The place of sulfonylureas in the therapy for type 2 diabetes mellitus

Characterization of Plant-Derived Natural Inhibitors of Dipeptidyl Peptidase-4 as Potential Antidiabetic Agents: A Computational Study

Diabetes, characterized by elevated blood sugar levels, poses significant health and economic risks, correlating with complications like cardiovascular disease, kidney failure, and blindness. Dipeptidyl peptidase-4 (DPP-4), also referred to as T-cell activation antigen CD26 (EC 3.4.14.5.), plays a crucial role in glucose metabolism and immune function. Inhibiting DPP-4 was anticipated as a potential new therapy for diabetes. Therefore, identification of plant-based natural inhibitors of DPP-4 would help in eradicating diabetes worldwide. Here, for the identification of the potential natural inhibitors of DPP-4, we developed a phytochemicals library consisting of over 6000 phytochemicals detected in 81 medicinal plants that exhibited anti-diabetic potency. The library has been docked against the target proteins, where isorhamnetin, Benzyl 5-Amino-5-deoxy-2,3-O-isopropyl-alpha-D-mannofuranoside (DTXSID90724586), and 5-Oxo-7-[4-(trifluoromethyl) phenyl]-4H,6H,7H-[1,2]thiazolo[4,5-b]pyridine 3-carboxylic acid (CHEMBL3446108) showed binding affinities of -8.5, -8.3, and -8.3 kcal/mol, respectively. These compounds exhibiting strong interactions with DPP-4 active sites (Glu205, Glu206, Tyr547, Trp629, Ser630, Tyr662, His740) were identified. ADME/T and bioactivity predictions affirmed their pharmacological safety. Density functional theory calculations assessed stability and reactivity, while molecular dynamics simulations demonstrated persistent stability. Analyzing parameters like RMSD, RG, RMSF, SASA, H-bonds, MM-PBSA, and FEL confirmed stable protein-ligand compound formation. Principal component analysis provided structural variation insights. Our findings suggest that those compounds might be possible candidates for developing novel inhibitors targeting DPP-4 for treating diabetes.

Metformin HCl-loaded transethosomal gel; development, characterization, and antidiabetic potential evaluation in the diabetes-induced rat model

Herein we designed, optimized, and characterized the Metformin Hydrochloride Transethosomes (MTF-TES) and incorporate them into Chitosan gel to develop Metformin Hydrochloride loaded Transethosomal gel (MTF-TES gel) that provides a sustained release, improved transdermal flux and improved antidiabetic response of MTF. Design Expert® software (Ver. 12, Stat-Ease, USA) was applied for the statistical optimization of MTF-TES. The formulation with Mean Particle Size Distribution (MPSD) of 165.4 ± 2.3 nm, Zeta Potential (ZP) of -21.2 ± 1.9 mV, Polydispersity Index (PDI) of 0.169 ± 0.033, and MTF percent Entrapment Efficiency (%EE) of 89.76 ± 4.12 was considered to be optimized. To check the chemical incompatibility among the MTF and other formulation components, Fourier Transform Infrared (FTIR) spectroscopy was performed and demonstrated with no chemical interaction. Surface morphology, uniformity, and segregation were evaluated through Transmission Electron Microscopy (TEM). It was revealed that the nanoparticles were spherical and round in form with intact borders. The fabricated MTF-TES has shown sustained release followed by a more pronounced effect in MTF-TES gel as compared to the plain MTF solution (MTFS) at a pH of 7.4. The MTF-TES has shown enhanced permeation followed by MTF-TES gel as compared to the MTFS at a pH of 7.4. In vivo antidiabetic assay was performed and results have shown improved antidiabetic potential of the MTF-TES gel, in contrast to MTF-gel. Conclusively, MTF-TES is a promising anti-diabetic candidate for transdermal drug delivery that can provide sustained MTF release and enhanced antidiabetic effect.

Identification and screening of potential inhibitors obtained from Plumeria rubra L. compounds against type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is the inability of the body's cells to retaliate to insulin, which can periodically culminate into absolute insulin deficiency. Hyperinsulinemia can be alleviated by administering oral medications or insulin. Prevailing medicaments engender repercussions with prolonged use, as they transmute to an inefficacious form. Hence, it will be advantageous to design plant-derived antihyperglycemic drugs with remarkable efficacy and safety quotients to address T2DM and associated comorbidities. Based on prior research, we have identified 7 novel phytocompounds from Plumeria rubra L. and 5 co-crystals that serve as an important residence for T2DM. The compounds are assessed for their inhibitory activity and dynamic stability against five major receptors which are responsible for T2DM. Additionally, in silico ADMET assessment followed by GPU-enabled GROMACS was performed on the selected compounds. The results demonstrated that β-d-Hexaglucoside had the highest binding affinity, hydrophobicity and bond length in contrast to all the targeted receptors. β-d-Hexaglucoside was subjected to dynamic simulation to analyze the root mean square deviation and root mean square fluctuation graph rates using the GROMOS force field in GROMACS software. Furthermore, β-d-Hexaglucoside exhibited inhibitory activity against diabetic receptors with a docking score of -9.5 kcal/mol. The current study proposes β-d-Hexaglucoside as a potential candidate for in-vitro or pre-clinical investigations to ameliorate T2DM management.Communicated by Ramaswamy H. Sarma.

Protective effects and mechanisms of opuntia polysaccharide in animal models of diabetes mellitus: A systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Opuntia speciesis used in traditional medicine to treat diabetes mellitus (DM). Polysaccharide is one of the main components of Opuntia. Opuntia polysaccharide (OPS) is a kind of natural active macromolecular substance, numerous animal experiments have been conducted to treat DM, however, its protective effect and mechanism in animal models of DM has not been clarified.

AIM OF THE STUDY

The aim of this study is to evaluate the efficacy of OPS on DM through a stematic review and meta-analysis of animal models, and whether its improves blood glucose (BG) levels, body weight (BW), food intake, water intake, and lipid levels, and to summarize the potential mechanism of OPS in the treatment of DM.

MATERIALS AND METHODS

We searched relevant Chinese and English databases from the date of construction to March 2022, including PubMed (MEDLINE), Embase, Cochrane Library, Scopus and Web of Science, China National Knowledge Infrastructure (CNKI), Chinese Biomedicine Literature Database (CBM), Chinese Science and Technology Periodicals Database (VIP), Wanfang Database. 16 studies were included for meta-analysis.

RESULTS

The results showed that compared with the model group, the OPS significantly improved BG, BW, food intake, water intake, total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C). Meta-regression and subgroup analysis showed that intervention dose, animal species, duration and modeling method may be the source of the heterogeneity. There was no statistical difference between the positive control group and the OPS treatment group in improving BW, food intake, water intake, TC, TG, HDL-C, and LDL-C.

CONCLUSIONS

OPS can effectively improve the symptoms of hyperglycemia, polydipsia, polyphagia, low body weight, and dyslipidemia in DM animals. The possible protective mechanisms of OPS on DM animals are immune regulation, repair of damaged pancreatic β cells, and inhibition of oxidative stress and cell apoptosis.

Venom Peptides, Polyphenols and Alkaloids: Are They the Next Antidiabetics That Will Preserve β-Cell Mass and Function in Type 2 Diabetes?

Improvement of insulin secretion by pancreatic β-cells and preservation of their mass are the current challenges that future antidiabetic drugs should meet for achieving efficient and long-term glycemic control in patients with type 2 diabetes (T2D). The successful development of glucagon-like peptide 1 (GLP-1) analogues, derived from the saliva of a lizard from the Helodermatidae family, has provided the proof of concept that antidiabetic drugs directly targeting pancreatic β-cells can emerge from venomous animals. The literature reporting on the antidiabetic effects of medicinal plants suggests that they contain some promising active substances such as polyphenols and alkaloids, which could be active as insulin secretagogues and β-cell protectors. In this review, we discuss the potential of several polyphenols, alkaloids and venom peptides from snake, frogs, scorpions and cone snails. These molecules could contribute to the development of new efficient antidiabetic medicines targeting β-cells, which would tackle the progression of the disease.

