by measuring HbA1c.

RESULT

Out of 478 patients, 373 were responders to metformin monotherapy while 105 were non-responders. The pharmacogenetic impact was evaluated by genotype, haplotype, and pharmacogenetic analyses. 'GG' genotype and 'G' allele of SLC22A1 rs628031 G/A were observed in 48.8% and 67.7% of Met responders, respectively, while 20.9% and 49.1 % were in non-responders. Therefore, there was a 2.18-fold increase in the success rate of Met therapeutics.

CONCLUSION

Individuals carrying the 'GG' genotype or 'G' allele for SLC22A1 gene variant rs628031 G/A are better responders for Metformin monotherapy.

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.

Transcriptomics-based network medicine approach identifies metformin as a repurposable drug for atrial fibrillation

Effective drugs for atrial fibrillation (AF) are lacking, resulting in significant morbidity and mortality. This study demonstrates that network proximity analysis of differentially expressed genes from atrial tissue to drug targets can help prioritize repurposed drugs for AF. Using enrichment analysis of drug-gene signatures and functional testing in human inducible pluripotent stem cell (iPSC)-derived atrial-like cardiomyocytes, we identify metformin as a top repurposed drug candidate for AF. Using the active compactor, a new design analysis of large-scale longitudinal electronic health record (EHR) data, we determine that metformin use is significantly associated with a reduced risk of AF (odds ratio = 0.48, 95%, confidence interval [CI] 0.36-0.64, p < 0.001) compared with standard treatments for diabetes. This study utilizes network medicine methodologies to identify repurposed drugs for AF treatment and identifies metformin as a candidate drug.

Metformin attenuates osteoarthritis by targeting chondrocytes, synovial macrophages and adipocytes

OBJECTIVE

To investigate the therapeutic effect and mechanism of metformin on knee osteoarthritis (OA) in normal diet (ND) mice or high-fat diet (HFD)-induced obese mice.

METHODS

Destabilization of the medial meniscus surgery was performed in ND mice or HFD mice, and metformin was administrated in drinking water or not. The changes of OA joint structure, infiltration and polarization of synovial macrophages and circulating and local levels of leptin and adiponectin were evaluated. In vitro, the effects of metformin on chondrocytes and macrophages, and of conditioned mediums derived from mouse abdominal fat on murine chondrogenic cell line ATDC5 and murine macrophage cell line RAW264.7, were detected.

RESULTS

Metformin showed protective effects on OA, characterized by reductions on OARSI score (2.00, 95% CI [1.15-2.86] for ND mice and 3.17, 95% CI [2.37-3.96] for HFD mice) and synovitis score (1.17, 95% CI [0.27-2.06] for ND mice and 2.50, 95% CI [1.49-3.51] for HFD mice) after 10 weeks of treatment, and the effects were more significant in HFD mice than in ND mice. Mechanistically, in addition to decreasing apoptosis and matrix-degrading enzymes expression in chondrocytes as well as infiltration and pro-inflammatory differentiation of synovial macrophages, metformin reduced leptin secretion by adipose tissue in HFD mice.

CONCLUSIONS

Metformin protects against knee OA which could be through reducing apoptosis and catabolism of chondrocytes, and suppressing infiltration and pro-inflammatory polarization of synovial macrophages. For obese mice, metformin has a greater protective effect in knee OA additionally through reducing leptin secretion from adipose tissue.

Metformin enhances LDL-cholesterol uptake by suppressing the expression of the pro-protein convertase subtilisin/kexin type 9 (PCSK9) in liver cells

PURPOSE

Metformin (MF) intake associates with reduced levels of circulating low-density lipoprotein-cholesterol (LDL-C). This has been attributed to the activation of AMPK, which differentially regulates the expression of multiple genes involved in cholesterol synthesis and trafficking. However, the exact mechanism underlying the LDL-C lowering effect of MF remains ambiguous.

METHODS

MF-treated Hep-G2 and HuH7 cells were evaluated for cell viability and the expression status of key lipid metabolism-related genes along with LDL-C uptake efficiency.

RESULTS

MF treatment resulted in decreased expression and secretion of PCSK9, increased expression of LDLR and enhanced LDL-C uptake in hepatocytes. It also resulted in increased expression of activated AMPK (p-AMPK) and decreased expression of SREBP2 and HNF-1α proteins. Transcriptomic analysis of MF-treated Hep-G2 cells confirmed these findings and showed that other key lipid metabolism-related genes including those that encode apolipoproteins (APOB, APOC2, APOC3 and APOE), MTTP and LIPC are downregulated. Lastly, MF treatment associated with reduced HMG-CoA reductase expression and activity.

CONCLUSIONS

These findings suggest that MF treatment reduces circulating LDL-C levels by suppressing PCSK9 expression and enhancing LDLR expression; hence the potential therapeutic utility of MF in hypercholesterolemia.

Updated Understanding of the Crosstalk Between Glucose/Insulin and Cholesterol Metabolism

Glucose and cholesterol engage in almost all human physiological activities. As the primary energy substance, glucose can be assimilated and converted into diverse essential substances, including cholesterol. Cholesterol is mainly derived from de novo biosynthesis and the intestinal absorption of diets. It is evidenced that glucose/insulin promotes cholesterol biosynthesis and uptake, which have been targeted by several drugs for lipid-lowering, e.g., bempedoic acid, statins, ezetimibe, and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors. Inversely, these lipid-lowering drugs may also interfere with glucose metabolism. This review would briefly summarize the mechanisms of glucose/insulin-stimulated cholesterol biosynthesis and uptake, and discuss the effect and mechanisms of lipid-lowering drugs and genetic mutations on glucose homeostasis, aiming to help better understand the intricate relationship between glucose and cholesterol metabolism.

Metformin combats obesity by targeting FTO in an m6A-YTHDF2-dependent manner

Obesity has become a health threat and hard enough to deal with. Evidences show that metformin could inhibit adipogenesis and combat obesity, while its mechanisms remain to be elucidated more comprehensively. In this study, we found that administration of metformin could combat obesity induced by high-fat diet (HFD), indicated by strikingly decreased body weight and weight of inguinal white adipose tissue (iWAT) and epidydimal white adipose tissue (eWAT) compared to the control group. Mechanically, we revealed that metformin could inhibit protein expression of FTO, leading to increased m⁶A methylation levels of cyclin D1 (Ccnd1) and cyclin dependent kinase 2 (Cdk2), two crucial regulators in cell cycle. Ccnd1 and Cdk2 with increased m⁶A levels were recognized by YTH m⁶A RNA binding protein 2 (YTHDF2), causing a YTHDF2-dependent decay and decreased protein expressions. In consequence, mitotic clonal expansion (MCE) process was blocked and adipogenesis was inhibited.

