Impact of pregnancy vaccine uptake and socio-demographic determinants on subsequent childhood Measles, Mumps and Rubella vaccine uptake: A UK birth cohort study

BACKGROUND

We examined the association between socio-demographic determinants and uptake of childhood Measles, Mumps & Rubella (MMR) vaccines and the association between pregnant women's pertussis vaccine uptake and their children's MMR vaccine uptake.

METHODS

We used nationally-representative linked mother-baby electronic records from the United Kingdom's Clinical-Practice-Research-Datalink. We created a birth cohort of children born between 01.01.2000 and 12.12.2020. We estimated the proportion vaccinated with first MMR vaccine by age 2 years and first and second MMR vaccines by age 5 years. We used survival-analysis and Cox proportional hazard models to examine the association between deprivation, ethnicity and maternal age and pertussis vaccination in pregnancy and children's MMR uptake.

RESULTS

Overall, 89.4 % (710,797/795,497) of children had first MMR by age 2 years and 92.6 % (736,495/795,497) by age 5 years. Among children still in the cohort when second MMR was due, 85.9 % (478,480/557,050) had two MMRs by age 5 years. Children from the most-deprived areas, children of Black ethnicity and children of mothers aged < 20 years had increased risk of being unvaccinated compared with children from the least-deprived areas, White children and children of mothers aged 31-40 years: first MMR by 5 years, adjusted Hazard Ratios (HR):0.86 (CI:0.85-0.87), HR:0.87 (CI:0.85-0.88) & HR:0.89 (CI:0.88-0.90) respectively. Deprivation was the determinant associated with the greatest risk of missed second MMR: adjusted HR:0.82 (CI:0.81-0.83). Children of mothers vaccinated in pregnancy were more likely than children of unvaccinated mothers to have MMR vaccines after adjusting for ethnicity, deprivation, and maternal age (First and Second MMRs adjusted HRs:1.43 (CI:1.41-1.45), 1.49 (CI:1.45-1.53).

CONCLUSION

Children from most-deprived areas are less likely to have MMR vaccines compared with children from least-deprived areas. Mothers who take up pregnancy vaccines are more likely to have their children vaccinated with MMR. Healthcare services should promote and facilitate access to both maternal and childhood vaccines during pregnancy.

Diagnostic performance of saliva RT-PCR test as a diagnostic tool and its utility in the detection of SARS-CoV-2 shedding with different patient characteristics: Prospective observational study

BACKGROUND

Salivary shedding of SARS-CoV-2 is a known entity and its role has been established in transmission of the disease. The present study was performed to evaluate the duration of viral shedding in saliva in COVID-19 patients and its variation among symptomatic and asymptomatic patients with or without co-morbidities.

METHODS

The present prospective observational study was conducted at the COVID-19 care hospital associated with primary to tertiary care in New Delhi, India. A total of 124 COVID-19 confirmed cases enrolled in two phases (January-March 2021; April-June 2021) who consented for 48hrly saliva and nasopharyngeal swab (NPS) specimens till discharge from the hospital for SARS-CoV-2 detection were included. The specimens obtained were tested for SARS-CoV-2 by Real-Time PCR.

RESULTS

The sensitivity and the specificity of RT-PCR on saliva were 81.7 ​% and 85.0 ​%, respectively. The sensitivity of saliva-based PCR was comparable in symptomatic and asymptomatic patients (81.6 ​% vs 82.1 ​%). The sensitivity of saliva-based PCR markedly increased in the second phase of enrollment as compared to the first phase (92.6 ​% vs 78.5 ​%) indicating higher level of salivary shedding by the delta variant of SARS-CoV-2. The sensitivity of PCR on saliva was the highest up to day seven of illness. The median duration of RNA shedding in saliva was comparable among the symptomatic and asymptomatic patients. The severity of the disease was not associated with the duration of SARS-CoV-2 shedding in saliva.

CONCLUSIONS

SARS-CoV-2 shedding in saliva continued till seven days in large number of patients including asymptomatic patients. Saliva is non-inferior to NPS specimen in the diagnosis of SARS-CoV-2. Saliva specimen is recommended as a good alternate to NPS for SARS-CoV-2 testing.

How did the covid-19 pandemic affect lower respiratory tract infections in young children in England?

Background

Social distancing policies to reduce transmission of covid-19 also reduced children's exposures to endemic respiratory viruses. We aimed to examine the impact of the covid-19 pandemic on lower respiratory tract infections in under 5s presenting to primary care in England.