Pancreatic Islets as a Target of Adipokines

Rising rates of obesity are intricately tied to the type 2 diabetes epidemic. The adipose tissues can play a central role in protection against or triggering metabolic diseases through the secretion of adipokines. Many adipokines may improve peripheral insulin sensitivity through a variety of mechanisms, thereby indirectly reducing the strain on beta cells and thus improving their viability and functionality. Such effects will not be the focus of this article. Rather, we will focus on adipocyte-secreted molecules that have a direct effect on pancreatic islets. By their nature, adipokines represent potential druggable targets that can reach the islets and improve beta-cell function or preserve beta cells in the face of metabolic stress. © 2022 American Physiological Society. Compr Physiol 12:1-27, 2022.

Treatment of diabetes mellitus has borne much fruit in the prevention of cardiovascular disease

Cardiovascular (CV) disease is the most alarming complication of diabetes mellitus (DM), and a strategy aiming at cardiovascular event prevention in diabetes mellitus has long been debated. Large landmark clinical trials have shown cardiovascular benefits of intensive glycemic control as a ‘legacy effect’ in newly diagnosed type 2 diabetes mellitus. In contrast, we have learned that excessive intervention aimed at strong glycemic control could cause unexpected cardiovascular death in patients who are resistant to treatments against hyperglycemia. It has also been shown that the comprehensive multifactorial intervention for cardiovascular risk factors that was advocated in the current guideline provided substantial cardiovascular event reduction. The impact of classical antidiabetic agents launched before 1990s on cardiovascular events is controversial. Although there are many clinical or observational studies assessing the impact of those agents on cardiovascular events, the conclusions are inconsistent owing to variable patient backgrounds and concomitant antidiabetic agents among the studies. Moreover, most of them were not large‐scale, randomized, cardiovascular outcome trials. In contrast, GLP‐1RA (glucagon‐like peptide‐1 receptor agonist) and SGLT2 (sodium‐glucose cotransporter 2) inhibitors have demonstrated undeniable cardiovascular benefits in large‐scale, randomized, controlled trials. Whereas GLP‐1RAs decrease atherosclerotic disease, especially stroke, SGLT2 inhibitors mainly prevent heart failure. SGLT2 inhibitors are superior to GLP‐1RAs with respect to hard renal outcomes. Therefore, it can be said that drugs such as GLP‐1RAs and SGLT2 inhibitors that prevent cardiovascular events, in addition to their glucose‐lowering effect, are incredible novel tools that we have gained for use in diabetic treatment.

Is Time-Restricted Eating Safe in the Treatment of Type 2 Diabetes?-A Review of Intervention Studies

Time-restricted eating (TRE) has been shown to improve body weight and glucose metabolism in people at high risk of type 2 diabetes. However, the safety of TRE in the treatment of type 2 diabetes is unclear. We investigated the safety of TRE interventions in people with type 2 diabetes by identifying published and ongoing studies. Moreover, we identified the commonly used antidiabetic drugs and discussed the safety of TRE in people with type 2 diabetes considering the use of these drugs. In addition, we addressed the research needed before TRE can be recommended in the treatment of type 2 diabetes. A literature search was conducted to identify published (MEDLINE PubMed) and ongoing studies (ClinicalTrials.gov) on TRE in people with type 2 diabetes. To assess the usage of antidiabetic drugs and to discuss pharmacodynamics and pharmacokinetics in a TRE context, the most used antidiabetic drugs were identified and analysed. Statistics regarding sale of pharmaceuticals were obtained from MEDSTAT.DK which are based on data from the national Register of Medicinal Product Statistics, and from published studies on medication use in different countries. Four published studies investigating TRE in people with type 2 diabetes were identified as well as 14 ongoing studies. The completed studies suggested that TRE is safe among people with type 2 diabetes. Common antidiabetic drugs between 2010 and 2019 were metformin, insulin, dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists, sulfonylureas, and sodium-glucose cotransporter-2 inhibitors. Existing studies suggest that TRE is not associated with major safety issues in people with type 2 diabetes as long as medication is monitored and adjusted. However, because of low generalisability of the few studies available, more studies are needed to make concrete recommendations regarding efficacy and safety of TRE in people with type 2 diabetes.

Review of pharmaceutical and therapeutic approaches for type 2 diabetes and related disorders

One of the essential diseases that are increasing in the world is type 2 diabetes (T2D), which many people around the world live with this disease. Various studies have revealed that insulin resistance, lessened insulin production has been associated with T2D, and they also show that this disease can have a genetic origin and is associated with different genes such as KCNQ1, PPAR-γ, calpain-10, ADIPOR2, TCF7L2 that can be utilized as a therapeutic target. Different therapeutic approaches and strategies such as exercise and diet, pharmacological approaches, and utilization of nanoparticles in drug delivery and gene therapy can be effective in the treatment and control of T2D. Glucagon-like peptide 1 (GLP-1) and sodium glucose cotransporter-2 (SGLT2) have both been considered as drug classes in the treatment of T2D and T2D-related diseases such as cardiovascular disease and renal disease, and have considerable influences such as diminished cardiovascular mortality in individuals with T2D, ameliorate postprandial glycaemia, ameliorate fasting glycaemia, and diminish body weight on disease treatment and improvement process. In the present review article, we have made an attempt to explore the risk factors, Genes, and diseases associated with T2D, therapeutic approaches in T2D, the influences of drugs such as Dapagliflozin, Metformin, Acarbose, Januvia (Sitagliptin), and Ertugliflozin on T2D in clinical trials and animal model studies. Research in clinical trials has promising results that support the role of these drug approaches in T2D prophylaxis and ameliorate safety even though additional clinical research is still obligatory.

Functionalized Gadofullerene Ameliorates Impaired Glycolipid Metabolism in Type 2 Diabetic Mice

The soaring global prevalence of diabetes makes it urgent to explore new drugs with high efficacy and safety. Nanomaterial-derived bioactive agents are emerging as one of the most promising candidates for biomedical application. In the present study, we investigated the anti-diabetic effects of a functionalized gadofullerene (GF) using obese db/db and non-obese MKR mouse T2DM models. In both mouse models, the diabetic phenotypes including hyperglycemia, impaired glucose tolerance and insulin sensitivity were ameliorated following 2 or 4 weeks of i.p. administration of GF. GF lowered blood glucose levels in a dose-dependent manner. Importantly, the restored blood glucose levels could persist 10 days after withdrawal of GF treatment. The hepatic AKT/GSK3β/FoxO1 pathway is shown to be the main target of GF for re-balancing gluconeogenesis and glycogen synthesis in vivo and in vitro. In addition, GF treatment significantly reduced weight gain of db/db mice with reduced hepatic fat storage by the inhibition of de novo lipogenesis through mTOR/S6K/SREBP1 pathway. Our data provide compelling evidence to support the promising application of GF for the treatment of T2DM.

Amino Acid Signature of Oxidative Stress in Patients with Type 2 Diabetes: Targeted Exploratory Metabolomic Research

Oxidative stress plays a key role in the development of chronic diabetes-related complications. Previous metabolomic studies showed a positive association of diabetes and insulin resistance with branched-chain amino acids (AAs) and aromatic AAs. The purpose of this research is to identify distinct metabolic changes associated with increased oxidative stress, as assessed by nitrotyrosine levels, in type 2 diabetes (T2DM). Serum samples of 80 patients with insulin-treated T2DM are analyzed by AA-targeted metabolomics using ultrahigh-performance liquid chromatography/mass spectrometry. Patients are divided into two groups based on their nitrotyrosine levels: the highest level of oxidative stress (Q4 nitrotyrosine) and lower levels (Q1–Q3 nitrotyrosine). The identification of biomarkers is performed in MetaboAnalyst version 5.0 using a t-test corrected for false discovery rate, unsupervised principal component analysis and supervised partial least-squares discriminant analysis (PLS-DA). Four AAs have significantly different levels between the groups for highest and lower oxidative stress. Cysteine, phenylalanine and tyrosine are substantially increased while citrulline is decreased (p-value <0.05 and variable importance in the projection [VIP] >1). Corresponding pathways that might be disrupted in patients with high oxidative stress are phenylalanine, tyrosine and tryptophan biosynthesis, arginine biosynthesis, phenylalanine metabolism, cysteine and methionine metabolism and tyrosine metabolism.