Metformin attenuates hypothalamic inflammation via downregulation of RIPK1-independent microglial necroptosis in diet-induced obese mice

Necroptosis, a form of programmed cell death, accounts for many inflammations in a wide range of diseases. Diet-induced obesity is manifested by low-grade inflammation in the mediobasal hypothalamus (MBH), and microglia are implicated as critical responsive components for this process. Here, we demonstrate that microglial necroptosis plays a pivotal role in obesity-related hypothalamic inflammation, facilitating proinflammatory cytokine production, such as TNF-α and IL-1β. Treatment with the anti-diabetic drug metformin effectively reduces the obese phenotypes in the high-fat diet (HFD)-fed mice, attributing to remission of hypothalamic inflammation partly through repressing microglial necroptosis. Importantly, using the receptor-interacting protein kinase 1 inhibitor, necrostatin-1s, could not suppress the microglial inflammation nor prevent body weight gain in the obese mice, indicating that the microglial necroptosis is RIPK1-independent. Altogether, these findings offer new insights into hypothalamic inflammation in diet-induced obesity and provide a novel mechanism of action for metformin in obesity treatment.

Biguanides drugs: Past success stories and promising future for drug discovery

Biguanides have attracted much attention a century ago and showed resurgent interest in recent years after a long period of dormancy. They constitute an important class of therapeutic agents suitable for the treatment of a wide spectrum of diseases. Therapeutic indications of biguanides include antidiabetic, antimalarial, antiviral, antiplaque, and bactericidal applications. This review presents an extensive overview of the biological activity of biguanides and different mechanisms of action of currently marketed biguanide-containing drugs, as well as their pharmacological properties when applicable. We highlight the recent developments in research on biguanide compounds, with a primary focus on studies on metformin in the field of oncology. We aim to provide a critical overview of all main bioactive biguanide compounds and discuss future perspectives for the design of new drugs based on the biguanide fragment.

Metformin use is associated with a reduced risk of acute appendicitis in Taiwanese patients with type 2 diabetes mellitus

This retrospective cohort study used the nationwide database of Taiwan’s National Health Insurance to investigate whether metformin would reduce the risk of acute appendicitis in patients with type 2 diabetes mellitus. We first identified 423,949 patients newly diagnosed of diabetes from 1999 to 2005. After excluding patients having type 1 diabetes mellitus, missing data, previous history of acute appendicitis, aged < 15 years, aged > 80 years and followed up for < 6 months, 338,172 ever users and 21,861 never users of metformin were followed up from January 1, 2006 until December 31, 2011. Incidence of acute appendicitis was estimated for never users, ever users and subgroups (divided by median, tertiles and quartiles, respectively) of dose–response indicators including cumulative duration (months), cumulative dose (mg) and average daily dose (mg/day) of metformin therapy. We used Cox regression incorporated with the inverse probability of treatment weighting using propensity score to estimate the overall hazard ratio for ever versus never users, and the hazard ratios for subgroups of dose–response indicators versus never users. Results showed that new-onset acute appendicitis was diagnosed in 1558 ever users and 179 never users during follow-up. The incidence was 98.15 per 100,000 person-years in ever users and was 189.48 per 100,000 person-years in never users. The overall hazard ratio (95% confidence interval) of 0.514 (0.441–0.600) suggested a lower risk of acute appendicitis associated with metformin use. A dose–response pattern was consistently observed in the analyses of different subgroups of dose–response indicators and the reduced risk associated with metformin use was consistently observed in various sensitivity analyses. An average daily dose of 1000–1500 mg/day can significantly reduce the risk by > 50%. The benefit did not differ between different formulations of metformin, and the estimated hazard ratio for conventional/immediate-release metformin versus never users was 0.516 (0.441–0.603) and was 0.509 (0.421–0.615) for prolonged/slow-release metformin versus never users. It is concluded that metformin use is associated with a reduced risk of acute appendicitis in patients with type 2 diabetes mellitus.

Effects of metformin on atrial and ventricular arrhythmias: evidence from cell to patient

Metformin has been shown to have various cardiovascular benefits beyond its antihyperglycemic effects, including a reduction in stroke, heart failure, myocardial infarction, cardiovascular death, and all-cause mortality. However, the roles of metformin in cardiac arrhythmias are still unclear. It has been shown that metformin was associated with decreased incidence of atrial fibrillation in diabetic patients with and without myocardial infarction. This could be due to the effects of metformin on preventing the structural and electrical remodeling of left atrium via attenuating intracellular reactive oxygen species, activating 5′ adenosine monophosphate-activated protein kinase, improving calcium homeostasis, attenuating inflammation, increasing connexin-43 gap junction expression, and restoring small conductance calcium-activated potassium channels current. For ventricular arrhythmias, in vivo reports demonstrated that activation of 5′ adenosine monophosphate-activated protein kinase and phosphorylated connexin-43 by metformin played a key role in ischemic ventricular arrhythmias reduction. However, metformin failed to show anti-ventricular arrhythmia benefits in clinical trials. In this review, in vitro and in vivo reports regarding the effects of metformin on both atrial arrhythmias and ventricular arrhythmias are comprehensively summarized and presented. Consistent and controversial findings from clinical trials are also summarized and discussed. Due to limited numbers of reports, further studies are needed to elucidate the mechanisms and effects of metformin on cardiac arrhythmias. Furthermore, randomized controlled trials are needed to clarify effects of metformin on cardiac arrhythmias in human.

