Metformin monotherapy for type 2 diabetes mellitus

Diabetes Mellitus and Cardiovascular Disease: Exploring Epidemiology, Pathophysiology, and Treatment Strategies

Diabetes mellitus (DM) affects 537 million people as of 2021, and is projected to rise to 783 million by 2045. This positions DM as the ninth leading cause of death globally. Among DM patients, cardiovascular disease (CVD) is the primary cause of morbidity and mortality. Notably, the prevalence rates of CVD is alarmingly high among diabetic individuals, particularly in North America and the Caribbean (46.0%), and Southeast Asia (42.5%). The predominant form of CVD among diabetic patients is coronary artery disease (CAD), accounting for 29.4% of cases. The pathophysiology of DM is complex, involving insulin resistance, β-cell dysfunction, and associated cardiovascular complications including diabetic cardiomyopathy (DCM) and cardiovascular autonomic neuropathy (CAN). These conditions exacerbate CVD risks underscoring the importance of managing key risk factors including hypertension, dyslipidemia, obesity, and genetic predisposition. Understanding the genetic networks and molecular processes that link diabetes and cardiovascular disease can lead to new diagnostics and therapeutic interventions. Imeglimin, a novel mitochondrial bioenergetic enhancer, represents a promising medication for diabetes with the potential to address both insulin resistance and secretion difficulties. Effective diabetes management through oral hypoglycemic agents (OHAs) can protect the cardiovascular system. Additionally, certain antihypertensive medications can significantly reduce the risk of diabetes-related CVD. Additionally, lifestyle changes, including diet and exercise are vital in managing diabesity and reducing CVD risks. These interventions, along with emerging therapeutic agents and ongoing clinical trials, offer hope for improved patient outcomes and long-term DM remission. This study highlights the urgent need for management strategies to address the overlapping epidemics of DM and CVD. By elucidating the underlying mechanisms and risk factors, this study aims to guide future perspectives and enhance understanding of the pathogenesis of CVD complications in patients with DM, thereby guiding more effective treatment strategies.

1-DNJ Alleviates Obesity-Induced Testicular Inflammation in Mice Model by Inhibiting IKKβ/ NF-kB Pathway

Obesity is associated with chronic inflammation that affects various organs in the body, including the reproductive system, which is a key factor in male infertility. 1-Deoxynojirimycin (1-DNJ) is a natural alkaloid in mulberry leaves, which has anti-inflammatory capabilities, yet, it's effects on obesity-induced inflammation-related male infertility remain unclear. Therefore, this research investigates the underlying mechanism by which 1-DNJ may mitigate fertility impairment in male mice caused by obesity-related inflammation. Male mice with high-fat diet (HFD)-induced obesity were treated with 1-DNJ or metformin for 8 weeks. Metabolic profiles were evaluated by enzyme method. Reproductive capacity was assessed by sperm viability, motility and counts, immunohistochemistry was performed to evaluate the testicular damage caused by obesity and inflammation. The inflammation was assessed by measuring the levels of tumor necrosis factor α (TNFα), interleukin 1β (IL-1β), and interleukin 6 (IL-6). The activation of IκB kinase β (IKKβ) and nuclear factor κB (NF-κB) was examined using western blot and immunohistochemistry. HFD induced obesity in mice with obvious lipid metabolism disorder. The obese male mice had a decreased testosterone level, impaired sperm motility, and increased inflammatory factors. 1-DNJ treatment improved the testosterone level in the obese mice, ameliorated the testicular structure damage and improve sperm viability. In addition, 1-DNJ treatment inhibited IKKβ/NF-kB signaling pathway and reduced inflammation in obese mice. 1-DNJ can improve the fertility of obese men by reducing obesity as well as obesity-induced inflammation. These findings provide new insights for 1-DNJ to alleviate inflammation caused by obesity and provide future possibilities for treating male infertility.

Influence of antidiabetic drugs on glucose metabolism and immune response in patients with metastatic pancreatic ductal adenocarcinoma receiving gemcitabine plus nab-paclitaxel as first-line treatment

BACKGROUND

Association between pancreatic ductal adenocarcinoma (PDAC) and type 2 diabetes mellitus (DM2) has long been evaluated. Indeed, DM2 can be both an epiphenomenon of PDAC and a risk factor. The present study aimed to investigate the correlation between overall survival (OS) and antidiabetic drugs in patients with metastatic pancreatic ductal adenocarcinoma and DM2.

METHOD

Data from 232 patients were collected retrospectively from 2014 to 2021. 174 from AOU Cagliari Medical Oncology and 58 from AOU Ancona Medical Oncology. All patients received gemcitabine plus nab-paclitaxel first-line chemotherapy. We aimed to evaluate the correlation between DM2, anti-diabetic medications and overall survival. Survival distribution was assessed by Kaplan-Meier curves.

RESULTS

Median age was 68±9, 127 (55%) were male. 138/232 (59%) patients were not affected by DM2, 94/232 (41%) were affected by DM2. 57 were insulin-treated and 37 were metformin-treated. DM2 treated patients showed an higher median overall survival (26 vs 12 months, p = 0,0002). Among DM2 patients insulin-treated and metformin-treated showed an mOS of 21 months and 33 months, respectively.

CONCLUSIONS

Results showed a correlation between treated DM2 and higher mOS in patients with mPDAC. Limitations due to retrospective data collection must be considered. Further studies in this setting are needed.

A new insight into the treatment of diabetes by means of pan PPAR agonists

PPARs stand for 'peroxisome proliferator-activated receptors' and are ligand-activated transcription factors of nuclear hormone receptor superfamily. A list of the most commonly used single receptor PPAR agonists, that is α (alpha) PPAR agonists, β/δ(beta/delta) PPAR agonists, γ(gamma) PPAR agonists, along with pan PPAR agents, that are being researched on, are marketed, are in clinical trials or are being studied for further derivative findings, has been listed. Type 2 diabetes constitutes about 90% of total diabetes cases. Pan PPAR ligands could very well pave the foundation for a new class of agents, that can act on all 3 PPAR receptors, and produce better effects in general, than the individual receptor-acting ligands or dual combination ligands (α/ γ). In this review paper, we have detailed various pan PPAR agonists that can be used to treat type 2 diabetes, which can generate potential derivatives as well.

Metformin Improves the Prognosis of Adult Mice with Sepsis-Associated Encephalopathy Better than That of Aged Mice

Sepsis-associated encephalopathy (SAE) is often associated with increased ICU occupancy and hospital mortality and poor long-term outcomes, with currently no specific treatment. Pathophysiological mechanisms of SAE are complex and may involve activation of microglia, multiple intracranial inflammatory factors, and inflammatory pathways. We hypothesized that metformin may have an effect on microglia, which affects the prognosis of SAE. In this study, metformin treatment of mice with SAE induced by lipopolysaccharide (LPS) reduced the expression of microglia protein and related inflammatory factors. Poor prognosis of SAE is related to increased expression of tumor necrosis factor-α (TNF-α) and interleukin-1 beta (IL-1β) in brain tissues. Levels of inflammatory cytokines produced by LPS-induced SAE mouse microglia were significantly increased compared with those in the sham group. In addition, ionized calcium-binding adapter molecule 1 (Iba-1) was significantly reduced in metformin-treated SAE mice compared with untreated SAE mice, suggesting that metformin can reduce microgliosis and inhibit central nervous system inflammation, thereby improving patient outcomes. In conclusion, our results stipulate that metformin inhibits inflammation through the adenosine 5'-monophosphate (AMP-) activated protein kinase pathway by inhibiting nuclear factor kappa beta (NF-κB). Metformin can partially reverse the severe prognosis caused by sepsis by blocking microglial proliferation and inhibiting the production of inflammatory factors.