Design and synthesis of hydrazinecarbothioamide sulfones as potential antihyperglycemic agents

New hydrazinecarbothioamides with a phenylsulfonyl group were synthesized and their structures were identified by different spectroscopic data (¹ H NMR, ¹³ C NMR, two-dimensional NMR, mass spectrometry, elemental analysis, and single-crystal X-ray analysis). The mechanism describing the formation of the products was also discussed. The antidiabetic activity of the isolated products was investigated histochemically. The synthesized sulfonylalkylthiosemicarbazide exhibited antihyperglycemic activity in streptozotocin-induced diabetic mice. Compounds 5a and 5c significantly lowered the blood glucose level to 103.3 ± 1.8 and 102 ± 3.9 mg/dl, respectively. Also, they caused a significant decrease in malondialdehyde levels and normalized the glutathione levels in streptozotocin-induced diabetic mice, compared with the diabetic group. The results suggest that the synthesized hydrazinocarbothioamides may effectively inhibit the development of oxidative stress in diabetes.

A Library of Thiazolidin-4-one Derivatives as Protein Tyrosine Phosphatase 1B (PTP1B) Inhibitors: An Attempt To Discover Novel Antidiabetic Agents

Protein tyrosine phosphatase 1B (PTP1B) is an important target for the treatment of diabetes. A series of thiazolidin-4-one derivatives 8-22 was designed, synthesized and investigated as PTP1B inhibitors. The new molecules inhibited PTP1B with IC₅₀ values in the micromolar range. 5-(Furan-2-ylmethylene)-2-(4-nitrophenylimino)thiazolidin-4-one (17) exhibited potency with a competitive type of enzyme inhibition. structure-activity relationship studies revealed various structural facets important for the potency of these analogues. The findings revealed a requirement for a nitro group-including hydrophobic heteroaryl ring for PTP1B inhibition. Molecular docking studies afforded good correlation with experimental results. H-bonding and π-π interactions were responsible for optimal binding and effective stabilization of virtual protein-ligand complexes. Furthermore, in-silico pharmacokinetic properties of test compounds predicted their drug-like characteristics for potential oral use as antidiabetic agents.Additionally, a binding site model demonstrating crucial pharmacophoric characteristics influencing potency and binding affinity of inhibitors has been proposed, which can be employed in the design of future potential PTP1B inhibitors.

Insulin Resistance and β-Cell Function of Lean versus Overweight or Obese Filipino Patients with Newly Diagnosed Type 2 Diabetes Mellitus

Objectives

To compare the level of insulin resistance and β-cell function between lean and overweight/obese Filipino patients with newly diagnosed type 2 diabetes mellitus (T2DM).

Methodology

This was a cross-sectional analytical study including newly diagnosed T2DM Filipino patients from St. Luke’s Medical Center - Quezon City. The patients were classified as either lean or overweight/obese. Age, sex, smoking history, anthropometric measures and blood pressure were obtained. Insulin resistance and β-cell function were determined using the homeostasis model assessment (HOMA). The original model (HOMA1) and the updated model (HOMA2) were used.

Results

A total of 80 subjects were included. There were 40 subjects in each group. The overweight/obese subjects had significantly higher mean insulin resistance (HOMA1-IR 9.8±11.7, HOMA2-IR 3.0±2.0) compared to the lean group (HOMA1-IR 2.9±1.5, HOMA2-IR 1.3±0.5). This was consistent in both HOMA1 and HOMA2 (p-values=0.001 and <0.001, respectively). The mean β-cell function of the overweight/obese patients was significantly higher than the lean subjects when using HOMA1 (lean=57.8±35.5, overweight/obese=93.6±66.4, p-value=0.003), but not in HOMA2 (lean=57.6±30.5, overweight/obese=74.8±45.7, p-value=0.051). Overweight/obesity increased HOMA1-IR by 4.0 and HOMA1-B by 46.1 (p-values= 0.002 and <0.001, respectively). Through the use of HOMA2, overweight/obesity increased HOMA2-IR by 1.4 and HOMA2-B by 29.1 (p-values<0.001). Being overweight/obese was also associated with significantly higher odds for developing greater insulin resistance (HOMA1-IR adjOR = 5.6, 95%CI= 1.7-19.2, p-value=0.005; HOMA2-IR adjOR=10.9, 95%CI=3.4-34.9, p-value<0.001) and lower odds for a decreased β-cell function (HOMA1-B adjOR = 0.2, 95%CI = 0.05-0.9, p-value=0.033; HOMA2-B adjOR=0.2, 95%CI=0.04-0.9, p-value=0.043) compared to being lean.

Conclusion

Newly diagnosed overweight/obese T2DM had higher mean insulin resistance and β-cell function compared to lean T2DM. Overweight/obesity was also associated with higher odds of developing insulin resistance and lower odds for a decreased β-cell function compared to being lean. The overweight/obese T2DM group also had worse metabolic profile manifested by higher FPG, HbA1c, SGPT and blood pressures compared to the lean T2DM group.

Glucocrinology of Modern Sulfonylureas: Clinical Evidence and Practice-Based Opinion from an International Expert Group

AIM

The primary objective of this document is to develop practice-based expert group opinion on certain important but less discussed endocrine and metabolic effects of modern sulfonylureas (SUs) and their usage in the management of diabetes mellitus (DM).

BACKGROUND

Modern SUs may be considered a panacea in DM care with their beneficial extra-pancreatic, pleiotropic, and cardiovascular effects. Safe glycemic control with SUs could be achieved with appropriate patient selection, drug and dosage selection, and patient empowerment. Additionally, sulfonylureas also exhibit certain endocrine and metabolic effects, which could be considered beneficial in the management of DM. In this regard, a group of international clinical experts discussed the less known beneficial aspects of SUs and safe and smart prescription of modern SUs in DM care.

RESULTS

The concept of glucocrinology or the relationship of glycemia with the endocrine system was emphasized during the meetings. Clinical experts arrived at a consensus for the usage of modern SUs in the presence of other endocrine dysfunction and the impact of these drugs on endocrine health. The beneficial pleiotropic and cardiovascular effects of modern SUs were also discussed. The key discussion points were considered to develop clinical expert opinions for the use of modern SUs in persons with DM. Clinical expert opinions were developed for indications, pleiotropic benefits, cardiovascular outcomes, adherence, and safe use of modern SUs.

CONCLUSIONS

Appropriate clinical judgement coupled with a patient-centered approach is crucial to achieve the best outcome in persons with DM. Owing to their safety, efficacy, extra-pancreatic benefits including effects on endocrine and metabolic aspects, and low cost of therapy, modern SUs could be considered as drugs/agents of choice for the treatment of diabetes.

FUNDING

Sanofi India.

Frequency and Severity of Hypoglycemia in Type 2 Diabetes Mellitus Patients Treated with a Sulfonylurea-Based Regimen at University-Affiliated Hospitals in Korea: The Naturalistic Evaluation of Hypoglycemic Events in Diabetic Subjects Study

Background

We assessed the frequency and severity of hypoglycemia in type 2 diabetes mellitus patients treated with sulfonylurea monotherapy or sulfonylurea+metformin.

Methods

We conducted a retrospective, observational, cross-sectional study in 2011 and 2012 including patients with type 2 diabetes mellitus aged ≥30 years who were treated with ≥6 months of sulfonylurea monotherapy or sulfonylurea+metformin at 20 university-affiliated hospitals in Korea. At enrollment, glycated hemoglobin (HbA1c) was assessed; participants completed self-reported questionnaires describing hypoglycemia incidents over the past 6 months. A review of medical records up to 12 months before enrollment provided data on demographics, disease history, comorbidities, laboratory results, and drug usage.

Results

Of 726 enrolled patients, 719 were included (55.6% male); 31.7% and 68.3% were on sulfonylurea monotherapy and sulfonylurea+metformin, respectively. Mean±standard deviation age was 65.9±10.0 years; mean HbA1c level was 7.0%±1.0%; 77.8% of patients had hypertension (89.4% used antihypertensive medication); 60.5% had lipid disorders (72.5% used lipid-lowering medication); and 52.0% had one or more micro- or macrovascular diseases. Among patients with A1c measurement (n=717), 56.4% achieved therapeutic goals (HbA1c <7.0%); 42.4% (305/719) experienced hypoglycemia within 6 months of enrollment; and 38.8%, 12.9%, 12.7%, and 3.9% of patients experienced mild, moderate, severe, and very severe hypoglycemia symptoms, respectively. Several reported hypoglycemia frequency as 1–2 times over the last 6 months. The mean number of very severe hypoglycemia episodes was 3.5±5.5.