Role of metformin in various pathologies: state-of-the-art microcapsules for improving its pharmacokinetics

Metformin was originally derived from a botanical ancestry and became the most prescribed, first-line therapy for Type 2 diabetes in most countries. In the last century, metformin was discovered twice for its antiglycemic properties in addition to its antimalarial and anti-influenza effects. Metformin exhibits flip-flop pharmacokinetics with limited oral bioavailability. This review outlines metformin pharmacokinetics, pharmacodynamics and recent advances in polymeric particulate delivery systems as a potential tool to target metformin delivery to specific tissues/organs. This interesting biguanide is being rediscovered this century for multiple clinical indications as anticancer, anti-aging, anti-inflammatory, anti-Alzheimer's and much more. Microparticulate delivery systems of metformin may improve its oral bioavailability and optimize the therapeutic goals expected.

Androgen Therapy in Male Patients Suffering from Type 2 Diabetes: A Review of Benefits and Risks

BACKGROUND

The current estimated numbers of patients with Type 2 Diabetes (T2D) is believed to be close to 10% of the whole populations of many geographical regions, causing serious concerns over the resulting elevated morbidity and mortality as well as the impact on health care systems around the world. In addition to negatively affecting the quality of life, diabetes is associated with cardiovascular and cerebrovascular complications, indicating that appropriate drug therapy should not only deal with metabolic dysfunction but also protect the vascular system, kidney function and skeletal muscle mass from the effects of the epigenetic changes induced by hyperglycaemia.

OBJECTIVE

To provide an insight into the management of hypogonadism associated with T2D, this review focuses on clinical observations related to androgen therapy in qualified diabetic patients, and discusses the lines of evidence for its benefits and risks. The potential interactions of testosterone with medicines used by patients with T2D will also be discussed.

CONCLUSION

From recent clinical findings, it became evident that a considerable percentage of patients suffering from T2D manifested low serum testosterone and experienced diminished sexual activity, as well as reduced skeletal muscle mass and lower bone density. Although there are some controversies, Testosterone Replacement Therapy (TRT) for this particular population of patients appears to be beneficial overall only if it is implemented carefully and monitored regularly.

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.

Are SGLT2 inhibitors joining the mainstream therapy for diabetes type 2?

BACKGROUND

Conventional therapies to prevent type 2 diabetes mellitus (T2DM) complications are only partially effective. Therefore, new therapeutic approaches leading to additional risk reduction are required. While many anti-diabetic medications have been prescribed world-wide for controlling T2DM over the past half-century, sodium-glucose co-transporter-2 (SGLT2) inhibitors are relatively new. In addition to their plasma glucose lowering effect, SGLT2 inhibitors have been shown to reduce considerably cardiovascular mortality rate in patients with T2DM.

AIM

Since, a risk and benefit analysis of co-administration of SGLT2 inhibitors and other anti-diabetic agents in patients who suffer from hypertension, heart failure or renal deficiency is currently lacking, the main objective of this article is to review the recent literature and provide the health care professionals with evidence-based opinions on the subject.

CONCLUSION

SGLT2 inhibitors have relatively safe profiles and can efficiently decrease HbA1c as well as fasting and postprandial glucose levels. Furthermore, SGLT2 inhibitors administrations are not associated with significant hypoglycemic episodes or weight gain. Thus, combination of SGLT2 inhibitors and other less harmful anti-diabetic medicines could be considered if there is no any contraindication.

Endometrium receptivity in premature ovarian insufficiency - how to improve fertility rate and predict diseases?

More empathized approach is required and is obligatory to women with premature ovarian insufficiency (POI) interested for pregnancy. In order to improve fertility rate in POI patients our suggestions would be: (1) To decrease FSH value to 10-15 IU/L by increasing estrogen. Oocyte donation can be suggested after a minimum of six month interval from FSH between 10-15 IU/L and when no dominant follicles are found. (2) To perform oral glucose tolerance test (OGTT). Insulin sensitizing agents has to be included, when indicated, 3-6 month before pregnancy. (3) TSH has to be 1-2.5 mM/L during 3-6 months before pregnancy. (4) Tests for thrombophyllia (Leiden V, FII, MTHFR, PAI) have to be obligatory. They are less expensive than those repeated in vitro fertilizations. Therapy has to be included according to the indications. (5) In order to regulate disturbed immune response in POI patients with endometriosis oral contraceptive therapy is needed for atleast six months prior to the pregnancy. (5) Encourage the patients and advice them about healthy life style and eating habits. (6) Add other drugs, when they are indicated. Complex interplay between endocrine, immunological, haematological, and psychological factors are very often underdetected in POI patients. It is very important to find out the real time for oocyte donation after correcting all the disturbances, improving endometrium receptivity and reaching women's acceptable psychological status. Untreated disturbances induce cardiovascular diseases, diabetes mellitus, thyroid diseases, coagulopathioes etc.

Metformin induces significant reduction of body weight, total cholesterol and LDL levels in the elderly - A meta-analysis

Background

Metformin is the first-choice drug for patients with Type 2 diabetes, and this therapy is characterized by being weight neutral. However, in the elderly an additional unintentional weight loss could be considered as an adverse effect of the treatment.

Objectives

We aimed to perform a meta-analysis of placebo-controlled studies investigating the body weight changes upon metformin treatment in participants older than 60 years.

Materials and methods

PubMed, EMBASE and the Cochrane Library were searched. We included at least 12 week-long studies with placebo control where the mean age of the metformin-treated patients was 60 years or older and the body weight changes of the patients were reported. We registered our protocol on PROSPERO (CRD42017055287).

Results

From the 971 articles identified by the search, 6 randomized placebo-controlled studies (RCTs) were included in the meta-analysis (n = 1541 participants). A raw difference of -2.23 kg (95% CI: -2.84 –-1.62 kg) body weight change was detected in the metformin-treated groups as compared with that of the placebo groups (p<0.001). Both total cholesterol (-0.184 mmol/L, p<0.001) and LDL cholesterol levels (-0.182 mmol/L, p<0.001) decreased upon metformin-treatment.

Conclusions

Our meta-analysis of RCTs showed a small reduction of body weight together with slight improvement of the blood lipid profile in patients over 60 years. With regard to the risk of unintentional weight loss, metformin seems to be a safe agent in the population of over 60 years. Our results also suggest that metformin treatment may reduce the risk of major coronary events (-4-5%) and all-cause mortality (-2%) in elderly diabetic populations.

