Is metformin still the most efficacious first-line oral hypoglycaemic drug in treating type 2 diabetes? A network meta-analysis of randomized controlled trials

Extensive therapeutic effects, underlying molecular mechanisms and disease treatment prediction of Metformin: a systematic review

Metformin (Met), a first-line management for type 2 diabetes mellitus, has been expansively employed and studied with results indicating its therapeutic potential extending beyond glycemic control. Beyond its established role, this therapeutic drug demonstrates a broad spectrum of action encompassing over 60 disorders, encompassing metabolic conditions, inflammatory disorders, carcinomas, cardiovascular diseases, and cerebrovascular pathologies. There is clear evidence of Met's action targeting specific nodes in the molecular pathways of these diseases and, intriguingly, interactions with the intestinal microbiota and epigenetic processes have been explored. Furthermore, novel Met derivatives with structural modifications tailored to diverse diseases have been synthesized and assessed. This manuscript proffers a comprehensive thematic review of the diseases amenable to Met treatment, elucidates their molecular mechanisms, and employs informatics technology to prospect future therapeutic applications of Met. These data and insights gleaned considerably contribute to enriching our understanding and appreciation of Met's far-reaching clinical potential and therapeutic applicability.

How efficacious are traditional Chinese medicine injections in treating angina pectoris? A network meta-analysis of randomized controlled trials

ETHNOPHARMACOLOGICAL RELEVANCE

Over 50 million adults in China suffer from angina pectoris, which are often treated with traditional Chinese medicine injections (TCMIs). However, the efficacies of TCMIs and conventional drugs as determined by randomized controlled trials (RCTs) were not rigorously compared with one another by network meta-analysis (NMA). This PRISMA-compliant NMA aimed to compare the efficacy and assess the evidence strengths of 24 TCMIs in treating adults with angina pectoris of RCTs.

MATERIALS AND METHODS

Following the protocol (PROSPERO registration number CRD42018117720), the RCTs that compared any TCMI with another TCMI or conventional drug on outcome measures including symptomatic and electrocardiography improvements were included. The quality of included RCTs was assessed with the Cochrane's risk of bias 2 tool. Frequentist statistical analyses were performed, including NMA, pairwise meta-analysis (PMA), subgroup analysis, sensitivity analysis, meta-regression, and publication bias analysis. The certainty of evidence was assessed with the GRADE approach.

RESULTS

Totally, 556 eligible RCTs with 57015 participants were identified while the quality of all but five included RCTs was poor. The significant efficacy estimates and insignificant heterogeneity assessment from PMA and NMA indicated that nearly all TCMIs were more efficacious than conventional treatments for angina pectoris. Adequate subgroup and sensitivity analyses found the robust and consistent results. However, the evidence strengths of meta-analyses were assessed as very low to low due to the high risk of RCTs. The comprehensive efficacy estimates suggested that 4 TCMIs (HH, Honghua injection; HHH, Honghua Huangsesu injection; GLP, Gualoupi injection; and SM, Shenmai injection) was the best anti-anginal drugs for adults with angina pectoris.

CONCLUSION

TCMIs appear to be efficacious for angina pectoris, although evidence evaluation of high-quality RCTs of TCMIs would be necessary. In particular, randomization and blinding procedures of the RCTs should be explicated to meet the CONSORT requirements.

The METRO study: a retrospective analysis of the efficacy of metformin for type 2 diabetes in Japan

Metformin monotherapy as first-line treatment for patients with type 2 diabetes (T2D) has been shown to effectively improve blood glucose levels and motivation to undergo treatment and prevent complications. However, no studies have reported its effect when combined with other drugs or compared the effect based on administration time. This study aimed to investigate the effect of metformin administration in Japanese patients with T2D, examine how the introduction line impacts the effect of metformin, and examine the characteristics of patients demonstrating improved blood glucose levels. Data on characteristics of patients who were newly prescribed metformin with no shifting of hypoglycemic agents in the subsequent 24-week observation period, and their age [mean, 56.8 years], body mass index [mean, 27.5 kg/m²], glycated hemoglobin [HbA1c] [mean, 8.1%], and duration of diabetes [mean, 3.0 years] were obtained from the medical records of 201 patients. The changes in HbA1c by introduction line after 24 weeks were -1.59%, -0.91%, -0.89%, and -0.65% in the first, second, third, and fourth induction lines, respectively; earlier introduction more significantly improved blood glucose. The factors significantly associated with HbA1c changes were early introduction, high baseline HbA1c, high estimated glomerular filtration rate, decreased insulin secretion, short estimated duration of diabetes, and increased metformin dose. Furthermore, factors contributing to the largest HbA1c improvement by metformin were high baseline HbA1c and early administration. Metformin is expected to lower blood glucose levels in Japanese patients with T2D, even in those with decreased insulin secretion, due to its early introduction as a first-line drug.