Conclusion

Among type 2 diabetes mellitus patients treated with sulfonylurea-based regimens, glycemic levels were relatively well controlled but hypoglycemia remained a prevalent side effect.

Antioxidant properties of drugs used in Type 2 diabetes management: could they contribute to, confound or conceal effects of antioxidant therapy?

OBJECTIVES

This is a narrative review, investigating the antioxidant properties of drugs used in the management of diabetes, and discusses whether these antioxidant effects contribute to, confound, or conceal the effects of antioxidant therapy.

METHODS

A systematic search for articles reporting trials, or observational studies on the antioxidant effect of drugs used in the treatment of diabetes in humans or animals was performed using Web of Science, PubMed, and Ovid. Data were extracted, including data on a number of subjects, type of treatment (and duration) received, and primary and secondary outcomes. The primary outcomes were reporting on changes in biomarkers of antioxidants concentrations and secondary outcomes were reporting on changes in biomarkers of oxidative stress.

RESULTS

Diabetes Mellitus is a disease characterized by increased oxidative stress. It is often accompanied by a spectrum of other metabolic disturbances, including elevated plasma lipids, elevated uric acid, hypertension, endothelial dysfunction, and central obesity. This review shows evidence that some of the drugs in diabetes management have both in vivo and in vitro antioxidant properties through mechanisms such as scavenging free radicals and upregulating antioxidant gene expression.

CONCLUSION

Pharmaceutical agents used in the treatment of type 2 diabetes has been shown to exert an antioxidant effect..

Comparison of antidiabetic drugs added to sulfonylurea monotherapy in patients with type 2 diabetes mellitus: A network meta-analysis

AIMS

This study aimed to investigate the efficacy and safety of dual therapy comprising sulfonylurea (SU) plus antidiabetic drugs for the treatment of type 2 diabetes mellitus (T2DM).

METHODS

We searched the PubMed, Cochrane library, and Embase databases for randomized clinical trials (≥24 weeks) published up to December 28, 2017. Subsequently, we conducted pairwise and network meta-analyses to calculate the odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (CIs) of the outcomes.

RESULTS

The final analyses included 24 trials with a total of 10,032 patients. Compared with placebo, all treatment regimens were associated with a significantly higher risk of hypoglycemia, except the combinations of SU plus sodium-glucose co-transporter-2 inhibitor (SGLT-2i) [OR, 1.35 (95% CI: 0.81 to 2.25)] or alpha-glucosidase inhibitor (AGI) [OR, 1.16 (95% CI: 0.55 to 2.44)]. Notably, the combination of SU plus glucagon-like peptide-1 receptor agonist (GLP-1RA) was associated with the most significant increase in the risk of hypoglycemia. Furthermore, all SU-based combination regimens reduced the glycated hemoglobin (HbA1c) and fasting plasma glucose levels (FPG). However, only combinations containing SGLT-2i [MD, -1.00 kg (95% CI: -1.73 to -0.27)] and GLP-1RA [MD, -0.56 kg (95% CI: -1.10 to -0.02)] led to weight loss.

CONCLUSIONS

Our findings highlight the importance of considering the risk of hypoglycemia when selecting antidiabetic drugs to be administered concomitantly with SU. Although all classes of antidiabetic drugs improved glucose control when administered in combination with SU, SGLT-2i might be the best option with respect to factors such as hypoglycemia and body weight.

A Portulaca oleracea L. extract promotes insulin secretion via a K+ATP channel dependent pathway in INS-1 pancreatic β-cells

BACKGROUND/OBJECTIVE

This study was designed to investigate how a Portulaca oleracea L. extract (POE) stimulates insulin secretion in INS-1 pancreatic β-cells.

MATERIALS/METHOD

INS-1 pancreatic β-cells were incubated in the presence of various glucose concentrations: 1.1 or 5.6, 16.7 mM glucose. The cells were treated with insulin secretagogues or insulin secretion inhibitor for insulin secretion assay using an insulin ELISA kit. In order to quantify intracellular influx of Ca²⁺ caused by POE treatment, the effect of POE on intracellular Ca²⁺ in INS-1 pancreatic β-cells was examined using Fluo-2 AM dye.

RESULTS

POE at 10 to 200 µg/mL significantly increased insulin secretion dose-dependently as compared to the control. Experiments at three glucose concentrations (1.1, 5.6, and 16.7 mM) confirmed that POE significantly stimulated insulin secretion on its own as well as in a glucose-dependent manner. POE also exerted synergistic effects on insulin secretion with secretagogues, such as L-alanine, 3-isobutyl-1-methylxanthine, and especially tolbutamide, and at a depolarizing concentration of KCl. The insulin secretion caused by POE was significantly attenuated by treatment with diazoxide, an opener of the K⁺_ATP channel (blocking insulin secretion) and by verapamil (a Ca²⁺ channel blocker). The insulinotropic effect of POE was not observed under Ca²⁺-free conditions in INS-1 pancreatic β-cells. When the cells were preincubated with a Ca²⁺ fluorescent dye, Fluo-2 (acetoxymethyl ester), the cells treated with POE showed changes in fluorescence in red, green, and blue tones, indicating a significant increase in intracellular Ca²⁺, which closely correlated with increases in the levels of insulin secretion.

CONCLUSIONS

These findings indicate that POE stimulates insulin secretion via a K⁺_ATP channel-dependent pathway in INS-1 pancreatic β-cells.

Efficacy and safety of gemigliptin, a dipeptidyl peptidase-4 inhibitor, in patients with type 2 diabetes mellitus inadequately controlled with combination treatment of metformin and sulphonylurea: a 24-week, multicentre, randomized, double-blind, placebo-controlled study (TROICA study)

AIMS

To assess the efficacy and safety of gemigliptin, a dipeptidyl peptidase-4 inhibitor, added to metformin and sulphonylurea in patients with type 2 diabetes (T2DM).

MATERIALS AND METHODS

We conducted a randomized, double-blind, placebo-controlled trial in 219 Korean patients inadequately controlled with metformin and glimepiride. Participants were randomized to gemigliptin 50 mg once daily or placebo added to metformin and glimepiride. The primary endpoint was change in glycated haemoglobin (HbA1c) level from baseline to week 24.

RESULTS

The baseline HbA1c was 8.2% in both groups. The addition of gemigliptin to metformin and glimepiride significantly reduced HbA1c levels at week 24 compared with placebo (between-group difference in adjusted mean change -0.87%, 95% confidence interval [CI] -1.09% to -0.64%). Fasting plasma glucose level was also significantly reduced with gemigliptin (-0.93 mmol/L, 95% CI -1.50 to -0.35 mmol/L), and a higher proportion of participants achieved an HbA1c level of <7% (39.3% vs 5.5%; P <.001) in the gemigliptin group than in the placebo group. Total cholesterol and LDL cholesterol were modestly but significantly reduced in the gemigliptin group compared with the placebo group (-0.21 mmol/L, 95% CI -0.38 to -0.03 mmol/L for total cholesterol, -0.18 mmol/L, 95% CI -0.34 to -0.01 mmol/L for LDL cholesterol). The incidence of hypoglycaemia was 9.4% in the gemigliptin group and 2.7% in the placebo group.

CONCLUSIONS

Gemigliptin significantly improved glycaemic control in patients with T2DM inadequately controlled with metformin and sulphonylurea. The incidence of hypoglycaemia was higher with gemigliptin than with placebo, which highlights the importance of optimal dose adjustment for sulphonylurea.