Effect of metformin on glycaemic control in patients with type 1 diabetes: A meta-analysis of randomized controlled trials

BACKGROUND

For type 1 diabetes (T1D) patients, adding metformin to insulin therapies is thought to improve blood glucose levels, but current evidence does not support this clinical benefit. Additional data from large clinical trials are now available; therefore, we conducted a meta-analysis of studies on assessing the efficacy and adverse effects of metformin.

METHODS

We searched the MEDLINE, EMBASE, and Cochrane Library databases for data from randomized controlled trials. We performed statistical analyses by using Review Manager 5.2.

RESULTS

Thirteen randomized controlled trials that compared metformin versus placebo met our inclusion criteria and were included in the study. The final meta-analysis included a total of 1183 participants with T1D. Metformin was associated with reductions in BMI (-1.14, 95% CI -2.05 to -0.24, P = .01), insulin requirements (-0.47, 95% CI -0.70 to -0.23, P = .0001), total cholesterol (-0.23, 95% CI -0.34 to -0.12, P < .0001), and low-density lipoprotein cholesterol (-0.20, 95% CI -0.29 to -0.11, P < .0001) in T1D patients. No clear evidence indicated that metformin improved HbA1c, triglyceride, or high-density lipoprotein cholesterol levels. A safety analysis showed that metformin slightly increased the risk of severe hypoglycaemia (1.23, 95% CI 1.00 to 1.52, P = .05) and mainly gastrointestinal adverse events (2.67, 95% CI 2.06 to 3.45, P < .00001). No evidence showed that metformin increased diabetic ketoacidosis events.

CONCLUSIONS

Compared with placebo, metformin was not associated with glycaemic control in T1D patients. Although it exhibited other benefits, such as lower BMI and reduced insulin requirements, total cholesterol, and low-density lipoprotein cholesterol, negative outcomes, such as gastrointestinal adverse effects and severe hypoglycaemia, should also be considered in the use of metformin for T1D patients.

Postprandial lipemia: factoring in lipemic response for ranking foods for their healthiness

One of the limitations for ranking foods and meals for healthiness on the basis of the glycaemic index (GI) is that the GI is subject to manipulation by addition of fat. Postprandial lipemia, defined as a rise in circulating triglyceride containing lipoproteins following consumption of a meal, has been recognised as a risk factor for the development of cardiovascular disease and other chronic diseases. Many non-modifiable factors (pathological conditions, genetic background, age, sex and menopausal status) and life-style factors (physical activity, smoking, alcohol and medication use, dietary choices) may modulate postprandial lipemia. The structure and the composition of a food or a meal consumed also plays an important role in the rate of postprandial appearance and clearance of triglycerides in the blood. However, a major difficulty in grading foods, meals and diets according to their potential to elevate postprandial triglyceride levels has been the lack of a standardised marker that takes into consideration both the general characteristics of the food and the food’s fat composition and quantity. The release rate of lipids from the food matrix during digestion also has an important role in determining the postprandial lipemic effects of a food product. This article reviews the factors that have been shown to influence postprandial lipemia with a view to develop a novel index for ranking foods according to their healthiness. This index should take into consideration not only the glycaemic but also lipemic responses.

Identification and characterization of metformin on peptidomic profiling in human visceral adipocytes

To gain insight into the effect of metformin on losing weight from peptidomic perspective and to screen potential active peptides for reducing fat lipid deposition. After determining the proper concentration of metformin on human primary visceral adipocytes, we constructed a comparative peptidomic profiling between control and metformin treatment group (n = 3) using a stable isobaric labeling strategy involving tandem mass tag reagents, followed by liquid chromatography tandem mass spectrometry. We identified and quantified 3065 non-redundant peptides, 304 of which were differentially expressed after metformin treatment, 206 peptides were up regulated and 98 peptides were down regulated significantly. Gene ontology (GO) enrichment and pathway analysis were performed to study differentially peptides though their precursor proteins. We concluded three peptides located within the functional domains of their precursor proteins could be candidate bioactive peptides for obesity. On one hand, these results confirmed the versatile effects of metformin on adipocyte and advance our current understanding of metformin, on the other hand, these identified peptides might play putative roles in treatment of obesity.

Glucose dysregulation and response to common anti-diabetic agents in the FATZO/Pco mouse

The FATZO/Pco mouse is the result of a cross of the C57BL/6J and AKR/J strains. The crossing of these two strains and the selective inbreeding for obesity, insulin resistance and hyperglycemia has resulted in an inbred strain exhibiting obesity in the presumed presence of an intact leptin pathway. Routinely used rodent models for obesity and diabetes research have a monogenic defect in leptin signaling that initiates obesity. Given that obesity and its sequelae in humans are polygenic in nature and not associated with leptin signaling defects, the FATZO mouse may represent a more translatable rodent model for study of obesity and its associated metabolic disturbances. The FATZO mouse develops obesity spontaneously when fed a normal chow diet. Glucose intolerance with increased insulin levels are apparent in FATZO mice as young as 6 weeks of age. These progress to hyperglycemia/pre-diabetes and frank diabetes with decreasing insulin levels as they age. The disease in these mice is multi-faceted, similar to the metabolic syndrome apparent in obese individuals, and thus provides a long pre-diabetic state for determining the preventive value of new interventions. We have assessed the utility of this new model for the pre-clinical screening of agents to stop or slow progression of the metabolic syndrome to severe diabetes. Our assessment included: 1) characterization of the spontaneous development of disease, 2) comparison of metabolic disturbances of FATZO mice to control mice and 3) validation of the model with regard to the effectiveness of current and emerging anti-diabetic agents; rosiglitazone, metformin and semaglutide.

CONCLUSION

Male FATZO mice spontaneously develop significant metabolic disease when compared to normal controls while maintaining hyperglycemia in the presence of high leptin levels and hyperinsulinemia. The disease condition responds to commonly used antidiabetic agents.