Metformin-Loaded Polymer-Based Microbubbles/Nanoparticles Generated for the Treatment of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease that is increasingly common all over the world with a high risk of progressive hyperglycemia and high microvascular and macrovascular complications. The currently used drugs in the treatment of T2DM have insufficient glucose control and can carry detrimental side effects. Several drug delivery systems have been investigated to decrease the side effects and frequency of dosage, and also to increase the effect of oral antidiabetic drugs. In recent years, the use of microbubbles in biomedical applications has greatly increased, and research into microactive carrier bubbles continues to generate more and more clinical interest. In this study, various monodisperse polymer nanoparticles at different concentrations were produced by bursting microbubbles generated using a T-junction microfluidic device. Morphological analysis by scanning electron microscopy, molecular interactions between the components by FTIR, drug release by UV spectroscopy, and physical analysis such as surface tension and viscosity measurement were carried out for the particles generated and solutions used. The microbubbles and nanoparticles had a smooth outer surface. When the microbubbles/nanoparticles were compared, it was observed that they were optimized with 0.3 wt % poly(vinyl alcohol) (PVA) solution, 40 kPa pressure, and a 110 μL/min flow rate, thus the diameters of the bubbles and particles were 100 ± 10 μm and 70 ± 5 nm, respectively. Metformin was successfully loaded into the nanoparticles in these optimized concentrations and characteristics, and no drug crystals and clusters were seen on the surface. Metformin was released in a controlled manner at pH 1.2 for 60 min and at pH 7.4 for 240 min. The process and structures generated offer great potential for the treatment of T2DM.

Clinical Effects of Exercise Rehabilitation Combined with Repaglinide in the Treatment of Diabetes

Objective

Diabetes, a common endocrine and metabolic disease in clinical practice, generally manifests a certain defect in insulin secretion due to several factors, thereafter leading to a metabolic disorder such as hyperglycemia. This study was conducted to explore the clinical effects of repaglinide combined with exercise rehabilitation on improving the blood glucose of patients with diabetes.

Methods

In this retrospective study, 100 patients with diabetes treated in our hospital from January 2018 to January 2020 were assessed for eligibility and recruited. They were assigned at a ratio of 1 : 1 to receive either repaglinide (control group) or repaglinide plus exercise rehabilitation (experimental group). Outcome measures include fasting blood glucose, 2 h postprandial blood glucose, glycosylated hemoglobin, time to normal blood glucose, blood glucose fluctuation, insulin dosage, adverse reactions, and blood glucose adequate rate.

Results

All eligible patients showed similar pretreatment fasting blood glucose, glycosylated hemoglobin, and 2 h postprandial blood glucose (P > 0.05). After treatment, repaglinide plus exercise rehabilitation resulted in lower levels of fasting blood glucose, glycosylated hemoglobin, and 2 h postprandial blood glucose versus repaglinide alone (P < 0.05). Repaglinide plus exercise rehabilitation was associated with a significantly shorter time to normal blood glucose and a milder fluctuation versus repaglinide (P < 0.05). The incidence of adverse reactions and blood glucose adequate rate was 6% and 94% in the experimental group and 50% and 52% in the control group, respectively (P < 0.05).

Conclusion

Repaglinide plus exercise rehabilitation results in effective blood glucose control and reduced incidence of adverse reactions and yields a promising efficacy, so it is worthy of clinical promotion and application.

The effect of oral diabetes medications on glycated haemoglobin (HbA1c) in Asians in primary care: a retrospective cohort real-world data study

BACKGROUND

Clinical trials have demonstrated that initiating oral anti-diabetic drugs (OADs) significantly reduce glycated hemoglobin (HbA1c) levels. However, variability in lifestyle modifications and OAD adherence impact on their actual effect on glycemic control. Furthermore, evidence on dose adjustments and discontinuation of OAD on HbA1c is lacking. This study aims to use real-world data to determine the effect of OAD initiation, up-titration, down-titration, and discontinuation on HbA1c levels, among Asian patients managed in primary care.

METHODS

A retrospective cohort study over a 5-year period, from Jan 2015 to Dec 2019 was conducted on a cohort of multi-ethnic adult Asian patients with clinical diagnosis of type 2 diabetes mellitus (T2DM) managed by a network of primary care clinics in Singapore. Nine OADs from five different classes (biguanides, sulphonyurea, dipeptidyl peptidase-4 [DPP-4] inhibitors, sodium-glucose cotransporter-2 [SGLT-2] inhibitors, and alpha-glucosidase inhibitors) were evaluated. Patients were grouped into "No OAD", "Non-titrators," and "Titrators" cohorts based on prescribing patterns. For the "Titrators" cohort, the various OAD titrations were identified. Subsequently, a descriptive analysis of HbA1c values before and after each titration was performed to compute a mean difference for each unique titration identified.

RESULTS

Among the cohort of 57,910 patients, 43,338 of them had at least one OAD titration, with a total of 76,990 pairs of HbA1c values associated with an OAD titration. There were a total of 206 unique OAD titrations. Overall, initiation of OADs resulted in a reduction of HbA1c by 3 to 12 mmol/mol (0.3 to 1.1%), respectively. These results were slightly lower than those reported in clinical trials of 6 to 14 mmol/mol (0.5 to 1.25%). The change of HbA1c levels due to up-titration, down-titration, and discontinuation were -1 to -8 mmol/mol (-0.1 to -0.7%), +1 to 7 mmol/mol (+0.1 to +0.6%), and +2 to 11 mmol/mol (+0.2 to +1.0%), respectively. The HbA1c lowering effect of initiating newer OADs, namely DPP-4 inhibitors and SGLT-2 inhibitors was 8 to 11 mmol/mol (0.7 to 0.9%) and 7 to 11 mmol/mol (0.6 to 1.0%), respectively.

