Association between Boarding of Frail Individuals in the Emergency Department and Mortality: A Systematic Review

(1) Background: Older patients who attend emergency departments are frailer than younger patients and are at a high risk of adverse outcomes; (2) Methods: To conduct this systematic review, we adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Guidelines. We systematically searched literature from PubMed, Embase, OVID Medline®, Scopus, CINAHL via EBSCOHost, and the Cochrane Library up to May 2023, while for grey literature we used Google Scholar. No time restrictions were applied, and only articles published in English were included. Two independent reviewers assessed the eligibility of the studies and extracted relevant data from the articles that met our predefined inclusion criteria. The Critical Appraisal Skills Program (CASP) was used to assess the quality of the studies; (3) Results: Evidence indicates that prolonged boarding of frail individuals in crowded emergency departments (Eds) is associated with adverse outcomes, exacerbation of pre-existing conditions, and increased mortality risk; (4) Conclusions: Our results suggest that frail individuals are at risk of longer ED stays and higher mortality rates. However, the association between the mortality of frail patients and the amount of time a patient spends in exposure to the ED environment has not been fully explored. Further studies are needed to confirm this hypothesis.

Sleep Quality and Its Relationship to Anxiety and Hardiness in a Cohort of Frontline Italian Nurses during the First Wave of the COVID-19 Pandemic

INTRODUCTION

The COVID-19 pandemic has had a considerable impact on the psychological and psychopathological status of the population and health care workers in terms of insomnia, anxiety, depression, and post-traumatic stress disorder. The primary aim of this study was to describe and evaluate the impact of the pandemic on insomnia levels of a cohort of Italian nurses, particularly those involved in the care of COVID-19 patients. The secondary aim was to identify the interaction between insomnia and hardiness, anxiety, and sleep disturbances.

MATERIALS AND METHODS

A descriptive-exploratory study was conducted using an online survey during the first wave of the COVID-19 pandemic (March to July 2020). The questionnaire consisted of multiple-choice, open-ended, closed, and semi-closed questions. The psychometric tools administered were the Dispositional Resilience Scale (DRS-15), the State-Trait Anxiety Inventory (STAI-Y), and the Insomnia Severity Index (ISI).

RESULTS

a cohort of 1167 nurses fully completed the questionnaire (86.2% of total respondents). The insomnia scale survey showed an increase in post-pandemic scores compared to those before the pandemic, implying that insomnia levels increased after the first pandemic wave. Insomnia scores were directly correlated with anxiety levels (r = 0.571; p ≤ 0.05) and inversely correlated with hardiness levels (r = -0.324; p < 0.001). Multivariate analysis revealed the following protective factors: not having worked in COVID-19 wards, high levels of hardiness (commitment), and the presence of high pre-pandemic insomnia disorder. The main risk factor for insomnia reported in the analysis was a high anxiety score.

DISCUSSION AND CONCLUSION

Anxiety represented the main risk factor for insomnia severity in our sample, while hardiness was confirmed as a protective factor. Thus, it is necessary to design further studies to identify additional risk factors for poor sleep quality and to develop educational courses and strategies aimed at enhancing rest and sleep quality, especially for frontline nurses.

Variation in Communication and Family Visiting Policies in Italian Intensive Care Units during the COVID-19 Pandemic: A Secondary Analysis of the COVISIT International Survey

BACKGROUND

During COVID-19 pandemic, restrictions to in-person visiting of caregivers to patients admitted to intensive care units (ICU) were applied in many countries. Our aim was to describe the variations in communication and family visiting policies in Italian ICUs during the pandemic.

METHODS

A secondary analysis from the COVISIT international survey was conducted, focusing on data from Italy.

RESULTS

Italian ICUs provided 118 (18%) responses out of 667 responses collected worldwide. A total of 12 Italian ICUs were at the peak of COVID-19 admissions at the time of the survey and 42/118 had 90% or more of patients admitted to ICU affected by COVID-19. During the COVID-19 peak, 74% of Italian ICUs adopted a no-in-person-visiting policy. This remained the most common strategy (67%) at the time of the survey. Information to families was provided by regular phone calls (81% in Italy versus 47% for the rest of the world). Virtual visiting was available for 69% and most commonly performed using devices provided by the ICU (71% in Italy versus 36% outside Italy).

CONCLUSION

Our study showed that restrictions to the ICU applied during the COVID-19 pandemic were still in use at the time of the survey. The main means of communication with caregivers were telephone and virtual meetings.

Dapagliflozin improves Myocardial Flow Reserve in patients with Type 2 Diabetes: the DAPAHEART Trial

Objective

Cardiovascular (CV) outcome trials have shown that in patients with type 2 diabetes (T2D), treatment with sodium-glucose cotransporter-2 inhibitors (SGLT-2i) reduces CV mortality and admission rates for heart failure (HF). However, the mechanisms behind these benefits are not fully understood. This study was performed to investigate the effects of the SGLT-2i dapagliflozin on whole body insulin sensitivity, myocardial perfusion, and metabolism in patients with T2D without HF.

Research design and methods

This was a single-center, prospective, randomized, double-blind controlled clinical trial including 16 patients with T2D randomized to SGLT-2i dapagliflozin (10 mg) or placebo. Whole body glucose uptake (WBGU) and myocardial glucose uptake (MGU) were measured with PET/CT with FDG during euglycemic hyperinsulinemic clamp. Stress (i.v. adenosine infusion) and resting myocardial blood flow (MBF) and myocardial flow reserve (MFR) were calculated by PET/CT with 13N-ammonia.

Results

16 patients were randomized (8 dapagliflozin; 8 placebo). The groups were well-matched for baseline characteristics (age, diabetes duration, HbA1c, renal and heart function). Dapagliflozin significantly improved MFR (2.56±0.26 vs 3.59±0.35) compared with placebo group (2.34±0.21 vs 2.38±0.24; p for interaction =0.001) and was associated to a reduction of resting MBF corrected for cardiac workload (p=0.045). A trend toward an increase in stress MBF was also detected (p=0.058). Moreover, in dapagliflozin group we observed an increase of WBGU of borderline statistical significance (p=0.06) and no effects on MGU (p=0.41).

Conclusions

At the best of our knowledge, our study, for the first time, demonstrated that SGLT-2 inhibition increases MFR in T2D patients. The data presented provide a new potential explanation of cardiovascular benefits with SGLT-2i as they make patients more tolerant to the detrimental impact of obstructive coronary atherosclerosis on MFR.

Funding Acknowledgement

Type of funding sources: None.

Association between night-time extubation and clinical outcomes in adult patients: A systematic review and meta-analysis

BACKGROUND

Whether night-time extubation is associated with clinical outcomes is unclear.

OBJECTIVE

The aim of this systematic review and meta-analysis was to evaluate the association between night-time extubation and the reintubation rate, mortality, ICU and in-hospital length of stay in adult patients, compared with daytime extubation.

DESIGN

A systematic review and meta-analysis.

DATA SOURCES

PubMed, EMBASE, CINAHL and Web of Science from inception to 2 January 2021 (PROSPERO registration - CRD42020222812).

ELIGIBILITY CRITERIA

Randomised, quasi and cluster randomised, and nonrandomised studies describing associations between adult patients' outcomes and time of extubation (daytime/night-time) in intensive care or postanaesthesia care units.

RESULTS

Seven retrospective studies were included in the systematic review and meta-analysis, for a total of 293 663 patients. All the studies were performed in United States (USA). All the studies were judged at moderate risk of bias for reintubation and mortality. The analyses were conducted with random effects models. The analyses from adjusted estimates demonstrated no association between night-time extubation and increased risk of either reintubation (OR 1.00; 95% CI 0.88 to 1.13; P = 1.00; I2 = 66%; low-certainty evidence) or all-cause mortality at the longest available follow-up (OR 1.11; 95% CI 0.87 to 1.42; P = 0.39; I2 = 79%; low-certainty evidence), in comparison with daytime extubation. Analyses from unadjusted data for reintubation, mortality and ICU or in-hospital length of stay showed no significant association with night-time extubation. Analyses based on type of admission, number of centres or duration of mechanical ventilation showed no significant subgroup effects.