Leptin signals via TGFB1 to promote metastatic potential and stemness in breast cancer

Epidemiological studies have shown obesity to be linked with poorer outcomes in breast cancer patients. The molecular mechanisms responsible for the increased risk of invasive/metastatic disease with obesity are complex, but may include elevated levels of adipokines such as leptin. Using physiological levels of leptin found in obesity in a novel chronic in vitro treatment model (≤200 ng/ml for 14 days), we confirmed the occurrence of leptin-mediated changes in growth, apoptosis and metastatic behavior, and gene expression changes representing epithelial-to-mesenchymal transition (EMT) and a cancer stem cell (CSC) like phenotype in breast epithelial and cancer cell lines (MCF10A, MCF10AT1, MCF7 and MDA-MB-231). Further, we have discovered that these effects were accompanied by increased expression of TGFB1, and could be significantly reduced by co-treatment with neutralizing antibody against TGFB1, indicating that the induction of these characteristics was mediated via TGFB1. Occurring in both MCF7 and MCF10AT1 cells, it suggests these actions of leptin to be independent of estrogen receptor status. By linking leptin signalling to the established TGFB1 pathway of metastasis / EMT, this study gives a direct mechanism by which leptin can contribute to the poorer outcomes of obese cancer patients. Inhibitors of TGFB1 are in currently in phase III clinical trials in other malignancies, thus identifying the connection between leptin and TGFB1 will open new therapeutic opportunities for improving outcomes for obese breast cancer patients.

Metformin causes a futile intestinal-hepatic cycle which increases energy expenditure and slows down development of a type 2 diabetes-like state

OBJECTIVE

Metformin, the first line drug for treatment of type 2 diabetes, suppresses hepatic gluconeogenesis and reduces body weight in patients, the latter by an unknown mechanism.

METHODS

Mice on a high fat diet were continuously fed metformin in a therapeutically relevant dose, mimicking a retarded formulation.

RESULTS

Feeding metformin in pharmacologically relevant doses to mice on a high fat diet normalized HbA1c levels and ameliorated glucose tolerance, as expected, but also considerably slowed down weight gain. This was due to increased energy expenditure, since food intake was unchanged and locomotor activity was even decreased. Metformin caused lactate accumulation in the intestinal wall and in portal venous blood but not in peripheral blood or the liver. Increased conversion of glucose-1-¹³C to glucose-1,6-¹³C under metformin strongly supports a futile cycle of lactic acid production in the intestinal wall, and usage of the produced lactate for gluconeogenesis in liver.

CONCLUSIONS

The reported glucose-lactate-glucose cycle is a highly energy consuming process, explaining the beneficial effects of metformin given continuously on the development of a type 2 diabetic-like state in our mice.

Effect of Metformin on Different Non-Diabetes Related Conditions, a Special Focus on Malignant Conditions: Review of Literature

Metformin has been proven to be one of the most safe and effective antihyperglycemic agents. Through more than six decades of metformin use, it became the most studied hypoglycemic agent; through these studies, it showed a marvelous non-glycemic related effect. These effects include modulation of different points of cancer timeline, weight reduction, cardiovascular health, thyroid diseases, polycystic ovaries disease and many other medical conditions. The aim of this review was to assess the effect of metformin on non-diabetes related medical diseases. We have examined the studies published in PubMed and summarized different randomized controlled trials, observational trials and review articles. This review has summarized most of the non-glycemic effects of metformin. Metformin has been solidly shown to be effective in weight control with certain medications, effective in neuroprotection, in endothelial health, in control of anti-HIV agent side effects and many other crucial health jeopardies. The effects in cancer timeline modulation have taken the biggest part, since it was the most studied area outside the diabetes field. Having mentioned all the above privileges, and in addition to the robust evidence in glycemic control, this consolidates the position of metformin as a first line agent in treatment of diabetes and pre-diabetes. Perhaps in the near future, we may see other indications to use metformin in non-diabetes patients.

The desert gerbil Psammomys obesus as a model for metformin-sensitive nutritional type 2 diabetes to protect hepatocellular metabolic damage: Impact of mitochondrial redox state

Introduction

While metformin (MET) is the most widely prescribed antidiabetic drug worldwide, its beneficial effects in Psammomys obesus (P. obesus), a rodent model that mimics most of the metabolic features of human diabetes, have not been explored thoroughly. Here, we sought to investigate whether MET might improve insulin sensitivity, glucose homeostasis, lipid profile as well as cellular redox and energy balance in P. obesus maintained on a high energy diet (HED).

Materials and methods

P. obesus gerbils were randomly assigned to receive either a natural diet (ND) consisting of halophytic plants (control group) or a HED (diabetic group) for a period of 24 weeks. MET (50 mg/kg per os) was administered in both animal groups after 12 weeks of feeding, i.e., the time required for the manifestation of insulin resistance in P. obesus fed a HED. Parallel in vitro experiments were conducted on isolated hepatocytes that were shortly incubated (30 min) with MET and energetic substrates (lactate + pyruvate or alanine, in the presence of octanoate).

Results

In vivo, MET lowered glycemia, glycosylated haemoglobin, circulating insulin and fatty acid levels in diabetic P. obesus. It also largely reversed HED-induced hepatic lipid alterations. In vitro, MET increased glycolysis but decreased both gluconeogenesis and ketogenesis in the presence of glucogenic precursors and medium-chain fatty acid. Importantly, these changes were associated with an increase in cytosolic and mitochondrial redox states along with a decline in respiration capacity.

Conclusions

MET prevents the progression of insulin resistance in diabetes-prone P. obesus, possibly through a tight control of gluconeogenesis and fatty acid β-oxidation depending upon mitochondrial function. While the latter is increasingly becoming a therapeutic issue in diabetes, the gut microbiota is another promising target that would need to be considered as well.

The Root Extract of Pueraria lobata and Its Main Compound, Puerarin, Prevent Obesity by Increasing the Energy Metabolism in Skeletal Muscle

Radix Pueraria lobata (RP) has been reported to prevent obesity and improve glucose metabolism; however, the mechanism responsible for these effects has not been elucidated. The mechanism underlying anti-obesity effect of RP was investigated in high-fat diet (HFD) induced obese mice and skeletal muscle cells (C2C12). Five-week-old C5BL/6 mice were fed a HFD containing or not containing RP (100 or 300 mg/kg) or metformin (250 mg/kg) for 16 weeks. RP reduced body weight gain, lipid accumulation in liver, and adipocyte and blood lipid levels. In addition, RP dose-dependently improved hyperglycemia, insulinemia, and glucose tolerance, and prevented the skeletal muscle atrophy induced by HFD. Furthermore, RP increased the peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) expression and phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) in skeletal muscle tissues. RP and its main component, puerarin, increased mitochondrial biogenesis and myotube hypertrophy in C2C12 cells. The present study demonstrates that RP can prevent diet-induced obesity, glucose tolerance, and skeletal muscle atrophy in mouse models of obesity. The mechanism responsible for the effect of RP appears to be related to the upregulation of energy metabolism in skeletal muscle, which at the molecular level may be associated with PGC-1α and AMPK activation.