CONCLUSION

The real-world data on Asians with T2DM in this study show that the magnitudes of OAD initiation and dose titration are marginally lower than the results from clinical trials. During shared decision-making in selecting treatment options, the results enable physicians to communicate realistic expectation of the effect of oral medications on the glycemic control of their patients in primary care.

Efficacy and Safety of Metformin Versus the Other Oral Antidiabetic Drugs in Japanese Type 2 Diabetes Patients: A Network Meta-analysis

Introduction

Although metformin is recommended as a first-line treatment for patients with type 2 diabetes (T2D) in Western countries, no specific treatment is recommended in Japan, and various agents are used. Metformin has long been used at low doses in Japan, and information regarding its effect at the maximum maintenance dose is lacking. Here, we compared the efficacy and safety of metformin at 1500 mg/day with those of the other oral anti-diabetic drugs (OADs) approved in Japan.

Methods

Randomized controlled trials comparing a change in hemoglobin A1c (HbA1c) from baseline at 12 weeks or later (ΔHbA1c) among OADs (including placebo) as a first-line treatment in adult patients with T2D were selected by systematic review with comprehensive searching of CENTRAL, MEDLINE, Ichushi Web, and EMBASE and manual searching of clinical trial registries. The ΔHbA1c and incidence of hypoglycemia were compared among OAD treatments using Bayesian network meta-analysis (NMA). The relative risk (RR) of the incidence of hypoglycemia was determined relative to that of placebo.

Results

Forty-six randomized controlled trials were identified in the systematic review, and 37 studies, comprising 38 different types of treatments, including placebos, were selected for the NMA of ΔHbA1c. Compared with metformin 1500 mg/day, 20 OAD treatments were significantly less effective in reducing HbA1c from baseline (differences from metformin 1500 mg/day: 0.40–0.96%). Two treatments (glimepiride 2 mg/day and pioglitazone 45 mg/day) showed greater mean reductions in HbA1c from baseline than metformin 1500 mg/day (− 0.38% and − 0.03%), although these differences were not significant. Regarding the incidence of hypoglycemia, only pioglitazone 30 mg/day among 31 treatments showed a lower RR (< − 0.01), whereas 23 treatments showed a significantly higher RR (1.02–66.71) than metformin 1500 mg/day.

Conclusion

The NMA suggested a preferable efficacy and safety profile of metformin 1500 mg/day compared with the other OADs approved in Japan.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01979-1.

Metformin Repurposing for Parkinson Disease Therapy: Opportunities and Challenges

Parkinson disease (PD) is a severe neurodegenerative disorder that affects around 2% of the population over 65 years old. It is characterized by the progressive loss of nigrostriatal dopaminergic neurons, resulting in motor disabilities of the patients. At present, only symptomatic cures are available, without suppressing disease progression. In this frame, the anti-diabetic drug metformin has been investigated as a potential disease modifier for PD, being a low-cost and generally well-tolerated medication, which has been successfully used for decades in the treatment of type 2 diabetes mellitus. Despite the precise mechanisms of action of metformin being not fully elucidated, the drug has been known to influence many cellular pathways that are associated with PD pathology. In this review, we present the evidence in the literature supporting the neuroprotective role of metformin, i.e., autophagy upregulation, degradation of pathological α-synuclein species, and regulation of mitochondrial functions. The epidemiological studies conducted in diabetic patients under metformin therapy aimed at evaluating the correlation between long-term metformin consumption and the risk of developing PD are also discussed. Finally, we provide an interpretation for the controversial results obtained both in experimental models and in clinical studies, thus providing a possible rationale for future investigations for the repositioning of metformin for PD therapy.

First-line pharmacotherapy for incident type 2 diabetes: Prescription patterns, adherence and associated costs

AIMS

To use real-world prescription data from Alberta, Canada to: (a) describe the prescribing patterns for initial pharmacotherapy for those with newly diagnosed uncomplicated type 2 diabetes; (b) describe medication-taking behaviours (adherence and persistence) in the first year after initiating pharmacotherapy; and (c) explore healthcare system costs associated with prescribing patterns.

METHODS

We employed a retrospective cohort design using linked administrative datasets from 2012 to 2017 to define a cohort of those with uncomplicated incident diabetes. We summarized the initial prescription patterns, adherence and costs (healthcare and pharmaceutical) over the first year after initiation of pharmacotherapy. Using multivariable regression, we determined the association of these outcomes with various sociodemographic characteristics.

RESULTS

The majority of individuals for whom metformin was indicated as first-line therapy received a prescription for metformin monotherapy (89%). Older individuals, those with higher baseline A1C and those with no comorbidities, were most likely to be started on non-metformin agents. Adherence with the initially prescribed regimen was suboptimal overall, with nearly half (48%) being non-adherent over the first year. One-third of those who started metformin discontinued it in the first 3 months. Those started on non-metformin agents had roughly twice the healthcare costs, and five to seven times higher medication costs, compared to those started on metformin, in the first year after starting therapy.

