Sulfonylureas: a new look at old therapy

Development of value-added nutritious crackers with high antidiabetic properties from blends of Acha (Digitaria exilis) and blanched Pigeon pea (Cajanus cajan)

Pigeon pea was treated by blanching and used to supplement acha flour for the development of functional cracker biscuits. The flour ratios for acha and pigeon pea were 100:0 (ACC), 80:20 (APC1), and 70:30 (APC2), respectively. The developed cracker biscuits were evaluated for chemical acid compositions, antioxidant, as well as antidiabetic properties. Protein contents of the formulated crackers increased with increase in supplementation with pigeon pea flour. The antinutrient content of the formulated snack was low hence may not adversely affect nutrient bioavailability. Glutamic and aspartic acids were the predominant amino acids while methionine and lysine significantly increased as a result of supplementation with pigeon pea flour. The biscuit exhibited good antioxidant properties indicated by its strong ability to scavenge hydroxyl, superoxide, DPPH radicals, and reduced Fe3+ to Fe2+. The formulated snack especially APC2 possessed low glycemic index (47.95%) and significantly inhibited the key digestive enzymes (α-amylase and α-glucosidase). All parameters evaluated indicated that APC2 could serve as a functional snack in the management of hyperglycemia (diabetes) and prevention of associated degenerative diseases.

Do sulphonylureas still have a place in clinical practice?

Sulphonylureas have been commercially available since the 1950s, but their use continues to be associated with controversy. Although adverse cardiovascular outcomes in some observational studies have raised concerns about sulphonylureas, findings from relatively recent, robust, and high-quality systematic reviews have indicated no increased risk of all-cause mortality associated with sulphonylureas compared with other active treatments. Results from large, multicentre, randomised controlled trials such as the UK Prospective Diabetes Study and ADVANCE have confirmed the microvascular benefits of sulphonylureas, a reduction in the incidence or worsening of nephropathy and retinopathy, and no increase in all-cause mortality, although whether these benefits were due to sulphonylurea therapy and not an overall glucose-lowering effect could not be confirmed. A comparison of sulphonylureas and pioglitazone in the TOSCA.IT trial also confirmed the efficacy and cardiovascular safety of sulphonylureas. Investigators of randomised controlled trials have reported an increased risk of hypoglycaemia and weight gain with sulphonylureas, but data from observational studies suggest that the incidence of severe hypoglycaemia is lower in people taking sulphonylurea than in people taking insulin, and weight gain with sulphonylureas has been relatively modest in large cohort studies. 80% of people with diabetes live in low-to-middle income countries, so the effectiveness, affordability, and safety of sulphonylureas are particularly important considerations when prescribing glucose-lowering therapy. Results of ongoing head-to-head studies with new drugs, such as the comparison of glimepiride with linagliptin in the CAROLINA study and the comparison of various therapies (including sulphonylureas) for glycaemic control in the GRADE study, will determine the place of sulphonylureas in glucose-lowering therapy algorithms for patients with type 2 diabetes.

Sulfonylurea and neuroprotection: The bright side of the moon

Sulfonylurea (SUR) agents are the second and most used oral hypoglycemic drugs after metformin and they still as an imperative tool for most favorable of glucose control. SURs are used mainly in the management of Type 2 diabetes mellitus since; they are effective in the glycemic control and reduction of microvascular complications. First-generation SUR represents 3% of used oral hypoglycemic agents while second and third generations are used in about 25% in patients with Type 2 diabetes mellitus. Upregulation of SUR1 receptor has been observed after stroke and traumatic brain injury, therefore, SUR such as glibenclamide inhibits brain edema and astrocyte swelling following brain insults. SUR drugs mainly glibenclamide is effective at a low dose in the management of cerebral stroke and could be a contestant with corticosteroid in controlling brain edema.

Modern Sulfonylureas Strike Back - Exploring the Freedom of Flexibility

This editorial discusses the concept of flexibility in diabetes care. Flexibility of an oral antidiabetic drug (OAD) is defined as its ability to be used efficaciously and safely, in flexible, convenient doses and frequencies, at flexible timings of administration. This flexibility also includes OAD usage alone or in combination with a wide spectrum of drugs, in a wide spectrum of patients, irrespective of their age, gender, health status, or dietary patterns, with flexible dose titration, glucose monitoring and healthcare contact schedules. This editorial examines the flexibility of the modern sulfonylureas such as gliclazide extended (modified) release (MR) preparation in the management of diabetes. Using evidence-based rationale, we demonstrate that gliclazide MR is a flexible, and useful option for the management of type 2 diabetes.

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.