CONCLUSION

Night-time extubation of adult patients was not associated with higher adjusted risks for reintubation or death, in comparison with daytime extubation, but the certainty of the evidence was low.

The prevention of pressure injuries in the positioning and mobilization of patients in the ICU: a good clinical practice document by the Italian Society of Anesthesia, Analgesia, Resuscitation and Intensive Care (SIAARTI)

BACKGROUND

The aim of this document is to support clinical decision-making concerning positioning and mobilization of the critically ill patient in the early identification and resolution of risk factors (primary prevention) and in the early recognition of those most at risk (secondary prevention). The addresses of this document are physicians, nurses, physiotherapists, and other professionals involved in patient positioning in the intensive care unit (ICU).

METHODS

A consensus pathway was followed using the Nominal Focus Group and the Delphi Technique, integrating a phase of focused group discussion online and with a pre-coded guide to an individual phase. A multidisciplinary advisory board composed by nine experts on the topic contributed to both the phases of the process, to reach a consensus on four clinical questions positioning and mobilization of the critically ill patient.

RESULTS

The topics addressed by the clinical questions were the risks associated with obligatory positioning and therapeutic positions, the effective interventions in preventing pressure injuries, the appropriate instruments for screening for pressure injuries in the ICU, and the cost-effectiveness of preventive interventions relating to ICU positioning. A total of 27 statements addressing these clinical questions were produced by the panel. Among the statements, nine provided guidance on how to manage safely some specific patients' positions, including the prone position; five suggested specific screening tools and patients' factors to consider when assessing the individual risk of developing pressure injuries; five gave indications on mobilization and repositioning; and eight focused on the use of devices, such as positioners and preventive dressings.

CONCLUSIONS

The statements may represent a practical guidance for a broad public of healthcare professionals involved in the management of critically ill patients.

[Continuous bedside pressure mapping in a general intensive care unit: a prospective observational study]

. Continuous bedside pressure mapping in a general intensive care unit: a prospective observational study.

INTRODUCTION

A continuous bedside pressure mapping device (PMD) can provide real-time feedback of ideal body position to allow off-loading of high-pressure areas to prevent pressure ulcers development.

OBJECTIVE

To describe the implementation of a PMD to measure tissue interface pressure (PIT) in Intensive Care (ICU) patients.

METHODS

Prospective observational study in ICU critically ill mechanically ventilated adults, in an Italian University Hospital. Subjects were enrolled in the first 24 hours after ICU admission. A pressure mapping system (M.A.P. System TM) was used and 3 measurements of PIT with patient in supine position, every 6 hours after admission, were performed. The following anti-decubitus surfaces were used: Duo2® - Hill-Rom, Proficare®, Nimbus 3® or Therakair Visio® - Arjohuntleigh, Getinge Group.

RESULTS

27 patients (8 females) were enrolled; average Body Mass Index 27±6 (range: 16-43); 4 patients (14%) were diabetic. The average pressure of the 1215 areas analyzed was 26.7±19.6 mmHg (range: 3-78); the region with the highest contact pressure was the dorsal region (average: 48.7±12.5 mmHg), followed by the occipital (44.7±19.6 mmHg), and sacrum (44.7±10.7 mmHg). The three anti-decubitus surfaces showed different performances in the distribution of PITs, with statistically significant differences for the following factors: body weight (p = 0.017), patient height (p = 0.034), with increased pressures in taller patients, and higher BMI (p <0.0001).

CONCLUSIONS

Mean values of PIT were above critical levels, especially in the dorsal, occipital and sacrum region.

Personal protective equipment use by healthcare workers in intensive care unit during the early phase of COVID-19 pandemic in Italy: a secondary analysis of the PPE-SAFE survey

BACKGROUND

Italy was the first Western country to be heavily affected by COVID-19. Healthcare workers (HCWs) were exposed to a high risk of occupational infection, partially due to insufficient personal protective equipment (PPE) supplies. This study aimed to describe the practices, availability, training, confidence in PPE use and the adverse effects due to extended PPE use, as reported by HCWs in Italy. We also aimed to provide a comparison between Italian data and those from other countries.

METHODS

This study was a secondary analysis of a previously published international study, the PPE-SAFE Survey, conducted in April 2020. Data were analysed from the original study database.

RESULTS

We analysed the responses from 380 healthcare workers based in Italy, out of the 2711 respondents to the international survey. Among the Italian respondents, FFP2 and FFP3 respirators or equivalent were the most used masks for routine tasks (respectively 188/380, 50%; and 163/380, 43%). The median time of wearing PPE without taking a break was 5 h [interquartile range (IQR) 4-6], with statistically significant difference from other countries [median 4 h (IQR 2-5) p < 0.0001]. In Italy, 249 out of 380 (65%) HCWs had never performed a formal fit test for a N95 mask or equivalent and 91/380 (24%) never had a partner for donning and doffing procedures. Most of the respondents (299/380, 79%) had received formal training in PPE use at any time.

CONCLUSION

Most of the surveyed Italian HCWs reported working at above usual capacity, long shifts with PPE without breaks and routine use in intensive care unit of aerosol protection (e.g. FFP2/FFP3), hazmat suits and face shields/visors. The correct adherence to safety procedures (e.g. donning/doffing in pairs, performing fit test) has substantial scope for improvement in the future.

Material and Technology: Back to the Future for the Choice of Interface for Non-Invasive Ventilation - A Concise Review

Non-invasive ventilation (NIV) has dramatically changed the treatment of both acute and chronic respiratory failure in the last 2 decades. The success of NIV is correlated to the application of the "best ingredients" of a patient's "tailored recipe," including the appropriate choice of the selected candidate, the ventilator setting, the interface, the expertise of the team, and the education of the caregiver. The choice of the interface is crucial for the success of NIV. Type (oral, nasal, nasal pillows, oronasal, hybrid mask, helmet), size, design, material and headgears may affect the patient's comfort with respect to many aspects, such as air leaks, claustrophobia, skin erythema, eye irritation, skin breakdown, and facial deformity in children. Companies are paying great attention to mask development, in terms of shape, materials, comfort, and leak reduction. Although the continuous development of new products has increased the availability of interfaces and the chance to meet different requirements, in patients necessitating several daily hours of NIV, both in acute and in chronic home setting, the rotational use of different interfaces may remain an excellent strategy to decrease the risk of skin breakdown and to improve patient's tolerance. The aim of the present review was to give the readers a background on mask technology and materials in order to enhance their "knowledge" in making the right choice for the interface to apply during NIV in the different clinical scenarios.

Update I. A systematic review on the efficacy and safety of chloroquine/hydroxychloroquine for COVID-19

PURPOSE

To assess efficacy and safety of chloroquine (CQ)/hydroxychloroquine (HCQ) for treatment or prophylaxis of COVID-19 in adult humans.

MATERIALS AND METHODS

MEDLINE, PubMed, EMBASE and two pre-print repositories (bioRxiv, medRxiv) were searched from inception to 8th June 2020 for RCTs and nonrandomized studies (retrospective and prospective, including single-arm, studies) addressing the use of CQ/HCQ in any dose or combination for COVID-19.

RESULTS

Thirty-two studies were included (6 RCTs, 26 nonrandomized, 29,192 participants). Two RCTs had high risk, two 'some concerns' and two low risk of bias (Rob2). Among nonrandomized studies with comparators, nine had high risk and five moderate risk of bias (ROBINS-I). Data synthesis was not possible. Low and moderate risk of bias studies suggest that treatment of hospitalized COVID-19 with CQ/HCQ may not reduce risk of death, compared to standard care. High dose regimens or combination with macrolides may be associated with harm. Postexposure prophylaxis may not reduce the rate of infection but the quality of the evidence is low.

CONCLUSIONS

Patients with COVID-19 should be treated with CQ/HCQ only if monitored and within the context of high quality RCTs. High quality data about efficacy/safety are urgently needed.

