The Potential Role of Gossypetin in the Treatment of Diabetes Mellitus and Its Associated Complications: A Review

Type 2 diabetes mellitus (T2DM) is a metabolic disorder caused by insulin resistance and dysfunctional beta (β)-cells in the pancreas. Hyperglycaemia is a characteristic of uncontrolled diabetes which eventually leads to fatal organ system damage. In T2DM, free radicals are continuously produced, causing extensive tissue damage and subsequent macro-and microvascular complications. The standard approach to managing T2DM is pharmacological treatment with anti-diabetic medications. However, patients' adherence to treatment is frequently decreased by the side effects and expense of medications, which has a detrimental impact on their health outcomes. Quercetin, a flavonoid, is a one of the most potent anti-oxidants which ameliorates T2DM. Thus, there is an increased demand to investigate quercetin and its derivatives, as it is hypothesised that similar structured compounds may exhibit similar biological activity. Gossypetin is a hexahydroxylated flavonoid found in the calyx of Hibiscus sabdariffa. Gossypetin has a similar chemical structure to quercetin with an extra hydroxyl group. Furthermore, previous literature has elucidated that gossypetin exhibits neuroprotective, hepatoprotective, reproprotective and nephroprotective properties. The mechanisms underlying gossypetin's therapeutic potential have been linked to its anti-oxidant, anti-inflammatory and immunomodulatory properties. Hence, this review highlights the potential role of gossypetin in the treatment of diabetes and its associated complications.

Effects of pioglitazone and linagliptin on glycemic control, lipid profile and hs-CRP in metformin-treated patients with type 2 diabetes: a comparative study

OBJECTIVES

The purpose of this study was to compare the effects of pioglitazone and linagliptin on glycemic control, lipid profile and high-sensitivity C-reactive protein (hs-CRP) parameters in patients with type 2 diabetes treated with metformin.

METHODS

The present randomized clinical trial was conducted on 60 patients with type 2 diabetes treated with metformin in the age range of 30-60 years. The participants with informed consent were randomly assigned to receive pioglitazone or linagliptin. The first intervention group (n=30) received 30 mg of pioglitazone daily and the second intervention group (n=30) received 5 mg of linagliptin daily for 12 weeks. Fasting blood samples were taken from patients at the baseline and after 12 weeks to measure related variables. The current study was approved in Kashan University of Medical Sciences (with the code of ethics of IR.KAUMS.MEDNT.REC.1398.016), and the Iranian Registry of Clinical Trials (with the registration number of IRCT20170513033941N66).

RESULTS

The linagliptin administration significantly reduced serum levels of fasting blood sugar (p=0.03), blood sugar 2 h after a meal (p=0.02), glycosylated hemoglobin (p=0.02) and hs-CRP (p=0.005) after 12 weeks compared with pioglitazone. In contrast, the pioglitazone administration significantly decreased triglyceride levels (p=0.01) and increased HDL-cholesterol (p=0.002) compared to linagliptin. In addition, the administration of both linagliptin and pioglitazone drugs had no significant effect on LDL-cholesterol, total cholesterol, systolic and diastolic blood pressure, creatinine and blood urea.

CONCLUSIONS

The present study demonstrated the superiority of linagliptin over pioglitazone for glycemic control, although pioglitazone compared to linagliptin showed greater efficacy in reducing triglycerides and raising HDL-cholesterol.

Metformin, Empagliflozin, and Their Combination Modulate Ex-Vivo Macrophage Inflammatory Gene Expression

Type-2 Diabetes Mellitus is a complex, chronic illness characterized by persistent high blood glucose levels. Patients can be prescribed anti-diabetes drugs as single agents or in combination depending on the severity of their condition. Metformin and empagliflozin are two commonly prescribed anti-diabetes drugs which reduce hyperglycemia, however their direct effects on macrophage inflammatory responses alone or in combination are unreported. Here, we show that metformin and empagliflozin elicit proinflammatory responses on mouse bone-marrow-derived macrophages with single agent challenge, which are modulated when added in combination. In silico docking experiments suggested that empagliflozin can interact with both TLR2 and DECTIN1 receptors, and we observed that both empagliflozin and metformin increase expression of Tlr2 and Clec7a. Thus, findings from this study suggest that metformin and empagliflozin as single agents or in combination can directly modulate inflammatory gene expression in macrophages and upregulate the expression of their receptors.

Structural Characterization and Hypoglycemic Function of Polysaccharides from Cordyceps cicadae

The polysaccharides isolated and purified from different parts of the medicinal fungus Cordyceps cicadae were identified, and three extracts displaying significant biological activities were selected for further study. The bacterium substance polysaccharides (BSP), spore powder polysaccharides (SPP), and pure powder polysaccharides (PPP) were separated, purified, and collected from the sclerotia, spores, and fruiting bodies of Cordyceps cicadae, respectively. The structures of Cordyceps cicadae polysaccharides were analyzed using gas chromatography, Fourier-transform infrared spectroscopy, methylation analysis, and one-dimensional (¹H and ¹³C) nuclear magnetic resonance spectroscopy. Moreover, the hypoglycemic effect of Cordyceps cicadae polysaccharides was examined in both in vitro and in vivo models. BSP, SPP, and PPP significantly increased glucose absorption in HepG2 cells, and alleviated insulin resistance (IR) in the in vitro model. SPP was the most effective, and was therefore selected for further study of its hypoglycemic effect in vivo. SPP effectively improved body weight and glucose and lipid metabolism in type 2 diabetes model mice, in addition to exerting a protective effect on liver injury. SPP regulated the mRNA expression of key PI3K/Akt genes involved in the insulin signaling pathway. The hypoglycemic mechanism of SPP may reduce hepatic insulin resistance by activating the PI3K/Akt signaling pathway. Spore powder polysaccharides (SPP) extracted from Cordyceps cicadae effectively improved body weight and glucose and lipid metabolism in type 2 diabetes model mice, in addition to exerting a protective effect on liver injury. The mechanism underlying the hypoglycemic effect of SPP regulates the mRNA expression of key PI3K/Akt genes involved in the insulin signaling pathway to alleviate insulin resistance. Our results provide a theoretical basis for research into the hypoglycemic effect of Cordyceps cicadae, and lay the foundation for the development of functional products.