Query-constraint-based mining of association rules for exploratory analysis of clinical datasets in the National Sleep Research Resource

Background

Association Rule Mining (ARM) has been widely used by biomedical researchers to perform exploratory data analysis and uncover potential relationships among variables in biomedical datasets. However, when biomedical datasets are high-dimensional, performing ARM on such datasets will yield a large number of rules, many of which may be uninteresting. Especially for imbalanced datasets, performing ARM directly would result in uninteresting rules that are dominated by certain variables that capture general characteristics.

Methods

We introduce a query-constraint-based ARM (QARM) approach for exploratory analysis of multiple, diverse clinical datasets in the National Sleep Research Resource (NSRR). QARM enables rule mining on a subset of data items satisfying a query constraint. We first perform a series of data-preprocessing steps including variable selection, merging semantically similar variables, combining multiple-visit data, and data transformation. We use Top-k Non-Redundant (TNR) ARM algorithm to generate association rules. Then we remove general and subsumed rules so that unique and non-redundant rules are resulted for a particular query constraint.

Results

Applying QARM on five datasets from NSRR obtained a total of 2517 association rules with a minimum confidence of 60% (using top 100 rules for each query constraint). The results show that merging similar variables could avoid uninteresting rules. Also, removing general and subsumed rules resulted in a more concise and interesting set of rules.

Conclusions

QARM shows the potential to support exploratory analysis of large biomedical datasets. It is also shown as a useful method to reduce the number of uninteresting association rules generated from imbalanced datasets. A preliminary literature-based analysis showed that some association rules have supporting evidence from biomedical literature, while others without literature-based evidence may serve as the candidates for new hypotheses to explore and investigate. Together with literature-based evidence, the association rules mined over the NSRR clinical datasets may be used to support clinical decisions for sleep-related problems.

Electronic supplementary material

The online version of this article (10.1186/s12911-018-0633-7) contains supplementary material, which is available to authorized users.

Determination of gliclazide minimum concentration in type 2 diabetes mellitus patients

Type 2 diabetes mellitus is a worldwide health problem. Many drugs can be used in its treatment. One of them is gliclazide - the sulfonylurea derivative. It is dosed in modified release tablets. The study aimed to determine the minimum steady-state concentration of gliclazide at patients taking modified release tablets. Fasting plasma glucose, insulin level, and glycated hemoglobin were also assayed in this study. Ten patients of the primary care physician clinic took 30-90 mg of gliclazide daily. The statistical analysis proved that there is a statistically significant correlation between insulin level and body weight (p = 0.044) as well as between the dose and gliclazide concentrations (p = 0.015) and also between insulin level and minimum concentration of the drug (p = 0.0074). The linear correlation between dose and gliclazide's minimum steady state concentration proved its linear pharmacokinetics. The correlation between the minimum concentration of gliclazide and insulin level might be a potential predictor of patients compliance.

Pharmacogenetics of Antidiabetic Drugs

Pharmacogenetic studies of antidiabetic drugs have so far focused largely on response to metformin, which is the first-line therapy for treatment of type 2 diabetes (T2D). The first studies of metformin pharmacogenetics were focused on candidate genes that were implicated in metformin pharmacokinetics and transport. Since 2011, genome-wide association studies have been conducted in large cohorts of individuals with T2D identifying genes that are associated with glycemic response to metformin. There have been fewer pharmacogenetic studies of other antidiabetic drugs, and those have been largely limited to candidate gene studies with small sample sizes. Understanding the pharmacogenetics of antidiabetes medications is important for the integration of genetic screening into therapeutic decision making, and to achieve the goal of "precision medicine" for patients with T2D. In this chapter, we provide a review of the pharmacogenetics investigations of metformin and other antidiabetes medications. In addition, we highlight the importance of collaborative efforts with large sample size and representation from multiple ethnic groups in pharmacogenetics studies.

Mechanism of action of camphoryl-benzene sulfonamide derivative on glucose uptake in adipose tissue

The aim of the present study was to investigate the mechanism of action of a sulfonamide derivative on glucose uptake in adipose tissue, as well as to characterize the effects of this compound on intestinal disaccharidases and advanced glycation end-products (AGEs) formation. Camphoryl-benzene sulfonamide (CS) was able to stimulate glucose uptake in isolated adipocytes, adipose tissue, and in soleus muscle. The stimulatory effect of the compound (10 μM) on glucose uptake on adipose tissue was blocked by diazoxide, wortmannin, U73122, colchicine, and N-ethylmaleimide. On the other hand, the effects of CS were not blocked by glibenclamide, an inhibitor of the K⁺ -ATP channel, or even by the inhibitor of protein p38 MAPK, SB 203580. In vivo, this compound reduced intestinal disaccharidase activity, while, in vitro, CS reduced the formation of AGEs at 7, 14, and 28 days of incubation. The stimulatory effect of CS on glucose uptake requires the activation of the K⁺ -ATP channel, translocation, and fusion of GLUT4 vesicles to the plasma membrane on adipocytes for glucose homeostasis. In addition, the inhibition of disaccharidase activity contributes to the glucose homeostasis in a short-term as well as the remarkable reduction in AGE formation indicates that the CS may prevent of complications of late diabetes.