Metformin and the heart: Update on mechanisms of cardiovascular protection with special reference to comorbid type 2 diabetes and heart failure

Metformin has been in clinical use for the management of type 2 diabetes for more than 60 years and is supported by a vast database of clinical experience: this includes evidence for cardioprotection from randomised trials and real-world studies. Recently, the position of metformin as first choice glucose-lowering agent has been supplanted to some extent by the emergence of newer classes of antidiabetic therapy, namely the sodium-glucose co-transporter-2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists. These agents have benefitted through support from large cardiovascular outcomes trials with more modern trial designs than earlier studies conducted to assess metformin. Nevertheless, clinical research on metformin continues to further assess its many potentially advantageous effects. Here, we review the evidence for improved cardiovascular outcomes with metformin in the context of the current era of diabetes outcomes trials. Focus is directed towards the potentially cardioprotective actions of metformin in patients with type 2 diabetes and heart failure (HF), now recognised as the most common complication of diabetes.

Mechanistic insight into the role of metformin in Alzheimer's disease

Alzheimer's disease (AD), a type of dementia, is characterized by progressive memory decline and cognition impairment. Despite the considerable body of evidence regarding AD pathophysiology, current therapies merely slow down the disease progression, and a comprehensive therapeutic approach is unavailable. Accordingly, finding an efficient multifunctional remedy is necessary to blunt the increasing rate of AD incidence in the upcoming years. AD shares pathophysiological similarities (e.g., impairment of cognitive functions, insulin sensitivity, and brain glucose metabolism) with noninsulin-dependent diabetes mellitus (NIDDM), which offers the utilization of metformin, a biguanide hypoglycemic agent, as an alternative therapeutic approach in AD therapy. Emerging evidence has revealed the impact of metformin in patients suffering from AD. It has been described that metformin employs multiple mechanisms to improve cognition and memory impairment in pre-clinical AD models, including reduction of hippocampal amyloid-beta (Aβ) plaque and neurofibrillary tangles (NFTs) load, suppression of inflammation, amelioration of mitochondrial dysfunction and oxidative stress, restriction of apoptotic neuronal death, and induction of neurogenesis. This review discusses the pre-clinical evidence, which may shed light on the role of metformin in AD and provide a more comprehensive mechanistic insight for future studies in this area of research.

Targeting Molecular Inflammatory Pathways in Granuloma as Host-Directed Therapies for Tuberculosis

Globally, more than 10 million people developed active tuberculosis (TB), with 1.4 million deaths in 2020. In addition, the emergence of drug-resistant strains in many regions of the world threatens national TB control programs. This requires an understanding of host-pathogen interactions and finding novel treatments including host-directed therapies (HDTs) is of utter importance to tackle the TB epidemic. Mycobacterium tuberculosis (Mtb), the causative agent for TB, mainly infects the lungs causing inflammatory processes leading to immune activation and the development and formation of granulomas. During TB disease progression, the mononuclear inflammatory cell infiltrates which form the central structure of granulomas undergo cellular changes to form epithelioid cells, multinucleated giant cells and foamy macrophages. Granulomas further contain neutrophils, NK cells, dendritic cells and an outer layer composed of T and B lymphocytes and fibroblasts. This complex granulomatous host response can be modulated by Mtb to induce pathological changes damaging host lung tissues ultimately benefiting the persistence and survival of Mtb within host macrophages. The development of cavities is likely to enhance inter-host transmission and caseum could facilitate the dissemination of Mtb to other organs inducing disease progression. This review explores host targets and molecular pathways in the inflammatory granuloma host immune response that may be beneficial as target candidates for HDTs against TB.

Availability, affordability and price components of insulin products in different-level hospital pharmacies: Evidence from two cross-sectional surveys in Nanjing, China

The essential medicine——insulin cannot be easily accessed and afforded in many countries. To help address this issue, we evaluated the availability, affordability and price of insulin products in Nanjing, eastern China. Two cross-sectional studies were conducted in 2016 and 2018. A total of 56 hospital pharmacies were sampled, using a simplified and adapted World Health Organization/Health Action International (WHO/HAI) methodology. Prices were expressed as Median Price Ratios (MPRs) to Australian Pharmaceutical Benefit Scheme (PBS) prices. In addition, we investigated the price components of seven selected insulin products as a case study before and after the Online Centralized Procurement Policy for Hospital Drugs in May, 2018. Affordability was presented as the number of daily wages of the lowest paid unskilled government worker (LPGW) required to purchase 1000IU of insulin based on the average courses of treatment, approximately 30 days’ treatment. The availability of insulin products was very high in secondary hospitals and tertiary hospitals both in 2016 and 2018, but in community hospitals was very low. In 2018, the availability of prandial insulin products showed fluctuation compared to 2016. The availability of pre-mixed human insulin products was over 95% overall, and also very high (80%) in community hospitals in 2018. The prices of insulin products were much lower than PBS prices of Australian in this study, with the MPRs less than 1 (0.32 to 0.71 in 2016 vs. 0.30 to 0.68 in 2018) for all insulin types. But insulin products in Nanjing in 2016 and 2018 were considered unaffordable, because the number of daily wages of the LPGW needed to purchase for the 30 days treatment of insulin products ranged from 2.26 to 8.49 in 2016 and 1.88 to 7.09 in 2018. The manufacturers’ selling price contributed the main part (74.15% to 77.70% before and 74.86% to 91.51% after the implementation of the bidding policy) of the price components of target insulin brands. The availability of insulin products was high in secondary hospitals and tertiary hospitals, but lower in community hospitals. However, the affordability in community hospitals was better than other hospitals, but the insulin products were still unaffordable for patients on low incomes. Further improvements of the availability accessibility and affordability of medicines in advancing health insurance policies and lowering drug prices should be put forward.

Anti-diabetic drugs and weight loss in patients with type 2 diabetes

INTRODUCTION

Obesity is frequently a comorbidity of type 2 diabetes. Even modest weight loss can significantly improve glucose homeostasis and lessen cardiometabolic risk factors in patients with type 2 diabetes, but lifestyle-based weight loss strategies are not long-term effective. There is an increasing need to consider pharmacological approaches to assist weight loss in the so called diabesity syndrome. Aim of this review is to analyze the weight-loss effect of non-insulin glucose lowering drugs in patients with type 2 diabetes.

MATERIAL AND METHODS

A systematic analysis of the literature on the effect of non-insulin glucose lowering drugs on weight loss in patients with type 2 diabetes was performed. For each class of drugs, the following parameters were analyzed: kilograms lost on average, effect on body mass index and body composition.

RESULTS

Our results suggested that anti-diabetic drugs can be stratified into 3 groups based on their efficacy in weight loss: metformin, acarbose, empagliflozin and exenatide resulted in a in a mild weight loss (less than 3.2% of initial weight); canagliflozin, ertugliflozin, dapagliflozin and dulaglutide induces a moderate weight loss (between 3.2% and 5%); liraglutide, semaglutide and tirzepatide resulted in a strong weight loss (greater than 5%).

CONCLUSIONS

This study shows that new anti-diabetic drugs, particularly GLP1-RA and Tirzepatide, are the most effective in inducing weight loss in patients with type 2 diabetes. Interestingly, exenatide appears to be the only GLP1-RA that induces a mild weight loss.

Metformin inhibits polyphosphate-induced hyper-permeability and inflammation

Circulating inflammatory factor inorganic polyphosphate (polyP) released from activated platelets could enhance factor XII and bradykinin resulted in increased capillary leakage and vascular permeability. PolyP induce inflammatory responses through mTOR pathway in endothelial cells, which is being reported in several diseases including atherosclerosis, thrombosis, sepsis, and cancer. Systems and molecular biology approaches were used to explore the regulatory role of the AMPK activator, metformin, on polyP-induced hyper-permeability in different organs in three different models of polyP-induced hyper-permeability including local, systemic short- and systemic long-term approaches in murine models. Our results showed that polyP disrupts endothelial barrier integrity in skin, liver, kidney, brain, heart, and lung in all three study models and metformin abrogates the disruptive effect of polyP. We also showed that activation of AMPK signaling pathway, regulation of oxidant/anti-oxidant balance, as well as decrease in inflammatory cell infiltration constitute a set of molecular mechanisms through which metformin elicits it's protective responses against polyP-induced hyper-permeability. These results support the clinical values of AMPK activators including the FDA-approved metformin in attenuating vascular damage in polyP-associated inflammatory diseases.