Effects of Low Dose Metformin on Metabolic Traits in Clozapine-Treated Schizophrenia Patients: An Exploratory Twelve-Week Randomized, Double-Blind, Placebo-Controlled Study

Background

Metformin has been used for alleviating metabolic abnormalities in patients with schizophrenia. The lowest dose of metformin to treat metabolic abnormalities in clozapine-treated patients is 1000 mg/d. This study was designed to determine whether metformin at 500 mg/d and 1000 mg/d is effective in improving the metabolic profiles of clozapine-treated patients with pre-existing metabolic abnormalities, and whether its effectiveness depends on metformin dosage.

Methods

In this 12-week, randomized, double-blind, placebo-controlled trial, metformin at 500 mg/d or 1000 mg/d was prescribed to clozapine-treated patients with schizophrenia who had pre-existing metabolic abnormalities. The recruited patients underwent physical and laboratory evaluations at weeks 4, 8, and 12. The outcomes were any changes in metabolic traits.

Results

Among the 96 clozapine-treated patients with schizophrenia screened for the trial, 55 patients with pre-existing metabolic abnormalities were randomly assigned to placebo (n = 18), metformin dosage at 500 mg/d (n = 18), and metformin dosage at 1000 mg/d (n = 19) groups. The body weight (BW) of patients in the metformin 1000 mg/d group significantly decreased, by a mean of 0.97 kg over the 12 week trial period. Moreover, patients in the metformin at 500 mg/d and 1000 mg/d groups had a significant decrease in body mass index (BMI) after 12 weeks, with the mean decrease being 0.70 and 0.50 kg/m², respectively. No significant changes were observed in the other metabolic parameters of patients in the three groups.

Conclusions

Our results demonstrated that a low metformin dosage of either 500 mg/d or 1000 mg/d for 12 weeks slightly reduced the BW and BMI of clozapine-treated patients with pre-existing metabolic abnormalities. A longer period of treatment with a larger sample is warranted to determine the factors that influence the metformin treatment response.

Trial Registration

ClinicalTrials.gov NCT02751307

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 and dietary advice to improve insulin sensitivity and promote gestational restriction of weight among pregnant women who are overweight or obese: the GRoW Randomised Trial

Background

Obesity is a significant global health problem, with approximately 50% of women entering pregnancy having a body mass index greater than or equal to 25 kg/m². Obesity during pregnancy is associated with a well-recognised increased risk of adverse health outcomes both for the woman and her infant. Currently available data from large scale randomised trials and systematic reviews highlight only modest effects of antenatal dietary and lifestyle interventions in limiting gestational weight gain, with little impact on clinically relevant pregnancy outcomes. Further information evaluating alternative strategies is required.

The aims of this randomised controlled trial are to assess whether the use of metformin as an adjunct therapy to dietary and lifestyle advice for overweight and obese women during pregnancy is effective in improving maternal, fetal and infant health outcomes.

Methods

Design: Multicentre randomised, controlled trial.

Inclusion Criteria: Women with a singleton, live gestation between 10⁺⁰-20⁺⁰ weeks who are obese or overweight (defined as body mass index greater than or equal to 25 kg/m²), at the first antenatal visit.

Trial Entry & Randomisation: Eligible, consenting women will be randomised between 10⁺⁰ and 20⁺⁰ weeks gestation using an online computer randomisation system, and randomisation schedule prepared by non-clinical research staff with balanced variable blocks. Stratification will be according to maternal BMI at trial entry, parity, and centre where planned to give birth.

Treatment Schedules: Women randomised to the Metformin Group will receive a supply of 500 mg oral metformin tablets. Women randomised to the Placebo Group will receive a supply of identical appearing and tasting placebo tablets. Women will be instructed to commence taking one tablet daily for a period of one week, increasing to a maximum of two tablets twice daily over four weeks and then continuing until birth. Women, clinicians, researchers and outcome assessors will be blinded to the allocated treatment group.

All women will receive three face-to-face sessions (two with a research dietitian and one with a trained research assistant), and three telephone calls over the course of their pregnancy, in which they will be provided with dietary and lifestyle advice, and encouraged to make change utilising a SMART goals approach.

Primary Study Outcome: infant birth weight >4000 grams.

Sample Size: 524 women to detect a difference from 15.5% to 7.35% reduction in infants with birth weight >4000 grams (p = 0.05, 80% power, two-tailed).

Discussion

This is a protocol for a randomised trial. The findings will contribute to the development of evidence based clinical practice guidelines.

Trial registration

Australian and New Zealand Clinical Trials Registry ACTRN12612001277831, prospectively registered 10^th of December, 2012.

Elevated adiponectin but varied response in circulating leptin levels to falciparum malaria in type 2 diabetics and non-diabetic controls

Background

To investigate effects of falciparum malaria on circulating levels of leptin and adiponectin in type 2 diabetes mellitus (T2DM) and non-diabetic controls in relation to measures of adiposity.

Methods

Levels of leptin and adiponectin were measured in 100 type 2 diabetics and 100 age-matched controls before and during falciparum malaria in a 2-year prospective study. Also, waist circumference (WC), weight, height and hip circumference were measured. Body mass index (BMI) and waist-to-hip ratio (WHR) were computed.

Results

At baseline, diabetics had significantly (p < 0.05) higher WC and BMI but lower WHR, leptin and adiponectin levels. Baseline leptin correlated positively with WC (r = 0.633; p < 0.001) and BMI (r = 0.63; p < 0.001) in diabetics but only BMI (0.562; p < 0.001) in non-diabetic controls. Baseline leptin and adiponectin correlated positively (r = 0.249; p = 0.029) in non-diabetic respondents only. Adiponectin correlated negatively with WC (r = −0.58; p = 0.006) in diabetic males only. During malaria, mean levels of leptin and adiponectin were comparable (p > 0.05) between diabetics and controls. However, compared to baseline levels, significant (p < 0.001) elevation of adiponectin was found in both study groups. In respect of leptin, significant (p < 0.001) rise but decline was observed in diabetics and controls respectively. Malaria-induced leptin correlated negatively with adiponectin (r = −0.694; p < 0.001) in non-diabetic controls only.