Rahim AA, Eliana F, Shrestha HK, Chaudhary S, Ngugi N, Mbanya JC, Aye TT, Latt TS, Akanov ZA, Syed AR, Tandon N, Unnikrishnan AG, Madhu SV, Jawa A, Chowdhury S, Bajaj S, Das AK. Consensus Recommendations on Sulfonylurea and Sulfonylurea Combinations in the Management of Type 2 Diabetes Mellitus - International Task Force

For decades, sulfonylureas (SUs) have been important drugs in the antidiabetic therapeutic armamentarium. They have been used as monotherapy as well as combination therapy. Focus on newer drugs and concerns about the risk of severe hypoglycemia and weight gain with some SUs have led to discussion on their safety and utility. It has to be borne in mind that the adverse events associated with SUs should not be ascribed to the whole class, as many modern SUs, such as glimepiride and gliclazide modified release, are associated with better safety profiles. Furthermore, individualization of treatment, using SUs in combination with other drugs, backed with careful monitoring and patient education, ensures maximum benefits with minimal side effects. The current guidelines, developed by experts from Africa, Asia, and the Middle East, promote the safe and smart use of SUs in combination with other glucose-lowering drugs.

Antidiabetic therapies and male reproductive function: where do we stand?

Diabetes mellitus has been increasing at alarming rates in recent years, thus jeopardizing human health worldwide. Several antidiabetic drugs have been introduced in the market to manage glycemic levels, and proven effective in avoiding, minimizing or preventing the appearance or development of diabetes mellitus-related complications. However, and despite the established association between such pathology and male reproductive dysfunction, the influence of these therapeutic interventions on such topics have been scarcely explored. Importantly, this pathology may contribute toward the global decline in male fertility, giving the increasing preponderance of diabetes mellitus in young men at their reproductive age. Therefore, it is mandatory that the reproductive health of diabetic individuals is maintained during the antidiabetic treatment. With this in mind, we have gathered the available information and made a critical analysis regarding the effects of several antidiabetic drugs on male reproductive function. Unlike insulin, which has a clear and fundamental role on male reproductive function, the other antidiabetic therapies' effects at this level seem incoherent. In fact, studies are highly controversial possibly due to the different experimental study approaches, which, in our opinion, suggests caution when it comes to prescribing such drugs to young diabetic patients. Overall, much is still to be determined and further studies are needed to clarify the safety of these antidiabetic strategies on male reproductive system. Aspects such as the effects of insulin levels variations, consequent of insulin therapy, as well as what will be the impact of the side effect hypoglycemia, common to several therapeutic strategies discussed, on the male reproductive system are still to be addressed.

Current Therapies That Modify Glucagon Secretion: What Is the Therapeutic Effect of Such Modifications?

PURPOSE OF REVIEW

Hyperglucagonemia contributes significantly to hyperglycemia in type 2 diabetes and suppressed glucagon levels may increase the risk of hypoglycemia. Here, we give a brief overview of glucagon physiology and the role of glucagon in the pathophysiology of type 2 diabetes and provide insights into how antidiabetic drugs influence glucagon secretion as well as a perspective on the future of glucagon-targeting drugs.

RECENT FINDINGS

Several older as well as recent investigations have evaluated the effect of antidiabetic agents on glucagon secretion to understand how glucagon may be involved in the drugs' efficacy and safety profiles. Based on these findings, modulation of glucagon secretion seems to play a hitherto underestimated role in the efficacy and safety of several glucose-lowering drugs. Numerous drugs currently available to diabetologists are capable of altering glucagon secretion: metformin, sulfonylurea compounds, insulin, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors, sodium-glucose cotransporter 2 inhibitors and amylin mimetics. Their diverse effects on glucagon secretion are of importance for their individual efficacy and safety profiles. Understanding how these drugs interact with glucagon secretion may help to optimize treatment.

Hypoglycaemia seriousness and weight gain as determinants of cardiovascular disease outcomes among sulfonylurea users

AIMS

Certain treatments for type 2 diabetes mellitus cause hypoglycaemia and weight gain, and thus might counteract the benefits of intensive glucose control. We quantify the association of cardiovascular disease (CVD) outcomes with hypoglycaemia and weight gain among patients with type 2 diabetes treated with sulfonylureas.

