Adherence, per-protocol effects, and the estimands framework

In the statistical literature, treatment effects in clinical trials are frequently described as either ITT or per-protocol effects. The estimand given for the per-protocol effect is the effect in adherers, where adherers are typically defined as adhering to the intervention as specified in the trial protocol. This dichotomy of treatment effects is unhelpful when there are in reality multiple treatment effects that can be of clinical interest and relevance. The terms "per-protocol" and "adherence" are confusing to non-statisticians. Protocols always allow for discontinuation of randomized treatment so participants discontinuing have actually followed the protocol. When rescue or additional medication is available, the effect in adherers could mean the effect regardless of use of these medications or the effect in a counterfactual world where the participant did not take the medication. Adherence can mean continuing to be prescribed a treatment or some arbitrary level of compliance with a medication that has been prescribed. The ICH E9 (R1) estimands framework provides an improved alternative for the description of treatment effects in clinical trials. Identification of important intercurrent events and the strategy used to handle these events is key to determining the treatment effect. When designing a trial, estimands should be properly defined according to this framework. It is time the statistical literature abandoned describing treatment effects as the effect in adherers or the per-protocol effect.

Why estimands are needed to define treatment effects in clinical trials

BACKGROUND

The estimand for a clinical trial is a precise definition of the treatment effect to be estimated. Traditionally, estimates of treatment effects are based on either an ITT analysis or a per-protocol analysis. However, there are important clinical questions which are not addressed by either of these analyses. For example, consider a trial where patients take a rescue medication. The ITT analysis includes data after use of rescue, while the per-protocol analysis excludes these patients altogether. Neither of these analyses addresses the important question of what the treatment effect would have been if patients did not take rescue medication.

MAIN TEXT

Trial estimands provide a broader perspective compared to the limitations of ITT and per-protocol analysis. Trial treatment effects depend on how events occurring after treatment initiation such as use of alternative medication or discontinuation of the intervention are included in the definition. These events can be accounted for in different ways, depending on the clinical question of interest.

CONCLUSION

The estimand framework is an important step forward in improving the clarity and transparency of clinical trials. The centrality of estimands to clinical trials is currently not reflected in methods recommended by the Cochrane group or the CONSORT statement, the current standard for reporting clinical trials in medical journals. We encourage revisions to these guidelines.

Terpene-Containing Analogues of Glitazars as Potential Therapeutic Agents for Metabolic Syndrome

Metabolic syndrome is a complex of abnormalities involving impaired glucose and lipid metabolism, which needs effective pharmacotherapy. One way to reduce lipid and glucose levels associated with this pathology is the simultaneous activation of nuclear PPAR-alpha and gamma. For this purpose, we synthesized a number of potential agonists based on the pharmacophore fragment of glitazars with the inclusion of mono- or diterpenic moiety in the molecular structure. The study of their pharmacological activity in mice with obesity and type 2 diabetes mellitus (C57Bl/6^Ay) revealed one substance that was capable of reducing the triglyceride levels in the liver and adipose tissue of mice by enhancing their catabolism and expressing a hypoglycemic effect connected with the sensitization of mice tissue to insulin. It has also been shown to have no toxic effects on the liver.

Skeletal manifestations in a streptozotocin-induced C57BL/6 model of Type 1 diabetes

Diabetes Mellitus is a metabolic disease which profoundly affects many organ systems in the body, including the skeleton. As is often the case with biology, there are inherent differences between the sexes when considering skeletal development and disease progression and outcome. Therefore, the aim of this study was to develop a protocol to reliably induce diabetes in both sexes of the C57BL/6 mouse utilizing streptozotocin (STZ) and to characterize the resulting bone phenotype. We hypothesized that destruction of the β-cells in the pancreatic islet by STZ would result in a diabetic state with downstream skeletal manifestations. Beginning at 8 weeks of age, mice were injected for 5 consecutive days with STZ (65 mg/kg males, 90 mg/kg females) dissolved in a citrate buffer. The diabetic state of the mice was monitored for 5 weeks to ensure persistent hyperglycemia and mice were euthanized at 15 weeks of age. Diabetes was confirmed through blood glucose monitoring, glucose and insulin tolerance testing, HbA1c measurement, and histological staining of the pancreas. The resulting bone phenotype was characterized using microcomputed tomography to assess bone structure, and whole bone mechanical testing to assess bone functional integrity. Mice from both sexes experienced loss of β-cell mass and increased glycation of hemoglobin, as well as reduced trabecular thickness and trabecular tissues mineral density (TMD), and reduced cortical thickness and cortical bone area fraction. In female mice the change area fraction was driven by a reduction in overall bone size while in male mice, the change was driven by increased marrow area. Males also experienced reduced cortical TMD. Mechanical bending tests of the tibiae showed significant results in females with a reduction in yield force and ultimate force driving lower work to yield and total work and a roughly 40 % reduction of stiffness. When tissue level parameters were estimated using beam theory, there was a significant reduction in yield and ultimate stresses as well as elastic modulus. The previously reported mechanistic similarity in the action of STZ on murine animals, as well as the ease of STZ administration via IP injection make this model is a strong candidate for future exploration of osteoporotic bone disease, Diabetes Mellitus, and the link between estrogen and glucose sensitivity.

Marking 2-Years of New Thinking in Clinical Trials: The Estimand Journey

The ICH E9(R1) addendum on Estimands and Sensitivity Analyses in Clinical Trials has introduced a new estimand framework for the design, conduct, analysis, and interpretation of clinical trials. We share Pharmaceutical Industry experiences of implementing the estimand framework in the first two years since the final guidance became available with key lessons learned and highlight what else needs to be done to continue the journey in embedding the estimand framework in clinical trials. Emerging best practices and points to consider on strategies for implementing a new estimand thinking process are provided. Whilst much of the focus of implementing ICH E9(R1) to date has been on defining estimands, we highlight some of the important aspects relating to the choice of statistical analysis methods and sensitivity analyses to ensure estimands can be estimated robustly with minimal bias. In particular, we discuss the implications if complete follow-up is not possible when the treatment policy strategy is being used to handle intercurrent events. ICH E9(R1) was introduced just before the start of the COVID-19 pandemic, but a positive outcome from the pandemic has been an acceleration in the adoption of the estimand framework, including differentiating intercurrent events related or not related to the pandemic. In summary, much has been learned on the estimand journey and continued sharing of case studies will help to further advance the understanding and increase awareness across all clinical researchers of the estimand framework.