Methods

Longitudinal trends analysis using electronic health records from a nationally representative primary care database. Our target population was children aged &lt;5 years registered with a primary care practice from January 2015 to March 2021.

Our main outcome was total weekly contacts with primary care for a lower respiratory tract infection (LRTI). We defined three pandemic phases from March 2020 - March 2021: i) first national lockdown (late March to early June 2020), ii) childcare settings reopened and second national lockdown with schools open (mid-June to mid-December 2020) and iii) third national lockdown with schools closed (late December 2020 to end of March 2021). We compared outcomes during each of the three phases with corresponding calendar weeks during pre-pandemic years 2015 to 2019.

Results

Our study population included 843 020 children &lt;5 years who had 1 076 181 contacts with primary care for LRTIs. During the first phase (first lockdown) there were falls of 79.3% (95% CI: 73.6 to 84.5) from an average of 28 547 primary care contacts for LRTI in 2015 - 2019 to 5915 in 2020; there was a 78.9% (95% CI: 73.7 to 83.9) fall in phase two (childcare settings reopened and second lockdown) from 107 873 to 22 792 contacts; and a 77.7% (95% CI: 73.5 to 81.4) fall in phase three (third lockdown) from 57 200 to 12 764 contacts.

Conclusions

Children under 5 in England had fewer contacts with primary care for LRTIs during the covid-19 pandemic. This change likely reflects lower prevalence of respiratory illness due to fewer social contacts. This may impact on future health service use as these children have had less exposure, and therefore may have less immunity, to respiratory diseases.

Key messages

• Children under 5 had fewer contacts with primary care for lower respiratory tract infections during the covid-19 pandemic in England likely due to the restrictions in place to reduce social contacts.

• The falls in lower respiratory tract infections during the covid-19 pandemic in under 5s may mean they have less immunity to respiratory viruses which may impact upon their future health service use.

The use of EPR spectroscopy to study transcription mechanisms

Electron paramagnetic resonance (EPR) spectroscopy has become a promising structural biology tool to resolve complex and dynamic biological mechanisms in-vitro and in-cell. Here, we focus on the advantages of continuous wave (CW) and pulsed EPR distance measurements to resolve transcription processes and protein-DNA interaction. The wide range of spin-labeling approaches that can be used to follow structural changes in both protein and DNA render EPR a powerful method to study protein-DNA interactions and structure-function relationships in other macromolecular complexes. EPR-derived data goes well beyond static structural information and thus serves as the method of choice if dynamic insight is needed. Herein, we describe the conceptual details of the theory and the methodology and illustrate the use of EPR to study the protein-DNA interaction of the copper-sensitive transcription factor, CueR.

P302 Disseminated histoplasmosis: Rare entity in immunocompromised individuals in India

 

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PM

Invasive mycoses kill more than one million people every year. The disease burden of mycoses has increased over the last 20 years and the importance of fungal disease is expected to keep increasing in the years to come. One of these mycoses, histoplasmosis, a disease caused by species of dimorphic genera, Histoplasma and is endemic in the USA, Asia, and Africa with sporadic cases reported from India. In the United States alone, 3.4 cases/100 000 people occur yearly. In India, prevalence of histoplasmosis is seen in the eastern part of the country and few cases are reported from north India. Here, we present four cases of classic progressive disseminated histoplasmosis from non-endemic central and northern parts of India.

Cases I and II: Two cases, firstly a 51-year-old male resident of Delhi, came with complaints of fever, generalized weakness and weight loss for the past 6 months, and another a 55-year-old in an apparently immunocompetent female from a non-endemic state in central India. The disease was diagnosed by bone marrow aspirate incidentally.

Cases III and IV: A 25-year-old female and a 29-year-old HIV-infected female, with chief complaints of multiple skins colored swellings on her face, neck, chest, and back and also on both limbs. Physical examination revealed multiple skin-colored papules and nodules coalescing to form large plaques on the face, neck, upper back, and chest which had overlying yellowish-brown crusting (Fig.1). Her entire face was involved with depression of the nasal bridge and madarosis. Multiple discrete 0.1-0.5 mm papules and nodules on bilateral upper and lower limbs. Patient was started on the treatment of cutaneous histoplasmosis with injection of liposomal amphotericin-B 100 mg intravenous (around 3 mg/kg/day) after pre-medication for 10 days. For both cases, capsule itraconazole 200 mg BD started for 4 days. Patient responded well to the treatment and follow-up showed improvement in the condition of the patient.