CONCLUSIONS

With the addition of new classes of medications, healthcare providers who look after those with type 2 diabetes have more pharmaceutical options than ever. Most individuals continue to be prescribed metformin monotherapy. However, adherence is suboptimal, and drops off considerably within the first 3 months.

Effect and Safety of Acupuncture for Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis of 21 Randomised Controlled Trials

OBJECTIVE

To evaluate the effects of acupuncture on hypoglycaemic outcomes in type 2 diabetes mellitus (T2DM).

METHODS

PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were searched from inception up to July 2020, to identify randomised controlled trials (RCTs) that enrolled patients with T2DM and compared acupuncture combined with antidiabetic drugs to antidiabetic drugs alone. The primary outcomes were haemoglobin A_1c (HbA_1c) and fasting blood glucose (FBG). The secondary outcomes included 2-h blood glucose (2hBG), fasting insulin (FINS), homeostatic model assessment for insulin resistance (HOMA-IR), and acupuncture-related adverse events. Mean difference (MD) and 95% confidence interval (CI) were used as the effect measure in the meta-analysis. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation tool.

RESULTS

Twenty-one RCTs (n=1,188) were included. The meta-analytic results showed that the acupuncture group had greater reductions in FBG (MD -6.46 mg/dL, 95% CI -11.95 to -0.98; moderate-quality evidence) and HOMA-IR (MD -1.23, 95% CI -2.16 to -0.31; low-quality evidence), but comparable changes in HbA_1c (MD -0.39%, 95% CI -0.84 to 1.61; very-low-quality evidence), 2hBG (MD -4.99 mg/dL, 95% CI -20.74 to 10.76; low-quality evidence), and FINS (MD -1.32 µIU/mL, 95% CI -3.76 to 1.12; low-quality evidence). No data on the incidence of diabetic complications were found. All acupuncture-related adverse events reported were mild.

CONCLUSIONS

The current evidence suggests that acupuncture, as a complementary therapy to antidiabetic drugs, has a small but statistically significant effect on decreasing FBG and improving insulin resistance. The effects of acupuncture on HbA_1c, 2hBG, and FINS remain uncertain. Acupuncture is generally safe in patients with mild diabetes. More evidence for the long-term effects of acupuncture on T2DM is needed. (Trial registration No. CRD42018115639).

Sulfonylureas in the Current Practice of Type 2 Diabetes Management: Are They All the Same? Consensus from the Gulf Cooperation Council (GCC) Countries Advisory Board on Sulfonylureas

Since their inception in the commercial market in the mid-twentieth century, sulfonylureas (SUs) have remained a therapeutic option in the management of type 2 diabetes (T2D). Despite their established glucose-lowering effects, there is no consensus among global experts and modern guidelines regarding the priority of SUs in relation to other therapeutic options, given the lack of evidence that SUs are associated with a low risk of macrovascular events and excess mortality. However, findings from recent trials and real-time observations have resolved this contentious issue somewhat, albeit to varying degrees. The present consensus discusses the role of SUs in contemporary diabetes management in the Gulf Cooperation Council (GCC) countries. Regional experts from these countries gathered virtually to formulate a consensus following presentations of topics relevant to SU therapy with an emphasis on gliclazide, including long-term efficacy, cost, end-organ benefits, and side effects, based on up-to-date evidence. The present narrative review reflects the conclusions of this assembly and provides a platform upon which future guidelines for the use of SUs in the GCC can be tailored.

Effect of Lactobacillus fermentum TKSN041 on improving streptozotocin-induced type 2 diabetes in rats

With the increasing incidence of type 2 diabetes, it is imperative to identify how to effectively prevent or treat this disease. Studies have shown that some lactic acid bacteria can improve type 2 diabetes with almost no side effects. Therefore, in this experimental study, we explored the preventive and therapeutic effects of Lactobacillus fermentum TKSN041 (L. fermentum TKSN041) on streptozotocin-induced type 2 diabetes in rats. The results showed that L. fermentum TKSN041 could reduce the amount of water intake, reduce weight loss, and control the increase in the fasting blood glucose level of diabetic rats. The organ index and tissue section results showed that L. fermentum TKSN041 could reduce the damage caused by diabetes to the liver, kidney, spleen, pancreatic, and brain tissue. Furthermore, L. fermentum TKSN041 decreased the levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL), aminotransferase (AST), alanine aminotransferase (ALT), glycated serum proteins (GSP), malondialdehyde (MDA), interleukin 1 beta (IL-1β), interleukin 6 (IL-6), and endothelin 1 (ET-1) in serum and increased the serum levels of high-density lipoprotein cholesterol (HDL) and interleukin 10 (IL-10). Finally, L. fermentum TKSN041 up-regulated the mRNA and protein expressions of NF-kappa-B inhibitor-α (IκB-α), AMP-activated protein kinase (AMPK), insulin receptor substrate-1 (IRS-1), liver kinase B1 (LKB1), and glucose transporter 4 (GLUT4) and down-regulated those of nuclear factor-κBp65 (NFκB-p65) and tumor necrosis factor alpha (TNF-α). Furthermore, LF-TKSN041 up-regulated the mRNA expressions of peroxisome proliferator-activated receptor γ (PPAR-γ) and down-regulated neuropeptide Y (NPY), sterol regulatory element-binding protein-1 (SREBF-1), and vascular endothelial growth factor (VEGF). These results suggest that L. fermentum TKSN041 may be a useful intervention factor for the prevention or treatment of type 2 diabetes induced by STZ. Clinical trials are needed to further demonstrate its effectiveness.