Estimands for overall survival in clinical trials with treatment switching in oncology

An addendum of the ICH E9 guideline on Statistical Principles for Clinical Trials was released in November 2019 introducing the estimand framework. This new framework aims to align trial objectives and statistical analyses by requiring a precise definition of the inferential quantity of interest, that is, the estimand. This definition explicitly accounts for intercurrent events, such as switching to new anticancer therapies for the analysis of overall survival (OS), the gold standard in oncology. Traditionally, OS in confirmatory studies is analyzed using the intention-to-treat (ITT) approach comparing treatment groups as they were initially randomized regardless of whether treatment switching occurred and regardless of any subsequent therapy (treatment-policy strategy). Regulatory authorities and other stakeholders often consider ITT results as most relevant. However, the respective estimand only yields a clinically meaningful comparison of two treatment arms if subsequent therapies are already approved and reflect clinical practice. We illustrate different scenarios where subsequent therapies are not yet approved drugs and thus do not reflect clinical practice. In such situations the hypothetical strategy could be more meaningful from patient's and prescriber's perspective. The cross-industry Oncology Estimand Working Group (www.oncoestimand.org) was initiated to foster a common understanding and consistent implementation of the estimand framework in oncology clinical trials. This paper summarizes the group's recommendations for appropriate estimands in the presence of treatment switching, one of the key intercurrent events in oncology clinical trials. We also discuss how different choices of estimands may impact study design, data collection, trial conduct, analysis, and interpretation.

Why ITT analysis is not always the answer for estimating treatment effects in clinical trials

For many years there has been a consensus among the Clinical Research community that ITT analysis represents the correct approach for the vast majority of trials. Recent worldwide regulatory guidance for pharmaceutical industry trials has allowed discussion of alternatives to the ITT approach to analysis; different treatment effects can be considered which may be more clinically meaningful and more relevant to patients and prescribers. The key concept is of a trial "estimand", a precise description of the estimated treatment effect. The strategy chosen to account for patients who discontinue treatment or take alternative medications which are not part of the randomised treatment regimen are important determinants of this treatment effect. One strategy to account for these events is treatment policy, which corresponds to an ITT approach. Alternative equally valid strategies address what the treatment effect is if the patient actually takes the treatment or does not use specific alternative medication. There is no single right answer to which strategy is most appropriate, the solution depends on the key clinical question of interest. The estimands framework discussed in the new guidance has been particularly useful in the context of the current COVID-19 pandemic and has clarified what choices are available to account for the impact of COVID-19 on clinical trials. Specifically, an ITT approach addresses a treatment effect that may not be generalisable beyond the current pandemic.

Comparison Between Isometric and Concentric Motor Fatigability in Persons With Multiple Sclerosis and Healthy Controls - exploring central and peripheral contributions of motor fatigability

BACKGROUND

Motor fatigability (i.e. contraction-induced reduction in muscle strength) from a concentric task associate stronger to walking and perception of fatigue in persons with multiple sclerosis (pwMS), compared with an isometric task. However, the central and peripheral contributions of motor fatigability between these tasks have not been investigated.

OBJECTIVE

Compare the central and peripheral contributions of motor fatigability in the knee extensors in a sustained isometric fatigability protocol versus a concentric fatigability protocol and in pwMS versus healthy controls (HCs).

METHODS

Participants (n=31 pwMS; n=15 HCs) underwent neuromuscular testing before and immediately after two knee extensor fatigability tasks (sustained isometric and concentric) in an isokinetic dynamometer. Neuromuscular testing of fatigability consisted of maximal voluntary contraction, voluntary activation (central/neural contributor), and resting twitch (peripheral/muscular contributor) determined by the interpolated twitch technique.

RESULTS

Sustained isometric and concentric fatigability protocols resulted in motor fatigability for both pwMS and HCs, with no between-protocols differences for either group. Regression analysis showed that motor fatigability variance in pwMS was mainly attributed to central fatigability in the sustained isometric protocol and to both central and peripheral fatigability in the concentric protocol. In HCs, the variance in sustained isometric and concentric fatigability were attributed to both peripheral and central fatigability.

CONCLUSION

Central and peripheral contributions of motor fatigability differed between sustained isometric and concentric protocols as well as between pwMS and HCs. These between-protocol differences in pwMS provide a neuromuscular dimension to the reported difference in the strength of associations of concentric and isometric tasks to walking and perception of fatigue in pwMS.

Glucose-induced structural changes and anomalous diffusion of elastin

Elastin is the principal protein component of elastic fiber, which renders essential elasticity to connective tissues and organs. Here, we adopted a multi-technique approach to study the transport, viscoelastic, and structural properties of elastin exposed to various glucose concentrations (X=[gluc]/[elastin]). Laser light scattering experiments revealed an anomalous behavior (anomaly exponent, β <0.6) of elastin. In this regime (β <0.6), the diffusion constant decreases by 40% in the presence of glucose (X> 10), which suggests the structural change in elastin. We have observed a peculiar inverse temperature transition of elastin protein, which is a measure of structural change, at 40 °C through rheology experiments. Moreover, we observe its shift towards lower temperature with a higher X. FTIR revealed that the presence of glucose (X < 10) favors the formation of β-sheet structure in elastin. However, for X > 10, dominative crowding effect reduces the mobility of protein and favors the increase in β-turns and γ-turns by 25 ± 1% over the β-sheet (β-sheet decreases by 12 ± 0.8%) and α-helix (α-helix decreases by 13 ± 0.8%). The stiffness of protein is estimated through Flory characteristic ratio, C_∞ and found to be increasing with X. These glucose-based structural changes in the elastin may explain the role of glucose in age-related issues of the skin.

Oncofertility: Pharmacological Protection and Immature Testicular Tissue (ITT)-Based Strategies for Prepubertal and Adolescent Male Cancer Patients

While the incidence of cancer in children and adolescents has significantly increased over the last decades, improvements made in the field of cancer therapy have led to an increased life expectancy for childhood cancer survivors. However, the gonadotoxic effect of the treatments may lead to infertility. Although semen cryopreservation represents the most efficient and safe fertility preservation method for males producing sperm, it is not feasible for prepubertal boys. The development of an effective strategy based on the pharmacological protection of the germ cells and testicular function during gonadotoxic exposure is a non-invasive preventive approach that prepubertal boys could benefit from. However, the progress in this field is slow. Currently, cryopreservation of immature testicular tissue (ITT) containing spermatogonial stem cells is offered to prepubertal boys as an experimental fertility preservation strategy by a number of medical centers. Several in vitro and in vivo fertility restoration approaches based on the use of ITT have been developed so far with autotransplantation of ITT appearing more promising. In this review, we discuss the pharmacological approaches for fertility protection in prepubertal and adolescent boys and the fertility restoration approaches developed on the utilization of ITT.

Circulating aryl hydrocarbon receptor-interacting protein (AIP) is independent of GH secretion

BACKGROUND

Aryl hydrocarbon receptor-interacting protein (AIP) is evolutionarily conserved and expressed widely throughout the organism. Loss-of-function AIP mutations predispose to young-onset pituitary adenomas. AIP co-localizes with growth hormone in normal and tumorous somatotroph secretory vesicles. AIP protein is detectable in circulation. We aimed to investigate possible AIP and GH co-secretion, by studying serum AIP and GH levels at baseline and after GH stimulation or suppression, in GH deficiency (GHD) and in acromegaly patients.

SUBJECTS AND METHODS

Insulin tolerance test (ITT) was performed in GHD patients (n = 13) and age-BMI-matched normal GH axis control patients (n = 31). Oral glucose tolerance test (OGTT) was performed in active acromegaly patients (n = 26) and age-BMI-matched normal GH axis control patients (n = 18). In-house immunometric assay was developed for measuring circulating AIP.