Cardiopulmonary resuscitation in prone position: A scoping review

Introduction

The ongoing pandemic of COVID-19 brought to the fore prone positioning as treatment for patients with acute respiratory failure. With the increasing number of patients in prone position, both spontaneously breathing and mechanically ventilated, cardiac arrest in this position is more likely to occur.

This scoping review aimed to summarize the available evidence on cardiopulmonary resuscitation in prone position (‘reverse CPR’) and knowledge or research gaps to be further evaluated. The protocol of this scoping review was prospectively registered on 10th May 2020 in Open Science Framework (https://osf.io/nfuh9).

Methods

We searched PubMed, EMBASE, MEDLINE and pre-print repositories (bioRxiv and medRxiv) for simulation, pre-clinical and clinical studies on reverse CPR until 31st May 2020.

Results

We included 1 study on manikins, 31 case reports (29 during surgery requiring prone position) and 2 nonrandomized studies describing reverse CPR. No studies were found regarding reverse CPR in patients with COVID-19.

Conclusions

Even if the algorithms provided by the guidelines on basic and advanced life support remain valid in cardiac arrest in prone position, differences exist in the methods of performing CPR. There is no clear evidence of superiority in terms of effectiveness of reverse compared to supine CPR in patients with cardiac arrest occurring in prone position. The quality of evidence is low and knowledge gaps (e.g. protocols, training of healthcare personnel, devices for skill acquisition) should be fulfilled by further research. Meanwhile, a case-by-case evaluation of patient and setting characteristics should guide the decision on how to start CPR in such cases.

•

Prone positioning has been used in patients with COVID-19

•

An increasing number of cardiac arrests is expected to occur in prone position

•

There is no clear evidence of superiority of reverse compared to supine cardiopulmonary resuscitation

•

Knowledge gaps should be fulfilled by further research

Medical masks and Respirators for the Protection of Healthcare Workers from SARS-CoV-2 and other viruses

The use of medical masks and respirators as personal protective equipment is pivotal to reducing the level of biological hazard to which healthcare workers are exposed during the outbreak of highly diffusible pathogens, such as the recent novel coronavirus SARS-CoV-2. Unfortunately, during this pandemic, supplies are rapidly running out worldwide, with potential consequences for the rate of occupational infections. Also, knowledge about specific characteristics of respirators is of utmost importance to select the proper type according to the clinical setting. A wide variety of literature is available on the topic, but mostly based on Influenza viruses infection models. Clinical evidence on the use of respirators is poor and interest in the topic has not been constant over time. A better understanding of SARS-CoV-2 transmission is needed, together with high-quality clinical data on the use of respirators or alternative devices. Moreover, healthcare workers, regardless of their level of experience, should receive specific training. This review aims to summarize the available evidence on the use of medical masks and respirators in the context of viral infections, especially the current coronavirus disease 2019 (COVID-19).

Regional anticoagulation with heparin of an extracorporeal CO2 removal circuit: a case report

Background

Extracorporeal carbon dioxide removal is an increasingly used respiratory support technique. As is true of all extracorporeal techniques, extracorporeal carbon dioxide removal needs proper anticoagulation. We report a case of a patient at risk of bleeding complications who was treated with extracorporeal carbon dioxide removal and anticoagulated with a regional technique.

Case presentation

A 56-year-old Caucasian man with a history of chronic obstructive pulmonary disease exacerbation required extracorporeal carbon dioxide removal for severe hypercapnia and acidosis despite mechanical ventilation. The extracorporeal circuit was anticoagulated using a regional heparin technique to limit the patient’s risk of bleeding due to a low platelet count. The patient underwent 96 h of effective extracorporeal carbon dioxide removal without any adverse events. He was successfully weaned from extracorporeal carbon dioxide removal. During the treatment, no bleeding complications or unexpected circuit clotting was observed.

Conclusions

The use of regional heparin anticoagulation technique seems to be feasible and safe during extracorporeal carbon dioxide removal.

Use of low dose of rFVIIa (recombinant Factor VII activated) to control late bleeding after percutaneous dilational tracheostomy

In our case, the use of a low intravenous bolus dose of rFVIIa (recombinant factor VII activated; 15-20 mcg/kg) was effective and uneventful in controlling late postprocedural PDT bleeding associated with thrombocytopenia that cannot be corrected and after all other treatments failed.

Fetal cardiac growth is associated with in utero gut colonization

BACKGROUND AND AIMS

Intra-uterine metabolic environment predicts newborns' cardiac morphology, metabolism and future health. In adults, gut microbiota composition relates to altered cardiac structure and metabolism. We investigated the relationship between gut microbiota colonization and fetal cardiac growth.

METHODS AND RESULTS

Bacterial composition in meconium samples of 26 healthy, full-term newborns was assessed by 16S rDNA gene sequencing. Its relationship with birth echocardiographic parameters, and the interaction with cord blood levels of inflammatory markers were investigated. Correlative and cluster analysis, linear discriminant analysis effect size and predictive functional analysis based on Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were applied. Fetal left ventricle growth was related to gut microbiota composition at birth. Specifically, left ventricle posterior wall thickness (LVPW) greater than 4 mm was associated with lower microbiota beta and alpha diversity, depletion (LDA score > 3) of several bacteria at each taxonomic level, including Lactobacillales, and enrichment (LDA score > 5) in Enterobacteriales and Enterobacteriaceae. The latter was significantly related to cord blood gamma-glutamyltransferase levels (r = 0.58, p = 0.0057). Functionally, a thicker LVPW was related to up-regulation of pathways involved in lipopolysaccharide biosynthesis (+50%, p = 0.045 in correlative analysis) and energy metabolism (+12%, p = 0.028), and down-regulation of pathways involved in xenobiotic biodegradation (-21 to -53%, p = 0.0063-0.039), PPAR signaling (-24%, p = 0.021) and cardiac muscle contraction (-100%, p = 0.049).

CONCLUSION

Fetal cardiac growth and gut colonization are associated. Greater neonatal LVPW thickness is related to lower diversity of the gut microbiota community, depletion of bacteria having anti-remodeling effects, and enrichment in bacteria functionally linked to inflammation.

Two episodes of Taravana syndrome in a breath-hold diver with hyperhomocysteinemia

Taravana syndrome is a rare dysbaric disease characterized by neurologic signs and symptoms. Differently from others decompression illness, it has unspecified pathophysiology and unclear predisposing factors. Our cases suggest that thrombophilic state due to hyperhomocysteinemia could increase the risk to develop Taravana syndrome.

Protocol of a Multicenter International Randomized Controlled Manikin Study on Different Protocols of Cardiopulmonary Resuscitation for laypeople (MANI-CPR)

INTRODUCTION

Out-of-hospital cardiac arrest is one of the leading causes of death in industrialised countries. Survival depends on prompt identification of cardiac arrest and on the quality and timing of cardiopulmonary resuscitation (CPR) and defibrillation. For laypeople, there has been a growing interest on hands-only CPR, meaning continuous chest compression without interruption to perform ventilations. It has been demonstrated that intentional interruptions in hands-only CPR can increase its quality. The aim of this randomised trial is to compare three CPR protocols performed with different intentional interruptions with hands-only CPR.

METHODS AND ANALYSIS

This is a prospective randomised trial performed in eight training centres. Laypeople who passed a basic life support course will be randomised to one of the four CPR protocols in an 8 min simulated cardiac arrest scenario on a manikin: (1) 30 compressions and 2 s pause; (2) 50 compressions and 5 s pause; (3) 100 compressions and 10 s pause; (4) hands-only. The calculated sample size is 552 people. The primary outcome is the percentage of chest compression performed with correct depth evaluated by a computerised feedback system (Laerdal QCPR). ETHICS AND DISSEMINATION: . Due to the nature of the study, we obtained a waiver from the Ethics Committee (IRCCS Policlinico San Matteo, Pavia, Italy). All participants will sign an informed consent form before randomisation. The results of this study will be published in peer-reviewed journal. The data collected will also be made available in a public data repository.

TRIAL REGISTRATION NUMBER

NCT02632500.