Regulation of pancreatic β-cell function and mass dynamics by prostaglandin signaling

Prostaglandins (PGs) are signaling lipids derived from arachidonic acid (AA), which is metabolized by cyclooxygenase (COX)-1 or 2 and class-specific synthases to generate PGD₂, PGE₂, PGF_2α, PGI₂ (prostacyclin), and thromboxane A₂. PGs signal through G-protein coupled receptors (GPCRs) and are important modulators of an array of physiological functions, including systemic inflammation and insulin secretion from pancreatic islets. The role of PGs in β-cell function has been an active area of interest, beginning in the 1970s. Early studies demonstrated that PGE₂ inhibits glucose-stimulated insulin secretion (GSIS), although more recent studies have questioned this inhibitory action of PGE₂. The PGE₂ receptor EP3 and one of the G-proteins that couples to EP3, Gα_Z, have been identified as negative regulators of β-cell proliferation and survival. Conversely, PGI₂ and its receptor, IP, play a positive role in the β-cell by enhancing GSIS and preserving β-cell mass in response to the β-cell toxin streptozotocin (STZ). In comparison to PGE₂ and PGI₂, little is known about the function of the remaining PGs within islets. In this review, we discuss the roles of PGs, particularly PGE₂ and PGI₂, PG receptors, and downstream signaling events that alter β-cell function and regulation of β-cell mass.

Targeting hepatic glucose metabolism in the treatment of type 2 diabetes

Type 2 diabetes mellitus is characterized by the dysregulation of glucose homeostasis, resulting in hyperglycaemia. Although current diabetes treatments have exhibited some success in lowering blood glucose levels, their effect is not always sustained and their use may be associated with undesirable side effects, such as hypoglycaemia. Novel antidiabetic drugs, which may be used in combination with existing therapies, are therefore needed. The potential of specifically targeting the liver to normalize blood glucose levels has not been fully exploited. Here, we review the molecular mechanisms controlling hepatic gluconeogenesis and glycogen storage, and assess the prospect of therapeutically targeting associated pathways to treat type 2 diabetes.

Clinical Update: Cardiovascular Disease in Diabetes Mellitus: Atherosclerotic Cardiovascular Disease and Heart Failure in Type 2 Diabetes Mellitus - Mechanisms, Management, and Clinical Considerations

Cardiovascular disease remains the principal cause of death and disability among patients with diabetes mellitus. Diabetes mellitus exacerbates mechanisms underlying atherosclerosis and heart failure. Unfortunately, these mechanisms are not adequately modulated by therapeutic strategies focusing solely on optimal glycemic control with currently available drugs or approaches. In the setting of multifactorial risk reduction with statins and other lipid-lowering agents, antihypertensive therapies, and antihyperglycemic treatment strategies, cardiovascular complication rates are falling, yet remain higher for patients with diabetes mellitus than for those without. This review considers the mechanisms, history, controversies, new pharmacological agents, and recent evidence for current guidelines for cardiovascular management in the patient with diabetes mellitus to support evidence-based care in the patient with diabetes mellitus and heart disease outside of the acute care setting.

Investigating the Burden of Chronic Pain: An Inflammatory and Metabolic Composite

Background. Chronic pain is associated with increased morbidity and mortality, predominated by cardiovascular disease and cancer. Investigating related risk factor measures may elucidate the biological burden of chronic pain. Objectives. We hypothesized that chronic pain severity would be positively associated with the risk factor composite. Methods. Data from 12,982 participants in the 6th Tromsø study were analyzed. Questionnaires included demographics, health behaviors, medical comorbidities, and chronic pain symptoms. The risk factor composite was comprised of body mass index, fibrinogen, C-reactive protein, and triglycerides. Chronic pain severity was characterized by frequency, intensity, time/duration, and total number of pain sites. Results. Individuals with chronic pain had a greater risk factor composite than individuals without chronic pain controlling for covariates and after excluding inflammation-related health conditions (p < 0.001). A significant "dose-response" relationship was demonstrated with pain severity (p < 0.001). In individuals with chronic pain, the risk factor composite varied by health behavior, exercise, lower levels and smoking, and higher levels. Discussion. The risk factor composite was higher in individuals with chronic pain, greater with increasing pain severity, and influenced by health behaviors. Conclusions. Identification of a biological composite sensitive to pain severity and adaptive/maladaptive behaviors would have significant clinical and research utility.

Schisandra polysaccharide increased glucose consumption by up-regulating the expression of GLUT-4

In our previous study, a polysaccharide was extracted from Schisandra Chinensis (Trucz.) Baill and found with anti-diabetic effects. The aim of this study was to investigate the anti-diabetic effects of the low weight molecular polysaccharide (SCPP11) purified from crude Schisandra polysaccharide and illustrate the underlying mechanism in buffalo rat liver cells. The insulin resistance model of BRL cells was established by incubating with insulin solution for 24h. The effects of SCPP11 on regulating related protein and mRNA expression in an insulin and AMPK signal pathway were investigated by western blot and RT-PCR analysis. SCPP11 showed no cytotoxicity to BRL cells and could improve the glucose consumption in BRL cells. SCPP11 increased the protein expression of Akt, p-AMPK and GLUT-4 in BRL cells. Moreover, SCPP11 could enhance the mRNA expression levels of IRS-1, PI3K, Akt, GLUT-4, AMPKα and PPAR-γ in BRL cells at the same time. In conclusion, SCPP11 possessed effects in improving glucose consumption by up-regulating the expression of GLUT-4 which might occur via insulin and AMPK signal pathway and could be a potential functional food to prevent and mitigate the insulin resistance condition.

Yoga for Adults with Type 2 Diabetes: A Systematic Review of Controlled Trials

A growing body of evidence suggests yogic practices may benefit adults with type 2 diabetes (DM2). In this systematic review, we evaluate available evidence from prospective controlled trials regarding the effects of yoga-based programs on specific health outcomes pertinent to DM2 management. To identify qualifying studies, we searched nine databases and scanned bibliographies of relevant review papers and all identified articles. Controlled trials that did not target adults with diabetes, included only adults with type 1 diabetes, were under two-week duration, or did not include quantitative outcome data were excluded. Study quality was evaluated using the PEDro scale. Thirty-three papers reporting findings from 25 controlled trials (13 nonrandomized, 12 randomized) met our inclusion criteria (N = 2170 participants). Collectively, findings suggest that yogic practices may promote significant improvements in several indices of importance in DM2 management, including glycemic control, lipid levels, and body composition. More limited data suggest that yoga may also lower oxidative stress and blood pressure; enhance pulmonary and autonomic function, mood, sleep, and quality of life; and reduce medication use in adults with DM2. However, given the methodological limitations of existing studies, additional high-quality investigations are required to confirm and further elucidate the potential benefits of yoga programs in populations with DM2.

Design, Synthesis and in Vivo Evaluation of Novel Glycosylated Sulfonylureas as Antihyperglycemic Agents

Sulphonylurea compounds have versatile activities such as antidiabetic, diuretic, herbicide, oncolytic, antimalarial, antifungal and anticancer. The present study describes the design, synthesis and in vivo testing of novel glycosylated aryl sulfonylurea compounds as antihyperglycaemic agents in streptozocine-induced diabetic mice. The rational for the introduction of the glucosamine moiety is to enhance selective drug uptake by pancreatic β-cells in order to decrease the cardiotoxic side effect commonly associated with sulfonylurea agents. 2-Deoxy-2-(4-chlorophenylsulfonylurea)-d-glucopyranose was found to be the most potent antihyperglycaemic agents among the synthesized compounds in diabetic mice. This investigation indicates the importance of this novel class as potential antihyperglycaemic agents.

Safety and efficacy of addition of sitagliptin to rapid-acting insulin secretagogues for glycemic control, including post-prandial hyperglycemia, among Japanese with type 2 diabetes mellitus

The safety and efficacy of sitagliptin as add-on therapy to glinides, rapid-acting insulin secretagogues, were evaluated for Japanese patients with type 2 diabetes mellitus. This 52-week study consisted of a 12-week double-blind period, followed by a 40-week open-label period. During the double-blind period, patients were randomized to sitagliptin 50 mg q.d. (S/S group) or placebo (P/S group) as add-on therapy to glinide monotherapy. During the open-label period, all patients in both groups were administered sitagliptin 50 mg q.d. (or 100 mg q.d. after up-titration). During the double-blind period, the overall occurrence of adverse experiences (AE) was similar in both treatment groups. The frequency of reported AE of hypoglycemia in both groups was low and not notably different. The nature of clinical AE during the open-label period for both groups was not notably different from that of clinical AE in the sitagliptin group during the double-blind period. The between-group difference in HbA1c least squares (LS) mean of change from baseline (95 % CI) at Week 12 was -1.1 % (-1.3, -0.8) in favor of sitagliptin (P < 0.001). LS mean of reductions from baseline of fasting plasma glucose and 2-h postmeal glucose were significantly greater in the sitagliptin group than in the placebo group: -23.1 mg/dL (-32.2, -13.9) and -51.2 mg/dL (-67.4, -35.0), respectively (both P < 0.001). The changes from baseline in glycemic data in the S/S group remained generally stable throughout the 52-week treatment period.