RESULTS

Serum AIP levels were in the 0.1 ng/mL range independently of gender, age or BMI. Baseline AIP did not differ between GHD and non-GHD or between acromegaly and patients with no acromegaly. There was no change in peak, trough or area under the curve during OGTT or ITT. Serum AIP did not correlate with GH during ITT or OGTT.

CONCLUSIONS

Human circulating serum AIP in vivo was assessed by a novel immunometric assay. AIP levels were independent of age, sex or BMI and unaffected by hypoglycaemia or hyperglycaemia. Despite co-localization in secretory vesicles, AIP and GH did not correlate at baseline or during GH stimulation or suppression tests. A platform of reliable serum AIP measurement is established for further research of its circulatory source, role and impact.

Efficacy and safety of berberine for dyslipidaemias: A systematic review and meta-analysis of randomized clinical trials

BACKGROUND

In recent years, berberine has become widely used as an effective alternative to treat dyslipidaemias; much clinical evidence has emerged. It is important to systematically and critically evaluate the existing evidence.

PURPOSE

This study aims to evaluate the efficacy and safety of berberine in patients with dyslipidaemias.

STUDY DESIGN

A systematic review and meta-analysis of randomized clinical trials.

METHODS

Five electronic databases were searched up to Apr 15, 2018 to identify randomized controlled trials (RCTs) of berberine in treatment of dyslipidaemias. The outcomes were lipid profile parameters and adverse events. Study selection, data collection, risk of bias assessment, data analyses and interpretations were conducted according to the Cochrane handbook.

RESULTS

Sixteen trials with total of 2147 participants were judged to be eligible and were included in the meta-analysis. The included trials were assessed to be of high clinical heterogeneity. The methodological quality of the majority of the trials was generally low in terms of random sequence generation, allocation concealment, blinding and incomplete outcome data. Thus, selection bias, performance bias, detection bias, attrition bias and confounding bias might exist. Meta-analysis showed that berberine significantly reduced levels of total cholesterol (TC) (MD = -0.47  mmol/l 95% CI [-0.64, -0.31], p < 0.00001), low-density lipoprotein cholesterol (LDL-C) (MD =-0.38  mmol/l 95% CI [-0.53, -0.22], p < 0.00001) and triglycerides (TG) (MD = -0.28  mmol/l 95% CI [-0.46, -0.10], p = 0.002). Berberine also increased the level of high-density lipoprotein cholesterol (HDL-C) when used alone (MD = 0.08  mmol/l 95% CI [0.03, 0.12], p = 0.001). No significant differences were found between groups in terms of incidence of adverse events (RR = 0.64 95% CI [0.31, 1.30], p = 0.22). No severe adverse effects were reported in either group.

CONCLUSION

Berberine improves lipid profiles in dyslipidaemias with satisfactory safety. Nevertheless, these findings should be interpreted with caution because of the high clinical heterogeneity and high risk of bias in the included trials. Rigorous clinical trials should be carried out to provide more reliable evidence.

The robustness of diagnostic tests for GH deficiency in adults

Since the 1970s, GH treatment has been an important tool in paediatric endocrinology for the management of growth retardation. It is now accepted that adults with severe GH deficiency (GHD) demonstrate impaired physical and psychological well-being and may benefit from replacement therapy with recombinant human GH. There is, however, an ongoing debate on how to diagnose GHD, especially in adults. A GH response below the cut-off limit of a GH-stimulation test is required in most cases for establishing GHD in adults. No 'gold standard' GH-stimulation test exists, but some GH stimulation tests may be more robust to variations in patient characteristics such as age and gender, as well as to pre-test conditions like heat exposure due to a hot bath or bicycling. However, body mass index (BMI) is negatively associated with GH-responses to all available GH-stimulation tests and glucocorticoid treatment, including conventional substitution therapy, influences the GH-responses. Recently, the role of IGF-I measurements in the clinical decision making has been discussed. The aim of this review is to discuss the available GH-stimulation tests. In this author's opinion, tests which include growth-hormone-releasing hormone (GHRH) tend to be more potent and robust, especially the GHRH+arginine test which has been proven to be of clinical use. In contrast, the insulin tolerance test (ITT) and the glucagon test appear to have too many drawbacks.

Electromyographic analysis of responses to third person intergroup threat

This study attempts to replicate and extend the findings from Davis and Stephan's (2011) article investigating facial electromyographic (EMG) responses to individually directed or group-directed realistic threat. Using news footage from the Columbine school shootings as a third-person threatening stimulus, participants were instructed to view the clips while considering how they felt during the original events (individually primed) or how students felt during the original events (group-primed). EMG analysis of activity levels of the medial frontalis and the corrugator supercilii indicated differential activation based on the instructions. Individually primed participants experienced more fontalis activity and group-primed participants experienced more corrugator supercilii activity. These findings replicated the Davis and Stephan results and extended it to a third person-based intergroup threat.

Important methodological issues in evaluating community-based interventions

BACKGROUND

Evaluation of offending behavior programs has become reasonably controversial in recent times as some researchers have advocated that evaluations should use a treatment as received (TR) model, which ignores dropouts and refusers, despite criticism that this removes the ability to make inferences about the effectiveness of the program. Some of those arguing in favor of a TR methodology suggest that the large number of noncompleters in community-based evaluations will make it impossible to detect treatment effects. A further issue with evaluation of community-based offender behavior programs is the fact that many programs are reasonably long. Evaluation methodologies inherited from custodial programs count recidivism from day one-which is before any benefits from the program are hypothesized to occur.

OBJECTIVES

This article explores these issues to find solutions that are scientifically robust but also sensitive to actual program effects.

CONCLUSION

The current authors argue that evaluations should use an intention-to-treat (ITT) model which includes noncompleters and that, using this methodology, an effective program, delivered with high integrity, should be able to demonstrate an impact on offending. However, the time period selected for evaluation should relate to the hypothesized effects of the program, not just begin from the start of supervision or commencement of the program. In doing so, the evaluators should ensure that both treatment and control groups are treated equally.

Good intentions and ICH-GCP: Trial conduct training needs to go beyond the ICH-GCP document and include the intention-to-treat principle

BACKGROUND

It is assumed investigators and statisticians fully understand the importance of avoiding missing outcomes and the intention-to-treat principle during design and analysis phases of a randomised controlled trial in order to obtain the most valuable and reliable results. However, many personnel undertaking day-to-day trial conduct and data collection commonly rely exclusively for guidance on the widely implemented, indeed regulated, International Conference on Harmonisation-Good Clinical Practice document as the guideline and standard for trial conduct.

PURPOSE

This article describes adverse consequences of omission of intention-to-treat principles from training for trial personnel and explores the need for training in addition to the International Conference on Harmonisation-Good Clinical Practice guideline document.

METHODS

Data from the Breast Boost Study were used to illustrate a comparison of actual results, where vigilant senior investigators re-enforced intention-to-treat requirements throughout all aspects of trial conduct with results that could easily have occurred if study personnel did not understand the importance of intention-to-treat principles. Experience as a co-ordinating centre for an international trial (Trans-Tasman Radiation Oncology Group 08.06 Breast STARS) acted as an audit of data-management culture regarding intention-to-treat in Australia and New Zealand.