The Synthetic Flavonoid Hidrosmin Improves Endothelial Dysfunction and Atherosclerotic Lesions in Diabetic Mice

In diabetes, chronic hyperglycemia, dyslipidemia, inflammation and oxidative stress contribute to the progression of macro/microvascular complications. Recently, benefits of the use of flavonoids in these conditions have been established. This study investigates, in two different mouse models of diabetes, the vasculoprotective effects of the synthetic flavonoid hidrosmin on endothelial dysfunction and atherogenesis. In a type 2 diabetes model of leptin-receptor-deficient (db/db) mice, orally administered hidrosmin (600 mg/kg/day) for 16 weeks markedly improved vascular function in aorta and mesenteric arteries without affecting vascular structural properties, as assessed by wire and pressure myography. In streptozotocin-induced type 1 diabetic apolipoprotein E-deficient mice, hidrosmin treatment for 7 weeks reduced atherosclerotic plaque size and lipid content; increased markers of plaque stability; and decreased markers of inflammation, senescence and oxidative stress in aorta. Hidrosmin showed cardiovascular safety, as neither functional nor structural abnormalities were noted in diabetic hearts. Ex vivo, hidrosmin induced vascular relaxation that was blocked by nitric oxide synthase (NOS) inhibition. In vitro, hidrosmin stimulated endothelial NOS activity and NO production and downregulated hyperglycemia-induced inflammatory and oxidant genes in vascular smooth muscle cells. Our results highlight hidrosmin as a potential add-on therapy in the treatment of macrovascular complications of diabetes.

Evaluation of selected antidiabetics in cardiovascular complications associated with cancer cachexia

So far, the cardio-protective potential of antidiabetics is proved, but their effect on cardiovascular complications associated with cancer cachexia is not explored until now. Insulin resistance and glucose intolerance along with systemic inflammation are prominent in cachexia but the potential effect of antidiabetic agents especially those belonging to biguanide, DPP4 inhibitors and SGLT2 on the heart are not studied till now. In present study, the effect of metformin, vildagliptin, teneligliptin, dapagliflozin and empagliflozin on cardiovascular complications associated with cancer cachexia by using B16F1 induced metastatic cancer cachexia and urethane-induced cancer cachexia was studied. These antidiabetic agents proved to be beneficial against cachexia-induced atrophy of the heart, preserved ventricular weights, maintained cardiac hypertrophic index, preserved the wasting of cardiac muscles assessed by HE staining, Masson trichrome staining, periodic acid Schiff staining and picro-Sirius red staining. Altered cardiac gene expression was attenuated after treatment with selected antidiabetics, thus preventing cardiac atrophy. Also, antidiabetic agents treatment improved the serum creatinine kinase MB, Sodium potassium ATPase and collagen in the heart. Reduction in blood pressure and heart rate was observed after treatment with antidiabetic agents. Results of our study show that the selected antidiabetics prove to be beneficial in attenuating the cardiac atrophy and helps in regulation of hemodynamic stauts in cancer cachexia-induced cardiovascular complications. Our study provides some direction towards use of selected antidiabetic agents in the management of cardiovascular complications associated with cancer cachexia and the study outcomes can be useful in desiging clinical trials.

Non-cardiovascular medication and readmission for heart failure: an observational cohort study

Background Among heart failure (HF) patients, hospital readmissions are a major concern. The medication taken by a patient may provide information on comorbidities and conditions and may be used as an indicator to identify populations at an increased risk of HF readmission. Aim This study explored the use of non-cardiovascular medication at hospital discharge from the first HF admission in search of indicators of high risk of readmission for HF. Method The study included 22,476 HF patients from the Dutch PHARMO Database Network at their first HF hospitalization. The data was divided into training and validation sets. A Cox regression model with demographics, date of first HF hospital admission and non-cardiovascular medication present at discharge, adjusted for cardiovascular medication, was developed in the training set and subsequently implemented in the validation set. Results The study included 22,476 patients, mean age 76.7 years (range 18-104) and median follow-up time 2.5 years (range 0-15.7 years). During the study period 6,725 (29.9%) patients were readmitted for HF, with a median time-to-readmission of 7 months (range 0-14.3 years). Non-cardiovascular medication associated with a high risk of readmission for HF were identified as indicators of high risk, with no implied causal relationship. Patients prescribed antigout medications presented a 25% increased risk of readmission (HR 1.25, 95%CI 1.09-1.45, P = 0.002). Patients using insulin had an 18% higher risk of readmission versus patients not using insulin (HR 1.18, 95%CI 1.06-1.32, P = 0.002), but not versus patients treated with other blood-glucose-lowering drugs. No association between the risk of readmission and NSAIDs use was observed. Conclusion The results suggest that diabetes is responsible for the higher HF-readmission risk observed in patients prescribed insulin. The observed risk in users of antigout medication should be further investigated. The absence of an association with the use of NSAIDs should be interpreted with caution.