MATERIALS AND METHODS

This cohort study included patients from January 2009 through December 2014 who were selected from within a deidentified nationwide electronic health records repository, including multiple provider networks and electronic medical records systems. Hypoglycaemia measures from structured data fields and free text clinical notes were categorized as serious or non-serious. Covariate adjusted Poisson regression analysis was used to assess the association between frequency of hypoglycaemia (by severity), or magnitude of weight change, and incidence of acute myocardial infarction (AMI), congestive heart failure (CHF) and stroke.

RESULTS

Among 143 635 eligible patients, we observed 5669 cases of AMI, 14 109 incident cases of CHF and 7017 cases of stroke. Overall incidence rates were 1.53, 4.26 and 1.92 per 100 person-years for AMI, CHF and stroke, respectively. The associations between overall hypoglycaemia and each of the CVD outcomes were positive, with stronger associations observed for serious hypoglycaemia and attenuated or null associations observed for non-serious hypoglycaemia. Weight change exhibited a U-shaped association with increased risks associated with both weight loss and weight gain relative to stable weight.

CONCLUSIONS

This study provides evidence of increased CVD risk associated with hypoglycaemia, especially with serious hypoglycaemia events. While associations were attenuated with non-serious hypoglycaemia, the results were suggestive of a potential increased risk.

Bioactive Peptides

The increased consumer awareness of the health promoting effects of functional foods and nutraceuticals is the driving force of the functional food and nutraceutical market. Bioactive peptides are known for their high tissue affinity, specificity and efficiency in promoting health. For this reason, the search for food-derived bioactive peptides has increased exponentially. Over the years, many potential bioactive peptides from food have been documented; yet, obstacles such as the need to establish optimal conditions for industrial scale production and the absence of well-designed clinical trials to provide robust evidence for proving health claims continue to exist. Other important factors such as the possibility of allergenicity, cytotoxicity and the stability of the peptides during gastrointestinal digestion would need to be addressed. This review discusses our current knowledge on the health effects of food-derived bioactive peptides, their processing methods and challenges in their development.

A Novel Diphenylthiosemicarbazide Is a Potential Insulin Secretagogue for Anti-Diabetic Agen

Insulin secretagogues are used for treatment of type 2 diabetes. We attempted to discover novel small molecules to stimulate insulin secretion by using in silico similarity search using sulfonylureas as query, followed by measurement of insulin secretion. Among 38 compounds selected by in silico similarity search, we found three diphenylsemicarbazides and one quinolone that stimulate insulin secretion. We focused on compound 8 (C8), which had the strongest insulin-secreting effect. Based on the structure-activity relationship of C8-derivatives, we identified diphenylthiosemicarbazide (DSC) 108 as the most potent secretagogue. DSC108 increased the intracellular Ca²⁺ level in MIN6-K8 cells. Competitive inhibition experiment and electrophysiological analysis revealed sulfonylurea receptor 1 (SUR1) to be the target of DSC108 and that this diphenylthiosemicarbazide directly inhibits ATP-sensitive K⁺ (K_ATP) channels. Pharmacokinetic analysis showed that DSC108 has a short half-life in vivo. Oral administration of DSC108 significantly suppressed the rises in blood glucose levels after glucose load in wild-type mice and improved glucose tolerance in the Goto-Kakizaki (GK) rat, a model of type 2 diabetes with impaired insulin secretion. Our data indicate that DSC108 is a novel insulin secretagogue, and is a lead compound for development of a new anti-diabetic agent.

Molecular action of sulphonylureas on KATP channels: a real partnership between drugs and nucleotides

Sulphonylureas stimulate insulin secretion from pancreatic β-cells primarily by closing ATP-sensitive K⁺ channels in the β-cell plasma membrane. The mechanism of channel inhibition by these drugs is unusually complex. As direct inhibitors of channel activity, sulphonylureas act only as partial antagonists at therapeutic concentrations. However, they also exert an additional indirect inhibitory effect via modulation of nucleotide-dependent channel gating. In this review, we summarize current knowledge and recent advances in our understanding of the molecular mechanism of action of these drugs.

Sulphonylurea compared to DPP-4 inhibitors in combination with metformin carries increased risk of severe hypoglycemia, cardiovascular events, and all-cause mortality

AIMS

There are safety concerns related to sulphonylurea treatment. The objective of this nationwide study was to compare the risk of cardiovascular disease (CVD), all-cause mortality and severe hypoglycemia in patients with type 2 diabetes (T2D) starting second-line treatment with either metformin+sulphonylurea or metformin+dipeptidyl peptidase-4 inhibitor (DPP-4i).

METHODS

All patients with T2D in Sweden who initiated second-line treatment with metformin+sulphonylurea or metformin+DPP-4i during 2006-2013 (n=40,736 and 12,024, respectively) were identified in this nationwide study. The Swedish Prescribed Drug Register and the Cause of Death and National Patient Registers were used, and Cox survival models adjusted for age, sex, fragility, prior CVD, and CVD-preventing drugs were applied to estimate risks of events. Propensity score adjustments and matching methods were used to test the results.