RESULTS

Despite the Breast Boost Study exceeding planned accrual, it was demonstrated that the study, which found a statistically significant result, could have reported a negative or inconclusive result under the scenario of trial conduct personnel having lack of understanding of the importance of avoiding losses to follow-up. Trans-Tasman Radiation Oncology 08.06 co-ordination experience verified that data-management culture in Australia and New Zealand does not adequately recognise intention-to-treat principles, and this is reflected in trial conduct.

LIMITATIONS

Trial data described are limited to two trials and in the Australian and New Zealand setting.

CONCLUSION

To be both scientifically and ethically valid, guidelines for trial conduct should include and stress the importance of the intention-to-treat principle and in particular avoiding missing outcomes. Our discussion highlights the vitally important role played by personnel involved in day-to-day trial conduct. Inclusion of scientific principles in guideline documents and/or training which goes beyond International Conference on Harmonisation-Good Clinical Practice to include intention-to-treat is essential to achieve robust research results. Related aspects of randomised trial consent and ethics are discussed.

Depression-like behaviors in mice subjected to co-treatment of high-fat diet and corticosterone are ameliorated by AICAR and exercise

Major depressive disorder (MDD) and type II diabetes mellitus (T2DM) are highly co-morbid, and there may be a bi-directional connection between the two. Herein, we have described a mouse model of a depression-like and insulin-resistant (DIR) state induced by the co-treatment of high-fat diet (HFD) and corticosterone (CORT). 5-Aminoimidazole-4-carboxamide-1-β-d- ribofuranoside (AICAR), a pharmacological activator of AMP-activated protein kinase (AMPK), was originally used to improve insulin resistance (IR). Interestingly, our results show a clear potential for AICAR as a putative antidepressant with a chronic action on the DIR mice. In contrast to the traditional antidepressants, AICAR as a promising antidepressant avoids reducing insulin actions of skeletal muscle in the context of long-term HFD. Exercise also produced antidepressant effects. Our data suggest that the effects of AICAR and exercise on DIR may further increase our understanding on the link between depression and diabetes.

Rational Helicobacter pylori therapy: evidence-based medicine rather than medicine-based evidence

Data are available such that choice of Helicobacter pylori therapy for an individual patient can be reliably predicted. Here, treatment success is defined as a cure rate of 90% or greater. Treatment outcome in a population or a patient can be calculated based on the effectiveness of a regimen for infections with susceptible and with resistant strains coupled with the knowledge of the prevalence of resistance (ie, based on formal measurement, clinical experience, or both). We provide the formula for predicting outcome and we illustrate the calculations. Because clarithromycin-containing triple therapy and 10-day sequential therapy are now only effective in special populations, they are considered obsolete; neither should continue to be used as empiric therapies (ie, 7- and 14-day triple therapies fail when clarithromycin resistance exceeds 5% and 15%, respectively, and 10-day sequential therapy fails when metronidazole resistance exceeds 20%). Therapy should be individualized based on prior history and whether the patient is in a high-risk group for resistance. The preferred choices for Western countries are 14-day concomitant therapy, 14-day bismuth quadruple therapy, and 14-day hybrid sequential-concomitant therapy. We also provide details regarding the successful use of fluoroquinolone-, rifabutin-, and furazolidone-containing therapies. Finally, we provide recommendations for the efficient development (ie, identification and optimization) of new regimens, as well as how to prevent or minimize failures. The trial-and-error approach for identifying and testing regimens frequently resulted in poor treatment success. The described approach allows outcome to be predicted and should simplify treatment and drug development.

Chromanol 293B, an inhibitor of KCNQ1 channels, enhances glucose-stimulated insulin secretion and increases glucagon-like peptide-1 level in mice

Glucose-stimulated insulin secretion (GSIS) is a highly regulated process involving complex interaction of multiple factors. Potassium voltage-gated channel subfamily KQT member 1 (KCNQ1) is a susceptibility gene for type 2 diabetes (T2D) and the risk alleles of the KCNQ1 gene appear to be associated with impaired insulin secretion. The role of KCNQ1 channel in insulin secretion has been explored by previous work in clonal pancreatic β-cells but has yet to be investigated in the context of primary islets as well as intact animals. Genetic studies suggest that altered incretin glucagon-like peptide-1 (GLP-1) secretion might be a potential link between KCNQ1 variants and impaired insulin secretion, but this hypothesis has not been verified so far. In the current study, we examined KCNQ1 expression in pancreas and intestine from normal mice and then investigated the effects of chromanol 293B, a KCNQ1 channel inhibitor, on insulin secretion in vitro and in vivo. By double-immunofluorescence staining, KCNQ1 was detected in insulin-positive β-cells and GLP-1-positive L-cells. Administration of chromanol 293B enhanced GSIS in cultured islets and intact animals. Along with the potentiated insulin secretion during oral glucose tolerance tests (OGTT), plasma GLP-1 level after gastric glucose load was increased in 293B treated mice. These data not only provided new evidence for the participation of KCNQ1 in GSIS at the level of pancreatic islet and intact animal but also indicated the potential linking role of GLP-1 between KCNQ1 and insulin secretion.

Anti-hyperglycemic and hypolipidemic effects of Cistanche tubulosa in type 2 diabetic db/db mice

ETHNOPHARMACOLOGICAL RELEVANCE

The dried succulent stem of Cistanche tubulosa (Schenk) R. Wight is one component of traditional Chinese medicine prescriptions for diabetes. However, there have been no modern scientific reports to confirm this traditional claim for the Cistanche species until now. Thus, we investigated the effects of Cistanche tubulosa on glucose homeostasis and serum lipids in male BKS.Cg-Dock7(m) +/+ Lepr(db)/J (db/db) mice, a model of type 2 diabetes.

MATERIALS AND METHODS

The verbascoside and echinacoside contents of Cistanche tubulosa powder were evaluated using HPLC. The total phenolic content, polysaccharide content and antioxidant activity of Cistanche tubulosa powder were also evaluated. Then, different doses of Cistanche tubulosa (equivalent to 120.9, 72.6 or 24.2mg verbascoside/kg) were administered orally once daily for 45 days to male db/db mice. Age matched db/+ mice were used as normal controls. Body weight, fasting blood glucose, postprandial blood glucose and insulin tolerance test were measured during the experiment. At the time of sacrifice, blood was collected for measurement of insulin level, the homeostatic model assessment of insulin resistance (HOMA-IR), and total cholesterol, triglyceride, HDL-c, LDL-c and VLDL-c levels; liver and muscle were harvested for measurement of glycogen levels.

RESULTS

Cistanche tubulosa significantly suppressed the elevated fasting blood glucose and postprandial blood glucose levels, improved insulin resistance and dyslipidemia, and suppressed body weight loss in db/db mice. However, Cistanche tubulosa did not significantly affect serum insulin levels or hepatic and muscle glycogen levels.