Prevention of Hypertensive Disorders of Pregnancy-Is There a Place for Metformin?

The possibility of prophylaxis of hypertensive disorders of pregnancy (HDPs) such as preeclampsia (PE) and pregnancy-induced hypertension is of interest due to the unpredictable course of these diseases and the risks they carry for both mother and fetus. It has been proven that their development is associated with the presence of the placenta, and the processes that initiate it begin at the time of the abnormal invasion of the trophoblast in early pregnancy. The ideal HDP prophylaxis should alleviate the influence of risk factors and, at the same time, promote physiological trophoblast invasion and maintain the physiologic endothelium function without any harm to both mother and fetus. So far, aspirin is the only effective and recommended pharmacological agent for the prevention of HDPs in high-risk groups. Metformin is a hypoglycemic drug with a proven protective effect on the cardiovascular system. Respecting the anti-inflammatory properties of metformin and its favorable impact on the endothelium, it seems to be an interesting option for HDP prophylaxis. The results of previous studies on such use of metformin are ambiguous, although they indicate that in a certain group of pregnant women, it might be effective in preventing hypertensive complications. The aim of this study is to present the possibility of metformin in the prevention of hypertensive disorders of pregnancy with respect to its impact on the pathogenic elements of development

Efficacy and safety of the metformin-mazindol anorectic combination in rat

The current study investigates the anorectic interaction and safety of the mazindol-metformin combination in rats. Isobologram and interaction index were used to determine anorectic interaction between mazindol and metformin in the sweetened milk model. The safety profile of the mazindol-metformin combination was determined by measuring anxiety, blood pressure, hematic biometry and blood chemistry. An acute dose of mazindol and metformin administered per os, individually or as a mixture, has reduced the milk consumption in rats in a dose-dependent manner. Theoretical effective dose 40 (ED40t) did not differ from the experimental effective dose 40 (ED40e) obtained with the mazindol-metformin mixture in the anorexia experiments, by Student's t-test. In addition, the interaction index confirmed the additive anorectic effect between both drugs. A single oral dose of ED40e mazindol-metformin mixture induced anxiolysis in the elevated plus-maze test. Moreover, oral administration of mazindol-metformin combination for 3 months significantly decreased glycemia, but not blood pressure nor other parameters of hematic biometry and blood chemistry. Results suggest that mazindol-metformin combination exerts an additive anorectic effect, as well as anxiolytic and hypoglycemic properties. Mazindol-metformin combination might be useful in obese patients with anxiety disorders or diabetes risk factors.

Metformin activated AMPK signaling contributes to the alleviation of LPS-induced inflammatory responses in bovine mammary epithelial cells

Background

Lipopolysaccharides (LPS) derived from gram-negative bacterial are often regarded as primary inducer of bovine mammary inflammation. This study evaluated the biological response of metformin activated AMPK signaling on LPS-induced inflammatory responses and metabolic changes in primary bovine mammary epithelial cells (pbMEC). The pbMEC were exposed to either 3 mmol/L Metf. for 12 h as Metf. group (Metf.) or 2 μg/mL LPS for 6 h as LPS group (LPS). Cells pretreated with 3 mmol/L metformin for 12 h followed by washing and 2 μg/mL LPS exposure for 6 h were served as ML group (ML). PBS was added to cells as the control group (Con.).

Results

Pre-incubation with Metf. inhibited LPS-induced expression of pro-inflammatory genes (TNF, IL1B, IL6, CXCL8, MYD88 and TLR4) and proteins (IL-1β, TNF-α, NLRP3, Caspase1, ASC) and was accompanied by increased activation of AMPK signaling. Compared with the LPS group, phosphorylation of p65 and IκBα in the ML group were decreased and accumulation of NF-κB in the nucleus was significantly reduced by pretreatment with metformin. Metformin protects the cells from the increase of LPS-induced binding activity of NF-κB on both TNFA and IL1B promoters. Compared with the LPS group, genes (G6PC, PCK2) and proteins (SREBP1, SCD1) related to lipogenesis and carbohydrate metabolism were downregulated while catabolic ones (PPARA, ACSL1, Glut1, HK1) were upregulated in the ML group. Furthermore, increased acetylation of H3K14 by LPS challenge was reversed by pretreatment with metformin.

Conclusion

Altogether, our results indicated that pretreatment with metformin dampens LPS-induced inflammatory responses mediated in part by AMPK/NF-κB/NLRP3 signaling and modification of histone H3K14 deacetylation and metabolic changes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-02797-x.

Extract of Unifloral Camellia sinensis L. Pollen Collected by Apis mellifera L. Honeybees Exerted Inhibitory Effects on Glucose Uptake and Transport by Interacting with Glucose Transporters in Human Intestinal Cells

Bee pollen possesses potential hypoglycemic effects but its inhibitory mechanisms on glucose absorption and transportation in intestinal cells still need to be clarified. Here, we determined the inhibitory effects of bee pollen extract originating from Camellia sinensis L. (BP-Cs) as well as its representative phenolic compounds on glucose uptake and transport through a human intestinal Caco-2 cell monolayer model. It showed that three representative phenolic compounds, including gallic acid (GA), 3-O-[6'-O-(trans-p-coumaroyl)-β-d-glucopyranosyl]kaempferol (K1), and 3-O-[2',6'-di-O-(trans-p-coumaroyl)-β-d-glucopyranosyl]kaempferol (K2), with contents of 27.7 ± 0.86, 9.88 ± 0.54, and 7.83 ± 0.46 μg/mg in BP-Cs extract, respectively, exerted mutual antagonistic actions interacting with glucose transporters to inhibit glucose uptake and transport based on their combination index (CI) and molecular docking analysis. K1, K2, and GA might compete with d-glucose to form hydrogen bonds with the same active residues including GLU-412, GLY-416, GLN-314, and TRP-420 in GLUT2. These findings provide us a deep understanding of the mechanisms underlying the anti-hyperglycemia by bee pollen, which provide a new sight on dietary intervention strategies against diabetes.

Association of metformin monotherapy or combined therapy with cardiovascular risks in patients with type 2 diabetes mellitus

BACKGROUND

Metformin is a first-line drug in type 2 diabetes mellitus (T2DM) treatment, yet whether metformin may increase all-cause or cardiovascular mortality of T2DM patients remains inconclusive.

METHODS

We searched PubMed and Embase for data extracted from inception to July 14, 2020, with a registration in PROSPERO (CRD42020177283). This study included randomized controlled trials (RCT) assessing the cardiovascular effects of metformin for T2DM. This study is followed by PRISMA and Cochrane guideline. Risk ratio (RR) with 95% CI was pooled across trials by a random-effects model. Primary outcomes include all-cause mortality and cardiovascular mortality.

RESULTS

We identified 29 studies that randomly assigned patients with 371 all-cause and 227 cardiovascular death events. Compared with untreated T2DM patients, metformin-treated patients was not associated with lower risk of all-cause mortality (RR: 0.98; 95%CI: 0.69-1.38; P = 0.90), cardiovascular mortality (RR: 1.13; 95% CI: 0.60, 2.15; P = 0.70), macrovascular events (RR: 0.87; 95%CI: 0.70-1.07; P = 0.19), heart failure (RR: 1.02; 95% CI:0.61-1.71; P = 0.95), and microvascular events (RR: 0.78; 95% CI:0.54-1.13; P = 0.19). Combination of metformin with another hypoglycemic drug was associated with higher risk of all-cause mortality (RR: 1.49; 95% CI: 1.02, 2.16) and cardiovascular mortality (RR: 2.21; 95% CI: 1.22, 4.00) compared with hypoglycemic drug regimens with no metformin.

CONCLUSION

The combination of metformin treatment may impose higher risk in all-cause and cardiovascular mortality. This finding, at least in part, shows no evidence for benefits of metformin in combination in terms of all-cause/cardiovascular mortality and cardiovascular events for T2DM. However, the conclusion shall be explained cautiously considering the limitations from UK Prospective Diabetes Study (UKPDS).

Can Metformin Exert as an Active Drug on Endothelial Dysfunction in Diabetic Subjects?