RESULTS

Of 52,760 patients; 77% started metformin+SU and 23% metformin+DPP-4i. Crude incidences for severe hypoglycemia, CVD, and all-cause mortality in the SU cohort were 2.0, 19.6, and 24.6 per 1000 patient-years and in the DPP-4i cohort were 0.8, 7.6, and 14.9 per 1000 patient-years, respectively. Sulphonylurea compared with DPP4i was associated with higher risk of subsequent severe hypoglycemia, fatal and nonfatal CVD, and all-cause mortality; adjusted HR (95% CI): 2.07 (1.11-3.86); 1.17 (1.01-1.37); and 1.25 (1.02-1.54), respectively. Results were confirmed by additional propensity-adjusted and matched analyses. Among the SU drugs, glibenclamide had the highest risks.

CONCLUSIONS

Metformin+SU treatment was associated with an increased risk of subsequent severe hypoglycemia, cardiovascular events, and all-cause mortality compared with metformin+DPP4i. Results from randomized trials will be important to elucidate causal relationships.

Metformin treatment status and abdominal aortic aneurysm disease progression

OBJECTIVE

In population-based studies performed on multiple continents during the past two decades, diabetes mellitus has been negatively associated with the prevalence and progression of abdominal aortic aneurysm (AAA) disease. We investigated the possibility that metformin, the primary oral hypoglycemic agent in use worldwide, may influence the progression of AAA disease.

METHODS

Preoperative AAA patients with diabetes were identified from an institutional database. After tabulation of individual cardiovascular and demographic risk factors and prescription drug regimens, odds ratios for categorical influences on annual AAA enlargement were calculated through nominal logistical regression. Experimental AAA modeling experiments were subsequently performed in normoglycemic mice to validate the database-derived observations as well as to suggest potential mechanisms of metformin-mediated aneurysm suppression.

RESULTS

Fifty-eight patients met criteria for study inclusion. Of 11 distinct classes of medication considered, only metformin use was negatively associated with AAA enlargement. This association remained significant after controlling for gender, age, cigarette smoking status, and obesity. The median enlargement rate in AAA patients not taking oral diabetic medication was 1.5 mm/y; by nominal logistic regression, metformin, hyperlipidemia, and age ≥70 years were associated with below-median enlargement, whereas sulfonylurea therapy, initial aortic diameter ≥40 mm, and statin use were associated with above-median enlargement. In experimental modeling, metformin dramatically suppressed the formation and progression, with medial elastin and smooth muscle preservation and reduced aortic mural macrophage, CD8 T cell, and neovessel density.

CONCLUSIONS

Epidemiologic evidence of AAA suppression in diabetes may be attributable to concurrent therapy with the oral hypoglycemic agent metformin.

Hypoglycemia Secondary to Sulfonylurea Ingestion in a Patient with End Stage Renal Disease: Results from a 72-Hour Fast

Insulin, proinsulin, and C-peptide levels increase with sulfonylurea exposure but the acuity of increase has not been described in dialysis patients. We present a case of a dialysis patient who presented with hypoglycemia and was found to have accidental sulfonylurea ingestion. This is a 73-year-old man with ESRD on peritoneal dialysis, without history of diabetes, who presented with hypoglycemia. Past medical history includes multiple myeloma, congestive heart failure, and hypertension. At initial presentation, his blood glucose was 47 mg/dL, with concomitant elevations in the following: C-peptide 30.5 (nl: 0.8-3.5 ng/mL), insulin 76 (nl: 3-19 μIU/mL), and proinsulin 83.3 (nl: ≤8.0 pmol/L). During the 72-hour fast, which he completed without hypoglycemia, insulin declined to be within normal limits (to 12 μIU/mL); proinsulin (to 12.1 pmol/L) and C-peptide (to 7.2 ng/mL) levels decreased but remained elevated. The sulfonylurea screen ultimately returned positive for glipizide, clinching the diagnosis. This is the first reported case which characterizes the chronic elevation of proinsulin in a patient with ESRD, as well as its dramatic increase after a presumed solitary exposure to sulfonylurea. The 72-hour fast conducted gives insight into the clearance of insulin, proinsulin, and C-peptide after sulfonylurea ingestion in ESRD.

Severe hypoglycaemia during treatment with sulphonylureas in patients with type 2 diabetes in the Capital Region of Denmark

AIMS

Sulphonylureas (SU) are currently recommended as a well-established second line treatment in guidelines for type 2 diabetes (T2DM). In the Capital Region of Denmark 16,865 patients were given SU as part of their treatment of T2DM in 2010-2011. To what extent SU are associated with hospitalizations due to severe hypoglycaemic episodes, defined as episodes with a need for external assistance, was investigated. The prevalence and characteristics of these patients and potential risk factors were studied.