CONCLUSION

This study provides scientific evidence for the traditional use of Cistanche tubulosa to treat diabetes, suggesting that Cistanche tubulosa has the potential for development into a functional food ingredient or drug to prevent hyperglycemia and treat hyperlipidemia.

Hepatic menin recruits SIRT1 to control liver steatosis through histone deacetylation

BACKGROUND & AIMS

The development and progression of non-alcoholic fatty liver disease are associated with aging, obesity, and type 2 diabetes. Understanding the precise regulatory networks of this process will contribute to novel therapeutic strategies.

METHODS

Hepatocyte-specific Men1 knockout mice were generated using Cre/loxP technology. Lipid and glucose metabolic phenotypes and mechanisms were investigated in aging and high-fat diet fed mice.

RESULTS

The expression of menin, encoded by multiple endocrine neoplasia 1 (Men1) gene, is reduced in the liver of aging mice. Hepatocyte-specific deletion of Men1 induces liver steatosis in aging mice. Menin deficiency promotes high-fat diet-induced liver steatosis in mice. Menin recruits SIRT1 to control hepatic CD36 expression and triglyceride accumulation through histone deacetylation.

CONCLUSIONS

Our work reveals that the adaptor protein menin is critical for the progression of hepatic steatosis during aging and metabolic imbalance.

A refined-JinQi-JiangTang tablet ameliorates prediabetes by reducing insulin resistance and improving beta cell function in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Refined-JQ (JQ-R) is a mixture of refined extracts from three major herbal components of JinQi-JiangTang tablet: Coptis chinensis (Ranunculaceae), Astragalus membranaceus (Leguminosae), and Lonicera japonica (Caprifoliaceae). Our previous studies have indicated that JQ-R could decrease fasting blood glucose levels in diabetic mice and insulin resistance mice. Investigating the hypoglycemic effect of JQ-R on prediabetes has practical application value for preventing or delaying insulin resistance, impaired glucose tolerance and possibly the development of clinical diabetes.

MATERIALS AND METHODS

The anti-diabetic potential of JQ-R was investigated using a high fat-diet (HFD)-induced obesity mouse model. C57BL/6J mice (HFD-C57 mice) were fed with high-fat diet for 4 months. HFD-C57 mice were treated with either JQ-R (administered intragastrically once daily for 4 weeks) or metformin (as positive control), and the effects of JQ-R on body weight, blood lipids, glucose metabolism, insulin sensitivity, and beta cell function were monitored.

RESULTS

The body weight, serum cholesterol, and the Homeostasis Model Assessment ratio (insulin resistance index) were significantly reduced in JQ-R or metformin-treated mice, and the glucose tolerance was enhanced and insulin response was improved simultaneously. Moreover, both JQ-R and metformin could activate liver glycogen syntheses even under a relatively high glucose loading. Although glyconeogenesis was inhibited in the metformin treated mice, it was not observed in JQ-R treated mice. Similar to metformin, JQ-R could also improve the glucose infusion rate (GIR) in hyperglycemic clamp test. JQ-R was also shown to increase the levels of phosphorylated AMPKα and phosphorylated acetyl CoA carboxylase (ACC), similar to metformin.

CONCLUSION

JQ-R could reduce HFD-induced insulin resistance by regulating glucose and lipid metabolism, increasing insulin sensitivity through activating the AMPK signaling pathway, and subsequently improving β cell function. Therefore, JQ-R may offer an alternative in treating disorders associated with insulin resistance, such as prediabetes and T2DM.

Evidence for a regulatory role of Cullin-RING E3 ubiquitin ligase 7 in insulin signaling

Dysfunctional regulation of signaling pathways downstream of the insulin receptor plays a pivotal role in the pathogenesis of insulin resistance and type 2 diabetes. In this study we report both in vitro and in vivo experimental evidence for a role of Cullin-RING E3 ubiquitin ligase 7 (CRL7) in the regulation of insulin signaling and glucose homeostasis. We show that Cul7(-/-) mouse embryonic fibroblasts displayed enhanced AKT and Erk MAP kinase phosphorylation upon insulin stimulation. Depletion of CUL7 by RNA interference in C2C12 myotubes led to increased activation of insulin signaling pathways and cellular glucose uptake, as well as a reduced capacity of these cells to execute insulin-induced degradation of insulin receptor substrate 1 (IRS1). In vivo, heterozygosity of either Cul7 or Fbxw8, both key components of CRL7, resulted in elevated PI3 kinase/AKT activation in skeletal muscle tissue upon insulin stimulation when compared to wild-type controls. Finally, Cul7(+/-) or Fbxw8(+/-) mice exhibited enhanced insulin sensitivity and plasma glucose clearance. Collectively, our findings point to a yet unrecognized role of CRL7 in insulin-mediated control of glucose homeostasis by restraining PI3 kinase/AKT activities in skeletal muscle cells.

A prospective, randomized, double-blind, multicenter comparative study on the safety and efficacy of Celecoxib and GCSB-5, dried extracts of six herbs, for the treatment of osteoarthritis of knee joint

ETHNOPHARMACOLOGICAL RELEVANCE

This prospective, randomized, double-blind, multicenter study compared the efficacy and safety of Celecoxib and GCSB-5, a new product from extracts of six herbs, for the treatment of knee osteoarthritis.

MATERIALS AND METHODS

A total of 198 eligible patients were randomly assigned to the Celecoxib group (n=99 patients) or the GCSB-5 group (n=99 patients) for the 12-week study. The amount of change and percentage of the change in Western Ontario and McMaster Universities (WOMAC) Arthritis Index from the baseline, the change in pain on walking by visual analogue scale (VAS), physician's global assessment on response to therapy (PGART) by five point Likert scale, and the amount of rescue medicine taken were used as parameters for efficacy. Adverse drug reactions (ADRs) were carefully investigated.

RESULTS

The WOMAC score improved in both the Celecoxib group and GCSB-5 group by 20.5 and 21.3 (P=0.79). The percentage of the change in WOMAC score were -42.0% and -38.9% (P=0.54). The pain VAS score decreased by 29.9 and 27.9 (P=0.58). The responders by PGART were 95.3% and 93.8% (P= 0.66), and the median amount of rescue medicine taken were 2.0 and 6.5 tablets (P=0.06). The incidence of ADRs were 31.3% and 21.2% (P=0.11). The most common ADRs were gastrointestinal system related; 17.2% in GCSB-5 group and 22.2% in Celecoxib group. Any severe ADR was not observed in either group.

CONCLUSIONS

The result of this study supports that GCSB-5 is comparable to Celecoxib in terms of the efficacy and safety for the treatment of osteoarthritis of knee joint.

Antidiabetic effect of total flavonoids from Sanguis draxonis in type 2 diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Sanguis draxonis (SD) is a kind of red resin obtained from the wood of Dracaena cochinchinensis (Lour.) S. C. Chen (Dracaena cochinchinensis). It is a Chinese traditional herb that is prescribed for the handling of diabetic disorders, which is also supported by an array of scientific studies published in recent years. Although chemical constituents of this plant material have also been previously evaluated (Tang et al., 1995; Wei et al., 1998), it still remains poorly understood which constituent is the major contributor to its antidiabetic activities. Moreover, very little is known about the molecular mechanisms underlying antidiabetic activities of SD. Flavonoids exist at a high level in SD. The aim of this study is to evaluate the antidiabetic effects of total flavonoids from SD (SDF) in type 2 Diabetes mellitus (T2DM) rats.