Cardiovascular mortality is a major cause of death among in type 2 diabetes (T2DM). Endothelial dysfunction (ED) is a well-known important risk factor for the development of diabetes cardiovascular complications. Therefore, the prevention of diabetic macroangiopathies by preserving endothelial function represents a major therapeutic concern for all National Health Systems. Several complex mechanisms support ED in diabetic patients, frequently cross-talking each other: uncoupling of eNOS with impaired endothelium-dependent vascular response, increased ROS production, mitochondrial dysfunction, activation of polyol pathway, generation of advanced glycation end-products (AGEs), activation of protein kinase C (PKC), endothelial inflammation, endothelial apoptosis and senescence, and dysregulation of microRNAs (miRNAs). Metformin is a milestone in T2DM treatment. To date, according to most recent EASD/ADA guidelines, it still represents the first-choice drug in these patients. Intriguingly, several extraglycemic effects of metformin have been recently observed, among which large preclinical and clinical evidence support metformin’s efficacy against ED in T2DM. Metformin seems effective thanks to its favorable action on all the aforementioned pathophysiological ED mechanisms. AMPK pharmacological activation plays a key role, with metformin inhibiting inflammation and improving ED. Therefore, aim of this review is to assess metformin’s beneficial effects on endothelial dysfunction in T2DM, which could preempt development of atherosclerosis.

Effects of fitness qigong and tai chi on middle-aged and elderly patients with type 2 diabetes mellitus

Currently, qigong and tai chi exercises are the two most common preventive as well as therapeutic interventions for chronic metabolic diseases such as type 2 diabetes mellitus (T2DM). However, the quantitative evaluation of these interventions is limited. This study aimed to evaluate the therapeutic efficacy of qigong and tai chi intervention in middle-aged and older adults with T2DM. The study included 103 eligible participants, who were randomized to participate for 12 weeks, in one of the following intervention groups for the treatment of T2DM: fitness qigong, tai chi, and control group. Three biochemical measures, including fasting plasma glucose (FPG), glycated hemoglobin (HbA1C), and C-peptide (C-P) levels, assessed at baseline and 12 weeks, served as the primary outcome measures. During the training process, 16 of the 103 participants dropped out. After the 12-week intervention, there were significant influences on HbA1C (F2,83 = 4.88, p = 0.010) and C-P levels (F2,83 = 3.64, p = 0.031). Moreover, significant reduction in C-P levels was observed after 12-week tai chi practice (p = 0.004). Furthermore, there was a significant negative correlation between the duration of T2DM and the relative changes in FPG levels after qigong intervention, and the relative changes in HbA1C levels were positively correlated with waist-to-height ratio after tai chi practice. Our study suggests that targeted qigong exercise might have a better interventional effect on patients with a longer duration of T2DM, while tai chi might be risky for people with central obesity. Trial registration: This trial was registered in Chinese Clinical Trial Registry. The registration number is ChiCTR180020069. The public title is "Health-care qigong · study for the prescription of chronic diabetes intervention."

A randomized controlled trial of metformin on left ventricular hypertrophy in patients with coronary artery disease without diabetes: the MET-REMODEL trial

Aim

We tested the hypothesis that metformin may regress left ventricular hypertrophy (LVH) in patients who have coronary artery disease (CAD), with insulin resistance (IR) and/or pre-diabetes.

Methods and results

We randomly assigned 68 patients (mean age 65 ± 8 years) without diabetes who have CAD with IR and/or pre-diabetes to receive either metformin XL (2000 mg daily dose) or placebo for 12 months. Primary endpoint was change in left ventricular mass indexed to height^1.7 (LVMI), assessed by magnetic resonance imaging. In the modified intention-to-treat analysis (n = 63), metformin treatment significantly reduced LVMI compared with placebo group (absolute mean difference −1.37 (95% confidence interval: −2.63 to −0.12, P = 0.033). Metformin also significantly reduced other secondary study endpoints such as: LVM (P = 0.032), body weight (P = 0.001), subcutaneous adipose tissue (P = 0.024), office systolic blood pressure (BP, P = 0.022) and concentration of thiobarbituric acid reactive substances, a biomarker for oxidative stress (P = 0.04). The glycated haemoglobin A1C concentration and fasting IR index did not differ between study groups at the end of the study.

Conclusion

Metformin treatment significantly reduced LVMI, LVM, office systolic BP, body weight, and oxidative stress. Although LVH is a good surrogate marker of cardiovascular (CV) outcome, conclusive evidence for the cardio-protective role of metformin is required from large CV outcomes trials.

Cardiovascular Effects of Hypoglycemic Agents in Diabetes Mellitus

BACKGROUND

Despite substantial improvements over the years, diabetes mellitus is still associated with cardiovascular disease, heart failure, and excess mortality.

OBJECTIVE

The objective of this article is to examine existing data on the reduction of cardiovascular morbidity and mortality in diabetes. Control of glycemia, lipid levels, and blood pressure are described in brief. The main scope of this article is, however, to review the glucose-independent cardiovascular effect of antidiabetic pharmacological agents (mainly other than insulin).

METHODS

The article is a narrative review based on recently published reviews and meta-analyses complemented with data from individual trials, when relevant.

RESULTS AND DISCUSSION

Older data suggest a cardioprotective role of metformin (an inexpensive and safe drug); a role to date not convincingly challenged. The cardiovascular effects of thiazolidinediones, sulphonylurea, and glinides are debatable. Recent large-scale cardiovascular outcome trials suggest a neutral profile of dipeptidyl peptidase 4 inhibitors, yet provide compelling evidence of cardioprotective effects of glucagon-like 1 receptor antagonists and sodium-glucose transporter 2 inhibitors.

CONCLUSION

Metformin may have a role in primary and secondary prevention of cardiovascular disease; glucagon-like 1 receptor antagonists and sodium-glucose co-transporter 2 inhibitors play a role in secondary prevention of atherosclerotic cardiovascular disease. Sodium-glucose transporter 2 inhibitors have a role to play in both primary and secondary prevention of heart failure; yet, they carry a small risk of the potentially dangerous adverse effect, euglycemic diabetic ketoacidosis.

Metformin monotherapy for adults with type 2 diabetes mellitus

BACKGROUND

Worldwide, there is an increasing incidence of type 2 diabetes mellitus (T2DM). Metformin is still the recommended first-line glucose-lowering drug for people with T2DM. Despite this, the effects of metformin on patient-important outcomes are still not clarified.

OBJECTIVES

To assess the effects of metformin monotherapy in adults with T2DM.

SEARCH METHODS

We based our search on a systematic report from the Agency for Healthcare Research and Quality, and topped-up the search in CENTRAL, MEDLINE, Embase, WHO ICTRP, and ClinicalTrials.gov. Additionally, we searched the reference lists of included trials and systematic reviews, as well as health technology assessment reports and medical agencies. The date of the last search for all databases was 2 December 2019, except Embase (searched up 28 April 2017).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with at least one year's duration comparing metformin monotherapy with no intervention, behaviour changing interventions or other glucose-lowering drugs in adults with T2DM.

DATA COLLECTION AND ANALYSIS

Two review authors read all abstracts and full-text articles/records, assessed risk of bias, and extracted outcome data independently. We resolved discrepancies by involvement of a third review author. For meta-analyses we used a random-effects model with investigation of risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We assessed the overall certainty of the evidence by using the GRADE instrument.

