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Aims/hypothesis The aim of this study was to investigate insulin secretion, insulin sensitivity, disposition index and insulin clearance by glucose tolerance status in individuals with cystic fibrosis (CF) and exocrine pancreatic insufficiency. Methods In a cross-sectional study, we conducted an extended (ten samples) OGTT in individuals with pancreatic-insufficient CF (PI-CF). Participants were divided into normal glucose tolerance (NGT), early glucose intolerance (EGI), impaired glucose tolerance (IGT) and CF-related diabetes (CFRD) groups. We used three different oral minimal models to assess insulin secretion, insulin sensitivity and insulin clearance during the OGTT. We evaluated insulin secretion using total secretion (Φ total), first-phase secretion (Φ dynamic) and second-phase secretion (Φ static) from the model, and we estimated the disposition index by multiplying Φ total and insulin sensitivity. Results Among 61 participants (NGT 21%, EGI 33%, IGT 16%, CFRD 30%), insulin secretion indices (Φ total, dynamic and static) were significantly lower in the CFRD group compared with the other groups. Insulin sensitivity declined with worsening in glucose tolerance ( p value for trend <0.001) and the disposition index declined between NGT and EGI and between IGT and CFRD. Those with CFRD had elevated insulin clearance compared with NGT ( p =0.019) and low insulin secretion (Φ total) was also associated with high insulin clearance ( p <0.001). Conclusions/interpretation In individuals with PI-CF, disposition index declined with incremental impairment in glucose tolerance due to a reduction in both insulin secretion and insulin sensitivity. Moreover in CF, reduced insulin secretion was associated with higher insulin clearance. Graphical Abstract

Laboratory experiments have uncovered many basic aspects of bacterial physiology and behavior. After the past century of mostly in vitro experiments, we now have detailed knowledge of bacterial behavior in standard laboratory conditions, but only a superficial understanding of bacterial functions and behaviors during human infection. It is well-known that the growth and behavior of bacteria are largely dictated by their environment, but how bacterial physiology differs in laboratory models compared with human infections is not known. To address this question, we compared the transcriptome of Pseudomonas aeruginosa during human infection to that of P. aeruginosa in a variety of laboratory conditions. Several pathways, including the bacterium’s primary quorum sensing system, had significantly lower expression in human infections than in many laboratory conditions. On the other hand, multiple genes known to confer antibiotic resistance had substantially higher expression in human infection than in laboratory conditions, potentially explaining why antibiotic resistance assays in the clinical laboratory frequently underestimate resistance in patients. Using a standard machine learning technique known as support vector machines, we identified a set of genes whose expression reliably distinguished in vitro conditions from human infections. Finally, we used these support vector machines with binary classification to force P. aeruginosa mouse infection transcriptomes to be classified as human or in vitro. Determining what differentiates our current models from clinical infections is important to better understand bacterial infections and will be necessary to create model systems that more accurately capture the biology of infection.

Most people with cystic fibrosis (pwCF) develop pancreatic insufficiency and are treated with pancreatic enzyme replacement therapy (PERT). We aimed to describe the use of PERT and assess the correlates of PERT dose in adult pwCF. In a cross-sectional study at the Copenhagen CF Centre, the participants reported PERT intake, gastrointestinal (GI) symptoms and the use of concomitant treatments. Demographic and clinical characteristics were extracted from the Danish CF Registry. We used linear regression to assess the correlates of PERT dose per kg bodyweight (U-lipase/kg). We included 120 pwCF with a median age of 32.9 years, 46% women and 72% F508delta homozygote. The PERT dose ranged from 0 to 6160 U-lipase/kg per main meal (mean 1828; SD 1115). The PERT dose was associated with participants’ sex (men vs. women: 661; 95% CI: 302; 1020 U-lipase/kg), age (−16; 95% CI: −31; −1 U-lipase/kg per year) and weight (−45; 95% CI: −58; −31 U-lipase/kg per kg). Having less frequent constipation and being lung transplanted were also associated with a higher PERT dose. A third of participants did not take PERT for snacks, and this was associated with the frequency of diarrhoea. These findings indicate that PERT intake may be improved to reduce GI symptoms.