Impact of glucose-lowering drugs on cardiovascular disease in type 2 diabetes

Type 2 diabetes mellitus (T2DM) is characterized by multiple pathophysiologic abnormalities. With time, multiple glucose-lowering medications are commonly required to reduce and maintain plasma glucose concentrations within the normal range. Type 2 diabetes mellitus individuals also are at a very high risk for microvascular complications and the incidence of heart attack and stroke is increased two- to three-fold compared with non-diabetic individuals. Therefore, when selecting medications to normalize glucose levels in T2DM patients, it is important that the agent not aggravate, and ideally even improve, cardiovascular risk factors (CVRFs) and reduce cardiovascular morbidity and mortality. In this review, we examine the effect of oral (metformin, sulfonylureas, meglitinides, thiazolidinediones, DPP4 inhibitors, SGLT2 inhibitors, and α-glucosidase inhibitors) and injectable (glucagon-like peptide-1 receptor agonists and insulin) glucose-lowering drugs on established CVRFs and long-term studies of cardiovascular outcomes. Firm evidence that in T2DM cardiovascular disease can be reversed or prevented by improving glycaemic control is still incomplete and must await large, long-term clinical trials in patients at low risk using modern treatment strategies, i.e., drug combinations designed to maximize HbA1c reduction while minimizing hypoglycaemia and excessive weight gain.

[Sulfonylureas in today's blood glucose lowering therapy. New data on advantages and potential barriers of an "old" antidiabetic group]

Sulfonylurea compounds have been basic elements of antidiabetic treatment in type 2 diabetes for a long time. However, with the introduction of incretin type insulin secretagogues it is often arises, whether is still there a place for sulfonylureas in the today's therapy. To answer this question the author overviews general pharmaceutical characteristics of the sulfonylurea compounds as well as individual particularities of the second generation derivatives used at present in Hungary. The author details also the most important differences between incretin type drugs - first of all dipeptidyl peptidase-4 inhibitors - and sulfonylureas. On the basis of available data it can be concluded in accordance with the latest international guidelines, that sulfonylureas have still role in the blood glucose lowering therapy of type 2 diabetes, though they became somewhat pushed back among insulin secretagogue type drugs. If a sulfonylurea compound is the drug of choice, it is important to select the appropriate molecule (in case of normal renal function gliclazide or glimepiride). It is also important to re-educate the patient, as well as to apply the minimal dose providing the desired glycaemic effect.

Optimal candidates for the switch from glimepiride to sitagliptin to reduce hypoglycemia in patients with type 2 diabetes mellitus

BACKGROUND

Sitagliptin is a novel antidiabetic agent with a low risk for hypoglycemia. We investigated the efficacy and safety of sitagliptin when patients switched from a sulfonylurea to sitagliptin and identified good candidates for the switch.

METHODS

Sixty-one patients with type 2 diabetes switched from glimepiride with metformin to sitagliptin with metformin due to clinical hypoglycemia. Serum glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), and 2-hour postprandial plasma glucose (2h-PPG) before and 12 and 24 weeks after the drug switch were checked.

RESULTS

HbA1c and FPG levels did not change 12 or 24 weeks after the switch; however, the 2h-PPG level decreased from 218.0±67.5 mg/dL at baseline to 197.1±69.9 mg/dL at 12 weeks and 192.3±67.4 mg/dL at 24 weeks after switching drugs (P=0.045, P=0.018, respectively). All but one patient no longer experienced hypoglycemia after discontinuing glimepiride. In a multivariate logistic regression analysis, a high homeostasis model assessment of insulin resistance and low baseline HbA1c level were independent predictors of an HbA1c ≤7% after switching to sitagliptin.

CONCLUSION

Glycemic control was not aggravated in patients 24 weeks after the drug switch, and symptomatic hypoglycemia decreased significantly. Patients with dominant insulin resistance may be good candidates for switching from a sulfonylurea to sitagliptin to reduce hypoglycemia.

Withdrawal of sulfonylureas from patients with type 2 diabetes receiving long-term sulfonylurea and insulin combination therapy results in deterioration of glycemic control: a randomized controlled trial

BACKGROUND

The benefit of sulfonylureas (SUs) to patients with type 2 diabetes mellitus receiving long-term insulin treatment is unclear. This study evaluated glycemic control and beta-cell function after SU withdrawal in these patients.

METHODS

In this 8-week randomized controlled study, patients with type 2 diabetes who had been treated with insulin for at least 3 years plus moderate to high doses of SUs were randomly assigned to withdrawal (n=16) or continuation (n=16) of SUs. Clinical characteristics, glycemic control, hypoglycemic events, and insulin secretion, including homeostasis model assessment of beta-cell function (HOMA-B) score, C-peptide concentration, and Matsuda index, were evaluated at baseline and after 2 and 8 weeks.

RESULTS

Thirty patients (16 in the SU withdrawal group and 14 in the SU continuation group) completed the study. Median duration of diabetes was 17 (range 5-40) years. Baseline clinical characteristics, glycemic control, and HOMA-B were similar in the two groups, but the mean fasting C-peptide concentration was higher in the SU withdrawal group. After 8 weeks, the SU withdrawal group showed a significant increase in mean glycosylated hemoglobin levels from 7.8%±0.5% (62±5 mmol/mol) to 8.6%±1.2% (71±13 mmol/mol; P=0.002), whereas the SU continuation group showed a slight but not significant increase from 7.7%±0.5% (61±5 mmol/mol) to 7.9%±1.2% (63±13 mmol/mol; P=0.37). Insulin secretion, as measured by C-peptide and HOMA-B, decreased by 18% and 36%, respectively, in the SU withdrawal group. Hypoglycemic events were significantly more frequent in the SU continuation group whereas body weight did not change significantly in either group.

CONCLUSION

Withdrawal of SU from patients with type 2 diabetes receiving long-term combination treatment with SU and insulin resulted in deterioration of glycemic control and insulin secretion.

Effectiveness and safety of glimepiride and iDPP4, associated with metformin in second line pharmacotherapy of type 2 diabetes mellitus: systematic review and meta-analysis

OBJECTIVE

Our review analyses the studies that have specifically compared the association iDPP4/metformin with glimepiride/metformin, both in second line pharmacotherapy of type 2 diabetes mellitus (DM2).

METHODS

Systematic literature review with a meta-analysis of clinical trials comparing glimepiride with any iDPP4, both used together with metformin as a second line treatment of DM2. The effectiveness variables used were as follows: %HbA1c variation, fasting plasma glucose variation, patients achieving the therapeutic objective of HbA1c <7%, treatment dropouts due to lack of effectiveness and rescue treatments needed. The safety variables included were as follows: weight variation at the end of treatment; presentation of any type of adverse event; presentation of serious adverse events; patients who experienced any type of hypoglycaemia; patients who experienced severe hypoglycaemia; treatments suspended due to adverse effects; and deaths for any reason.

RESULTS

Four studies met the inclusion criteria. The group treated with glimepiride showed better results in all effectiveness variables. Regarding safety variables, the main differences observed were in the greater number of cases with hypoglycaemia in the group treated with glimepiride, and the serious adverse events or treatment discontinuations due to these which occurred in slightly over 2% more cases in this group compared to the iDPP4 group. The remaining adverse events, including mortality, did not show any differences between both groups. The variation in the weight difference between groups (2.1 kg) is not considered clinically relevant.

CONCLUSIONS

A greater effectiveness is seen in the glimepiride/metformin association, which should not be diminished by slight differences in adverse effects, with absence of severe hypoglycaemia in over 98% of patients under treatment. The association of glimepiride/metformin, both due to cost as well as effectiveness and safety, may be the preferential treatment for most DM2 patients, and it offers a potential advantage in refractory hyperglycemic populations, tolerant to treatment.