MAIN RESULTS

We included 18 RCTs with multiple study arms (N = 10,680). The percentage of participants finishing the trials was approximately 58% in all groups. Treatment duration ranged from one to 10.7 years. We judged no trials to be at low risk of bias on all 'Risk of bias' domains. The main outcomes of interest were all-cause mortality, serious adverse events (SAEs), health-related quality of life (HRQoL), cardiovascular mortality (CVM), non-fatal myocardial infarction (NFMI), non-fatal stroke (NFS), and end-stage renal disease (ESRD). Two trials compared metformin (N = 370) with insulin (N = 454). Neither trial reported on all-cause mortality, SAE, CVM, NFMI, NFS or ESRD. One trial provided information on HRQoL but did not show a substantial difference between the interventions. Seven trials compared metformin with sulphonylureas. Four trials reported on all-cause mortality: in three trials no participant died, and in the remaining trial 31/1454 participants (2.1%) in the metformin group died compared with 31/1441 participants (2.2%) in the sulphonylurea group (very low-certainty evidence). Three trials reported on SAE: in two trials no SAE occurred (186 participants); in the other trial 331/1454 participants (22.8%) in the metformin group experienced a SAE compared with 308/1441 participants (21.4%) in the sulphonylurea group (very low-certainty evidence). Two trials reported on CVM: in one trial no CVM was observed and in the other trial 4/1441 participants (0.3%) in the metformin group died of cardiovascular reasons compared with 8/1447 participants (0.6%) in the sulphonylurea group (very low-certainty evidence). Three trials reported on NFMI: in two trials no NFMI occurred, and in the other trial 21/1454 participants (1.4%) in the metformin group experienced a NFMI compared with 15/1441 participants (1.0%) in the sulphonylurea group (very low-certainty evidence). One trial reported no NFS occurred (very low-certainty evidence). No trial reported on HRQoL or ESRD. Seven trials compared metformin with thiazolidinediones (very low-certainty evidence for all outcomes). Five trials reported on all-cause mortality: in two trials no participant died; the overall RR was 0.88, 95% CI 0.55 to 1.39; P = 0.57; 5 trials; 4402 participants). Four trials reported on SAE, the RR was 0,95, 95% CI 0.84 to 1.09; P = 0.49; 3208 participants. Four trials reported on CVM, the RR was 0.71, 95% CI 0.21 to 2.39; P = 0.58; 3211 participants. Three trial reported on NFMI: in two trials no NFMI occurred and in one trial 21/1454 participants (1.4%) in the metformin group experienced a NFMI compared with 25/1456 participants (1.7%) in the thiazolidinedione group. One trial reported no NFS occurred. No trial reported on HRQoL or ESRD. Three trials compared metformin with dipeptidyl peptidase-4 inhibitors (one trial each with saxagliptin, sitagliptin, vildagliptin with altogether 1977 participants). There was no substantial difference between the interventions for all-cause mortality, SAE, CVM, NFMI and NFS (very low-certainty evidence for all outcomes). One trial compared metformin with a glucagon-like peptide-1 analogue (very low-certainty evidence for all reported outcomes). There was no substantial difference between the interventions for all-cause mortality, CVM, NFMI and NFS. One or more SAEs were reported in 16/268 (6.0%) of the participants allocated to metformin compared with 35/539 (6.5%) of the participants allocated to a glucagon-like peptide-1 analogue. HRQoL or ESRD were not reported. One trial compared metformin with meglitinide and two trials compared metformin with no intervention. No deaths or SAEs occurred (very low-certainty evidence) no other patient-important outcomes were reported. No trial compared metformin with placebo or a behaviour changing interventions. Four ongoing trials with 5824 participants are likely to report one or more of our outcomes of interest and are estimated to be completed between 2018 and 2024. Furthermore, 24 trials with 2369 participants are awaiting assessment.

AUTHORS' CONCLUSIONS

There is no clear evidence whether metformin monotherapy compared with no intervention, behaviour changing interventions or other glucose-lowering drugs influences patient-important outcomes.

Metformin and cardiorenal outcomes in diabetes: A reappraisal

The guidance issued to the pharmaceutical industry by the US Food and Drug Administration in 2008 has led to the publication of a series of randomized, controlled cardiovascular outcomes trials with newer therapeutic classes of glucose-lowering medications. Several of these trials, which evaluated the newer therapeutic classes of sodium-glucose co-transporter-2 inhibitors and glucagon-like peptide-1 receptor agonists, have reported a reduced incidence of major adverse cardiovascular and/or renal outcomes, usually relative to placebo and standard of care. Metformin was the first glucose-lowering agent reported to improve cardiovascular outcomes in the UK Prospective Diabetes Study (UKPDS) and thus became the foundation of standard care. However, as this clinical trial reported more than 20 years ago, differences from current standards of trial design and evaluation complicate comparison of the cardiovascular profiles of older and newer agents. Our article revisits the evidence for cardiovascular protection with metformin and reviews its effects on the kidney.

The effects of metformin administration on liver enzymes and body composition in non-diabetic patients with non-alcoholic fatty liver disease and/or non-alcoholic steatohepatitis: An up-to date systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. One treatment is the use of metformin but its efficacy remains to be established.

OBJECTIVE

The present systematic review and meta-analysis aimed to provide a more robust examination of the evidence for the effectiveness of metformin for treating non-diabetic NAFLD patients.

METHODS

An extensive literature search was undertaken using online databases (PubMed, Embase, Scopus, Web of Science and Cochrane Library) to detect randomized controlled trials (RCTs) investigating the effect of metformin administration on liver enzymes and body composition in non-diabetic NAFLD patients up to 10 December 2019. A random-effects or fixed-effect models were performed to pool weighted mean difference (WMD) and 95% confidence intervals (CI).

RESULTS

Six RCTs involving 307 individuals were included to the present meta-analysis. Compared to controls, metformin significantly reduced body mass index (BMI) (WMD: -0.77 kg/m², 95 % CI = [-1.46, -0.07], P = 0.03, I² = 0.0 %) and serum aspartate aminotransferase (AST) (WMD: -5.94 U/L, 95 % CI = [-11.51, -0.38], P = 0.03, I² = 67.6 %). Also, body weight (WMD: -2.70 kg, 95 % CI = [-5.49, 0.09], P = 0.05, I² = 33.7%) was marginally significant and serum alanine transaminase (ALT) (WMD: -5.04 U/L, 95 % CI = [-13.92, 3.84], P = 0.26, I² = 60.9 %) was not statistically significant affected by metformin administration. There was no evidence of publication bias.

CONCLUSION

In summary, the present study emphasizes the clinical importance of metformin administration for improving liver function and body composition in non-diabetic NAFLD patients. Moreover, the further large-scale and well-designed RCTs are required to confirm these findings.

Post-Transplantation Diabetes Mellitus

Solid organ transplantation (SOT) is an established therapeutic option for chronic disease resulting from end-stage organ dysfunction. Long-term use of immunosuppression is associated with post-transplantation diabetes mellitus (PTDM), placing patients at increased risk of infections, cardiovascular disease and mortality. The incidence rates for PTDM have varied from 10 to 40% between different studies. Diagnostic criteria have evolved over the years, as a greater understating of PTDM has been reached. There are differences in pathophysiology and clinical course of type 2 diabetes and PTDM. Hence, managing this condition can be a challenge for a diabetes physician, as there are several factors to consider when tailoring therapy for post-transplant patients to achieve better glycaemic as well as long-term transplant outcomes. This article is a detailed review of PTDM, examining the pathogenesis, diagnostic criteria and management in light of the current evidence. The therapeutic options are discussed in the context of their safety and potential drug-drug interactions with immunosuppressive agents.

Why the endothelium? The endothelium as a target to reduce diabetes-associated vascular disease

Over the past 66 years, our knowledge of the role of the endothelium in the regulation of cardiovascular function and dysfunction has advanced from the assumption that it is a single layer of cells that serves as a barrier between the blood stream and vascular smooth muscle to an understanding of its role as an essential endocrine-like organ. In terms of historical contributions, we pay particular credit to (1) the Canadian scientist Dr. Rudolf Altschul who, based on pathological changes in the appearance of the endothelium, advanced the argument in 1954 that "one is only as old as one's endothelium" and (2) the American scientist Dr. Robert Furchgott, a 1998 Nobel Prize winner in Physiology or Medicine, who identified the importance of the endothelium in the regulation of blood flow. This review provides a brief history of how our knowledge of endothelial function has advanced and now recognize that the endothelium produces a plethora of signaling molecules possessing paracrine, autocrine, and, arguably, systemic hormone functions. In addition, the endothelium is a therapeutic target for the anti-diabetic drugs metformin, glucagon-like peptide I (GLP-1) receptor agonists, and inhibitors of the sodium-glucose cotransporter 2 (SGLT2) that offset the vascular disease associated with diabetes.