Cristen Willer, Kristian Hveem and colleagues use an exome array to identify a coding variant in TM6SF2 that is associated with total cholesterol levels. They further show that transient overexpression of TM6SF2 or knockdown of Tm6sf2 in mice alters serum lipid profiles, implicating TM6SF2 as a causal regulator of lipid traits. Blood lipid levels are heritable, treatable risk factors for cardiovascular disease. We systematically assessed genome-wide coding variation to identify new genes influencing lipid traits, fine map known lipid loci and evaluate whether low-frequency variants with large effects exist for these traits. Using an exome array, we genotyped 80,137 coding variants in 5,643 Norwegians. We followed up 18 variants in 4,666 Norwegians and identified ten loci with coding variants associated with a lipid trait ( P < 5 × 10 −8 ). One variant in TM6SF2 (encoding p.Glu167Lys), residing in a known genome-wide association study locus for lipid traits, influences total cholesterol levels and is associated with myocardial infarction. Transient TM6SF2 overexpression or knockdown of Tm6sf2 in mice alters serum lipid profiles, consistent with the association observed in humans, identifying TM6SF2 as a functional gene within a locus previously known as NCAN-CILP2-PBX4 or 19p13. This study demonstrates that systematic assessment of coding variation can quickly point to a candidate causal gene.

Objective To investigate the association between serum 25-hydroxyvitamin D concentrations (25(OH)D) and mortality in a large consortium of cohort studies paying particular attention to potential age, sex, season, and country differences.Design Meta-analysis of individual participant data of eight prospective cohort studies from Europe and the US.Setting General population.Participants 26 018 men and women aged 50-79 yearsMain outcome measures All-cause, cardiovascular, and cancer mortality.Results 25(OH)D concentrations varied strongly by season (higher in summer), country (higher in US and northern Europe) and sex (higher in men), but no consistent trend with age was observed. During follow-up, 6695 study participants died, among whom 2624 died of cardiovascular diseases and 2227 died of cancer. For each cohort and analysis, 25(OH)D quintiles were defined with cohort and subgroup specific cut-off values. Comparing bottom versus top quintiles resulted in a pooled risk ratio of 1.57 (95% CI 1.36 to 1.81) for all-cause mortality. Risk ratios for cardiovascular mortality were similar in magnitude to that for all-cause mortality in subjects both with and without a history of cardiovascular disease at baseline. With respect to cancer mortality, an association was only observed among subjects with a history of cancer (risk ratio, 1.70 (1.00 to 2.88)). Analyses using all quintiles suggest curvilinear, inverse, dose-response curves for the aforementioned relationships. No strong age, sex, season, or country specific differences were detected. Heterogeneity was low in most meta-analyses.Conclusions Despite levels of 25(OH)D strongly varying with country, sex, and season, the association between 25(OH)D level and all-cause and cause-specific mortality was remarkably consistent. Results from a long term randomised controlled trial addressing longevity are being awaited before vitamin D supplementation can be recommended in most individuals with low 25(OH)D levels.

Daniel Gudbjartsson and colleagues report a genome-wide association study for atrial fibrillation, a condition associated with increased risk of stroke. They report a variant in ZFHX3 associated with atrial fibrillation as well as ischemic stroke. We expanded our genome-wide association study on atrial fibrillation (AF) in Iceland, which previously identified risk variants on 4q25, and tested the most significant associations in samples from Iceland, Norway and the United States. A variant in the ZFHX3 gene on chromosome 16q22, rs7193343-T, associated significantly with AF (odds ratio OR = 1.21, P = 1.4 × 10 −10 ). This variant also associated with ischemic stroke (OR = 1.11, P = 0.00054) and cardioembolic stroke (OR = 1.22, P = 0.00021) in a combined analysis of five stroke samples.

Monoclonal IgG antibodies constitute the fastest growing class of therapeutics. Thus, there is an intense interest to design more potent antibody formats, where long plasma half-life is a commercially competitive differentiator affecting dosing, frequency of administration and thereby potentially patient compliance. Here, we report on an Fc-engineered variant with three amino acid substitutions Q311R/M428E/N434W (REW), that enhances plasma half-life and mucosal distribution, as well as allows for needle-free delivery across respiratory epithelial barriers in human FcRn transgenic mice. In addition, the Fc-engineered variant improves on-target complement-mediated killing of cancer cells as well as both gram-positive and gram-negative bacteria. Hence, this versatile Fc technology should be broadly applicable in antibody design aiming for long-acting prophylactic or therapeutic interventions. Antibody based biologics are a rapidly growing class of therapeutics with interest to enhance their performance, distribution, longevity and effectivity. Here, authors report the engineering of human IgG Fc to enhance plasma half-life, mucosal distribution and killing of cancer cells and bacteria.