Primary Prevention of Cardiovascular and Heart Failure Events With SGLT2 Inhibitors, GLP-1 Receptor Agonists, and Their Combination in Type 2 Diabetes

OBJECTIVE

To assess associations between current use of sodium-glucose cotransporter 2 inhibitors (SGLT2is), glucagon-like peptide 1 receptor agonists (GLP-1RAs), and their combination and risk for major adverse cardiac and cerebrovascular events (MACCE) and heart failure (HF) in people with type 2 diabetes.

RESEARCH DESIGN AND METHODS

In three nested case-control studies involving patients with type 2 diabetes in England and Wales (primary care data from the Clinical Practice Research Datalink and Secure Anonymised Information Linkage Databank with linkage to hospital and mortality records), we matched each patient experiencing an event with up to 20 control subjects. Adjusted odds ratios (ORs) for MACCE and HF among patients receiving SGLT2i or GLP-1RA regimens versus other combinations were estimated using conditional logistic regression and pooled using random-effects meta-analysis.

RESULTS

Among 336,334 people with type 2 diabetes and without cardiovascular disease, 18,531 (5.5%) experienced a MACCE. In a cohort of 411,206 with type 2 diabetes and without HF, 17,451 (4.2%) experienced an HF event. Compared with other combination regimens, the adjusted pooled OR and 95% CI for MACCE associated with SGLT2i regimens was 0.82 (0.73, 0.92), with GLP-1RA regimens 0.93 (0.81, 1.06), and with the SGLT2i/GLP-1RA combination 0.70 (0.50, 0.98). Corresponding data for HF were SGLT2i 0.49 (0.42, 0.58), GLP-1RA 0.82 (0.71, 0.95), and SGLT2i/GLP-1RA combination 0.43 (0.28, 0.64).

CONCLUSIONS

SGLT2i and SGLT2i/GLP-1RA combination regimens may be beneficial in primary prevention of MACCE and HF and GLP-1RA for HF. These data call for primary prevention trials using these agents and their combination.

Amelioration of related complications by the combined usage of Gymnadenia orchidis Lindl and pumpkin seed in type 2 diabetic mice

BACKGROUND

Inflammation, insulin resistance, hyperinsulinemia and cell damage are the major patho-physiological reasons behind type 2 diabetes (T2DM), which is one of the most prevalent non communicable metabolic disorders in the world. Oral hypoglycemic drugs and insulin shots are usually exercised to treat the diabetic patients but it produces many side effects. Thereby paving the way for natural hypoglycemic agents; a Himalayan herb and alternative nutritional therapy; low glycaemic indexed pumpkin seed, are used in combination for a better management of the disease.

OBJECTIVES

To explore the combined efficacy of Gymnadenia orchidis Lindl root Salep and low-glycemic indexed-pumpkin seeds in better management of T2DM and associated complications.

METHODS

Balb/c mice were randomly allocated to six different groups (n=5). Streptozotocin along with high-fat-diet was used to induce T2DM. The experimental animals were supplemented with low-glycemic food or root Salep (200 mg/kg body weight) or combination of both according to their groups for 21 days, post which various biochemical tests were performed.

RESULTS

T2DM augmented the IL-6, IFN-γ, TNF-α, BAX, Insulin levels, and HOMA-IR with concurrent reduction of IL-4, QUICKI, Bcl-2, estradiol and progesterone levels. FACS revealed augmented cellular damage in T2DM mice. Interestingly, root Salep and pumpkin seeds normalized those parameters in T2DM animals suggesting significant (p<0.001) improvement of immunity of the diseased animals and ameliorated associated complications.

CONCLUSIONS

Root Salep and pumpkin seed display synergism among binomial set of herbal agents which may be safely used for T2DM management.

Cardiovascular Safety and Benefits of Noninsulin Antihyperglycemic Drugs for the Treatment of Type 2 Diabetes Mellitus: Part 2

Ideal drugs to improve outcomes in type 2 diabetes mellitus (T2DM) are those with antiglycemic efficacy, as well as cardiovascular safety that has to be determined in appropriately designed cardiovascular outcome trials as mandated by regulatory agencies. The more recent antihyperglycemic medications have shown promise with regards to cardiovascular disease (CVD) risk reduction in T2DM patients at a high cardiovascular risk. Sodium glucose cotransporter-2 inhibitors and glucagon-like peptide-1 receptor agonists are associated with better cardiovascular outcomes and mortality in T2DM patients than are dipeptidylpeptidase-4 inhibitors, leading to the Food and Drug Administration's approval of empagliflozin to reduce mortality, and of liraglutide to reduce CVD risk in high-risk T2DM patients. For heart failure outcomes, sodium glucose cotransporter-2 inhibitors are beneficial, while glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors are neutral. Ongoing and planned randomized controlled trials of these newer drugs should clarify the possibility of class effects and of CVD risk reduction benefits in low-moderate cardiovascular risk patients. While we eagerly await the results on ongoing studies, these medications should be appropriately prescribed in T2DM patients with baseline CVD or those at a high CVD risk after carefully evaluating the elevated risk for adverse events like gastrointestinal disturbances, bladder cancer, genital infections, and amputations. Studies to understand the pleotropic and novel pathophysiological mechanisms demonstrated by the sodium glucose cotransporter-2 inhibitors will shed light on the effects of the modulation of microvascular, inflammatory, and thrombotic milieu for improving the CVD risk in T2DM patients. This is part 2 of the series on noninsulin antihyperglycemic drugs for the treatment of T2DM.