Use of SGLT-2 Inhibitors in Patients with Type 2 Diabetes Mellitus and Abdominal Obesity: An Asian Perspective and Expert Recommendations

The prevalence of obesity in Asia is of epidemic proportions, with an estimated 1 billion overweight/obese individuals in the region. The majority of patients with type 2 diabetes mellitus (T2DM) are overweight/obese, which increases the risk of cardiorenal outcomes in these patients; hence, sustained reductions in body weight and visceral adiposity are important management goals. However, most of the glucose-lowering therapies such as insulin, sulfonylureas, glinides, and thiazolidinediones induce weight gain, which makes the management of overweight/obese T2DM patients challenging. Sodium-glucose cotransporter-2 (SGLT-2) inhibitors are the only oral glucose-lowering agents that have been shown to reduce body weight and visceral adiposity. In addition, SGLT-2 inhibitors therapy reduces ectopic fat deposition and improves adipose tissue function and weight-related quality of life. In this article, we aim to consolidate the existing literature on the effects of SGLT-2 inhibitors in Asian patients with T2DM and to produce clinical recommendations on their use in overweight or obese patients with T2DM. Recommendations from international and regional guidelines, as well as published data from clinical trials in Asian populations and cardiovascular outcomes trials are reviewed. Based on the available data, SGLT-2 inhibitors represent an evidence-based therapeutic option for the management of overweight/obese patients with T2DM.

GDF-15 as a Weight Watcher for Diabetic and Non-Diabetic People Treated With Metformin

Weight gain and obesity are global health concerns contributing to morbidity with increased risks of cardiovascular disease, diabetes, liver steatohepatitis and cancer. Pharmacological therapies or bariatric surgery are often required for those who fail to adhere to diet and lifestyle modifications. Metformin, a widely used antidiabetic agent, seems to have a health benefit beyond its anti-hyperglycemic properties, with few side effects. Emerging evidence shows weight loss to be associated with metformin in both diabetic and non-diabetic individuals. Recently, the growth differentiation factor 15 (GDF-15), a member of the transforming growth factor beta superfamily, has been identified as a key mediator of metformin-induced weight loss. Metformin increases the secretion of GDF-15, which binds exclusively to glial cell-derived neurotrophic factor family receptor alpha-like (GFRAL). This gut-brain cytokine works as a prominent player in reducing food intake and body weight in health and disease, like anorexia nervosa and cancer. Herein, we critically review advances in the understanding of the weight-reducing effects of metformin via the GDF-15 pathway.

Pleiotropic Activity of Metformin and Its Sulfonamide Derivatives on Vascular and Platelet Haemostasis

As type 2 diabetes mellitus (T2DM) predisposes patients to endothelial cell injury and dysfunction, improvement of vascular function should be an important target for therapy. The aim of this study was to evaluate the effects of metformin, its sulfenamide and sulfonamide derivatives on selected parameters of endothelial and smooth muscle cell function, and platelet activity. Metformin was not found to significantly affect the viability of human umbilical vein endothelial cells (HUVECs) or aortal smooth muscle cells (AoSMC); however, it decreased cell migration by approximately 21.8% in wound healing assays after 24 h stimulation (wound closure 32.5 µm versus 41.5 µm for control). Metformin reduced platelet aggregation manifested by 19.0% decrease in maximum of aggregation (Amax), and 20% reduction in initial platelet aggregation velocity (v0). Furthermore, metformin decreased spontaneous platelet adhesion by 27.7% and ADP-induced adhesion to fibrinogen by 29.6% in comparison to control. Metformin sulfenamide with an n-butyl alkyl chain (compound 1) appeared to exert the most unfavourable effects on AoSMC cell viability (IC50 = 0.902 ± 0.015 μmol/mL), while 4-nitrobenzenesulfonamide (compound 3) and 2-nitrobenzenesulfonamide (compound 4) derivatives of metformin did not affect AoSMC and HUVEC viability at concentrations up to 2.0 μmol/mL. These compounds were also found to significantly reduce migration of smooth muscle cells by approximately 81.0%. Furthermore, sulfonamides 3 and 4 decreased the initial velocity of platelet aggregation by 11.8% and 20.6%, respectively, and ADP-induced platelet adhesion to fibrinogen by 76.3% and 65.6%. Metformin and its p- and o-nitro-benzenesulfonamide derivatives 3, 4 appear to exert beneficial effects on some parameters of vascular and platelet haemostasis.

High-Intensity Interval Training Versus Moderate-Intensity Continuous Training in Middle-Aged and Older Patients with Type 2 Diabetes: A Randomized Controlled Crossover Trial of the Acute Effects of Treadmill Walking on Glycemic Control

Background: This study aimed to compare the acute effects of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) on glycemic control in middle-aged and older patients with type 2 diabetes (T2D), using treadmill walking as aerobic exercise mode. Methods: Fifteen patients with T2D (60.25 ± 3.14 years; glycated hemoglobin 7.03 ± 0.33%; medicated with metformin and/or gliptins), participated in a randomized controlled crossover trial. They underwent three experimental conditions (treadmill walking HIIT session (5 × (3 min at 70% of heart rate reserve (HRR) + 3 min at 30% HRR)); treadmill walking MICT session (30 min at 50% HRR); and a control session of rest (CON)) in random order and in the postprandial state. Measurements of capillary blood glucose (BG) were taken immediately before, during, and until 50 min after the experimental conditions. Results: Both HIIT and MICT treadmill walking sessions reduced BG levels during exercise and laboratory 50 min recovery period compared to CON (time*condition interaction effect; p < 0.001). The effect of HIIT was greater compared with MICT (p = 0.017). Conclusions: Treadmill walking HIIT seems a safe and more effective exercise strategy on immediate acute glycemic control compared with MICT in middle-aged and older patients with T2D under therapy with metformin and/or gliptins. Trial Registration Number: ISRCTN09240628.

Mechanisms of action of metformin with special reference to cardiovascular protection

Management guidelines continue to identify metformin as initial pharmacologic antidiabetic therapy of choice for people with type 2 diabetes without contraindications, despite recent randomized trials that have demonstrated significant improvements in cardiovascular outcomes with newer classes of antidiabetic therapies. The purpose of this review is to summarize the current state of knowledge of metformin's therapeutic actions on blood glucose and cardiovascular clinical evidence and to consider the mechanisms that underlie them. The effects of metformin on glycaemia occur mainly in the liver, but metformin-stimulated glucose disposal by the gut has emerged as an increasingly import site of action of metformin. Additionally, metformin induces increased secretion of GLP-1 from intestinal L-cells. Clinical cardiovascular protection with metformin is supported by three randomized outcomes trials (in newly diagnosed and late stage insulin-treated type 2 diabetes patients) and a wealth of observational data. Initial evidence suggests that cotreatment with metformin may enhance the impact of newer incretin-based therapies on cardiovascular outcomes, an important observation as metformin can be combined with any other antidiabetic agent. Multiple potential mechanisms support the concept of cardiovascular protection with metformin beyond those provided by reduced blood glucose, including weight loss, improvements in haemostatic function, reduced inflammation, and oxidative stress, and inhibition of key steps in the process of atherosclerosis. Accordingly, metformin remains well placed to support improvements in cardiovascular outcomes, from diagnosis and throughout the course of type 2 diabetes, even in this new age of improved outcomes in type 2 diabetes.

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.