MATERIALS AND METHODS

T2DM rats were induced by 4 weeks high-fat diet and a singular injection of streptozotocin (STZ) (35mg/kg). Then T2DM rats were treated with SDF for 21 days, using normal saline as the negative control. For comparison, a standard antidiabetic drug, metformin (200mg/kg), was used as a positive control. Three weeks later, relative biochemical indexes were determined and histopathological examinations were performed to assess the antidiabetic activities of SDF.

RESULTS

SDF not only exhibited a significant hypoglycemic activity, but also alleviated dyslipidemia, tissue steatosis, and oxidative stress associated with T2DM. Moreover, considerable pancreatic islet protecting effects could be observed after SDF treatment. Further investigations revealed a potential anti-inflammation activity of SDF by determining serum levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP).

CONCLUSIONS

This study demonstrates both hypoglycemic and hypolipidemic effects of SDF in T2DM rats, suggesting that flavonoids are the major active ingredients accounting for the antidiabetic activity of SD. Alleviating chronic inflammation responses and protecting pancreatic islets are possible mechanisms involved in the antidiabetic activity of SDF.

Comparison of two growth hormone stimulation tests and their cut-off limits in healthy adults at an outpatient clinic

OBJECTIVE

A peak GH less than 3 μg/L to insulin tolerance test (ITT) is commonly used as a threshold indicating severe adult GH deficiency (GHD). This cut-off is based on results obtained by polyclonal radioimmunoassays preferably under standard conditions at hospital. Our aim was to evaluate the validity of this cut-off limit using two currently used immunometric GH assays and to compare GH responses in the ITT and the GH releasing hormone + arginine (GHRH + ARG) test in healthy adults at our outpatient endocrine unit.

DESIGN

ITT was performed on 73 subjects and the GHRH + ARG test on those 28 who showed insufficient response to the ITT.

METHODS

GH was measured by an immunofluorometric and immunochemiluminometric assay.

RESULTS

GH peak above 3 μg/L was observed in 56% of the healthy volunteers with adequate hypoglycemia in the ITT. Among the 28 subjects with a peak GH below 3 μg/L, only two overweight men had a GH peak response below the commonly used cut-off limit of 9.1 μg/L in the GHRH + ARG test.

CONCLUSIONS

Lean healthy adults could erroneously be classified as GH deficient by the ITT while their results in the GHRH + ARG test were normal. The GH results are highly dependent on the immunoassay used, but false positive results in the ITT are often obtained even if lower cutoff limits determined on the basis on the calibration of the GH assay are used. Confounding factors seemed to blunt the GH response to the ITT more than to the GHRH + ARG test at our outpatient clinic.

Efficacy and safety of once-daily esomeprazole for the treatment of gastroesophageal reflux disease in neonatal patients

OBJECTIVE

To evaluate the efficacy and safety of proton pump inhibitors in infants aged <1 year with gastroesophageal reflux disease (GERD).

STUDY DESIGN

In this randomized, double-blind, placebo-controlled multicenter study, neonates (premature to 1 month corrected age; n = 52) with signs and symptoms of GERD received esomeprazole 0.5 mg/kg or placebo once daily for up to 14 days. Change from baseline in the total number of GERD symptoms (from video monitoring) and GERD-related signs (from cardiorespiratory monitoring) was assessed with simultaneous esophageal pH, impedance, cardiorespiratory, and 8-hour video monitoring.

RESULTS

There were no significant differences between the esomeprazole and placebo groups in the percentage change from baseline in the total number of GERD-related signs and symptoms (-14.7% vs -14.1%, respectively). Mean change from baseline in total number of reflux episodes was not significantly different between esomeprazole and placebo (-7.43 vs -0.2, respectively); however, the percentage of time pH was <4.0 and the number of acidic reflux episodes >5 minutes in duration was significantly decreased with esomeprazole vs placebo (-10.7 vs 2.2 and -5.5 vs 1.0, respectively; P ≤ .0017). The number of patients with adverse events was similar between treatment groups.

CONCLUSIONS

Signs and symptoms of GERD traditionally attributed to acidic reflux in neonates were not significantly altered by esomeprazole treatment. Esomeprazole was well tolerated and reduced esophageal acid exposure and the number of acidic reflux events in neonates.

Effects of linaclotide in patients with irritable bowel syndrome with constipation or chronic constipation: a meta-analysis

BACKGROUND & AIMS

Linaclotide is a minimally absorbed, 14-amino acid peptide used to treat patients with irritable bowel syndrome with constipation (IBS-C) or chronic constipation (CC). We performed a meta-analysis to determine the efficacy of linaclotide, compared with placebo, for patients with IBS-C or CC.

METHODS

MEDLINE, EMBASE, and the Cochrane central register of controlled trials were searched for randomized, placebo-controlled trials examining the effect of linaclotide in adults with IBS-C or CC. Dichotomous results were pooled to yield a relative risk (RR), 95% confidence intervals (CIs), and number needed to treat (NNT).

RESULTS

The search identified 7 trials of linaclotide in patients with IBS-C or CC; 6 were included in the analysis. Two of 3 trials of IBS-C used the end point recommended by the U.S. Food and Drug Administration: an increase from baseline of 1 or more complete spontaneous bowel movement (CSBM)/week and a 30% or more reduction from baseline in the weekly average of daily worst abdominal pain scores for 50% of the treatment weeks. On the basis of this end point, the RR for response to treatment with 290 μg linaclotide, compared with placebo, was 1.95 (95% CI, 1.3-2.9), and the NNT was 7 (95% CI, 5-11). For CC, on the basis of data from 3 trials of patients with CC, the RR for the primary end point (more than 3 CSBMs/week and an increase in 1 or more CSBM/week, for 75% of weeks) was 4.26 for 290 μg linaclotide vs placebo (95% CI, 2.80-6.47), and the NNT was 7 (95% CI, 5-8). Linaclotide also improved stool form and reduced abdominal pain, bloating, and overall symptom severity in patients with IBS-C or CC.

CONCLUSIONS

On the basis of a meta-analysis, linaclotide improves bowel function and reduces abdominal pain and overall severity of IBS-C or CC, compared with placebo.

Resveratrol modulates autophagy and NF-κB activity in a murine model for treating non-alcoholic fatty liver disease

In this study, we aimed to investigate the therapeutic effects and involved mechanisms of resveratrol on an established non-alcoholic fatty liver disease (NAFLD) murine model. Wild-type and autophagic mediator ULK1 heterozygous knockout mice were induced to have NAFLD by high-fat diet for 8weeks. After that, resveratrol treatment was applied with the high-fat diet feeding for another 4weeks. Typical features of NAFLD, including histological changes, fibrosis, insulin resistance, oxidative status, and inflammation were characterized. After-treatment with resveratrol showed ameliorative effects on all measured features of NAFLD, from histology, insulin resistance, glucose tolerance to oxidative stress and inflammation. resveratrol treatment also reduced the activity of nuclear factor-κB (NF-κB) through the restoration of its inhibitor IκBα. Partial inhibition of ULK1 expression impaired the ameliorative effects of resveratrol on hepatic histology, fibrosis, oxidative status, inflammation, and NF-κB activity. In conclusion, resveratrol improved NAFLD-caused hepatic injury partially through regulating autophagic and IκBα-NF-κB pathways.