Conclusion

Diabetics and controls exhibited increased adiponectin levels due to falciparum malaria but differed in response in terms of leptin levels.

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.

Renaissance of leptin for obesity therapy

Diet-induced obesity and its metabolic comorbidities constitute an overwhelming health crisis and there is an urgent need for safe and effective pharmacological interventions. Being largely shelved for decades, scientists are now revisiting the anti-obesity virtues of leptin. Whereas it remains evident that leptin as a stand-alone therapy is not an effective approach, the potential for employing sensitising pharmacology to unleash the weight-lowering properties of leptin has injected new hope into the field. Fascinatingly, these leptin-sensitising agents seem to act via distinct metabolic pathways and may thus, in parallel with their clinical development, serve as important research tools to progress our understanding of the molecular, physiological and behavioural pathways underlying energy homeostasis and obesity pathophysiology. This review summarises a presentation given at the 'Is leptin coming back?' symposium at the 2015 annual meeting of the EASD. It is accompanied by two other reviews on topics from this symposium (by Thomas Meek and Gregory Morton, DOI: 10.1007/s00125-016-3898-3 , and by Gerald Shulman and colleagues, DOI: 10.1007/s00125-016-3909-4 ) and an overview by the Session Chair, Ulf Smith (DOI: 10.1007/s00125-016-3894-7 ).

Metformin: A Hopeful Promise in Aging Research

Even though the inevitable process of aging by itself cannot be considered a disease, it is directly linked to life span and is the driving force behind all age-related diseases. It is an undisputable fact that age-associated diseases are among the leading causes of death in the world, primarily in industrialized countries. During the last several years, an intensive search of antiaging treatments has led to the discovery of a variety of drugs that promote health span and/or life extension. The biguanide compound metformin is widely used for treating people with type 2 diabetes and appears to show protection against cancer, inflammation, and age-related pathologies. Here, we summarize the recent developments about metformin use in translational aging research and discuss its role as a potential geroprotector.

Neuroprotective effects of metformin against Aβ-mediated inhibition of long-term potentiation in rats fed a high-fat diet

Metformin (Met) is used to treat neurodegenerative disorders such as Alzheimer's disease (AD). Conversely, high-fat diets (HFD) have been shown to increase AD risk. In this study, we investigated the neuroprotective effects of Met on β-amyloid (Aβ)-induced impairments in hippocampal synaptic plasticity in AD model rats that were fed a HFD. In this study, 32 adult male Wistar rats were randomly assigned to four groups: group I (control group, regular diet); group II (HFD+vehicle); group III (HFD+Aβ); or group IV (Met+HFD+Aβ). Rats fed a HFD were injected with Aβ to induce AD, allowed to recover, and treated with Met for 8 weeks. The rats were then anesthetized with intraperitoneal injections of urethane and placed in a stereotaxic apparatus for surgery, electrode implantation, and field potential recording. In vivo electrophysiological recordings were then performed to measure population spike (PS) amplitude and excitatory postsynaptic potential (EPSP) slope in the hippocampal dentate gyrus. Long-term potentiation (LTP) was induced by high-frequency stimulation of the perforant pathway. Blood samples were then collected to measure plasma levels of triglycerides, low-density lipoproteins, very low-density lipoprotein, and cholesterol. After induction of LTP, PS amplitude and EPSP slope were significantly decreased in Aβ-injected rats fed a HFD compared to vehicle-injected animals or untreated animals that were fed a normal diet. Met treatment of Aβ-injected rats significantly attenuated these decreases, suggesting that Met decreased the effects of Aβ on LTP. These findings suggest that Met treatment is neuroprotective against the detrimental effects of Aβ and HFDs on hippocampal synaptic plasticity.

Systematic Review of Metabolic Syndrome Biomarkers: A Panel for Early Detection, Management, and Risk Stratification in the West Virginian Population

INTRODUCTION

Metabolic syndrome represents a cluster of related metabolic abnormalities, including central obesity, hypertension, dyslipidemia, hyperglycemia, and insulin resistance, with central obesity and insulin resistance in particular recognized as causative factors. These metabolic derangements present significant risk factors for cardiovascular disease, which is commonly recognized as the primary clinical outcome, although other outcomes are possible. Metabolic syndrome is a progressive condition that encompasses a wide array of disorders with specific metabolic abnormalities presenting at different times. These abnormalities can be detected and monitored via serum biomarkers. This review will compile a list of promising biomarkers that are associated with metabolic syndrome and this panel can aid in early detection and management of metabolic syndrome in high risk populations, such as in West Virginia.

METHODS

A literature review was conducted using PubMed, Science Direct, and Google Scholar to search for markers related to metabolic syndrome. Biomarkers searched included adipokines (leptin, adiponectin), neuropeptides (ghrelin), pro-inflammatory cytokines (IL-6, TNF-α), anti-inflammatory cytokines (IL-10), markers of antioxidant status (OxLDL, PON-1, uric acid), and prothrombic factors (PAI-1).

RESULTS

According to the literature, the concentrations of pro-inflammatory cytokines (IL-6, TNF-α), markers of pro-oxidant status (OxLDL, uric acid), and prothrombic factors (PAI-1) were elevated in metabolic syndrome. Additionally, leptin concentrations were found to be elevated in metabolic syndrome as well, likely due to leptin resistance. In contrast, concentrations of anti-inflammatory cytokines (IL-10), ghrelin, adiponectin, and antioxidant factors (PON-1) were decreased in metabolic syndrome, and these decreases also correlated with specific disorders within the cluster.

CONCLUSION

Based on the evidence presented within the literature, the aforementioned biomarkers correlate significantly with metabolic syndrome and could provide a minimally-invasive means for early detection and specific treatment of these disorders. Further research is encouraged to determine the efficacy of applying these biomarkers to diagnosis and treatment in a clinical setting.

Hyperactive mTORC1 signaling is unaffected by metformin treatment in aged skeletal muscle

INTRODUCTION

Appropriate activation of growth signaling pathways, specifically mammalian target of rapamycin complex 1 (mTORC1), is central to muscle mass and metabolism. The goal of these studies was to examine the effects of metformin on mTORC1 signaling in aged skeletal muscle in an attempt to normalize growth signaling.