Paeonol Ameliorates Glucose and Lipid Metabolism in Experimental Diabetes by Activating Akt

Our previous study proved that paeonol (Pae) could lower blood glucose levels of diabetic mice. There are also a few reports of its potential use for diabetes treatment. However, the role of Pae in regulating glucose and lipid metabolism in diabetes remains largely unknown. Considering the critical role of serine/threonine kinase B (Akt) in glucose and lipid metabolism, we explored whether Pae could improve glucose and lipid metabolism disorders via Akt. Here, we found that Pae attenuated fasting blood glucose, glycosylated serum protein, serum cholesterol and triglyceride (TG), hepatic glycogen, cholesterol and TG in diabetic mice. Moreover, Pae enhanced glucokinase (GCK) and low-density lipoprotein receptor (LDLR) protein expressions, and increased the phosphorylation of Akt. In insulin-resistant HepG2 cells, Pae increased glucose uptake and decreased lipid accumulation. What’s more, Pae elevated LDLR and GCK expressions as well as Akt phosphorylation, which was consistent with the in vivo results. Knockdown and inhibition experiments of Akt revealed that Pae regulated LDLR and GCK expressions through activation of Akt. Finally, molecular docking assay indicated the steady hydrogen bond was formed between Pae and Akt2. Experiments above suggested that Pae ameliorated glucose and lipid metabolism disorders and the underlying mechanism was closely related to the activation of Akt.

Glucose-Lowering Therapies for Cardiovascular Risk Reduction in Type 2 Diabetes Mellitus: State-of-the-Art Review

Type 2 diabetes mellitus (T2DM) is a major cardiovascular (CV) risk factor. Although antihyperglycemic therapies have typically focused on glycemic control, a paradigm shift for the treatment of T2DM has occurred, with an increased focus on CV risk reduction. Clinicians should base their clinical decisions on the beneficial effects of specific glucose-lowering agents on CV outcomes, while avoiding those therapeutic strategies with potential detrimental effects. Importantly, the presence of comorbidities (eg, established cardiovascular diseases, hypertension, obesity) should also guide the clinical decision toward therapies proven to reduce CV outcomes in that specific population. In this state-of-the-art review resulting from a comprehensive literature search (Pubmed, Google Scholar), we summarize the evidence related to the CV outcomes trials reported in the past several decades. Finally, we propose a therapeutic plan for patients with T2DM, suggesting the use of specific glucose-lowering agents based on the characteristics and presence of comorbidities of the individual patient.

The effects of vildagliptin compared with metformin on vascular endothelial function and metabolic parameters: a randomized, controlled trial (Sapporo Athero-Incretin Study 3)

BACKGROUND

Dipeptidyl peptidase-4 (DPP-4) inhibitors may have protective effects in the early stage of atherosclerosis in patients with type 2 diabetes, although similar effects in advanced atherosclerosis were not shown in recent randomized placebo-controlled studies. Therefore, we investigated the efficacy of DPP-4 inhibitor on endothelial function and glycemic metabolism compared with high-dose metformin.

METHODS

In this multicenter, open-labeled, prospective, randomized, parallel-group comparison study, patients with type 2 diabetes treated with low-dose metformin (500-750 mg/day) were enrolled and randomly assigned to a vildagliptin, a DPP-4 inhibitor, add-on group (Vilda) or a double dose of metformin group (high Met) for 12 weeks. Flow-mediated dilation (FMD) and serum metabolic markers were assessed before and after treatment. In addition, glycemic control and metabolic parameters were also assessed.

RESULTS

Ninety-seven subjects (aged 58.7 ± 11.0 years; body mass index, 25.9 ± 4.4 kg/m2; HbA1c, 7.3 ± 0.5%; FMD, 5.8 ± 2.6%) were enrolled. Eight subjects dropped out by the end of the study. There were no significant differences between the two groups in baseline characteristics. After 12 weeks, HbA1c was significantly improved in the Vilda group compared with the high Met group (- 0.80 ± 0.38% vs. - 0.40 ± 0.47%, respectively; p < 0.01). However, there were no significant differences in FMD (- 0.51 [- 1.08-0.06]% vs. - 0.58 [- 1.20-0.04]%). Although the apolipoprotein B/apolipoprotein A1 ratio was significantly reduced in the Vilda group compared with baseline (0.66-0.62; p < 0.01), the change did not differ significantly between the two groups (- 0.04 vs. 0.00; p = 0.27). Adiponectin levels were significantly increased in the Vilda group compared with the high Met group (0.75 μg/mL vs. 0.01 μg/mL; p < 0.01).

CONCLUSIONS

Regardless of glycemic improvement, combination therapy of vildagliptin and metformin did not affect endothelial function but may exert favorable effects on adipokine levels and lipid profile in patients with type 2 diabetes without advanced atherosclerosis.

Value-Based Payments and Incentives to Improve Care: A Case Study of Patients with Type 2 Diabetes in Medicare Advantage

OBJECTIVES

To estimate the impact of increased glycated hemoglobin (A1C) monitoring and treatment intensification for patients with type 2 diabetes (T2D) on quality measures and reimbursement within the Medicare Advantage Star (MA Star) program.

METHODS

The primary endpoint was the share of patients with T2D with adequate A1C control (A1C ≤ 9%). We conducted a simulation of how increased A1C monitoring and treatment intensification affected this end point using data from the National Health and Nutrition Examination Survey and clinical trials. Using the estimated changes in measured A_1C levels, we calculated corresponding changes in the plan-level A_1C quality measure, overall star rating, and reimbursement.

RESULTS

At baseline, 24.4% of patients with T2D in the average plan had poor A1C control. The share of plans receiving the highest A1C rating increased from 27% at baseline to 49.5% (increased monitoring), 36.2% (intensification), and 57.1% (joint implementation of both interventions). However, overall star ratings increased for only 3.6%, 1.3%, and 4.8% of plans, respectively, by intervention. Projected per-member per-year rebate increases under the MA Star program were $7.71 (monitoring), $2.66 (intensification), and $10.55 (joint implementation).

CONCLUSIONS

The simulation showed that increased monitoring and treatment intensification would improve A1C levels; however, the resulting average increases in reimbursement would be small.

Impact of metformin on cardiovascular disease: a meta-analysis of randomised trials among people with type 2 diabetes

AIMS/HYPOTHESIS

Metformin is the most-prescribed oral medication to lower blood glucose worldwide. Yet previous systematic reviews have raised doubts about its effectiveness in reducing risk of cardiovascular disease, the most costly complication of type 2 diabetes. We aimed to systematically identify and pool randomised trials reporting cardiovascular outcomes in which the effect of metformin was 'isolated' through comparison to diet, lifestyle or placebo.

METHODS

We performed an electronic literature search of MEDLINE, EMBASE and the Cochrane Library. We also manually screened the reference lists of previous meta-analyses of trials of metformin identified through a MEDLINE search. We included randomised controlled trials of adults with type 2 diabetes comparing any dose and preparation of oral metformin with no intervention, placebo or a lifestyle intervention and reporting mortality or a cardiovascular outcome.

RESULTS

We included ten articles reporting 13 trials (including a total of 2079 individuals with type 2 diabetes allocated to metformin and a similar number to comparison groups) of which only four compared metformin with placebo and collected data on cardiovascular outcomes. Participants were mainly white, aged ≤65 years, overweight/obese and with poor glycaemic control. Summary estimates were based on a small number of events: 416 myocardial infarctions/ischaemic heart disease events in seven studies and 111 strokes in four studies. The UK Prospective Diabetes Study (UKPDS) contributed the majority of data to the summary estimates, with weights ranging from 52.3% for myocardial infarction to 70.5% for stroke. All outcomes, with the exception of stroke, favoured metformin, with limited heterogeneity between studies, but none achieved statistical significance. Effect sizes (Mantel-Haenszel RR) were: all-cause mortality 0.96 (95% CI 0.84, 1.09); cardiovascular death 0.97 (95% CI 0.80, 1.16); myocardial infarction 0.89 (95% CI 0.75, 1.06); stroke 1.04 (95% CI 0.73, 1.48); and peripheral vascular disease 0.81 (95% CI 0.50, 1.31).

CONCLUSIONS/INTERPRETATION

There remains uncertainty about whether metformin reduces risk of cardiovascular disease among patients with type 2 diabetes, for whom it is the recommended first-line drug. Although this is mainly due to absence of evidence, it is unlikely that a definitive placebo-controlled cardiovascular endpoint trial among people with diabetes will be forthcoming. Alternative approaches to reduce the uncertainty include the use of electronic health records in long-term pragmatic evaluations, inclusion of metformin in factorial trials, publication of cardiovascular outcome data from adverse event reporting in trials of metformin and a cardiovascular endpoint trial of metformin among people without diabetes.