Stratified medicine for the use of antidiabetic medication in treatment of type II diabetes and cancer: where do we go from here?

At present, the global diabetes epidemic is affecting 347 million individuals, 90% of whom are diagnosed with type II diabetes mellitus (T2DM). T2DM is commonly treated with more than one type of therapy, including oral antidiabetic drugs (OADs) and agents used in the treatment of diabetic complications. Several pharmacological classes of OADs are currently available for the treatment of T2DM, of which insulin secretagogues (i.e. sulphonylureas and meglitinides), insulin sensitizers [thiazolidinediones (TZDs)] and biguanides are the most commonly prescribed. Although many of these OADs have been used for more than half a century in the treatment of T2DM, the pharmacogenomic characteristics of these compounds have only recently been investigated, primarily in retrospective studies. Recent advances in pharmacogenomics have led to the identification of polymorphisms that affect the expression and function of drug-metabolizing enzymes and drug transporters, as well as drug targets and receptors. These polymorphisms have been shown to affect the therapeutic response to and side effects associated with OADs. The aim of this review was to provide an up-to-date summary of some of the pharmacogenomic data obtained from studies of T2DM treatment, with a focus on polymorphisms in genes affecting pharmacokinetics, pharmacodynamics and treatment outcome of the most commonly prescribed OADs. In addition, the implications of pharmacogenomics in the use of the OAD metformin in cancer will be briefly discussed. Finally, we will focus on recent advances in novel 'omics' technologies and discuss how these might aid in the personalized management of T2DM.

Chemo- and stereoselective synthesis of fluorinated enamides from ynamides in HF/pyridine: second-generation approach to potent ureas bioisosteres

(E)- and (Z)-α-fluoroenamides could be easily prepared with high levels of chemo- and regioselectivities by hydrofluorination of readily available ynamides with HF/pyridine. The scope and limitations of this new process for the hydrofluorination of ynamides, as well as the stability of the resulting α-fluoroenamides, have been extensively studied. Theoretical calculations at the MP2 and B3LYP levels of theory showed that the resulting fluoroenamides exhibit geometrical and electronic properties that partially mirror those of ureas, therefore demonstrating that the hydrofluorination of ynamides provides a general, straightforward, and user-friendly approach to bioisosteres of ureas, potent building blocks for biological studies and medicinal chemistry.

Oral antihyperglycemic treatment options for type 2 diabetes mellitus

Table 3 provides an overview of the oral antihyperglycemic drugs reviewed in this article. A 2011 meta-analysis by Bennett and colleagues found low or insufficient quality of evidence favoring an initial choice of metformin, SUs, glinides, TZDs, or (table see text) DPP-4 inhibitors (alpha-glucosidase inhibitors, bromocriptine mesylate, and SGLT2 inhibitors were not included in this meta-analysis) with regard to the outcomes measures of all-cause mortality, cardiovascular events and mortality, and incidence of microvascular disease (retinopathy, nephropathy, and neuropathy) in previously healthy individuals with newly diagnosed T2DM. Likewise, the Bennett and colleagues meta-analysis judged these drugs to be of roughly equal efficacy with regard to reduction of HbA1c (1%–1.6%) from the pretreatment baseline. The ADOPT clinical trial of 3 different and, at the time, popular, oral monotherapies for T2DM provides support for the consensus recommendation of metformin as first-line therapy. The ADOPT trial showed slightly superior HbA1c reduction for rosiglitazone compared with metformin, which was in turn superior to glyburide. However, significant adverse events, including edema, weight gain, and fractures, were more common in the rosiglitazone-treated patients. The implication of this trial is that the combination of low cost, low risk, minimal adverse effects, and efficacy of metformin justifies use of this agent as the cornerstone of oral drug treatment of T2DM. Judicious use of metformin in groups formerly thought to be at high risk for lactic acidosis (ie, those with CHF, chronic kidney disease [eGFR >30 mL/min/1.73 m2], and the elderly) may be associated with mortality benefit rather than increased risk. Secondary and tertiary add-on drug therapy should be individualized based on cost, personal preferences, and overall treatment goals, taking into account the wishes and priorities of the patient.

Liraglutide Versus Sitagliptin in a 24-week, Multicenter, Open-label, Randomized, Parallel-group Study in Japanese Type 2 Diabetes Mellitus Patients Responding Inadequately to a Sulfonylurea and/or One or Two Other Oral Antidiabetic Drugs (JDDM 33)

OBJECTIVE

Liraglutide (glucagon-like peptide-1 [GLP-1] receptor agonist) and sitagliptin (dipeptidyl peptidase-4 inhibitor) are approved in Japan for treating type 2 diabetes mellitus (T2DM). We compared the efficacy and safety of adding liraglutide or sitagliptin to a sulfonylurea in Japanese T2DM patients.

METHODS

Patients aged 18 to <80 years with hemoglobin A1c (HbA1c; National Glycohemoglobin Standardization Program [NGSP]) of 6.9–9.4%, body mass index ≤35 kg/m², and treatment with a sulfonylurea and/or one or two non-sulfonylurea oral antidiabetic drugs for greater than or equal to eight weeks before enrollment were eligible. Patients were randomized in an open-label manner to either 0.9 mg/day liraglutide (n = 50) or 50–100 mg/day sitagliptin (n = 49) and were treated for 24 weeks. Non-sulfonylureas were discontinued before randomization. Patients using other oral antidiabetic drugs started sulfonylurea treatment. The primary endpoint was the change in HbA1c from baseline to Week 24.

RESULTS

HbA1c decreased in both groups, and the reduction was significantly greater throughout in the liraglutide group except for Week 24 (0.59 ± 0.80 vs. 0.24 ± 0.94%; P = 0.0525). Fasting plasma glucose (FPG) decreased significantly in the liraglutide group compared with the sitagliptin group (−21.15 ± 31.22 vs. +0.46 ± 39.39 mg/dL; P = 0.0014). Homeostasis model assessment of β cell function and C-peptide increased significantly in the liraglutide group but not in the sitagliptin group. Hypoglycemic symptoms and adverse events occurred in four and nine patients, respectively, in the liraglutide group, and in two and five patients, respectively, in the sitagliptin group.

CONCLUSION

Treatment with liraglutide or sitagliptin together with a sulfonylurea improved HbA1c in Japanese T2DM patients in primary care. Both drugs were associated with low rates of adverse events and hypoglycemia. The improvement in β cell function probably contributed to the improvement in glycemic control in the liraglutide group.

A meta-analysis of the hypoglycaemic risk in randomized controlled trials with sulphonylureas in patients with type 2 diabetes

AIM

To assess hypoglycaemic risk with sulphonylureas in comparison with other drugs in randomized controlled trials.

METHODS

Randomized trials with a duration ≥ 24 weeks, enrolling patients with type 2 diabetes, comparing sulphonylureas with placebo or active drugs different from other sulphonylureas. The principal outcome was the effect of sulphonylureas on the incidence of any or severe hypoglycaemia. Cumulative incidence of hypoglycaemia was estimated combining sulphonylurea groups of different trials with a random effect model and used for meta-regression analyses.

RESULTS

The incidence of severe hypoglycaemia in patients treated with sulphonylureas was 1.2 [1.0-1.6]%. The overall risk of severe hypoglycaemia was increased more than threefold with sulphonylureas than with comparators. The proportion of patients with at least one hypoglycaemia while on sulphonylureas was 17.4 [14.5-20.8]%. The overall risk (Mantel-Haenszel Odds Ratio) of any hypoglycaemia with sulphonylureas versus comparators was 3.69 [3.47-3.93] (p < 0.001). Meta-regression analysis suggested that the incidence of any hypoglycaemia was higher in trials enrolling patients with higher body mass index (BMI) and lower haemoglobin A1c (HbA1c).

CONCLUSIONS

In conclusion, hypoglycaemia, including severe hypoglycaemia, is frequent in patients treated with sulphonylureas, particularly when baseline HbA1c levels are lower and BMI levels higher. Further studies are needed to characterize predictors for the identification of patients at higher risk.