The role of glucose, insulin and NEFA in regulating tissue triglyceride accumulation: Substrate cooperation in adipose tissue versus substrate competition in skeletal muscle

BACKGROUND AND AIMS

Metabolic factors initiating adipose tissue expansion and ectopic triglyceride accumulation are not completely understood. We aimed to investigate the independent role of circulating glucose, NEFA and insulin on glucose and NEFA uptake, and lipogenesis in skeletal muscle and subcutaneous adipose tissue (SCAT).

METHODS AND RESULTS

Twenty-two pigs were stratified according to four protocols: 1) and 2) low NEFA + high insulin ± high glucose (hyperinsulinaemia-hyperglycaemia or hyperinsulinaemia-euglycaemia), 3) high NEFA + low insulin (fasting), 4) low NEFA + low insulin (nicotinic acid). Positron emission tomography with [¹⁸F]fluoro-2-deoxyglucose and [¹¹C]acetate, was combined with [¹⁴C]acetate and [U-¹³C]palmitate enrichment techniques to assess glucose and lipid metabolism. Hyperinsulinaemia increased glucose extraction, whilst hyperglycaemia enhanced glucose uptake in skeletal muscle and SCAT. In SCAT, during hyperglycaemia, elevated glucose uptake was accompanied by greater [U-¹³C]palmitate-TG enrichment compared to the other groups, and by a 39% increase in de novo lipogenesis (DNL) compared to baseline, consistent with a 70% increment in plasma lipogenic index. Conversely, in skeletal muscle, [U-¹³C]palmitate-TG enrichment was higher after prolonged fasting.

CONCLUSIONS

Our data show the necessary role of hyperglycaemia-hyperinsulinaemia vs euglycaemia-hyperinsulinaemia in promoting expansion of TG stores in SCAT, by the consensual elevation in plasma NEFA and glucose uptake and DNL. In contrast, skeletal muscle NEFA uptake for TG synthesis is primarily driven by circulating NEFA levels. These results suggest that a) prolonged fasting or dietary regimens enhancing lipolysis might promote muscle steatosis, and b) the control of glucose levels, in association with adequate energy balance, might contribute to weight loss.

Procalcitonin for the diagnosis of invasive candidiasis: what is the evidence?

Procalcitonin is a widely used marker for the evaluation of infection and sepsis and to guide antibiotic therapy. During the last decade, several studies evaluated its role and diagnostic performance as a surrogate marker for the identification of Candida spp. in suspected invasive candidiasis. A low serum level and a favorable negative predictive value are the main findings for procalcitonin in this setting. The aim of this report is to provide an updated brief summary of the evidence supporting the use of PCT for the management of invasive candidiasis.

Use of a Real-Time Training Software (Laerdal QCPR®) Compared to Instructor-Based Feedback for High-Quality Chest Compressions Acquisition in Secondary School Students: A Randomized Trial

High-quality chest compressions are pivotal to improve survival from cardiac arrest. Basic life support training of school students is an international priority. The aim of this trial was to assess the effectiveness of a real-time training software (Laerdal QCPR^®) compared to a standard instructor-based feedback for chest compressions acquisition in secondary school students. After an interactive frontal lesson about basic life support and high quality chest compressions, 144 students were randomized to two types of chest compressions training: 1) using Laerdal QCPR^® (QCPR group– 72 students) for real-time feedback during chest compressions with the guide of an instructor who considered software data for students’ correction 2) based on standard instructor-based feedback (SF group– 72 students). Both groups had a minimum of a 2-minute chest compressions training session. Students were required to reach a minimum technical skill level before the evaluation. We evaluated all students at 7 days from the training with a 2-minute chest compressions session. The primary outcome was the compression score, which is an overall measure of chest compressions quality calculated by the software expressed as percentage. 125 students were present at the evaluation session (60 from QCPR group and 65 from SF group). Students in QCPR group had a significantly higher compression score (median 90%, IQR 81.9–96.0) compared to SF group (median 67%, IQR 27.7–87.5), p = 0.0003. Students in QCPR group performed significantly higher percentage of fully released chest compressions (71% [IQR 24.5–99.0] vs 24% [IQR 2.5–88.2]; p = 0.005) and better chest compression rate (117.5/min [IQR 106–123.5] vs 125/min [115–135.2]; p = 0.001). In secondary school students, a training for chest compressions based on a real-time feedback software (Laerdal QCPR^®) guided by an instructor is superior to instructor-based feedback training in terms of chest compression technical skill acquisition.

Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN12616000383460

Elevated Glucose Oxidation, Reduced Insulin Secretion, and a Fatty Heart May Be Protective Adaptions in Ischemic CAD

BACKGROUND

Insulin resistance, β-cell dysfunction, and ectopic fat deposition have been implicated in the pathogenesis of coronary artery disease (CAD) and type 2 diabetes, which is common in CAD patients. We investigated whether CAD is an independent predictor of these metabolic abnormalities and whether this interaction is influenced by superimposed myocardial ischemia.

METHODS AND RESULTS

We studied CAD patients with (n = 8) and without (n = 14) myocardial ischemia and eight non-CAD controls. Insulin sensitivity and secretion and substrate oxidation were measured during fasting and oral glucose tolerance testing. We used magnetic resonance imaging/spectroscopy, positron emission and computerized tomography to characterize CAD, cardiac function, pericardial and abdominal adipose tissue, and myocardial, liver, and pancreatic triglyceride contents. Ischemic CAD was characterized by elevated oxidative glucose metabolism and a proportional decline in β-cell insulin secretion and reduction in lipid oxidation. Cardiac function was preserved in CAD groups, whereas cardiac fat depots were elevated in ischemic CAD compared to non-CAD subjects. Liver and pancreatic fat contents were similar in all groups and related with surrounding adipose masses or systemic insulin sensitivity.

CONCLUSIONS

In ischemic CAD patients, glucose oxidation is enhanced and correlates inversely with insulin secretion. This can be seen as a mechanism to prevent glucose lowering because glucose is required in oxygen-deprived tissues. On the other hand, the accumulation of cardiac triglycerides may be a physiological adaptation to the limited fatty acid oxidative capacity. Our results underscore the urgent need of clinical trials that define the optimal/safest glycemic range in situations of myocardial ischemia.

Imaging of Organ Metabolism in Obesity and Diabetes: Treatment Perspectives

Obesity and diabetes are growing threats for cardiovascular diseases (CVD) and heart failure. In order to identify early and effective treatment or prevention targets, it is fundamental to dissect the role of each organ and the sequence of events leading from health to obesity, diabetes and cardiovascular diseases. The advancements in imaging modalities to evaluate organ-specific metabolism in humans in vivo is substantially contributing to the stratification of risk, identification of organ-specific culprits and development of targeted treatment strategies. This review summarizes the contribution provided by imaging of the heart, skeletal muscle, adipose tissue, liver, pancreas, gut and brain to the understanding of the pathogenesis and cardio-metabolic complications of obesity and diabetes, and to the monitoring of treatment responses in humans. We conclude by suggesting emerging fields of investigation, including the role of cardiac fat in the pathogenesis of cardiovascular disease, the conversion of white into brown adipose tissue in the treatment of obesity, the control of weight and energy balance by the brain, the integration between omics and imaging technologies to help establish biomarkers, and the characterization of gut metabolism in relation with the gut microbiome, opening a very promising preventive/therapeutic perspective.

Maternal adiposity and infancy growth predict later telomere length: a longitudinal cohort study

BACKGROUND/OBJECTIVES

Maternal overweight and obesity during pregnancy, and childhood growth patterns are risk factors influencing long-term health outcomes among the offspring. Furthermore, poor health condition has been associated with shorter leukocyte telomere length in adult subjects. We aimed to assess whether maternal adiposity during pregnancy and growth trajectory during infancy predict leukocyte telomere length (LTL) in later life.