Diabetic cardiomyopathy and inflammation: development of hostile microenvironment resulting in cardiac damage

Diabetes mellitus is emerging as a major risk factor for heart failure. Diabetic cardiomyopathy is defined as a myocardial dysfunction that is not caused by underlying hypertension or coronary artery disease. Studies about clinical features, natural history and outcomes of the disease are few and often conflicting, because a universally accepted operative definition of diabetic cardiomyopathy is still lacking. Hyperglycemia and related metabolic and endocrine disorders are the triggering factors of myocardial damage in diabetic cardiomyopathy through multiple mechanisms. Among these mechanisms, inflammation has a relevant role, similar to other chronic myocardial disease, such as hypertensive or ischemic heart disease. A balance between inflammatory damage and healing processes is fundamental for homeostasis of myocardial tissue, whereas diabetes mellitus produces an imbalance, promoting inflammation and delaying healing. Therefore, diabetes-related chronic inflammatory state can produce a progressive qualitative deterioration of myocardial tissue, which reflects on progressive left ventricular functional impairment, which can be either diastolic, with prevalent myocardial hypertrophy, or systolic, with prevalent myocardial fibrosis. The aim of this narrative review is to summarize the existing evidence about the role of inflammation in diabetic cardiomyopathy onset and development. Ultimately, potential pharmacological strategies targeting inflammatory response will be reviewed and discussed.

Beneficial actions of a long-acting apelin analogue in diabetes are related to positive effects on islet cell turnover and transdifferentiation

AIM

The current study has tested the hypothesis that the positive effects of apelin receptor activation in diabetes are linked to benefits on islet cell apoptosis, proliferation and transdifferentiation using Ins1^Cre/+ ;Rosa26-eYFP transgenic mice and induction of diabetes-like syndromes by streptozotocin (STZ) or high-fat feeding.

MATERIALS AND METHODS

Groups (n = 6-8) of streptozotocin (STZ)-induced diabetic and high-fat diet (HFD)-fed mice received once-daily injection (25 nmol/kg) of the long-acting acylated apelin-13 analogue, pGlu(Lys⁸ Glu-PAL)apelin-13 amide, for 10 or 12 days, respectively.

RESULTS

pGlu(Lys⁸ Glu-PAL)apelin-13 amide treatment partly reversed body weight loss induced by STZ and normalized circulating insulin. There was no effect of pGlu(Lys⁸ Glu-PAL)apelin-13 amide on these variables in HFD-fed mice, but an increase in pancreatic insulin content was observed. pGlu(Lys⁸ Glu-PAL)apelin-13 amide also fully, or partially, reversed the detrimental effects of STZ and HFD on plasma and pancreatic glucagon concentrations. In HFD-fed mice, the apelin analogue decreased dietary-induced elevations of islet, β- and α-cell areas, whilst reducing α-cell area in STZ-induced diabetic mice. In terms of islet cell lineage, pGlu(Lys⁸ Glu-PAL)apelin-13 amide effectively reduced β- to α-cell transdifferentiation and helped maintain β-cell identity, which was linked to elevated Pdx-1 expression. These islet effects were coupled with decreased β-cell apoptosis and α-cell proliferation in both models, and there was an accompanying increase of β-cell proliferation in STZ-induced diabetic mice.

CONCLUSION

Taken together these data demonstrate, for the first time, that pancreatic islet benefits of sustained APJ receptor activation in diabetes are linked to favourable islet cell transition events, leading to maintenance of β-cell mass.

Diabetic Control Agents and Their Impact on Cardiac Surgery Patients: A Clinical Overview

Chronic hyperglycemia is associated with poor cardiovascular surgical outcomes due to microvascular and macrovascular complications. This is a major concern as over one third of cardiovascular surgical patients have diabetes mellitus which greatly increases their risk of experiencing adverse cardiovascular events. A literature review was performed to identify articles discussing the effects of anti-diabetic medications (ADMs) on cardiovascular outcomes and surgical mortality and morbidity rates. Optimizing perioperative glucose levels remains a key factor in producing good surgical outcomes. In addition, recognizing gender differences, increasing patient satisfaction, and implementing dedicated diabetic teams all improve surgical mortality and morbidity rates in the diabetic population.

Effects of antidiabetic medications on cardiovascular outcomes

OBJECTIVES

Hyperglycemia is associated with an increased risk of adverse cardiovascular outcomes, such as heart failure, coronary heart disease, stroke, and in-hospital mortality. For those receiving cardiac surgery, up to half develop hyperglycemia while 30% have a diagnosis of diabetes, which is defined by chronic hyperglycemia. Due to a prothrombic state and endovascular damage, patients with diabetes have a twofold increased risk of cardiovascular events.

METHODS

Electronic literature search was done to identify articles that have discussed antidiabetic medications and how it is impacting the glycemia status as well as cardiovascular outcomes. No limits were placed on timing of the publication or type of the article. Key words and MeSH terms were used to conduct the search and the results are summarized in a narrative manner within each relevant section.