Efficacy and safety of sitagliptin monotherapy and combination therapy in Japanese type 2 diabetes patients

(J Diabetes Invest, doi: 10.1111/j.2040-1124.2012.00221.x, 2012) Aims/Introduction:  To determine the efficacy and safety of sitagliptin monotherapy and combination therapy in Japanese type 2 diabetes patients after 3 months' therapy.

MATERIALS AND METHODS

  A retrospective, observational study of 741 type 2 diabetes patients was carried out; 110 received sitagliptin monotherapy, and 631 received combination therapy with sitagliptin when other oral medications were insufficient. The primary outcome measure was glycated hemoglobin (HbA1c) measured at 0, 4 and 12 weeks of sitagliptin therapy.

RESULTS

  In the monotherapy and combination therapy groups, HbA1c decreased significantly after 12 weeks. Target HbA1c (<7%) was achieved in 39.1% overall. On logistic regression analysis, baseline HbA1c was the strongest contributing factor for achieving target HbA1c; baseline body mass index and duration of diabetes were also significant factors. A total of 82 patients (11%) were unresponsive to sitagliptin. These patients' baseline body mass index was significantly higher and their baseline HbA1c was significantly lower than those of patients who responded to sitagliptin. The most commonly co-administered drugs were sulfonylureas (508 patients). In these patients, the dose of sulfonylurea decreased with time. In 66 patients whose sulfonylurea dosage was reduced when sitagliptin was started, HbA1c and bodyweight decreased significantly after 12 weeks. A total of 24 patients receiving sulfonylureas had mild hypoglycemia, but none discontinued sitagliptin.

CONCLUSIONS

  Sitagliptin was effective and safe as both monotherapy and combination therapy in Japanese type 2 diabetes patients. When sulfonylureas were ineffective, sitagliptin improved glycemic control. In patients whose sulfonylurea dose was reduced at the start of sitagliptin, blood glucose improved and bodyweight decreased after 12 weeks.

Efficacy and safety of teneligliptin added to glimepiride in Japanese patients with type 2 diabetes mellitus: a randomized, double-blind, placebo-controlled study with an open-label, long-term extension

AIMS

To assess the efficacy and safety of teneligliptin in combination with glimepiride in Japanese patients with type 2 diabetes mellitus (T2DM) inadequately controlled with glimepiride monotherapy.

METHODS

In the initial 12-week, double-blind, placebo-controlled, parallel-group period, 194 patients [haemoglobin A1c (HbA1c): 8.4 ± 0.8%; fasting plasma glucose (FPG): 164.2 ± 28.1 mg/dl] were randomized to either teneligliptin 20 mg or placebo once daily while continuing stable glimepiride therapy. This randomized period was then followed by a 40-week, open-label period, where all patients received teneligliptin once daily. The primary endpoint was the change in HbA1c from baseline to week 12.

RESULTS

Teneligliptin reduced HbA1c significantly compared with placebo at week 12. The placebo-subtracted change in HbA1c was -1.0 ± 0.1% [least-squares (LS) mean ± s.e., p < 0.001]. Teneligliptin also significantly reduced FPG and 2-h postprandial glucose (PPG) as compared with placebo at week 12; the placebo-subtracted changes were -27.1 ± 3.2 and -49.1 ± 6.2 mg/dl (LS mean ± s.e., both p < 0.001), respectively. The blood glucose-lowering effects were sustained throughout the 40-week open-label period. The incidence rates of adverse events and adverse drug reactions, including hypoglycaemia, during the double-blind randomized period were similar in both groups. Therefore, teneligliptin was generally well tolerated when used in combination with glimepiride.

CONCLUSIONS

The addition of teneligliptin was effective and generally well tolerated in Japanese patients with T2DM inadequately controlled with glimepiride monotherapy. The improvements in glycaemic control were maintained for up to 52 weeks.

Clinical efficacy of a medically supervised outpatient high-protein, low-calorie diet program is equivalent in prediabetic, diabetic and normoglycemic obese patients

Objective:

Type 2 diabetes mellitus (T2DM) affects approximately 10% of Americans, while 79 million Americans are estimated to have glucose intolerance or prediabetes (pre-DM). The present study was designed to determine whether obese patients with pre-DM or T2DM would lose weight as effectively as obese normoglycemic patients, in a medically supervised high-protein, low-calorie-weight management program.

Method:

Patients enrolled in a self-paid, university-based, outpatient weight loss program using prescribed very-low-calorie diet (VLCD) (500–800 cal per day) or LCD diet (800–1200 cal per day), recommended exercise and group behavioral counseling were studied retrospectively. Patients entering the program for the first time and attending weekly clinic visits for more than 4 weeks were included in the analysis.

Results:

A total of 2093 obese patients, of whom 583 patients with pre-DM (fasting glucose ⩾100 and <126 mg dl⁻¹), 367 patients with T2DM and 1143 normoglycemic patients entered the program from 1991 to 2010, who met all the inclusion criteria were included in the analysis. The body weight at baseline was 104.0±20.0 kg for DM, 101.4±18.4 for pre-DM and 99.0±18.8 kg for non-DM. Weight loss and percent of weight loss within 12 months were analyzed using a linear mixed-effects model. There was no significant difference in weight loss between DM vs non-DM (P=0.4597) and pre-DM vs non-DM (P=0.6006) in 12 months. The length of enrollment in the program was positively correlated to weight loss rates in all patients (P<0.001).

Conclusion:

This study demonstrates that obese, pre-DM and DM patients all lost weight as effectively with VLCD or LCD over 12 months. Given the impact of weight loss on the progression of comorbid conditions, these data support the hypothesis that medically supervised diets, including VLCD and LCD, should be more widely used in the prevention and treatment of obese patients with pre-DM or T2DM.

Sleep loss as a factor to induce cellular and molecular inflammatory variations

A reduction in the amount of time spent sleeping occurs chronically in modern society. Clinical and experimental studies in humans and animal models have shown that immune function is impaired when sleep loss is experienced. Sleep loss exerts a strong regulatory influence on peripheral levels of inflammatory mediators of the immune response. An increasing number of research projects support the existence of reciprocal regulation between sleep and low-intensity inflammatory response. Recent studies show that sleep deficient humans and rodents exhibit a proinflammatory component; therefore, sleep loss is considered as a risk factor for developing cardiovascular, metabolic, and neurodegenerative diseases (e.g., diabetes, Alzheimer's disease, and multiple sclerosis). Circulating levels of proinflammatory mediators depend on the intensity and duration of the method employed to induce sleep loss. Recognizing the fact that the concentration of proinflammatory mediators is different between acute and chronic sleep-loss may expand the understanding of the relationship between sleep and the immune response. The aim of this review is to integrate data from recent published reports (2002-2013) on the effects of sleep loss on the immune response. This review may allow readers to have an integrated view of the mechanisms involved in central and peripheral deficits induced by sleep loss.

Effects of sleep deprivation on brain bioenergetics, sleep, and cognitive performance in cocaine-dependent individuals

In cocaine-dependent individuals, sleep is disturbed during cocaine use and abstinence, highlighting the importance of examining the behavioral and homeostatic response to acute sleep loss in these individuals. The current study was designed to identify a differential effect of sleep deprivation on brain bioenergetics, cognitive performance, and sleep between cocaine-dependent and healthy control participants. 14 healthy control and 8 cocaine-dependent participants experienced consecutive nights of baseline, total sleep deprivation, and recovery sleep in the research laboratory. Participants underwent ³¹P magnetic resonance spectroscopy (MRS) brain imaging, polysomnography, Continuous Performance Task, and Digit Symbol Substitution Task. Following recovery sleep, ³¹P MRS scans revealed that cocaine-dependent participants exhibited elevated global brain β-NTP (direct measure of adenosine triphosphate), α-NTP, and total NTP levels compared to those of healthy controls. Cocaine-dependent participants performed worse on the Continuous Performance Task and Digit Symbol Substitution Task at baseline compared to healthy control participants, but sleep deprivation did not worsen cognitive performance in either group. Enhancements of brain ATP levels in cocaine dependent participants following recovery sleep may reflect a greater impact of sleep deprivation on sleep homeostasis, which may highlight the importance of monitoring sleep during abstinence and the potential influence of sleep loss in drug relapse.