SUBJECTS/METHODS

We studied a cohort of 1082 subjects belonging to the Helsinki Birth Cohort Study, born between 1934 and 1944. They underwent two clinical visits 10 years apart (2001-2004 and 2011-2013), during which LTL and anthropometrics were assessed. Birth records included birth weight, length, maternal body mass index (BMI) at the end of pregnancy. Serial measurements of height and weight from birth to 11 years were available.

RESULTS

Higher maternal BMI was associated with shorter LTL in elderly women (r=-0.102, P=0.024) but not in men. Also, in women but not in men shorter LTL and greater telomere shortening over a 10-year interval were predicted by higher weight at 12 months of age (P=0.008 and P=0.029, respectively), and higher weight gain during the first 12 months of life (P=0.008 and P=0.006, respectively), particularly between 6 and 9 months of age (P=0.002 for both LTL and LTL shortening rate). A correlation between younger age at adiposity rebound and shorter LTL at 60 years (P=0.022) was also found.

CONCLUSIONS

High maternal adiposity during pregnancy is associated with shorter LTL in elderly female offspring, but not in men. Moreover, higher weight and weight gain during the first year of life and younger age at adiposity rebound predict shorter LTL in older age in women, suggesting that rapid growth during the perinatal period accelerates cellular aging in late adulthood.

Effect of High-Fidelity Simulation on Medical Students' Knowledge about Advanced Life Support: A Randomized Study

High-fidelity simulation (HFS) is a learning method which has proven effective in medical education for technical and non-technical skills. However, its effectiveness for knowledge acquisition is less validated. We performed a randomized study with the primary aim of investigating whether HFS, in association with frontal lessons, would improve knowledge about advanced life support (ALS), in comparison to frontal lessons only among medical students. The secondary aims were to evaluate the effect of HFS on knowledge acquisition of different sections of ALS and personal knowledge perception. Participants answered a pre-test questionnaire consisting of a subjective (evaluating personal perception of knowledge) and an objective section (measuring level of knowledge) containing 100 questions about algorithms, technical skills, team working/early warning scores/communication strategies according to ALS guidelines. All students participated in 3 frontal lessons before being randomized in group S, undergoing a HFS session, and group C, receiving no further interventions. After 10 days from the end of each intervention, both groups answered a questionnaire (post-test) with the same subjective section but a different objective one. The overall number of correct answers of the post-test was significantly higher in group S (mean 74.1, SD 11.2) than in group C (mean 65.5, SD 14.3), p = 0.0017, 95% C.I. 3.34 - 13.9. A significantly higher number of correct answers was reported in group S than in group C for questions investigating knowledge of algorithms (p = 0.0001; 95% C.I 2.22-5.99) and team working/early warning scores/communication strategies (p = 0.0060; 95% C.I 1.13-6.53). Students in group S showed a significantly higher score in the post-test subjective section (p = 0.0074). A lower proportion of students in group S confirmed their perception of knowledge compared to group C (p = 0.0079). HFS showed a beneficial effect on knowledge of ALS among medical students, especially for notions of algorithms and team working/early warning scores/communication.

Developmental determinants in non-communicable chronic diseases and ageing

Prenatal and peri-natal events play a fundamental role in health, development of diseases and ageing (Developmental Origins of Health and Disease (DOHaD)). Research on the determinants of active and healthy ageing is a priority to: (i) inform strategies for reducing societal and individual costs of an ageing population and (ii) develop effective novel prevention strategies. It is important to compare the trajectories of respiratory diseases with those of other chronic diseases.

Endothelin system mRNA variation in the heart of Zucker rats: evaluation of a possible balance with natriuretic peptides

BACKGROUND AND AIMS

The deregulation of neurohormonal systems, including the natriuretic peptide (NP) and endothelin (ET) systems, may increase the possibility of developing obesity-related risk. The aim of our paper was to evaluate ET system mRNA variation in heart of the Zucker rat model together with the simultaneous evaluation of the NP system transcriptomic profile. In order to analyze the link between the ET-1 system and the inflammatory process, the cardiac expression of interleukin (IL)-6 and tumor necrosis factor (TNF)-α was also measured.

METHODS AND RESULTS

Zucker rats of 11-13 weeks were subdivided into obese rats (O, n = 20) and controls (CO, n = 20): half of them were studied under fasting conditions (CO(fc)-O(fc)) and the remainder after the induction of acute hyperglycemia (CO(AH)-O(AH)). Cardiac mRNA expression of TNF-α, IL-6, and NP/ET-1 systems was evaluated by Real-Time polymerase chain reaction. No significant difference for pre-proET-1, ET-A, and ET-B mRNA expression was detected between O and CO, whereas significantly lower mRNA levels of the ECE-1 were observed in O (p = 0.02). Regarding NPs, only BNP mRNA expression decreased significantly in O with respect to CO (p = 0.01). A down-regulation of NPR-B and NPR-C and an up-regulation of NPR-A were observed in O. No significant difference for IL-6 and TNF-α mRNA was revealed. Subdividing into fasting and hyperglycemic rats, many of the genes studied maintained their mRNA expression pattern almost unchanged.

CONCLUSIONS

The modulation of ET-1/NP systems in obesity could be a useful starting point for future studies aimed at identifying new therapeutic strategies for the treatment of cardiometabolic syndrome.

Neutrophil CD64 as a marker of infection in patients admitted to the emergency department with acute respiratory failure

Introduction

Cluster of differentiation 64 (CD64) is expressed on neutrophils during bacterial infections and sepsis. The aim of our study was to assess the CD64 expression in patients admitted to the emergency department (ED) with a triage diagnosis of acute respiratory failure (ARF) and/or dyspnea and to verify a relationship between its value and the presence of infection.

Methods

We assessed neutrophil CD64 expression in peripheral blood of patients admitted to the ED with a diagnosis of ARF and/or dyspnea from September 2012 to April 2013. We measured CD64 index by flow cytometry (Leuko64™ kit) and classified patients as infected within 12 hours from admission, without an infection within 12 hours but infected within 72 hours from admission, and not infected. The primary outcome was differentiating CD64 values of patients with a diagnosis of infection within 12 hours and 72 hours from admission, from those of patients without a diagnosis of infection. The secondary outcome was verifying a relationship between CD64 values and patients’ characteristics, Sequential Organ Failure Assessment score, and intensive care unit admission.

Results

Of 212 patients included in the study, 40.1% were classified as infected within 12 hours from admission, 20.3% were without an infection 12 hours after admission but were infected within 72 hours, and 39.6% were not infected. The median CD64 index was higher in patients with an infection on admission (CD64 index: 3.58) than in those not considered infected (CD64 index: 1.37), P<0.0001. Among patients not infected at admission, the CD64 index was higher in those with an infection detected during the following hours of observation (CD64 index: 2.75) than in patients without a diagnosis of infection (CD64 index: 1.28), P<0.0001. A CD64 index >3.65 showed a sensitivity of 94.6%, a specificity of 86.8%, and an area under the receiver-operating characteristic curve of 0.952 for prediction of intensive care unit admission.

Conclusion

CD64 index could represent a useful diagnostic tool for differential diagnosis of ARF in the ED.

Validation of [18F]fluorodeoxyglucose and positron emission tomography (PET) for the measurement of intestinal metabolism in pigs, and evidence of intestinal insulin resistance in patients with morbid obesity

AIMS/HYPOTHESIS

The role of the intestine in the pathogenesis of metabolic diseases is gaining much attention. We therefore sought to validate, using an animal model, the use of positron emission tomography (PET) in the estimation of intestinal glucose uptake (GU), and thereafter to test whether intestinal insulin-stimulated GU is altered in morbidly obese compared with healthy human participants.

METHODS

In the validation study, pigs were imaged using [(18)F]fluorodeoxyglucose ([(18)F]FDG) and the image-derived data were compared with corresponding ex vivo measurements in tissue samples and with arterial-venous differences in glucose and [(18)F]FDG levels. In the clinical study, GU was measured in different regions of the intestine in lean (n = 8) and morbidly obese (n = 8) humans at baseline and during euglycaemic hyperinsulinaemia.