RESULTS

Antidiabetic medications play a key role in lowering blood glucose levels to reduce adverse cardiovascular outcomes. However, it is a challenge to assess their cardiovascular safety due to confounding factors, such as age, obesity, smoking, hyperlipidemia, and high blood pressure. Further research in this field is required to understand this correlation closely.

CONCLUSION

Optimizing blood glucose level during the perioperative period with correct medication and dose have a significant role in reducing morbidities. Measures should be taken to provide a safe blood glucose level for optimum outcomes.

Pharmacological therapy and cardiovascular risk reduction for type 2 diabetes

SUMMARY The pharmacological therapy for type 2 diabetes mellitus has presented important advances in recent years, which has impacted the treatment of patients with established cardiovascular disease or with high cardiovascular risk. In this scenario, two drug classes have emerged and demonstrated clear clinical benefits: SGLT-2 inhibitors and GLP-1 agonists. The present review discusses the pharmacology, adverse effects, and clinical trials that have demonstrated the benefits of these medications in reducing cardiovascular risk.

MORPHOLOGICAL AND STRUCTURAL CHANGES IN MYOCARDIUM, LIPID AND CARBOHYDRATE METABOLISM DURING DIFFERENT OUTCOMES OF CHRONIC HEART FAILURE IN PATIENTS WITH ISCHEMIC HEART DISEASE AND DIABETES MELLITUS TYPE II

Diabetes mellitus (DM) type II is an independent risk factor for cardiovascular system injury. To avoid progression of ischemic heart failure (IHF) it is important to find early signs of myocardial injury also as carbohydrate and lipid metabolism alterations. The objective of the study: to establish features of structural and functional changes in myocardium, carbohydrate and lipid metabolism, in patients with different outcomes of chronic heart failure (CHF), caused by IHD and DM type II. Material and methods. Examination of 100 patients who have CHF with IHF and DM type II was performed. Patients were divided in two groups, according to outcome: group I (n=66) – patients with favorable outcome, mean age 60.0 [55.8; 63.3] years, group II (n=34) – unfavorable outcome of CHF, mean age 58.0 [55.0; 60.3] years. We analysed complaints, cardiologycal anamnesis, cardiovascular risk factors, and physical examination data. Transthoracic echocardiography (TTE), carbohydrate and lipid panel were assessed to find out early specific signs of myocardial injury. Results. We find out statistically significant associations between TTE results, lipid panel and CHF progression in study population. Conclusions. Comparative analysis showed that degree of CHF in patients with IHD and DM type II that have preserved LV EF is associated with: duration of DM and CHF, arterial hypertension (AH) level and degree of carbohydrate and lipid metabolism disturbances. Early TTE signs of unfavorable outcome are: increase of transmitral deceleration time (Dt), increase of mean PA pressure (PA MP) even in range lower the 20 mmHg.

Vascular biomedicine in an era of chronic disease and multimorbidity

It is increasingly common that patients present with more than one disease and that diseases are chronic in nature. Cardiovascular conditions such as hypertension, heart failure and stroke, renal diseases and cardiometabolic conditions such as diabetes are prime examples of chronic diseases which pose major challenges in contemporary healthcare provision. The complex features of multimorbidity call for precision medicine approaches that take comorbidity and chronicity into account. The research basis of chronic disease and multimorbidity, however, is currently in its infancy. This applies to all domains including basic, translational and clinical science. In this article we call for development of new models, smarter use of existing models and better characterisation of vascular and cardiovascular phenotypes in studies not directly related to cardiovascular diseases. This has the potential to further improve the quality of translational research, papers in journals such as Clinical Science and ultimately translate into better patient care.

Novel ABCA1 peptide agonists with antidiabetic action

Previously, apoE-derived ABCA1 agonist peptides have been shown to possess anti-atherosclerotic and possibly antidiabetic properties. Here we assessed the in vitro and in vivo actions of a second generation of ABCA1 peptide agonists, CS6253 and T6991-2, on glucose homeostasis. The results show that these two peptides improve glucose tolerance in a prediabetic diet-induced obesity mouse model by enhancing insulin secretion. It was further demonstrated that T6991-2 also improved glucose tolerance in leptin-deficient (ob/ob) mice. CS6253 increased insulin secretion both under basal conditions and in response to high glucose stimulation in pancreatic INS-1 β-cells rendered leptin receptor deficient with specific siRNA. Additional in vitro cell studies suggest that the CS6253 agonist attenuates hepatic gluconeogenesis and glucose transport. It also potentiates insulin-stimulated glucose uptake and utilization. These observed anti-diabetic actions suggest additional benefits of the CS6253 and T6991-2 ABCA1 peptide agonists for cardiovascular disease beyond their direct anti-atherosclerosis properties previously described.