METHODS

ICD-10 diagnosis codes were used to identify patients hospitalized due to hypoglycaemia and T2DM for a period of 2 years (2010-2011). Inclusion criteria were T2DM, hospitalization due to hypoglycaemia and treatment with SU as monotherapy or in combination with other glucose-lowering drugs except insulin treatment.

RESULTS

We identified 161 patients fulfilling the inclusion criteria. Their mean age was 76 (53-97) years and 54% were males. Sixty percent of the patients had diabetic complications, including 19% with diabetic nephropathy. The major reason for severe hypoglycaemia was an unchanged dose of SU despite of a significant decline in food intake (45%). In 22% of the patients more than one reason was listed, most commonly a concomitant infection associated with decreased food intake and unchanged dose of SU.

CONCLUSION

The incidence of hospital admission-requiring severe hypoglycaemia in patients treated with SU was 0.48 episodes per 100 patient-years of SU-treated patients. It was mainly older patients with diminished food intake, excessive alcohol use or other medications, concomitant infection, and with diabetic complications.

Isoenergetic Polymorphism: The Puzzle of Tolazamide as a Case Study

In the present case study of tolazamide we illustrate how many seemingly contradictory results that have been obtained from experimental observations and theoretical calculations can finally start forming a consistent picture: a "puzzle put together". For many years, tolazamide was considered to have no polymorphs. This made this drug substance unique among the large family of sulfonylureas, which was known to be significantly more prone to polymorphism than many other organic compounds. The present work employs a broad and in-depth analysis that includes the use of optical microscopy, single-crystal and powder X-ray diffraction, IR and Raman spectroscopies, DSC, semiempirical PIXEL calculations and DFT of three polymorphs of tolazamide. This case study shows how the polymorphs of a molecular crystal can be overlooked even if discovered serendipitously on one of numerous crystallizations, and how very different molecular packings can be practically isoenergetic but still crystallize quite selectively and transform one into another irreversibly upon heating.

Systematic review and meta-analysis of the efficacy and hypoglycemic safety of gliclazide versus other insulinotropic agents

AIMS

Sulfonylureas are well positioned in treating type 2 diabetes, after lifestyle modification and metformin. The sulfonylurea gliclazide was given preference over glibenclamide in older people with type 2 diabetes in the World Health Organization model list of essential medicines. Consequently, a systematic review and meta-analysis of randomized controlled trials of the efficacy and safety of gliclazide versus other oral insulinotropic agents (sulfonylureas, dipeptidyl peptidase-4 inhibitors, and glinides) was performed.

METHODS

Two reviewers searched MEDLINE for studies of ≥12 weeks duration in adults with type 2 diabetes. The key search word was "gliclazide", filtered with "randomized controlled trial", "human" and "19+ years". Differences were explored in mean change in glycated hemoglobin (HbA(1c)) from baseline (primary outcome) and risk of hypoglycemia (secondary outcome) between gliclazide and other oral insulinotropic agents; and other sulfonylureas.

RESULTS

Nine out of 181 references reported primary outcomes, of which 7 reported secondary outcomes. Gliclazide lowered HbA1c more than other oral insulinotropic agents, with a weighted mean difference of -0.11% (95%, CI -0.19 to -0.03%, P=0.008, I(2)=60%), though not more than other sulfonylureas (-0.12%; 95%, CI -0.25 to 0.01%, P=0.07, I(2)=77%). Risk of hypoglycemia with gliclazide was not different to other insulinotropic agents (RR 0.85; 95%, CI 0.66 to 1.09, P=0.20, I(2)=61%) but significantly lower than other sulfonylureas (RR 0.47; 95%, CI 0.27 to 0.79, P=0.004, I(2)=0%).

CONCLUSION

Compared with other oral insulinotropic agents, gliclazide significantly reduced HbA1c with no difference regarding hypoglycemia risk. Compared with other sulfonylureas, HbA1c reduction with gliclazide was not significantly different, but hypoglycemia risk was significantly lower.