A high ratio of dietary n-3/n-6 polyunsaturated fatty acids improves obesity-linked inflammation and insulin resistance through suppressing activation of TLR4 in SD rats

Dietary ratios of n-3/n-6 polyunsaturated fatty acids (PUFAs) have been implicated in controlling markers of metabolic disorders, including obesity, insulin resistance (IR), inflammation, and lipid profiles, which are also presumed to be partly related to type 2 diabetes mellitus (T2DM). However, molecular mechanisms of the different PUFAs related to metabolic disorders have not been systematically addressed. The present study aimed to investigate the impact of dietary n-3/n-6 PUFA ratios on obesity and IR and, further, to determine the underlying mechanisms. For 16 weeks, 32 SD male rats, randomly divided into four groups (n = 8 per group), received one of the following diets: normal chow, high saturated fatty acid (SFA), high n-3/n-6 PUFA ratio (1∶1, PUFA¹:¹), or low n-3/n-6 PUFA ratio (1∶4, PUFA¹:⁴). Following the experimental diet period, metabolic parameters related to obesity and IR were measured. Compared to SFA diet-fed rats, PUFA¹:¹ diet-fed rats exhibited decreased body and visceral fat weight, lowered blood lipids, and improved glucose tolerance and insulin sensitivity. Interestingly, these changes were accompanied with decreased expression levels of circulating pro-inflammatory cytokines, including tumor necrosis factor α, interleukin-6, and C-reactive protein. Moreover, the TLR4 protein and mRNA levels were markedly down-regulated by PUFA¹:¹ compared with SFA; however, PUFA¹:⁴ diet-fed rats failed to exhibit these changes. Cumulatively, our data highlight a role for a PUFA¹:¹ diet in the prevention of obesity and related metabolic disorders by suppressing the activation of TLR4, a critical modulator of pro-inflammatory cytokines.

Melatonin ameliorates cognitive impairment induced by sleep deprivation in rats: role of oxidative stress, BDNF and CaMKII

Sleep deprivation (SD) has been shown to induce oxidative stress which causes cognitive impairment. Melatonin, an endogenous potent antioxidant, protects neurons from oxidative stress in many disease models. The present study investigated the effect of melatonin against SD-induced cognitive impairment and attempted to define the possible mechanisms involved. SD was induced in rats using modified multiple platform model. Melatonin (15 mg/kg) was administered to the rats via intraperitoneal injection. The open field test and Morris water maze were used to evaluate cognitive ability. The cerebral cortex (CC) and hippocampus were dissected and homogenized. Nitric oxide (NO) and malondialdehyde (MDA) levels and the superoxide dismutase (SOD) enzyme activity of hippocampal and cortical tissues (10% wet weight per volume) were performed to determine the level of oxidative stress. The expression of brain-derived neurotrophic factor (BDNF) and calcium-calmodulin dependent kinase II (CaMKII) proteins in CC and hippocampus was assayed by means of immunohistochemistry. The results revealed that SD impairs cognitive ability, while melatonin treatment prevented these changes. In addition, melatonin reversed SD-induced changes in NO, MDA and SOD in both of the CC and hippocampus. The results of immunoreactivity showed that SD decreased gray values of BDNF and CaMKII in CC and hippocamal CA1, CA3 and dentate gyrus regions, whereas melatonin improved the gray values. In conclusion, our results suggest that melatonin prevents cognitive impairment induced by SD. The possible mechanism may be attributed to its ability to reduce oxidative stress and increase the levels of CaMKII and BDNF in CC and hippocampus.

A search for variables predicting cortisol response to low-dose corticotropin stimulation following supraphysiological doses of glucocorticoids

OBJECTIVES

To determine which biological or clinical variables may predict cortisol response to low-dose adrenocorticotropic hormone (ACTH) stimulation following supraphysiological doses of glucocorticoids in children.

STUDY DESIGN

This retrospective study included all patients who underwent ACTH testing (1 μg) between October 2008 and June 2010 at the Sainte-Justine University Hospital Center, Montreal, after supraphysiological doses of glucocorticoids.

RESULTS

Data from 103 patients (median age, 8.0 years; range, 0.6-18.5 years; 57 girls) were analyzed, revealing growth deceleration in 37% and excessive weight gain in 33%. Reasons for glucocorticoid treatment included asthma (n = 30) and hematologic (n = 22), dermatologic (n = 19), rheumatologic (n = 16), and miscellaneous (n = 16) disorders. The following information was recorded: duration of glucocorticoid treatment (median, 374 days; range, 5-4226 days); duration of physiological hydrocortisone replacement (median, 118 days; range, 0-1089 days); maximum daily (median, 200 mg/m(2)/day; range, 12-3750 mg/m(2)/day) and cumulative (median, 16 728 mg/m(2); range, 82-178 209 mg/m(2)) doses, in hydrocortisone equivalents; and interval since the last dose (median, 43 days; range, 1-1584 days). Sixty-two patients (58%) exhibited a normal response (ie, peak cortisol >500 nmol/L) to ACTH stimulation. Peak cortisol level was not related to sex, prior morning cortisol level, duration of treatment, or cumulative glucocorticoid dose; 28% of the patients with normal baseline cortisol levels nevertheless demonstrated a subnormal response to ACTH.

CONCLUSION

Given the absence of clinical or biological predictors of the cortisol response to ACTH after suppressive doses of glucocorticoids, physicians have only 2 options: (1) empirically advocate glucocorticoid stress coverage during 18 months after cessation of high-dose glucocorticoid treatment; or (2) perform serial ACTH testing in all such patients until a normal peak cortisol level is attained.

A positive diagnostic strategy is noninferior to a strategy of exclusion for patients with irritable bowel syndrome

BACKGROUND & AIMS

Guidelines recommend a positive strategy based on symptom criteria to diagnose patients with irritable bowel syndrome (IBS). We conducted a randomized noninferiority trial to determine whether a positive diagnostic strategy is noninferior to a strategy of exclusion, with regard to patients' health-related quality of life (HRQOL).

METHODS

We studied 302 patients (18-50 years old) from primary care who were suspected of having IBS and referred by general practitioners. Patients who fulfilled the Rome III criteria for IBS with no alarm signals were randomly assigned to groups assessed by a strategy of exclusion (analyses of blood, stool samples for intestinal parasites, and sigmoidoscopies with biopsies) or a positive strategy (analyses of blood cell count and C-reactive protein). Patients were followed for 1 year. The primary end point was difference in change of HRQOL from baseline to 1 year between groups (on the basis of the Short Form 36 health survey, physical component summary, and noninferiority margin of 3 points). Secondary outcomes were change in gastrointestinal symptoms, satisfaction with management, and use of resources. Findings of diagnostic misclassification were registered.