Sodium Glucose Co-transporter-2 Inhibitor: Benefits beyond Glycemic Control

Type 2 diabetes mellitus (T2DM) is a family of metabolic disorders characterized by hyperglycemia as a consequence of abnormalities in insulin secretion and insulin sensitivity. It affects hundreds of millions of people worldwide and leads to increased morbidity, compromised quality of life, higher mortality sodium glucose co-transporter 2 (SGLT2) inhibitors, a new class of oral antidiabetic drugs, have garnered considerable attention in the recent past and are considered potential first-line candidates for the management of T2DM. This review outlines the evidence-based therapeutic efficacy, safety, limitations, and advantages of SGLT2 inhibitors in the management of T2DM. SGLT2 inhibitors work by preventing the kidneys from reabsorbing glucose back into the blood, leading to increase in excretion of glucose through urine, thereby lowering hyperglycemia. Treatment with SGLT2 inhibitors improves A1C levels, reduces blood pressure and body weight, and is overall well tolerated by patients with T2DM. However, additional data on long-term cardiovascular safety are still needed. Characteristic adverse events include mild genital - urinary tract infection more commonly seen in women than in men, but serious infection is uncommon. Their use should be exercised with extra caution in patients suffering from renal impairment. Further, advancing to dual/triple combinational therapies with SGLT2 inhibitors and existing oral antidiabetic options may prove to be a breakthrough in the management of T2DM.

Nanoparticulate-based drug delivery systems for small molecule anti-diabetic drugs: An emerging paradigm for effective therapy

Emergence of nanoparticulate drug delivery systems in diabetes has facilitated improved delivery of small molecule drugs which could dramatically improve the quality of life for diabetics. Conventional dosage forms of the anti-diabetic drugs exhibit variable/less bioavailability and short half-life, demanding frequent dosing and causing increased side-effects resulting in ineffectiveness of therapy and non-compliance with the patients. Considering the chronic nature of diabetes, nanotechnology-based approaches are more promising in terms of providing site-specific delivery of drugs with higher bioavailability and reduced dosage regimen. Nanomedicines act at the cellular and molecular levels to enhance the uptake of the drug into the cells or block the efflux mechanisms thus retaining the drug inside the cell for a longer duration of time. Many studies have hinted at the possibility of administering peptide drugs like glucagon like peptides orally by encapsulation into nanoparticles. Nanoparticles also allow further modifications including their encapsulation into microparticles, polyethylene glycol (PEG)-PEGylation- or functionalization with ligands for active targeting. Nevertheless, such remarkable benefits are fraught with their long-term safety concerns, regulatory hurdles, limitations of scale-up and ineffective patent protection which have hindered their commercialization. This review summarizes the latest advances in the area of nanoformulations as applied to the delivery of anti-diabetics. STATEMENT OF SIGNIFICANCE: The present work describes the latest advancements in the area of nanoformulations for anti-diabetic therapy along with highlighting the advantages that these nanoformulations offer at molecular level for diabetes. Although several potent orally active anti-hyperglycemic agents are available, the current challenges in efficient management of diabetes include optimization of the present therapies to ensure an optimum and stable level of glucose, and also to reduce the occurrence of long term complications associated with diabetes. Nanoformulations because of their high surface area to volume ratio provide improved efficacy, targeting their delivery to the desired site of action tends to minimize adverse effects and administration of peptide drugs by oral route is also possible by encapsulating them in nanoparticles. As we reflect on the success and failures of latest research on nanoformulations for the treatment of diabetes, it is important not to dwell on lack of FDA approvals but rather define future directions that guarantee more effective anti-diabetic treatment. In proposed review we have explored the latest advancement in anti-diabetic nanotechnology based formulations.

Association of metformin use with vitamin B12 deficiency in the institutionalized elderly

Elderly people living in long term care institutions are particularly at risk of vitamin B₁₂ deficiency. The prevalence of vitamin B₁₂ deficiency was 34.9% among the 1996 institutionalized elderly residents in our previous study. The present retrospective study evaluated the association of metformin use with vitamin B₁₂ deficiency in the same group of patients. Of 1996 patients, 507 (25.4%) had diabetes, of which 188 received metformin treatment. The prevalence of vitamin B₁₂ deficiency in diabetic patients taking metformin was 53.2% compared with 31% (P < 0.001) of diabetic patients not taking metformin and 33.3% (P < 0.001) of those without diabetes. Among the vitamin B₁₂ deficient patients, diabetic patients taking metformin had lower serum vitamin B₁₂ concentration (97 pmol/L) than the diabetic patients not taking metformin (113 pmol/L, P < 0.001) and those without diabetes (111 pmol/L, P < 0.001). Subanalysis of 174 metformin users found that dose and duration of metformin use were significantly associated with vitamin B₁₂ deficiency. Adjusted odds ratio for those taking metformin ≥1500 mg /day was 2.72 (95% CI 1.11-6.7, P = 0.029) compared with those using metformin <1000mg/day. Adjusted odds ratio for those taking metformin>4 years was 3.00 (95% CI 1.35-6.68, P = 0.007) compared with those taking metformin <2 years. Prevalence of vitamin B₁₂ deficiency among those taking metformin ≥1500 mg/day for >2 years was 75.9% and was more than 2 times that of patients taking metformin <1500 mg/day for ≤2 years (35.3%). In conclusion, metformin use is associated with increased risk and severity of vitamin B₁₂ deficiency in the institutionalized elderly residents. Patients taking metformin ≥1500 mg/day for >2 years are particularly at risk. Testing for vitamin B₁₂ status before and regularly after the start of metformin may be considered.