RESULTS

PET- and ex vivo-derived intestinal values were strongly correlated and most of the fluorine-18-derived radioactivity was accumulated in the mucosal layer of the gut wall. In the gut wall of pigs, insulin promoted GU as determined by PET, the arterial-venous balance or autoradiography. In lean human participants, insulin increased GU from the circulation in the duodenum (from 1.3 ± 0.6 to 3.1 ± 1.1 μmol [100 g](-1) min(-1), p < 0.05) and in the jejunum (from 1.1 ± 0.7 to 3.0 ± 1.5 μmol [100 g](-1) min(-1), p < 0.05). Obese participants failed to show any increase in insulin-stimulated GU compared with fasting values (NS).

CONCLUSIONS/INTERPRETATION

Intestinal GU can be quantified in vivo by [(18)F]FDG PET. Intestinal insulin resistance occurs in obesity before the deterioration of systemic glucose tolerance.

Similar patterns of myocardial metabolism and perfusion in patients with type 2 diabetes and heart disease of ischaemic and non-ischaemic origin

AIMS/HYPOTHESIS

Type 2 diabetes and insulin resistance are often associated with the co-occurrence of coronary atherosclerosis and cardiac dysfunction. The aim of this study was to define the independent relationships between left ventricular dysfunction or ischaemia and patterns of myocardial perfusion and metabolism in type 2 diabetes.

METHODS

Twenty-four type 2 diabetic patients--12 with coronary artery disease (CAD) and preserved left ventricular function and 12 with non-ischaemic heart failure (HF)--were enrolled in a cross-sectional study. Positron emission tomography (PET) was used to assess myocardial blood flow (MBF) at rest, after pharmacological stress and under euglycaemic hyperinsulinaemia. Insulin-mediated myocardial glucose disposal was determined with 2-deoxy-2-[(18)F]fluoroglucose PET.

RESULTS

There was no difference in myocardial glucose uptake (MGU) between the healthy myocardium of CAD patients and the dysfunctional myocardium of HF patients. MGU was strongly influenced by levels of systemic insulin resistance in both groups (CAD, r = 0.85, p = 0.005; HF, r = 0.77, p = 0.01). In HF patients, there was an inverse association between MGU and the coronary flow reserve (r = -0.434, p = 0.0115). A similar relationship was observed in non-ischaemic segments of CAD patients. Hyperinsulinaemia increased MBF to a similar extent in the non-ischaemic myocardial of CAD and HF patients.

CONCLUSIONS/INTERPRETATION

In type 2 diabetes, similar metabolic and perfusion patterns can be detected in the non-ischaemic regions of CAD patients with normal cardiac function and in the dysfunctional non-ischaemic myocardium of HF patients. This suggests that insulin resistance, rather than diagnosis of ischaemia or left ventricular dysfunction, affects the metabolism and perfusion features of patients with type 2 diabetes.

The interaction of blood flow, insulin, and bradykinin in regulating glucose uptake in lower-body adipose tissue in lean and obese subjects

CONTEXT

Impaired adipose tissue (AT) blood flow has been implicated in the pathogenesis of insulin resistance in obesity. Insulin and bradykinin are meal-stimulated promoters of AT blood flow and glucose metabolism.

OBJECTIVE

We tested whether blood flow regulates glucose metabolism in AT, insulin and bradykinin exert additive effects on AT blood flow and metabolism, and any of these actions explains the insulin resistance observed in obese individuals.

DESIGN

Perfusion and glucose metabolism in the AT of the thighs were studied by positron emission tomography and H(2)(15)O (flow tracer) and (18)F-2-fluoro-2-deoxyglucose. Study I included five subjects in whom positron emission tomography imaging was performed in the fasting state during intraarterial infusion of bradykinin in the left leg; the right leg served as a control. Study II included seven lean and eight obese subjects in whom the imaging protocol was performed during euglycemic hyperinsulinemia.

RESULTS

Bradykinin alone doubled fasting AT blood flow without modifying glucose uptake. Hyperinsulinemia increased AT blood flow (P ≤ 0.05) similarly in lean and obese individuals. In the lean group, bradykinin increased insulin-mediated AT glucose uptake from 8.6 ± 1.6 to 12.3 ± 2.4 μmol/min · kg (P = 0.038). In the obese group, AT glucose uptake was impaired (5.0 ± 1.0 μmol/min · kg, P = 0.05 vs. the lean group), and bradykinin did not exert any metabolic action (6.0 ± 0.8 μmol/min · kg, P = 0.01 vs. the lean group).

CONCLUSION

AT blood flow is not an independent regulator of AT glucose metabolism. Insulin is a potent stimulator of AT blood flow, and bradykinin potentiates the hemodynamic and metabolic actions of insulin in lean but not in obese individuals.

Contribution of organ blood flow, intrinsic tissue clearance and glycaemia to the regulation of glucose use in obese and type 2 diabetic rats: a PET study

BACKGROUND AND AIMS

Chronic hyperglycaemia aggravates obesity and diabetes mellitus. The use of glucose by body organs depends on several factors. We sought to investigate the role of blood flow, intrinsic tissue glucose clearance and blood glucose levels in regulating tissue glucose uptake under fasting conditions (FCs) and in response to acute hyperglycaemia (AH) in obese and type 2 diabetic rats.

METHODS AND RESULTS

Thirty-six Zucker rats were studied by positron emission tomography to quantify perfusion and glucose uptake during FC and after AH in the liver, myocardium, skeletal muscle and subcutaneous adipose tissue. Progressively higher glucose uptake rates were observed from lean to obese (p < 0.05) and to diabetic rats (p < 0.05) in all tissues during both FC and AH. In FC, they were increased of 7-18 times in obese rats and 11-30 times in diabetic rats versus controls. Tissue glucose uptake was increased by over 10-fold during AH in controls; this response was severely blunted in diseased groups. AH tended to stimulate organ perfusion in control rats. Tissue glucose uptake was a function of intrinsic clearance and glycaemia (mass action) in healthy animals, but the latter component was lost in diseased animals. Differences in perfusion did not account for those in glucose uptake.

CONCLUSIONS

Each organ participates actively in the regulation of its glucose uptake, which is dependent on intrinsic tissue substrate extraction and extrinsic blood glucose delivery, but not on perfusion, and it is potently stimulated by AH. Obese and diabetic rats had an elevated organ glucose uptake but a blunted response to acute glucose intake.

Metabolic toxicity of the heart: insights from molecular imaging

There is convincing evidence that alterations in myocardial substrate use play an important role in the normal and diseased heart. In this review, insights gained by using quantitative molecular imaging by positron emission tomography and magnetic resonance spectroscopy in the study of human myocardial metabolism will be discussed, and attention will be paid to the effects of nutrition, gender, aging, obesity, diabetes, cardiac hypertrophy, ischemia, and heart failure. The heart is an omnivore organ, relying on metabolic flexibility, which is compromised by the occurrence of defects in coronary flow reserve, insulin-mediated glucose disposal, and metabolic-mechanical coupling. Obesity, diabetes, and ischemic cardiomyopathy appear as states of high uptake and oxidation of fatty acids, that compromise the ability to utilize glucose under stimulated conditions, and lead to misuse of energy and oxygen, disturbing mechanical efficiency. Idiopathic heart failure is a complex disease frequently coexisting with diabetes, insulin resistance and hypertension, in which the end stage of metabolic toxicity manifests as severe mitochondrial disturbance, inability to utilize fatty acids, and ATP depletion. The current literature provides evidence that the primary events in the metabolic cascade outlined may originate in extra-cardiac organs, since fatty acid, glucose levels, and insulin action are mostly controlled by adipose tissue, skeletal muscle and liver, and that a broader vision of organ cross-talk may further our understanding of the primary and the adaptive events involved in metabolic heart toxicity.

Non-invasive estimation of hepatic blood perfusion from H2 15O PET images using tissue-derived arterial and portal input functions

PURPOSE

The liver is perfused through the portal vein and the hepatic artery. When its perfusion is assessed using positron emission tomography (PET) and (15)O-labeled water (H(2) (15)O), calculations require a dual blood input function (DIF), i.e., arterial and portal blood activity curves. The former can be generally obtained invasively, but blood withdrawal from the portal vein is not feasible in humans. The aim of the present study was to develop a new technique to estimate quantitative liver perfusion from H(2) (15)O PET images with a completely non-invasive approach.