Objective To investigate the impact of smoking and smoking cessation on cardiovascular mortality, acute coronary events, and stroke events in people aged 60 and older, and to calculate and report risk advancement periods for cardiovascular mortality in addition to traditional epidemiological relative risk measures.Design Individual participant meta-analysis using data from 25 cohorts participating in the CHANCES consortium. Data were harmonised, analysed separately employing Cox proportional hazard regression models, and combined by meta-analysis.Results Overall, 503 905 participants aged 60 and older were included in this study, of whom 37 952 died from cardiovascular disease. Random effects meta-analysis of the association of smoking status with cardiovascular mortality yielded a summary hazard ratio of 2.07 (95% CI 1.82 to 2.36) for current smokers and 1.37 (1.25 to 1.49) for former smokers compared with never smokers. Corresponding summary estimates for risk advancement periods were 5.50 years (4.25 to 6.75) for current smokers and 2.16 years (1.38 to 2.39) for former smokers. The excess risk in smokers increased with cigarette consumption in a dose-response manner, and decreased continuously with time since smoking cessation in former smokers. Relative risk estimates for acute coronary events and for stroke events were somewhat lower than for cardiovascular mortality, but patterns were similar.Conclusions Our study corroborates and expands evidence from previous studies in showing that smoking is a strong independent risk factor of cardiovascular events and mortality even at older age, advancing cardiovascular mortality by more than five years, and demonstrating that smoking cessation in these age groups is still beneficial in reducing the excess risk.

Purpose: To assess whether acute myocardial infarction (MI) diagnoses in national health registers are sufficiently correct and complete to replace manual collection of endpoint data for a population-based, epidemiological study. Patients and Methods: Using the Tromso Study Cardiovascular Disease Register for 2013-2014 as gold standard, we calculated correctness (defined as positive predictive value (PPV)) and completeness (defined as sensitivity) of MI cases in the Norwegian Myocardial Infarction Register and the Norwegian Patient Register separately and in combination. We calculated the sensitivity and PPV with 95% confidence intervals using the Clopper-Pearson Exact test. Results: We identified 153 MI cases in the gold standard. In the Norwegian Myocardial Infarction Register, we found a PPV of 97.1% (95% confidence interval (CI) 92.8-99.2) and a sensitivity of 88.2% (95% CI 82.0-92.9). In the Norwegian Patient Register, the PPV was 96.3% (95% CI 91.6-98.8) and the sensitivity was 85.6% (95% CI 79.0-90.8). The combined dataset of the Norwegian Myocardial Infarction Register and the Norwegian Patient Register had a PPV of 96.6% (95% CI 92.1-98.9) and a sensitivity of 91.5% (95% CI 85.995.4). Conclusion: MI diagnoses in both the Norwegian Myocardial Infarction Register and the Norwegian Patient Register were highly correct and complete, and each of the registers could be considered as endpoint sources for the Tromso Study. A combination of the two national registers seemed, however, to represent the most comprehensive data source overall. The benefits of using data from national registers as endpoints in epidemiological studies include faster, less resource-intensive access to nationwide data and considerably lower loss to follow-up, compared to manual data collection in a limited geographical area. Keywords: cardiovascular diseases, data quality, registers, data collection, quality control

Background The American Heart Association has proposed an impact goal for the year 2020 to improve cardiovascular health by 20%. The objectives of the study were to assess the association between the proposed cardiovascular health metric score and incident myocardial infarction (MI) and to estimate the generalized impact fraction (GIF). Methods The health metric score was derived from ideal levels of six cardiovascular risk factors from the population-based Tromsø Study of 22,121 residents of Tromsø, Norway aged 30 to 79 years, examined in 1994–95, 2001, and 2007–08. Incident events of MI were recorded from the date of enrollment in 1994–95 to the end of 2010. Adjudication of hospitalized and out-of hospital events was performed by an independent endpoints committee based on data from hospital and out-of hospital journals, autopsy records and death certificates. Cox proportional hazard regression was used to estimate hazard ratios (HR). GIF was calculated from age stratified analysis using a case-load weighted-sum method. Bootstrapping was used to estimate 95% simulation intervals. Results A total of 1652 MIs accrued over an average of 14.7 person-years of follow-up. Few men (0.96%) and women (3.6%) had ideal levels in all 6 metrics. 64.7% (men) and 55.7% (women) had ideal levels in 2 or 3 metrics. The age-adjusted HR per point increase in health score was 0.65 (95% confidence interval: 0.61, 0.70) in men and 0.59 (0.54, 0.64) in women. A shift of 30% of subjects from low score levels ≤3 to scores ≥4 was estimated to prevent 13.7% (11.2, 16.2) of incident MI in men and 15.9% (12.1, 19.4) in women. Conclusions The association between the health metric score and MI indicate that close to 15% of incident MIs could be prevented by attainable and realistic improvements in the health metrics.