Redox Functions of Heme Oxygenase-1 and Biliverdin Reductase in Diabetes

In patients with diabetes, the hyperglycemia-driven excess generation of reactive oxygen species (ROS) induces oxidative stress (OS) in a variety of tissues. OS is closely associated with chronic inflammation and has a key role in the pathogenesis of vascular complications. The enzymes that generate ROS and gasotransmitters are redox regulated and are implicated in cellular signaling. As a result of cellular metabolism, cells produce significant amounts of carbon monoxide (CO), mainly from heme degradation catalyzed by heme oxygenases (HOs). These reactions also generate biliverdin, bilirubin (BR), and iron. The conversion of biliverdin to BR is catalyzed by biliverdin reductase-A (BVR-A). In this review, we focus on the importance of the HO-1/CO system and BVR in the pathophysiology and therapy of inflammation associated with diabetes.

Investigation into Hypoglycemic, Antihyperlipidemic, and Renoprotective Potentials of Dennettia tripetala (Pepper Fruit) Seed in a Rat Model of Diabetes

This study investigated the hypoglycemic, antihyperlipidemic, and renoprotective potentials of Dennettia tripetala (DT) in a rat model of diabetes. The hypoglycemic activity in crude methanol seed extract of DT (CMEDT) and methanol seed fraction of DT (MFDT) measured by glucose oxidase method was increased by 47.37% and 28.72%, respectively, after 8 hours of administration. After 10 days of treatment, CMEDT and MFDT gave a good glycemic control with the highest percentage reduction of 75.82% and 71.34% in glucose level, respectively, which is closely compared with 79.91% in glibenclamide. Using the enzymatic assay and Friedewald's equation, there was a significant reduction in serum level of total cholesterol (TC), triglyceride (TG), very-low-density lipoprotein (VLDL), and low-density lipoprotein (LDL) and a significant increase in high-density lipoprotein (HDL) (p < 0.05) following treatment with CMEDT and MFDT, when compared with the untreated group, although results varied in dosed groups, with high dose of MFDT showing a better lipid-lowering activity. High dose of MFDT improved lipid metabolism and increased percentage protection against atherogenesis by 44%. However, neither CMEDT nor MFDT ameliorated the renal biochemical alteration in urea and creatinine. Thus, the study demonstrates hypoglycemic and antihyperlipidemic potentials of DT seed in diabetes.

An overview of the inflammatory signalling mechanisms in the myocardium underlying the development of diabetic cardiomyopathy

Heart failure is a highly morbid and mortal clinical condition that represents the last stage of most cardiovascular disorders. Diabetes is strongly associated with an increased incidence of heart failure and directly promotes cardiac hypertrophy, fibrosis, and apoptosis. These changes, in turn, contribute to the development of ventricular dysfunction. The clinical condition associated with the spectrum of cardiac abnormalities induced by diabetes is termed diabetic cardiomyopathy. Myocardial inflammation has recently emerged as a pathophysiological process contributing to cardiac hypertrophy, fibrosis, and dysfunction in cardiac diseases. Myocardial inflammation is also implicated in the development of diabetic cardiomyopathy. Several molecular mechanisms link diabetes to myocardial inflammation. The NF-κB signalling pathway and the renin-angiotensin-aldosterone system are strongly activated in the diabetic heart, thereby promoting myocardial inflammation. Advanced glycation end-products and damage-associated molecular pattern molecules also represent strong triggers for inflammation. The mediators resulting from this inflammatory process modulate specific intracellular signalling mechanisms in cardiac cells that promote the development of diabetic cardiomyopathy. This review article will provide an overview of the signalling molecular mechanisms linking diabetic cardiomyopathy to myocardial inflammation.

Cardiac Computed Tomography Angiographic Findings as Predictors of Late Heart Failure in an Asymptomatic Diabetic Cohort: An 8-Year Prospective Follow-Up Study

OBJECTIVES

Predictive models for heart failure (HF) in heterogeneous populations have had limited success. We examined cardiac computed tomography angiography (CTA) predictors of HF or cardiovascular death (HF-CVD) in a prospective study of asymptomatic diabetics undergoing baseline assessment by CTA.

METHODS

The subjects (n = 735, aged 55-74 years, 51.2% women) had no clinical history of cardiovascular disease at study entry. Coronary artery calcium (CAC) score, CTA-defined coronary atherosclerosis, cardiac chamber volumes, and clinical data were collected and late outcome events recorded over 8.4 ± 0.6 years (range 7.3-9.3).

RESULTS

HF-CVD occurred in 41 (5.6%) subjects, with HF occurring mostly (19/23, 82.6%) in subjects without preceding myocardial infarction. Baseline univariate clinical outcome predictors of HF-CVD included older age (p = 0.027), the duration of diabetes (p = 0.004), HbA1c (p < 0.0001), microvascular disease (retinopathy, microalbuminuria) (p < 0.0001), and systolic blood pressure (p = 0.035). Baseline univariate CTA predictors included CAC score (p = 0.004), coronary stenosis (p = 0.047), and a CTA-defined left/right atrial (LA/RA) volume ratio >1 (p < 0.0001). Independent predictors were an LA/RA volume ratio >1, microvascular disease, and systolic blood pressure (model C-statistic 0.792, 95% CI 0.758-0.824). Measures of the extent of coronary artery disease (CAD) were not independent predictors of HF-CVD.

CONCLUSIONS

In a low- to moderate-risk asymptomatic diabetic population, CTA LA enlargement (LA/RA volume ratio) but not the extent of CAD had independent prognostic value for HF-CVD in addition to the clinical variables.