Cardiovascular safety of non-insulin pharmacotherapy for type 2 diabetes

Patients with type 2 diabetes mellitus have a twofold increased risk of cardiovascular mortality compared with non-diabetic individuals. There is a growing awareness that glycemic efficacy of anti-diabetic drugs does not necessarily translate to cardiovascular safety. Over the past few years, there has been a number of trials evaluating the cardiovascular effects of anti-diabetic drugs. In this review, we seek to examine the cardiovascular safety of these agents in major published trials. Metformin has with-stood the test of time and remains the initial drug of choice. The sulfonylureas, despite being the oldest oral anti-diabetic drug, has been linked to adverse cardiovascular events and are gradually being out-classed by the various other second-line agents. The glitazones are contraindicated in heart failure. The incretin-based drugs have been at the fore-front of this era of cardiovascular safety trials and their performances have been reassuring, whereas the meglitinides and the alpha-glucosidase inhibitors still lack cardiovascular outcomes data. The sodium glucose cotransporter-2 inhibitors are an exciting new addition that has demonstrated a potential for cardiovascular benefit. Many of the currently available oral anti-diabetic agents have clinically relevant cardiovascular effects. The optimal approach to the reduction of cardiovascular risk in diabetic patients should focus on aggressive management of the standard cardiovascular risk factors rather than purely on intensive glycemic control.

Investigation of Risk Factors Affecting Lactate Levels in Japanese Patients Treated with Metformin

Metformin is a biguanaide antidiabetic drug used worldwide, and its effectiveness and benefits have already been established. However, the safety of high doses of metformin in Japanese patients, especially in elderly patients with a decreased renal function, remains unclear. Among the side effects of metformin, lactate acidosis is the most problematic due to a high mortality rate. Therefore, we assessed plasma lactate levels in metformin-treated patients to identify independent risk factors for hyperlactemia. 290 outpatients receiving various doses of metformin at our hospital were enrolled between March and July 2014. Serum electrolytes, Cre (creatinine), BUN (blood urea nitrogen), UA (uric acid), HbA1c (hemoglobin A1c), and lactate levels were investigated. Lactate levels did not significantly differ between the elderly (≥75 years) and non-elderly (<75 years) groups. Patients in the elderly group had a significantly lower daily metformin dose and estimated glomerular filtration rate (eGFR), compared with the non-elderly group (both p<0.005). Between with and without hyperlactemia groups, no significant differences were observed in either Cre or age. On the other hand, patients with hyperlactemia had a significantly higher dose of metformin than those without hyperlactemia (p<0.05). In this study, we found that old age and mildly impaired kidney function were not associated with increased lactate levels, and that a higher dose of metformin may be an independent risk factor for elevated lactate levels in Japanese patients.

Practical Review of Oral Antihyperglycemic Agents for Type 2 Diabetes Mellitus

This article gives a practical review of the pharmacology, clinical efficacy, safety, dosing, cost, and place in therapy for oral antihyperglycemic agents used in the treatment of type 2 diabetes mellitus. There are 5 classes of oral antihyperglycemic agents available in the United States: sulfonylurea secretagogues, biguanides, α-glucosidase inhibitors, thiazolidinediones, and nonsulfonylurea secretagogues. These agents have distinct characteristics that help in their selection for the treatment of type 2 diabetes.

Metformin: From Research to Clinical Practice

Metformin is the recommended first-line oral glucose-lowering drug initiated to control hyperglycemia in type 2 diabetes mellitus. It acts in the liver, small intestines, and skeletal muscles with its major effect on decreasing hepatic gluconeogenesis. It is safe, inexpensive, and weight neutral and can be associated with weight loss. It can reduce microvascular complication risk and its use is associated with a lower cardiovascular mortality compared with sulfonylurea therapy. It is also used to delay the onset of type 2 diabetes mellitus, in treating gestational diabetes, and in women with polycystic ovary syndrome.

Cardiovascular effects of anti-diabetes drugs

INTRODUCTION

Cardiovascular disease remains the major contributor to morbidity and mortality in diabetes. From the need to reduce cardiovascular risk in diabetes and to ensure that such risk is not exacerbated by drug treatments, governmental regulators and drug manufacturers have focused on clinical trials evaluating cardiovascular outcomes.

AREAS COVERED

Findings from mechanistic and clinical trials of biguanides, sulfonylureas, thiazolidinediones, dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, and sodium-glucose co-transporter 2 (SGLT-2) inhibitors will be reviewed. These drug classes will be compared within the context of available cardiovascular outcomes data. Clinical implications of new study regulations will be examined.

EXPERT OPINION

Recent cardiovascular studies provide a more comprehensive evaluation of specific anti-diabetes therapy in individuals with high cardiovascular risk. Long-term effects of anti-hyperglycemic agents in patients with lower cardiovascular risk are still speculative. Historical data supports continued use of metformin as a first-line agent. DPP-4 inhibitors and GLP-1 receptor agonists appear to have neutral effects on cardiovascular outcomes. The significantly decreased cardiovascular risk associated with empagliflozin SGLT-2 inhibitor therapy is impressive and may change how practitioners prescribe add-on therapy to metformin.

Randomized clinical trial of the safety and efficacy of sitagliptin and metformin co-administered to Chinese patients with type 2 diabetes mellitus

Introduction

The results of a clinical trial to evaluate the efficacy and safety of initial combination therapy with sitagliptin and metformin in Chinese patients with type 2 diabetes and inadequate glycemic control are reported here.

Materials and Methods

This was a multicenter, randomized, double‐blind, placebo‐controlled, parallel group, 24‐week clinical trial carried out in China. Patients (n = 744) with type 2 diabetes and inadequate glycemic control (glycated hemoglobin ≥7.5 and ≤11.0%) who were either drug‐naïve or washed out of previous therapy were randomized in equal ratios to sitagliptin 100 mg once daily (q.d.; S100), metformin 500 mg twice daily (b.i.d.; M1000), metformin 850 mg b.i.d. (M1700), sitagliptin 50 mg b.i.d. plus metformin 500 mg b.i.d. (S100/M1000), sitagliptin 50 mg b.i.d. plus metformin 850 mg b.i.d. (S100/M1700), or placebo.

Results

The mean baseline glycated hemoglobin in randomized patients was 8.7%. Least squares mean changes from baseline in glycated hemoglobin were −0.59% (placebo), −0.99% (S100), −1.29% (M1000), −1.56% (M1700), −1.67% (S100/M1000) and −1.83% (S100/M1700) (P < 0.05 for each active group vs placebo, for S100/M1700 and S100/M1000 vs S100, and for S100/M1000 vs M1000). All treatments were generally well‐tolerated. The overall incidence of hypoglycemia (symptomatic or asymptomatic) was higher in the two co‐administration groups (S100/M1700 and S100/M1000) compared with the placebo. The incidence of symptomatic hypoglycemia was low, and similar, across all treatment groups. The incidences of gastrointestinal adverse events were generally higher in high‐dose metformin groups than in the placebo group.

Conclusions

In Chinese patients with type 2 diabetes, initial combination therapy with sitagliptin and metformin was generally well‐tolerated, and provided improvement in glycemic control.

New-onset diabetes mellitus after renal transplantation

BACKGROUND AND AIM

Diabetes mellitus is a very common metabolic disease with a rising incidence. It is both a leading cause of chronic renal disease and one of the most serious comorbidities in renal transplant recipients. New-onset diabetes after renal transplantation (NODAT) is associated with poor graft function, higher rates of cardiovascular complications and a poor prognosis. The aim of this paper is to review current knowledge of NODAT including risk factors, diagnosis and management.

METHODS

A MEDLINE search was performed to retrieve both original and review articles addressing the epidemiology, risk factors, screening and management of NODAT. We also focused on microRNAs as potential biomarkers of NODAT.

RESULTS AND CONCLUSION

Understanding the risk factors (both modifiable-e.g. obesity, viruses, and unmodifiable-e.g. age, genetics) may help reduce the incidence and impact of NODAT using pre- and post-transplant management. This can lead to better long-term graft function and general transplant success.