RESULTS

A positive strategy was noninferior to a strategy of exclusion (difference, 0.64; 95% confidence interval, -2.74 to 1.45). The positive diagnostic strategy had lower direct costs. Each approach had similar effects on symptoms, satisfaction, and subsequent use of health resources. No cases of inflammatory bowel disease, colorectal cancer, or celiac disease were found.

CONCLUSIONS

In diagnosing IBS in primary care, use of a positive diagnostic strategy is noninferior to using a strategy of exclusion with regard to the patients' HRQOL. Our findings support the current guideline recommendations.

Spatial memory impairments in a prediabetic rat model

Diabetes is associated with an increased risk for brain disorders, namely cognitive impairments associated with hippocampal dysfunction underlying diabetic encephalopathy. However, the impact of a prediabetic state on cognitive function is unknown. Therefore, we now investigated whether spatial learning and memory deficits and the underlying hippocampal dysfunction were already present in a prediabetic animal model. Adult Wistar rats drinking high-sucrose (HSu) diet (35% sucrose solution during 9 weeks) were compared to controls' drinking water. HSu rats exhibited fasting normoglycemia accompanied by hyperinsulinemia and hypertriglyceridemia in the fed state, and insulin resistance with impaired glucose tolerance confirming them as a prediabetic rodent model. HSu rats displayed a poorer performance in hippocampal-dependent short- and long-term spatial memory performance, assessed with the modified Y-maze and Morris water maze tasks, respectively; this was accompanied by a reduction of insulin receptor-β density with normal levels of insulin receptor substrate-1 pSer636/639, and decreased hippocampal glucocorticoid receptor levels without changes of the plasma corticosterone levels. Importantly, HSu animals exhibited increased hippocampal levels of AMPA and NMDA receptor subunits GluA1 and GLUN1, respectively, whereas the levels of protein markers related to nerve terminals (synaptophysin) and oxidative stress/inflammation (HNE, RAGE, TNF-α) remained unaltered. These findings indicate that 9 weeks of sucrose consumption resulted in a metabolic condition suggestive of a prediabetic state, which translated into short- and long-term spatial memory deficits accompanied by alterations in hippocampal glutamatergic neurotransmission and abnormal glucocorticoid signaling.

CTLA-4Ig immunotherapy of obesity-induced insulin resistance by manipulation of macrophage polarization in adipose tissues

It has been established that obesity alters the metabolic and endocrine function of adipose tissue and, together with accumulation of adipose tissue macrophages, contributes to insulin resistance. Although numerous studies have reported that shifting the polarization of macrophages from M1 to M2 can alleviate adipose tissue inflammation, manipulation of macrophage polarization has not been considered as a specific therapy. Here, we determined whether cytotoxic T-lymphocyte-associated antigen-4IgG1 (CTLA-4Ig) can ameliorate insulin resistance by induction of macrophages from proinflammatory M1 to anti-inflammatory M2 polarization in the adipose tissues of high fat diet-induced insulin-resistant mice. CTLA4-Ig treatment prevented insulin resistance by changing gene expression to M2 polarization, which increased the levels of arginase 1. Furthermore, flow cytometric analysis confirmed the alteration of polarization from CD11c (M1)- to CD206 (M2)-positive cells. Concomitantly, CTLA-4Ig treatment resulted in weight reductions of epididymal and subcutaneous adipose tissues, which may be closely related to overexpression of apoptosis inhibitors in macrophages. Moreover, proinflammatory cytokine and chemokine levels decreased significantly. In contrast, CCAAT enhancer binding protein α, peroxisome proliferator-activated receptor γ, and adiponectin expression increased significantly in subcutaneous adipose tissue. This novel mechanism of CTLA-4lg immunotherapy may lead to an ideal anti-obesity/inflammation/insulin resistance agent.

Exercise for improving age-related hyperkyphotic posture: a systematic review

OBJECTIVE

To evaluate previous research to determine if exercise can improve preexisting hyperkyphosis by decreasing the angle of thoracic kyphosis in adults aged ≥45 years.

DATA SOURCES

PubMed, Embase, and the Cumulative Index to Nursing and Allied Health Literature databases were searched for studies related to posture, exercise, and age ≥45 years. Online conference proceedings of the American Society for Bone and Mineral Research, American Physical Therapy Association, and Gerontological Society of America were also searched.

STUDY SELECTION

Two independent reviewers screened the titles and abstracts and selected studies that tested the effect of exercise on measures of kyphosis, or forward head posture, in individuals with hyperkyphosis at baseline (defined as angle of kyphosis ≥40°). Reviews, letters, notes, and non-English language studies were excluded.

DATA EXTRACTION

A pilot-tested abstraction form was used by each reviewer to extract data from each study regarding details of exercise intervention, participant characteristics, safety, adherence, and results. The Cochrane Collaboration's tool for assessing risk of bias was used to assess methodologic quality. Discrepancies on the abstraction forms between the 2 reviewers were resolved by a third reviewer. A formal meta-analysis was not performed.

DATA SYNTHESIS

Thirteen studies were abstracted and included in the review; of these, 8 studies saw improvements in ≥1 measure of posture. The main sources of bias were related to blinding participants and incomplete outcome data. The adherence reported across studies suggests that exercise is an acceptable intervention for individuals with age-related hyperkyphosis.

CONCLUSIONS

The scarcity and quality of available data did not permit a pooled estimate of the effect of exercise on hyperkyphotic posture; however, the positive effects observed in high-quality studies suggest some benefit and support the need for an adequately designed randomized controlled trial examining the effect of exercise on hyperkyphosis.

A prospective, randomized, crossover, multicenter study comparing quality of life using compact versus standard catheters for intermittent self-catheterization

PURPOSE

Intermittent catheterization is the recommended standard treatment for neurogenic bladder dysfunction. However, standard intermittent catheters can be unwieldy, difficult to use and carry discreetly. This can influence patient ability to perform catheterization efficiently, discreetly and privately, therefore, affecting patient quality of life. We evaluated whether the discreet design of the compact catheter would improve quality of life in intermittent catheterization users compared with standard catheters.

MATERIALS AND METHODS

We performed a nonblinded, randomized, multicenter, 2-way crossover study with 2 treatment periods of 6 weeks ± 3 days. A total of 125 patients with neurogenic bladder dysfunction were included in the study from 17 study sites, including 7 in France, 3 each in Germany, Denmark and Sweden, and 1 in Norway. Quality of life was evaluated by the intermittent self-catheterization questionnaire. The difference in questionnaire scores between the compact catheter and standard hydrophilic coated catheters was analyzed using a mixed linear normal model.

RESULTS

The intermittent catheterization questionnaire score increased significantly due to compact catheter use. We noted an estimated mean difference of 17.0 between the compact and standard intermittent catheters (p <0.001), corresponding to a 28% increase. The primary study results were further supported by the positive results of the secondary objective of preference, that is 63% of patients preferred the compact catheter.

CONCLUSIONS

The discreet design of the compact catheter significantly improved patient quality of life related to intermittent self-catheterization.