METHODS

We studied normal pigs (n=14) in which arterial and portal blood tracer concentrations and Doppler ultrasonography flow rates were determined invasively to serve as reference measurements. Our technique consisted of using model DIF to create tissue model function and the latter method to simultaneously fit multiple liver time-activity curves from images. The parameters obtained reproduced the DIF. Simulation studies were performed to examine the magnitude of potential biases in the flow values and to optimize the extraction of multiple tissue curves from the image.

RESULTS

The simulation showed that the error associated with assumed parameters was <10%, and the optimal number of tissue curves was between 10 and 20. The estimated DIFs were well reproduced against the measured ones. In addition, the calculated liver perfusion values were not different between the methods and showed a tight correlation (r=0.90).

CONCLUSION

In conclusion, our results demonstrate that DIF can be estimated directly from tissue curves obtained through H(2) (15)O PET imaging. This suggests the possibility to enable completely non-invasive technique to assess liver perfusion in patho-physiological studies.

Association between expression of insulin resistance (IR) related genes and breast cancer outcome

10597

Background: IR is associated with adverse outcome in breast cancer. IR may affect patient outcome via the insulin and the IGF axis, acting through the tyrosine kinase signaling in enhancing cell proliferation. To date, no study explored the role of insulin- related gene expression in breast cancer progression. The aim of this study was to evaluate the prognostic value of a set of insulin-related genes using published microarray datasets. Methods: IR genes were sorted according to the “insulin sensitivity gene set” previously defined in peripheral tissues of healthy subjects screened for IR by the euglycaemic insulin clamp technique. One-hundred-forty- three genes were used to develop an outcome predictor on a training set of 102 primary breast tumors, randomly selected from 159 patients in the GEO database ( GSE1456 ). The outcome predictor was validated on the remaining 57 patients. Primary outcome measure was relapse free survival (RFS). Univariate non-parametric Mann-Whitney U test was used to identify genes differentially expressed. Expression of genes significantly correlated with relapse was combined in a linear score. Patients were classified as low or high risk with respect to the median score. Kaplan-Meier curves were used to evaluate the discriminating power of the score. Results: Fourteen genes resulted differentially expressed in the training set: the 8-year RFS was 91% (SE =4%) and 51% (SE = 8%) in the low risk and high risk group, respectively (p < .001). In the validation set, the 8-year RFS was 97% (SE = 3%) and 54% (SE = 10%), respectively (p = .009), supporting the discriminating ability of the score. By multivariate Cox analysis, the prognostic ability of the score was independent of subtype and grade (p < .001). Conclusions: Our data provide the first evidence that expression of insulin related genes can predict outcome, and indicate that the insulin pathway is involved in breast cancer progression. This is particularly important since IR is responsive to lifestyle interventions. We are currently validating the insulin-related score on independent breast cancer microarray datasets.

No significant financial relationships to disclose.

Non-esterified fatty acids impair insulin-mediated glucose uptake and disposition in the liver

AIMS/HYPOTHESIS

We investigated the effect of elevated circulating NEFA on insulin-mediated hepatic glucose uptake (HGU) and whole-body glucose disposal (M) in eight healthy male subjects.

METHODS

Studies were performed using positron emission tomography (PET) and [(18)F]-2-fluoro-2-deoxyglucose ([(18)F]FDG) during euglycaemic hyperinsulinaemia (0-120 min) and an Intralipid/heparin infusion (IL/Hep; -90-120 min). On a different day, similar measurements were taken during euglycaemic hyperinsulinaemia and saline infusion (SAL). Graphical and compartmental analyses were used to model liver data.

RESULTS

Circulating NEFA increased approximately three-fold during IL/Hep, and declined by 81+/-7% in the SAL study ( p</=0.01). Both M (-28+/-7%) and HGU (-25+/-9%) were significantly lowered by NEFA elevation ( p=0.004 and p=0.035 respectively). In the whole data set, the decreases in M and HGU were positively correlated ( r=0.78, p=0.038). No evidence of [(18)F]FDG outflow was detected during the scanning time. HGU was correlated with the phosphorylation rate parameter ( r=0.71, p=0.003) as derived by compartmental modelling.

CONCLUSIONS/INTERPRETATION

In healthy men, NEFA impair insulin-mediated HGU and whole-body glucose uptake to a similar extent. Our data suggest that multiple intracellular NEFA targets may concur to down-regulate glucose uptake by the liver.

Mismatch between insulin-mediated glucose uptake and blood flow in the heart of patients with Type II diabetes

AIMS/HYPOTHESIS

We investigated the effect of physiological hyperinsulinaemia on global and regional myocardial blood flow and glucose uptake in five patients with Type II (non-insulin-dependent) diabetes mellitus and seven healthy control subjects.

METHODS

Myocardial blood flow was assessed by positron emission tomography with oxygen-15 labelled water (H(2)(15)O) either before or after 1 h of euglycaemic hyperinsulinaemia. Myocardial glucose uptake was assessed by positron emission tomography and fluorine-18 labelled fluorodeoxyglucose ((18)FDG).

RESULTS

During hyperinsulinaemia, myocardial blood flow increased from 0.91+/-0.03 to 1.00+/-0.03 ml(.)min(-1.)g(-1) in control subjects ( p<0.005) and from 0.81+/-0.02 to 0.95+/-0.04 ml(.)min(-1.)g(-1) in diabetic patients ( p<0.0005). Corresponding glucose uptakes were 0.56+/-0.01 and 0.36+/-0.02 micro mol(.)min(-1.)g(-1) ( p<0.0001), respectively. During hyperinsulinaemia, the regional distribution of myocardial blood flow and glucose uptake showed higher values in the septum and anterolateral wall (short axis) and in the mid-ventricle (long axis) in control subjects, and insulin action was circumscribed to these regions. In diabetic patients, the regional distribution of glucose uptake was similar; however, insulin-induced increase of myocardial blood flow was mainly directed to the postero-inferior areas (short axis) and to the base (long axis) of the heart, thus cancelling the predominance of the anterior wall observed before insulin administration.

CONCLUSION/INTERPRETATION

These results provide evidence that insulin-mediated regulation of global myocardial blood flow is preserved in Type II diabetic patients. In contrast, the regional re-distribution of myocardial blood flow induced by insulin is directed to different target areas when compared with healthy subjects, thereby resulting in a mismatch between blood flow and glucose metabolism.

In vivo imaging of insulin receptors by PET: preclinical evaluation of iodine-125 and iodine-124 labelled human insulin

[A(14)-*I]iodoinsulin was prepared for studies to assess the suitability of labeled iodoinsulin for positron emission tomography (PET). Iodine-125 was used to establish the methods and for preliminary studies in rats. Further studies and PET scanning in rats were carried out using iodine-124. Tissue and plasma radioactivity was measured as the uptake index (UI = [cpm x (g tissue)(-1)]/[cpm injected x (g body weight)(-1)]) at 1 to 40 min after intravenous injection of either [A(14)-(125)I]iodoinsulin or [A(14)-(124)I]iodoinsulin. For both radiotracers, initial clearance of radioactivity from plasma was rapid (T(1/2) approximately 1 min), reaching a plateau (UI = 2.8) at approximately 5 min which was maintained for 35 min. Tissue biodistributions of the two radiotracers were comparable; at 10 min after injection, UI for myocardium was 2.4, liver, 4.0, pancreas, 5.4, brain, 0.17, kidney, 22, lung, 2.3, muscle, 0.54 and fat, 0.28. Predosing rats with unlabelled insulin reduced the UI for myocardium (0.95), liver (1.8), pancreas (1.2) and brain (0.08), increased that for kidney (61) but had no effect on that for lung (2.5), muscle (0.50) or fat (0.34). Analysis of radioactivity in plasma demonstrated a decrease of [(125)I]iodoinsulin associated with the appearance of labeled metabolites; the percentage of plasma radioactivity due to [(125)I]iodoinsulin was 40% at 5 min and 10% at 10 min. The heart, liver and kidneys were visualized using [(124)I]iodoinsulin with PET.