Place of sulfonylureas in the management of type 2 diabetes mellitus in South Asia: A consensus statement

Since their introduction in clinical practice in the 1950's, Sulfonylureas (SUs) have remained the main-stay of pharmacotherapy in the management of type 2 diabetes. Despite their well-established benefits, their place in therapy is inappropriately being overshadowed by newer therapies. Many of the clinical issues associated with the use of SUs are agent-specific, and do not pertain to the class as such. Modern SUs (glimepiride, gliclazide MR) are backed by a large body of evidence, experience, and most importantly, outcome data, which supports their role in managing patients with diabetes. Person-centred care, i.e., careful choice of SU, appropriate dosage, timing of administration, and adequate patient counseling, will ensure that deserving patients are not deprived of the advantages of this well-established class of anti-diabetic agents. Considering their efficacy, safety, pleiotropic benefits, and low cost of therapy, SUs should be considered as recommended therapy for the treatment of diabetes in South Asia. This initiative by SAFES aims to encourage rational, safe and smart prescription of SUs, and includes appropriate medication counseling.

Cardiovascular safety of sulphonylureas: over 40 years of continuous controversy without an answer

More than 40 years after publication of the University Group Diabetes Program trial, the cardiovascular safety of sulphonylureas is still contentious. Although several hypotheses linking sulphonylureas to adverse cardiovascular effects exist, none provide conclusive evidence. Adding to the controversy, current clinical trials and observational studies provide inconsistent, and sometimes conflicting, evidence for the cardiovascular effects of sulphonylureas. Overall, observational evidence suggests that an increased risk of adverse cardiovascular outcomes is associated with sulphonylureas; however, these data may be subject to residual confounding and bias. Although evidence from randomized controlled trials has suggested a neutral effect, the majority of these studies were not specifically designed to assess the effect of sulphonylureas on adverse cardiovascular event risk. Current ongoing large clinical trials may provide some clarity on the cardiovascular safety of sulphonylureas, but the results are not expected for several years. With the continued uncertainties concerning the cardiovascular safety of all antidiabetic drugs, a clear answer with regard to sulphonylureas is warranted. The objectives of the present article were to provide an overview of the controversy surrounding sulphonylurea-related cardiovascular effects, to discuss the limitations of the current literature, and to provide recommendations for future studies aiming to elucidate the true relationship between sulphonylureas and adverse cardiovascular effects in people with type 2 diabetes.

Emerging treatments for post-transplantation diabetes mellitus

Post-transplantation diabetes mellitus (PTDM), also known as new-onset diabetes mellitus (NODM), occurs in 10-15% of renal transplant recipients and is associated with cardiovascular disease and reduced lifespan. In the majority of cases, PTDM is characterized by β-cell dysfunction, as well as reduced insulin sensitivity in liver, muscle and adipose tissue. Glucose-lowering therapy must be compatible with immunosuppressant agents, reduced glomerular filtration rate (GFR) and severe arteriosclerosis. Such therapy should not place the patient at risk by inducing hypoglycaemic episodes or exacerbating renal function owing to adverse gastrointestinal effects with hypovolaemia. First-generation and second-generation sulphonylureas are generally avoided, and caution is currently advocated for the use of metformin in patients with GFR <60 ml/min/1.73 m(2). DPP-4 inhibitors do not interact with immunosuppressant drugs and have demonstrated safety in small clinical trials. Other therapeutic options include glinides and glitazones. Evidence-based treatment regimens used in patients with type 2 diabetes mellitus cannot be directly implemented in patients with PTDM. Studies investigating the latest drugs are required to direct the development of improved treatment strategies for patients with PTDM. This Review outlines the modern principles of glucose-lowering treatment in PTDM with specific reference to renal transplant recipients.

Xenopus as a Model for GI/Pancreas Disease

Diseases affecting endodermal organs like the pancreas, lung and gastrointestinal (GI) tract have a substantial impact on human welfare. Since many of these are congenital defects that arise as a result of defects during development broad efforts are focused on understanding the development of these organs so as to better identify risk factors, disease mechanisms and therapeutic targets. Studies implementing model systems, like the amphibian Xenopus, have contributed immensely to our understanding of signaling (e.g. Wnt, FGF, BMP, RA) pathways and gene regulation (e.g. hhex, ptf1a, ngn3) that underlie normal development as well as disease progression. Recent advances in genome engineering further enhance the capabilities of the Xenopus model system for pursuing biomedical research, and will undoubtedly result in a boom of new information underlying disease mechanisms ultimately leading to advancements in diagnosis and therapy.

GLP-1 based therapeutics: simultaneously combating T2DM and obesity

Glucagon-like peptide-1 (GLP-1) enhances meal-related insulin secretion, which lowers blood glucose excursions. In addition to its incretin action, GLP-1 acts on the GLP-1 receptor (GLP-1R) in the brain to suppress feeding. These combined actions of GLP-1R signaling cause improvements in glycemic control as well as weight loss in type II diabetes (T2DM) patients treated with GLP-1R agonists. This is a superior advantage of GLP-1R pharmaceuticals as many other drugs used to treat T2DM are weight neutral or actual cause weight gain. This review summarizes GLP-1R action on energy and glucose metabolism, the effectiveness of current GLP-1R agonists on weight loss in T2DM patients, as well as GLP-1R combination therapies.