Metformin, Macrophage Dysfunction and Atherosclerosis

Metformin is one of the most widely prescribed hypoglycemic drugs and has the potential to treat many diseases. More and more evidence shows that metformin can regulate the function of macrophages in atherosclerosis, including reducing the differentiation of monocytes and inhibiting the inflammation, oxidative stress, polarization, foam cell formation and apoptosis of macrophages. The mechanisms by which metformin regulates the function of macrophages include AMPK, AMPK independent targets, NF-κB, ABCG5/8, Sirt1, FOXO1/FABP4 and HMGB1. On the basis of summarizing these studies, we further discussed the future research directions of metformin: single-cell RNA sequencing, neutrophil extracellular traps (NETs), epigenetic modification, and metformin-based combination drugs. In short, macrophages play an important role in a variety of diseases, and improving macrophage dysfunction may be an important mechanism for metformin to expand its pleiotropic pharmacological profile. In addition, the combination of metformin with other drugs that improve the function of macrophages (such as SGLT2 inhibitors, statins and IL-1β inhibitors/monoclonal antibodies) may further enhance the pleiotropic therapeutic potential of metformin in conditions such as atherosclerosis, obesity, cancer, dementia and aging.

Lipidomics characterization of the mechanism of Cynomorium songaricum polysaccharide on treating type 2 diabetes

Although Cynomorium songaricum Rupr. polysaccharide (CSP) has been examined for its effects on glucose regulation, its underlying mechanism is still unclear. To address this issue, a MS-based lipidomics strategy was developed to gain a system-level understanding of the mechanism of CSP on improving type 2 diabetes mellitus (T2DM). UPLC-QTOF/MS and multivariate statistical tools were used to identify the alteration of serum metabolites associated with T2DM and responses to CSP treatment. As a result, 35 potential biomarkers were found and identified in serum, amongst which 26 metabolites were regulated to normal like levels after the administration of CSP. By analyzing the metabolic pathways, glycerophospholipid metabolism was suggested to be closely involved. These results indicated that the intake of CSP exhibited promising anti-diabetic activity, largely due to the regulation of phospholipid metabolism, including phosphatidylcholines, lysophosphatydylcholines, phosphtatidylethanolamines and sphingomyelins.

Research Progress of Herbal Medicines on Drug Metabolizing Enzymes: Consideration Based on Toxicology

The clinical application of herbal medicines is increasing, but there is still a lack of comprehensive safety data and in-depth research into mechanisms of action. The composition of herbal medicines is complex, with each herb containing a variety of chemical components. Each of these components may affect the activity of metabolizing enzymes, which may lead to herb-drug interactions. It has been reported that the combined use of herbs and drugs can produce some unexpected interactions. Therefore, this study reviews the progress of research on safety issues caused by the effects of herbs on metabolizing enzymes with reference to six categories of drugs, including antithrombotic drugs, non-steroidal anti-inflammatory drugs, anti-diabetic drugs, statins lipid-lowering drugs, immunosuppressants, and antineoplastic drugs. Understanding the effects of herbs on the activity of metabolizing enzymes could help avoid the toxicity and adverse drug reactions resulting from the co-administration of herbs and drugs, and help doctors to reduce the risk of prescription incompatibility.

Pharmacological modulation of the hydrogen sulfide (H2 S) system by dietary H2 S-donors: A novel promising strategy in the prevention and treatment of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) represents the most common age-related metabolic disorder, and its management is becoming both a health and economic issue worldwide. Moreover, chronic hyperglycemia represents one of the main risk factors for cardiovascular complications. In the last years, the emerging evidence about the role of the endogenous gasotransmitter hydrogen sulfide (H₂ S) in the pathogenesis and progression of T2DM led to increasing interest in the pharmacological modulation of endogenous "H₂ S-system". Indeed, H₂ S directly contributes to the homeostatic maintenance of blood glucose levels; moreover, it improves impaired angiogenesis and endothelial dysfunction under hyperglycemic conditions. Moreover, H₂ S promotes significant antioxidant, anti-inflammatory, and antiapoptotic effects, thus preventing hyperglycemia-induced vascular damage, diabetic nephropathy, and cardiomyopathy. Therefore, H₂ S-releasing molecules represent a promising strategy in both clinical management of T2DM and prevention of macro- and micro-vascular complications associated to hyperglycemia. Recently, growing attention has been focused on dietary organosulfur compounds. Among them, garlic polysulfides and isothiocyanates deriving from Brassicaceae have been recognized as H₂ S-donors of great pharmacological and nutraceutical interest. Therefore, a better understanding of the therapeutic potential of naturally occurring H₂ S-donors may pave the way to a more rational use of these nutraceuticals in the modulation of H₂ S homeostasis in T2DM.