Physiological hyperinsulinemia impairs insulin-stimulated glycogen synthase activity and glycogen synthesis

Although chronic hyperinsulinemia has been shown to induce insulin resistance, the basic cellular mechanisms responsible for this phenomenon are unknown. The present study was performed 1) to determine the time-related effect of physiological hyperinsulinemia on glycogen synthase (GS) activity, hexokinase II (HKII) activity and mRNA content, and GLUT-4 protein in muscle from healthy subjects, and 2) to relate hyperinsulinemia-induced alterations in these parameters to changes in glucose metabolism in vivo. Twenty healthy subjects had a 240-min euglycemic insulin clamp study with muscle biopsies and then received a low-dose insulin infusion for 24 (n = 6) or 72 h (n = 14) (plasma insulin concentration = 121 +/- 9 or 143 +/- 25 pmol/l, respectively). During the baseline insulin clamp, GS fractional velocity (0.075 +/- 0.008 to 0.229 +/- 0.02, P < 0.01), HKII mRNA content (0.179 +/- 0.034 to 0.354 +/- 0.087, P < 0.05), and HKII activity (2.41 +/- 0.63 to 3.35 +/- 0.54 pmol x min(-1) x ng(-1), P < 0.05), as well as whole body glucose disposal and nonoxidative glucose disposal, increased. During the insulin clamp performed after 24 and 72 h of sustained physiological hyperinsulinemia, the ability of insulin to increase muscle GS fractional velocity, total body glucose disposal, and nonoxidative glucose disposal was impaired (all P < 0.01), whereas the effect of insulin on muscle HKII mRNA, HKII activity, GLUT-4 protein content, and whole body rates of glucose oxidation and glycolysis remained unchanged. Muscle glycogen concentration did not change [116 +/- 28 vs. 126 +/- 29 micromol/kg muscle, P = nonsignificant (NS)] and was not correlated with the change in nonoxidative glucose disposal (r = 0.074, P = NS). In summary, modest chronic hyperinsulinemia may contribute directly (independent of change in muscle glycogen concentration) to the development of insulin resistance by its impact on the GS pathway.

Bromocriptine: a novel approach to the treatment of type 2 diabetes

OBJECTIVE

In vertebrates, body fat stores and insulin action are controlled by the temporal interaction of circadian neuroendocrine oscillations. Bromocriptine modulates neurotransmitter action in the brain and has been shown to improve glucose tolerance and insulin resistance in animal models of obesity and diabetes. We studied the effect of a quick-release bromocriptine formulation on glucose homeostasis and insulin sensitivity in obese type 2 diabetic subjects.

RESEARCH DESIGN AND METHODS

There were 22 obese subjects with type 2 diabetes randomized to receive a quick-release formulation of bromocriptine (n = 15) or placebo (n = 7) in a 16-week double-blind study. Subjects were prescribed a weight-maintaining diet to exclude any effect of changes in body weight on the primary outcome measurements. Fasting plasma glucose concentration and HbA(1c) were measured at 2- to 4-week intervals during treatment. Body composition (underwater weighing), body fat distribution (magnetic resonance imaging), oral glucose tolerance (oral glucose tolerance test [OGTT]), insulin-mediated glucose disposal, and endogenous glucose production (2-step euglycemic insulin clamp, 40 and 160 mU x min(-1) x m(-2)) were measured before and after treatment.

RESULTS

No changes in body weight or body composition occurred during the study in either placebo- or bromocriptine-treated subjects. Bromocriptine significantly reduced HbA(1c) (from 8.7 to 8.1%, P = 0.009) and fasting plasma glucose (from 190 to 172 mg/dl, P = 0.02) levels, whereas these variables increased during placebo treatment (from 8.5 to 9.1%, NS, and from 187 to 223 mg/dl, P = 0.02, respectively). The differences in HbA(1c) (delta = 1.2%, P = 0.01) and fasting glucose (delta = 54 mg/dl, P < 0.001) levels between the bromocriptine and placebo group at 16 weeks were highly significant. The mean plasma glucose concentration during OGTT was significantly reduced by bromocriptine (from 294 to 272 mg/dl, P = 0.005), whereas it increased in the placebo group. No change in glucose disposal occurred during the first step of the insulin clamp in either the bromocriptine- or placebo-treated group. During the second insulin clamp step, bromocriptine improved total glucose disposal from 6.8 to 8.4 mg x min(-1) kg(-1) fat-free mass (FFM) (P = 0.01) and nonoxidative glucose disposal from 3.3 to 4.3 mg min(-1) x kg(-1) FFM (P < 0.05), whereas both of these variables deteriorated significantly (P < or = 0.02) in the placebo group.

CONCLUSIONS

Bromocriptine improves glycemic control and glucose tolerance in obese type 2 diabetic patients. Both reductions in fasting and postprandial plasma glucose levels appear to contribute to the improvement in glucose tolerance. The bromocriptine-induced improvement in glycemic control is associated with enhanced maximally stimulated insulin-mediated glucose disposal.

Regulation of hexokinase II expression in human skeletal muscle in vivo

The phosphorylation of glucose to glucose-6-phosphate (G-6-P) is the first committed step in glucose uptake in skeletal muscle. This reaction is catalyzed by hexokinase (HK). Two HK isoforms, HKI and HKII, are expressed in human skeletal muscle, but only HKII is regulated by insulin. The present study was undertaken to determine the time course for the regulation of HK activity and expression by physiological plasma insulin concentrations in human skeletal muscle in vivo. A hyperinsulinemic-euglycemic glucose clamp and percutaneous muscle biopsy were performed in separate groups of healthy subjects after 60, 120, 180, and 360 minutes of euglycemic hyperinsulinemia. Muscle biopsies were subfractionated into soluble and particulate fractions to determine HKI and HKII activities. RNA was extracted from a separate portion of the muscle biopsy, and HKI and HKII mRNA content was determined using an RNase protection assay. Glycogen synthase (GS) activity and fractional velocity were also determined. HKII mRNA was increased 2-fold by 120 minutes and remained high versus the basal value for up to 360 minutes. HKI mRNA was unchanged throughout the study. HKII activity increased after 360 minutes of insulin infusion, and this increase was limited to the soluble fraction. In contrast, insulin induced a 1.5- to 2-fold increase in GS fractional velocity that was sustained for 360 minutes. The time course of the ability of hyperinsulinemia to increase HKII mRNA indicates that insulin is likely a physiological regulator of HKII expression in human skeletal muscle in vivo.

Independent influence of age on basal insulin secretion in nondiabetic humans. European Group for the Study of Insulin Resistance

Glucose tolerance deteriorates with aging. To test whether age per se impairs basal beta-cell function, we analyzed retrospective clamp data from a large group (n = 957) of nondiabetic Europeans over the 18-85 yr age range (the European Group for the Study of Insulin Resistance database). In this cohort, the fasting posthepatic insulin delivery rate [IDR, obtained as the product of clamp-derived posthepatic insulin MCR and fasting plasma insulin concentration] was 8.9 (6.6) mU/min (median and interquartile range), and it gradually increased with age. In univariate association, IDR was positively related to body mass index (P < 0.0001), fasting plasma glucose (P < 0.01), and waist-to-hip ratio (P < 0.001), and negatively related to insulin sensitivity (P < 0.0001). After controlling for these factors in a multivariate model, IDR declined significantly with age (P < 0.0001). This intrinsic effect of age on IDR was similar in men and women, and it averaged 25% between 18-85 yr. In the same statistical model, insulin MCR (but not fasting plasma insulin concentration) showed a significant (P < 0.0001) inverse relation to age. We conclude that, in nondiabetic Caucasian subjects of either sex, senescence per se is associated with a progressive decline in both insulin clearance and basal insulin release.