Cardiovascular benefits and safety of non-insulin medications used in the treatment of type 2 diabetes mellitus

Diabetes mellitus is a growing in exponential proportions. If the current growth trend continues, it may result in every third adult in the United States having diabetes mellitus by 2050, and every 10^th adult worldwide. Type 2 diabetes mellitus (T2DM) confers a 2- to 3-fold increased risk of cardiovascular (CV) events compared with non-diabetic patients, and CV mortality is responsible for around 80% mortality in this population. Patients with T2DM can have other features of insulin resistance-metabolic syndrome like hypertension, lipid abnormalities, and obesity which are all associated with increased CV disease and stroke risk even in the absence of T2DM. The management of a T2DM calls for employing a holistic risk factor control approach. Metformin is the first line therapy for T2DM and has been shown to have cardiovascular beneficial effects. Intense debate regarding the risk of myocardial infarction with rosiglitazone led to regulatory agencies necessitating cardiovascular outcome trials with upcoming anti-diabetic medications. Glucagon like peptide-1 agonists and sodium glucose co-transporter-2 inhibitors have shown promising CV safety and additional CV benefit in recent clinical trials. These drugs have favorable effects on traditional CV risk factors. The findings from these studies further support that fact that CV risk factor control plays an important role in reducing morbidity and mortality in T2DM patients. This review article will discuss briefly the cardiovascular safety and benefits of the oral medications which are currently being used for T2DM and will then discuss in detail about the newer medications being investigated for the treatment of T2DM.

Cardiovascular benefits of the newer medications for treating type 2 diabetes mellitus

Diabetes mellitus is growing in pandemic proportions and is associated with significant morbidity, mortality, and health care expenditure. Type 2 diabetes mellitus (T2DM) is the most common, accounting for about 90-95% of diagnosed diabetes in United States adults. Individuals with T2DM have a 2- to 3-fold increased risk of cardiovascular (CV) events compared with their non-diabetic counterparts, and CV mortality is responsible for around 80% of the mortality in T2DM. Emerging evidence suggest that in T2DM patients, hyperglycemia plays a little role in the progression of CV disease, and metabolic risk factors like insulin resistance, hypertension, obesity, and dyslipidemia are the major culprits in the initiation and progression of CV disease. This calls for development of drugs which control hyperglycemia as well as the various metabolic risk factors in T2DM patients to improve CV outcomes. Recent clinical trials of glucagon-like peptide 1 receptor agonists (GLP-1 RAs) and sodium glucose cotransporter-2 (SGLT-2) inhibitors showed encouraging CV outcomes in T2DM patients, which are attributed to the diverse extra-pancreatic effects of these medications. This review article will discuss the CV benefits of the newer incretin based therapies and SGLT-2 inhibitors as observed in their CV safety trials. As T2DM or insulin resistance syndrome, CV disease, and HF and frequently coexistent, it would be interesting to design studies evaluating the combinations of GLP-1 RAs, SGLT-2 inhibitors, and pioglitazone in T2DM patient at an elevated CV risk, and in non-diabetic patients with insulin resistance to study the possible CV protective role of these combinations.

Comparative effectiveness of oral antidiabetic drugs in preventing cardiovascular mortality and morbidity: A network meta-analysis

In the Guidance for Industry from the Food and Drug Administration in 2008, excess cardiovascular risk should be ruled out in trials of all new antidiabetic drugs; however, relatively few studies have focused on cardiovascular safety with antidiabetic drug use. We aimed to examine mortality and cardiovascular risk using a network meta-analysis. We searched the Medline, Embase, Cochrane, and ClinicalTrials.gov registry databases in March 2016 to identify randomized controlled trials reporting cardiovascular risk with the following oral antidiabetic drugs: metformin, sulfonylureas, thiazolidinedione (TZD), dipeptidyl peptidase-4 (DPP4) inhibitors, and sodium-glucose co-transporter-2 (SGLT2) inhibitors. We assessed the differences in the risks of all-cause mortality, cardiovascular-related mortality, acute coronary syndrome (ACS), and myocardial infarction (MI) among antidiabetic drugs with fixed effect models for direct pairwise comparisons and Bayesian network meta-analyses to integrate direct and indirect comparisons. Of the 101,183 patients in 73 randomized controlled trials, 3,434 (3.4%) died. The relative risks of all-cause mortality with SGLT2 inhibitor use were 0.68 (95% credible interval: 0.57–0.80), 0.74 (0.49–1.10), 0.63 (0.46–0.87), 0.71 (0.55–0.90), and 0.65 (0.54–0.78), compared with placebo, metformin, sulfonylurea, TZD, and DPP4 inhibitor, respectively. The relative risks of cardiovascular-related mortality with SGLT2 inhibitor use were 0.61 (0.50–0.76), 0.81(0.36–1.90), 0.52(0.31–0.88), 0.66(0.49–0.91), and 0.61(0.48–0.77), compared with placebo, metformin, sulfonylurea, TZD, and DPP4 inhibitor, respectively. The relative risks of ACS with SGLT2 inhibitor use was consistent with that of all-cause mortality. SGLT2 inhibitor use was associated with a lower risk of ACS than the other OADs and placebo. The relative risks of MI with SGLT2 inhibitor use were 0.77 (0.63–0.93) and 0.75 (0.60–0.94), compared with placebo and DPP4 inhibitor, respectively. The currently available data provide the evidence of cardiovascular benefit from use of SGLT2 inhibitors to patients with type 2 diabetes, although additional results from ongoing studies will be pivotal.