Pleiotropic ameliorative effects of ellagitannin geraniin against metabolic syndrome induced by high-fat diet in rats

OBJECTIVES

Metabolic syndrome (MetS), a multiplex risk factor for cardiovascular disease and type 2 diabetes, is increasingly prevalent worldwide. Ellagitannin geraniin, a polyphenol found in the rind of rambutan (Nephelium lappaceum), has demonstrated therapeutic effects against metabolism dysfunction. The aim of this study was to characterize the metabolic effects and possible mechanism of geraniin in rats with MetS induced by a high-fat diet (HFD).

METHODS

MetS was induced in Sprague Dawley rats on an HFD, followed by a daily oral gavage of geraniin (25 mg/kg) for 4 wk. The outcomes of geraniin-treated rats were compared with those of untreated rats on either a control diet or an HFD and with rats with MetS treated with metformin on a daily basis (200 mg/kg).

RESULTS

The supplementation of geraniin ameliorated multiple metabolic abnormalities caused by HFD, including hypertension, impaired glucose and lipid metabolism, ectopic fat deposition in the visceral fat and liver, and disturbed antioxidant mechanism and inflammatory response. The benefits conferred by geraniin were comparable to metformin. Transcriptomic analysis revealed a profound influence of geraniin on the hepatic expression profiles. The lipid and steroid metabolic processes that were aberrantly activated by HFD were suppressed by geraniin. Based on the differential transcriptomes, geraniin also exerted a significant modulatory effect on the expression of mitochondrial genes, potentially influencing the mitochondrial activity and leading to the observed beneficial effects.

CONCLUSION

Geraniin supplementation mitigated metabolic anomalies of MetS in rats, making it an attractive drug candidate for further investigation.

Comparative Effectiveness of Glucose-Lowering Drugs for Type 2 Diabetes: A Systematic Review and Network Meta-analysis

BACKGROUND

Several pharmacologic options for type 2 diabetes are available.

PURPOSE

To compare benefits and harms of glucose-lowering drugs in adults with type 2 diabetes.

DATA SOURCES

Several databases from inception through 18 December 2019 and ClinicalTrials.gov on 10 April 2020.

STUDY SELECTION

English-language randomized trials that had at least 24 weeks of intervention and assessed the effects of glucose-lowering drugs on mortality, glycemic, and vascular outcomes.

DATA EXTRACTION

Pairs of reviewers extracted data and appraised risk of bias.

DATA SYNTHESIS

453 trials assessing 21 antidiabetic interventions from 9 drug classes were included. Interventions included monotherapies (134 trials), add-on to metformin-based therapies (296 trials), and monotherapies versus add-on to metformin therapies (23 trials). There were no differences between treatments in drug-naive patients at low cardiovascular risk. Insulin regimens and specific glucagon-like peptide-1 receptor agonists (GLP-1 RAs) added to metformin-based background therapy produced the greatest reductions in hemoglobin A_1c level. In patients at low cardiovascular risk receiving metformin-based background treatment (298 trials), there were no clinically meaningful differences between treatments for mortality and vascular outcomes. In patients at increased cardiovascular risk receiving metformin-based background treatment (21 trials), oral semaglutide, empagliflozin, liraglutide, extended-release exenatide, and dapagliflozin reduced all-cause mortality. Oral semaglutide, empagliflozin, and liraglutide also reduced cardiovascular death. Odds of stroke were lower with subcutaneous semaglutide and dulaglutide. Sodium-glucose cotransporter-2 (SGLT-2) inhibitors reduced heart failure hospitalization and end-stage renal disease. Subcutaneous semaglutide and canagliflozin increased diabetic retinopathy and amputation, respectively.

LIMITATION

Inconsistent definitions of cardiovascular risk and low-level confidence in some estimates for patients at low cardiovascular risk.

CONCLUSION

In diabetic patients at low cardiovascular risk, no treatment differs from placebo for vascular outcomes. In patients at increased cardiovascular risk receiving metformin-based background therapy, specific GLP-1 RAs and SGLT-2 inhibitors have a favorable effect on certain cardiovascular outcomes.

PRIMARY FUNDING SOURCE

European Foundation for the Study of Diabetes, supported by an unrestricted educational grant from AstraZeneca. (PROSPERO: CRD42019122043).