METHODS

Aged (23m) and young (3m) male mice were fed a low fat diet without or with 0.5% metformin for up to 8 weeks, then mTORC1-related signaling was examined in the plantar flexor complex.

RESULTS

Metformin had no significant effect on lowering body weight or muscle mass in aged animals, nor altered p70 S6 Kinase 1 (S6K1) and 4E-binding protein 1 (4E-BP1) phosphorylation. However, it significantly (P < 0.05) reduced body weight and lowered S6K1 and rpS6 phosphorylation in the young.

CONCLUSIONS

Collectively, these data suggest metformin is ineffective at normalizing growth signaling in aged skeletal muscle.

Association of APOE polymorphisms with diabetes and cardiometabolic risk factors and the role of APOE genotypes in response to anti-diabetic therapy: results from the AIDHS/SDS on a South Asian population

BACKGROUND AND OBJECTIVES

Apolipoprotein E (APOE) gene polymorphisms have been examined extensively in multiple global populations particularly due to their crucial role in lipid metabolism and cardiovascular disease. However, the overall contribution of APOE polymorphisms in type 2 diabetes (T2D) and coronary artery disease (CAD) in South Asians is still under-investigated. The objectives of this investigation were: 1) to evaluate the distribution of APOE polymorphisms in a large diabetic case-control sample from South Asia, 2) to examine the impact of APOE polymorphisms on quantitative risk factors of T2D and CAD, and 3) to explore the contribution of APOE genotypes in the response to anti-diabetic therapy.

SUBJECTS AND METHODS

A total of 3564 individuals (1956 T2D cases and 1608 controls) used in this study were part of the Asian Indian Diabetic Heart Study/Sikh Diabetes Study (AIDHS/SDS). We assessed the association of APOE polymorphisms with T2D, CAD and cardiometabolic traits using logistic and linear regression analysis.

RESULTS AND CONCLUSIONS

No significant differences in the distribution of APOE genotypes were observed between T2D and CAD cases and controls. The APOE4 genotype carriers had moderately higher diastolic blood pressure (BP) (p=0.022), and lower HDL-cholesterol (p=0.026) compared to E4 non-carriers. Overall, the APOE genotype was not a significant predictor of cardiometabolic disease in this population. Further stratification of data from diabetic patients by APOE genotypes and anti-hyperglycemic agents revealed a significant (~23%) decrease in 2-hour glucose (p=0.004) and ~7% decrease in systolic BP (p<0.001) among APOE4 carriers compared to non-carriers on metformin and sulphonylurea (SU) combination therapy, and no such differences were seen in patients on other agents. Our preliminary findings point to the need for evaluating population-specific genetic variation and its interactions with therapeutic effects.

Effect of Low Glycemic Index Diet Versus Metformin on Metabolic Syndrome

BACKGROUND

Metabolic syndrome (MetS) continues to be highly prevalent and contributes to a rapidly growing problem worldwide. The most important therapeutic intervention for metabolic syndrome is diet modification, an intervention whose efficacy has been proven for metabolic syndrome.

OBJECTIVES

The aim of the present study was to compare the effects of low glycemic index diet versus metformin on MetS components in adults with MetS.

PATIENTS AND METHODS

Fifty-one adults with MetS participated in this randomized controlled clinical trial. Patients were randomly allocated to two groups of metformin and low glycemic index diet. The intervention period was eight weeks. The studied participants were compared at baseline and the end of the trial, regarding the following factors: weight, blood pressure, waist circumference, fasting blood sugar, hemoglobin A1c and lipid profiles (Triglyceride (TG), Total Cholesterol (TC), Low-Density Lipoprotein (LDL) cholesterol, and High-Density Lipoprotein (HDL) cholesterol).

RESULTS

The anthropometric measurements, Fasting Blood Sugar (FBS), Hemoglobin A1c, serum lipid profiles (TG, TC, LDL-C, HDL-C) and lipoprotein ratio (LDL/HDL) showed a significant decrease after the intervention in both groups (P < 0.05). Comparison of the difference between the two groups was not significant, except for the mean reduction in FBS, which was more in the metformin group although this was not clinically significant.

CONCLUSIONS

This study supports the assumption that low glycemic index diet as well as metformin can positively affect metabolic syndrome components.

Effects of metformin on metabolite profiles and LDL cholesterol in patients with type 2 diabetes

OBJECTIVE

Metformin is used as a first-line oral treatment for type 2 diabetes (T2D). However, the underlying mechanism is not fully understood. Here, we aimed to comprehensively investigate the pleiotropic effects of metformin.

RESEARCH DESIGN AND METHODS

We analyzed both metabolomic and genomic data of the population-based KORA cohort. To evaluate the effect of metformin treatment on metabolite concentrations, we quantified 131 metabolites in fasting serum samples and used multivariable linear regression models in three independent cross-sectional studies (n = 151 patients with T2D treated with metformin [mt-T2D]). Additionally, we used linear mixed-effect models to study the longitudinal KORA samples (n = 912) and performed mediation analyses to investigate the effects of metformin intake on blood lipid profiles. We combined genotyping data with the identified metformin-associated metabolites in KORA individuals (n = 1,809) and explored the underlying pathways.

RESULTS

We found significantly lower (P < 5.0E-06) concentrations of three metabolites (acyl-alkyl phosphatidylcholines [PCs]) when comparing mt-T2D with four control groups who were not using glucose-lowering oral medication. These findings were controlled for conventional risk factors of T2D and replicated in two independent studies. Furthermore, we observed that the levels of these metabolites decreased significantly in patients after they started metformin treatment during 7 years' follow-up. The reduction of these metabolites was also associated with a lowered blood level of LDL cholesterol (LDL-C). Variations of these three metabolites were significantly associated with 17 genes (including FADS1 and FADS2) and controlled by AMPK, a metformin target.

CONCLUSIONS

Our results indicate that metformin intake activates AMPK and consequently suppresses FADS, which leads to reduced levels of the three acyl-alkyl PCs and LDL-C. Our findings suggest potential beneficial effects of metformin in the prevention of cardiovascular disease.