Modelling endogenous insulin concentration in type 2 diabetes during closed-loop insulin delivery

Background

Closed-loop insulin delivery is an emerging treatment for type 1 diabetes (T1D) evaluated clinically and using computer simulations during pre-clinical testing. Efforts to make closed-loop systems available to people with type 2 diabetes (T2D) calls for the development of a new type of simulators to accommodate differences between T1D and T2D. Presented here is the development of a model of posthepatic endogenous insulin concentration, a component omitted in T1D simulators but key for simulating T2D physiology.

Methods

We evaluated six competing models to describe the time course of endogenous insulin concentration as a function of the plasma glucose concentration and time. The models were fitted to data collected in insulin-naive subjects with T2D who underwent two 24-h visits and were treated, in a random order, by either closed-loop insulin delivery or glucose-lowering oral agents. The model parameters were estimated using a Bayesian approach, as implemented in the WinBUGS software. Model selection criteria were used to identify the best model describing our clinical data.

Results

The selected model successfully described endogenous insulin concentration over 24 h in both study periods and provided plausible parameter estimates. Model-derived results were in concordance with a clinical finding which revealed increased posthepatic endogenous insulin concentration during the control study period (P < 0.05). The modelling results indicated that the excess amount of insulin can be attributed to the glucose-independent effect as the glucose-dependent effect was similar between visits (P > 0.05).

Conclusions

A model to describe endogenous insulin concentration in T2D including components of posthepatic glucose-dependent and glucose-independent insulin secretion was identified and validated. The model is suitable to be incorporated in a simulation environment for evaluating closed-loop insulin delivery in T2D.

Electronic supplementary material

The online version of this article (doi:10.1186/s12938-015-0009-5) contains supplementary material, which is available to authorized users.

Identifying factors associated with hypoglycemia-related hospitalizations among elderly patients with T2DM in the US: a novel approach using influential variable analysis

OBJECTIVE

Healthcare providers managing older patients with type 2 diabetes mellitus (T2DM) face a complex milieu of medical conditions and comorbidities, which increase the risk of unintended treatment consequences. The objective of this study was to understand factors associated with hypoglycemia-related hospitalizations among adults with T2DM with an emphasis on older patients.

RESEARCH DESIGN AND METHODS

A large retrospective cohort study using claims data from the United States was undertaken identifying actively registered patients diagnosed with T2DM and at least one diabetes medication prescription.

MAIN OUTCOME MEASURES

The main outcomes included hypoglycemia-related hospitalization and frequency of comorbidities.

RESULTS

Of patients with T2DM and hospitalization records (n = 887,182), 52.3% were male and 30.7% were aged ≥65 years. At baseline, the proportion of patients taking metformin was 52.4%, insulin 7.3%, and sulfonylurea 26.4%. Among those with diabetes-related hospitalizations, the incidence of hospitalization-related hypoglycemia in patients ≥65 years of age was greater than in patients <65 years of age (0.59 compared to 0.16 per 1000 person years). Using boosted regression tree modeling, age (older vs. younger), sulfonylurea use, insulin use, and renal disease were variables most associated with predicting hospitalizations associated with hypoglycemia. Elderly patients prescribed both insulin and sulfonylurea were most likely to experience hypoglycemia-related hospitalizations (odds ratio = 4.7; 95% CI 3.7-6.1).

CONCLUSIONS

Older patients using both insulin and sulfonylurea were most likely to experience a hypoglycemia-related hospitalization. Age, sulfonylurea use, insulin use, renal disease, a history of hypoglycemia-related hospitalization and general hospitalization were the leading variables associated with hypoglycemia-related hospitalization. Glucagon-like peptide and dipeptidyl peptidase-4 medication use was not significantly associated with hypoglycemia-related hospitalizations. The strength of this analysis, compared to similar studies, lies in the large and generalizable sample size and statistical methodology, which control for the interdependence of predictive variables. Limitations include lack of information, such as dietary intake and exercise habits, which are known to influence the rate of hypoglycemia in certain patients. Given the frequency of use of insulin and sulfonylurea in a population at risk for hypoglycemia (older patients with diabetes), care should be taken when balancing cost and efficacy against safety and increased risk of hospitalization due to hypoglycemia.

Incretin enhancement without hyperinsulinemia: α-glucosidase inhibitors

The α-glucosidase inhibitors are a time-tested, but under-utilized, class of oral hypoglycemic effects. Recent understanding of the importance of the incretin pathway, coupled with evidence about the incretin enhancing effects of these molecules, is covered in this editorial. The authors call for greater recognition of the beneficial effects of this class of drugs in the management of Type 2 diabetes.