Suppression of type 2 diabetes mellitus-induced aortic ultrastructural alterations in rats by insulin: an association of vascular injury biomarkers

Diabetes represents a major public health problem and an estimated 70% of people with diabetes die of cardiovascular complications. The protective effect of insulin treatment against ultrastructural damage to the tunica intima and tunica media of the aorta induced by type 2 diabetes mellitus (T2DM) has not been investigated before using transmission electron microscopy (TEM). Therefore, we induced T2DM in rats using high fat diet and streptozotocin (50 mg/kg) and administered insulin daily by i.v injection for 8 weeks to the treatment group. Whereas, the T2DM control group were left untreated for the duration of the experiment. A comparison was also made between the effect of insulin on aortic tissue and the blood level of biomarkers of vascular injury, inflammation, and oxidative stress. T2DM induced profound ultrastructural damage to the aortic endothelium and vascular smooth muscle cells, which were substantially protected with insulin. Furthermore, insulin returned blood sugar to a control level and significantly (p < .05) inhibited diabetic up-regulation of endothelial and leukocyte intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion protein 1 (VCAM-1), endothelial cell adhesion molecules, P-selectin and E-selectin, tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), and malondialdehyde (MDA). Furthermore, insulin augmented the blood level of the anti-oxidant enzyme superoxide dismutase (SOD). We conclude that in a rat model of T2DM, insulin treatment substantially reduces aortic injury secondary to T2DM for a period of 8 weeks, possibly due to the inhibition of hyperglycemia, vascular activation, inflammation, and oxidative stress.

Associations between taste preferences and chronic diseases: a population-based exploratory study in China

OBJECTIVE

To explore the associations between dietary tastes and chronic diseases quantitatively.

DESIGN

We used the Geodetector method to establish associations between seven tastes and a variety of chronic diseases from the perspective of spatial stratified heterogeneity and explained the effects of dietary tastes on the spatial distribution of chronic diseases.

SETTING

We used crowdsourcing online recipe data to extract multiple taste information about cuisines, combined with point of interest data on categorised restaurant data in different regions, to quantitatively analyse the taste preferences of people in different regions.

PARTICIPANTS

Crowdsourcing online recipe data and restaurant data in different regions.

RESULTS

The results showed that sixteen diseases were significantly associated with dietary tastes among the seventy-one types of chronic diseases. Compared with the effects of individual tastes, the interactions of tastes increased the risk of sixteen diseases, and many combinations of tastes produced nonlinear enhancement effects on the risk for diseases.

CONCLUSIONS

This study presents a quantitative study approach based on the crowdsourcing of data to explore potential health risk factors, which can be applied to the exploratory analysis of disease aetiology and help public health authorities to develop corresponding interventions.

Biguanides Induce Acute de novo Lipogenesis in Human Primary Sebocytes

Introduction

Acne arises during puberty, in part, due to elevated hormones and growth factors which stimulate de novo lipogenesis (DNL) in primary sebocytes to significantly increase sebum production. Oral isotretinoin is an effective acne therapy, reducing sebum production through inducing apoptosis in sebocytes. However, isotretinoin is teratogenic and has additional unwanted side effects, including an initial acne flare-up, which limits its utility. The biguanide, metformin has been found to alleviate severe acne in women with polycystic ovary syndrome (PCOS) through normalization of their insulin and androgen hormone levels. Metformin’s broader effectiveness to improve acne in non-PCOS populations lacks significant clinical support. In an effort to determine whether biguanides directly affect sebogenesis, we investigated their ability to alter DNL in cell-based assays in vitro.

Methods

De novo lipogenesis was measured in human primary sebocytes using [14C]-acetate labeling. Lipid species analysis was performed by extracting newly synthesized lipids and subjecting them to thin layer chromatography. Gene expression changes in sebocytes were identified through qPCR analysis of isolated RNA. Metabolic parameters including oxygen consumption rate, lactate production and activation of adenosine monophosphate-dependent protein kinase (AMPK) were assessed in human primary sebocytes.

Results

Using human primary sebocytes, we found that biguanides, isotretinoin and azithromycin induced an acute dose and time-dependent increase in [14C]-acetate labeling of neutral lipids, while AICAR, an AMPK activator, inhibited this DNL response. Biguanides did not activate AMPK in sebocytes, however, they significantly reduced oxygen consumption rate and increased lactate production. Treatment with biguanides, but not isotretinoin, significantly upregulated ACSS2 gene expression in primary sebocytes and showed synergism with lipogenic activators to induce DNL genes.

Discussion

These changes are consistent with an acute increase in sebocyte lipogenesis and support the potential of biguanides to cause an initial flare-up in patients suffering from severe acne.

Metformin inhibits IL-1β secretion via impairment of NLRP3 inflammasome in keratinocytes: implications for preventing the development of psoriasis

Psoriasis is a systemic inflammatory disease significantly associated with comorbidities including type 2 diabetes mellitus (T2DM). Metformin is utilized as a first-line agent for treating T2DM. Although metformin reportedly inhibits mature IL-1β secretion via NLRP3 inflammasome in macrophages of T2DM patients, it remains unclear whether it affects skin inflammation in psoriasis. To test this, we analysed normal human epidermal keratinocytes (NHEKs), a major skin component, stimulated with the key mediators of psoriasis development, TNF-α and IL-17A. This stimulation induced the upregulation of pro-IL-1β mRNA and protein levels, and subsequently mature IL-1β secretion, which was inhibited by metformin treatment. To further reveal the mechanism involved, we examined how metformin treatment affected NLRP3 inflammasome activated by TNF-α and IL-17A stimulation. We found that this treatment downregulated caspase-1 expression, a key mediator of NLRP3 inflammasome. Furthermore, inhibitors of AMPK and SIRT1 abrogated the downregulation of caspase-1 induced by metformin treatment, indicating that AMPK and SIRT1 are essential for the inhibitory effect on NLRP3 inflammasome in NHEKs. As IL-1β stimulation induced upregulation of IL-36γ, CXCL1, CXCL2, CCL20, S100A7, S100A8 and S100A9 mRNA and protein levels in NHEKs, we examined whether metformin treatment affects such gene expression. Metformin treatment inhibited upregulation of IL-36γ, CXCL1, CXCL2, CCL20, S100A7, S100A8 and S100A9 mRNA and protein levels induced by TNF-α and IL-17A stimulation. Finally, we examined whether metformin administration affected psoriasis development in an imiquimod-induced mouse psoriasis model. Oral metformin treatment significantly decreased ear thickness, epidermal hyperplasia and inflammatory cell infiltration. A cytokine profile in the epidermis under metformin treatment showed that IL-1β, Cxcl1, Cxcl2, S100a7, S100a8 and S100A9 mRNA levels were downregulated compared with control levels. These results indicate that metformin administration prevented psoriasis development in vivo. Collectively, our findings suggest that metformin-mediated anti-psoriatic effects on the skin have the potential for treating psoriasis in T2DM patients.

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

Background

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

Methods

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

Results

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

Conclusions

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

Design and synthesis of tricyclic terpenoid derivatives as novel PTP1B inhibitors with improved pharmacological property and in vivo antihyperglycaemic efficacy

Overexpression of protein tyrosine phosphatase 1B (PTP1B) induces insulin resistance in various basic and clinical research. In our previous work, a synthetic oleanolic acid (OA) derivative C10a with PTP1B inhibitory activity has been reported. However, C10a has some pharmacological defects and cytotoxicity. Herein, a structure-based drug design approach was used based on the structure of C10a to elaborate the smaller tricyclic core. A series of tricyclic derivatives were synthesised and the compounds 15, 28 and 34 exhibited the most PTP1B enzymatic inhibitory potency. In the insulin-resistant human hepatoma HepG2 cells, compound 25 with the moderate PTP1B inhibition and preferable pharmaceutical properties can significantly increase insulin-stimulated glucose uptake and showed the insulin resistance ameliorating effect. Moreover, 25 showed the improved in vivo antihyperglycaemic potential in the nicotinamide–streptozotocin-induced T2D. Our study demonstrated that these tricyclic derivatives with improved molecular architectures and antihyperglycaemic activity could be developed in the treatment of T2D.

MTNR1B Gene Polymorphisms Are Associated With the Therapeutic Responses to Repaglinide in Chinese Patients With Type 2 Diabetes Mellitus

The objective of this study was to investigate whether MTNR1B gene variants influence repaglinide response in Chinese patients with newly diagnosed type 2 diabetes mellitus (T2DM). A total of 300 patients with T2DM and 200 control subjects were enrolled to identify MTNR1B rs10830963 and rs1387153 genotypes by real-time polymerase chain reaction (PCR), with subsequent high-resolution melting (HRM) analysis. Ninety-five patients with newly diagnosed T2DM were randomly selected to undergo 8 weeks of repaglinide treatment (3 mg/day). After 8-week repaglinide monotherapy, patients with at least one G allele of MTNR1B rs10830963 showed a smaller decrease in fasting plasma glucose (FPG) (P = 0.031) and a smaller increase in homeostasis model assessment for beta cell function (HOMA-B) (P = 0.002) levels than those with the CC genotype did. The T allele carriers at rs1387153 exhibited a smaller decrease in FPG (P = 0.007) and smaller increases in postprandial serum insulin (PINS) (P = 0.016) and HOMA-B (P < 0.001) levels compared to individuals with the CC genotype. These data suggest that the MTNR1B rs10830963 and rs1387153 polymorphisms are associated with repaglinide monotherapy efficacy in Chinese patients with T2DM.

Gestational diabetes mellitus

Hyperglycaemia that develops during pregnancy and resolves after birth has been recognized for over 50 years, but uniform worldwide consensus is lacking about threshold hyperglycaemic levels that merit a diagnosis of 'gestational diabetes mellitus' (GDM) and thus treatment during pregnancy. GDM is currently the most common medical complication of pregnancy, and prevalence of undiagnosed hyperglycaemia and even overt diabetes in young women is increasing. Maternal overweight and obesity, later age at childbearing, previous history of GDM, family history of type 2 diabetes mellitus and ethnicity are major GDM risk factors. Diagnosis is usually performed using an oral glucose tolerance test (OGTT), although a non-fasting, glucose challenge test (GCT) is used in some parts of the world to screen women for those requiring a full OGTT. Dietary modification and increased physical activity are the primary treatments for GDM, but pharmacotherapy, usually insulin, is used when normoglycaemia is not achieved. Oral hypoglycaemic agents, principally metformin and glibenclamide (glyburide), are also used in some countries. Treatment improves immediate pregnancy outcomes, reducing excess fetal growth and adiposity and pregnancy-related hypertensive disorders. GDM increases the risk of long-term complications, including obesity, impaired glucose metabolism and cardiovascular disease, in both the mother and infant. Optimal management of mother and infant during long-term follow-up remains challenging, with very limited implementation of preventive strategies in most parts of the world.