Results

In all the cases, fine needle aspirate cytology of the lesions showed plenty of inflammatory cells and macrophages in pathological microscopic examination. Microscopic examination of skin tissue revealed that macrophages comprising of yeast forms of Histoplasma have pericellular halo around them. Moreover, on long incubation of biopsy sample on SDA media plate at 27˚C, white/buff colonies with yellow-tan on the back were observed. Furthermore, microscopic examination of grown fungal culture showed mycelial septate hyphae bearing round to pear-shaped, smooth-walled broadly elliptical microconidia, or tuberculate macroconidia. In all the cases, clinical suspicion, histopathological and mycological findings (microscopy, culture and post-culture sequencing) led to a confirmatory diagnosis of progressive disseminated Histoplasmosis by H. capsulatum var. capsulatum was made.

Conclusion

In all, 3 of these cases are of progressive disseminated histoplasmosis in apparently immunocompetent patients from the non-endemic states of north India. On the contrary, one of the cases was HIV positive with mucocutaneous lesions. Disseminated histoplasmosis in immunocompetent individuals is not a rare entity, in India. High clinical suspicion and awareness regarding the pathogen are required. From the point of good patient care, an accurate diagnosis, and timely management in cases of histoplasmosis are warranted.

Alien genome mobilization and fixation utilizing an apomixis mediated genome addition (AMGA) strategy in Pennisetum to improve domestication traits of P. squamulatum

An approach to release 'frozen' variability in apomictic species using sexuality of another species, eventually its utilization in crop improvement and de-novo domestication of crop wild relatives is presented. Pennisetum squamulatum, a secondary gene pool species of pearl millet (P. glaucum), harbours many desirable traits. However, it was neither utilized to improve pearl millet fodder traits nor improvement of its own domestication traits was attempted, due to the complexities of genomes and apomictic reproduction. To overcome this, we followed an Apomixis Mediated Genome Addition (AMGA) strategy and utilized the contrasting reproductive capacities (sexuality and apomixis) of both the species to access the otherwise un-available variability embedded in P. squamulatum. Segregating population of interspecific hybrids exhibited significant variability and heterosis for desired morphological, agronomical, and nutritional traits. Elite apomictic and perennial hybrids were evaluated in breeding trials, and eventually a novel grass cultivar was released for commercial cultivation in India. The performance of newly developed cultivar was superior to other adapted perennial grasses of arid and semi-arid rangelands. Through AMGA, the sexuality of one species was successfully utilized to 'release' the 'frozen' variability embedded in another species. Subsequently, the hybrids representing desirable trait combinations were again 'fixed' utilizing the apomixis alleles from the male parent in a back-and-forth apomixis-sexual-apomixis selection cycle. This study also demonstrated the potential of AMGA to improve crop relatives through genomes introgression as well as de novo domestication of new crops from wild species.

Effects of Probiotics at the Interface of Metabolism and Immunity to Prevent Colorectal Cancer-Associated Gut Inflammation: A Systematic Network and Meta-Analysis With Molecular Docking Studies

Background

Dysbiosis/imbalance in the gut microbial composition triggers chronic inflammation and promotes colorectal cancer (CRC). Modulation of the gut microbiome by the administration of probiotics is a promising strategy to reduce carcinogenic inflammation. However, the mechanism remains unclear.

Methods

In this study, we presented a systematic network, meta-analysis, and molecular docking studies to determine the plausible mechanism of probiotic intervention in diminishing CRC-causing inflammations.

Results

We selected 77 clinical, preclinical, in vitro, and in vivo articles (PRISMA guidelines) and identified 36 probiotics and 135 training genes connected to patients with CRC with probiotic application. The meta-analysis rationalizes the application of probiotics in the prevention and treatment of CRC. An association network is generated with 540 nodes and 1,423 edges. MCODE cluster analysis identifies 43 densely interconnected modules from the network. Gene ontology (GO) and pathway enrichment analysis of the top scoring and functionally significant modules reveal stress-induced metabolic pathways (JNK, MAPK), immunomodulatory pathways, intrinsic apoptotic pathways, and autophagy as contributors for CRC where probiotics could offer major benefits. Based on the enrichment analyses, 23 CRC-associated proteins and 7 probiotic-derived bacteriocins were selected for molecular docking studies. Results indicate that the key CRC-associated proteins (e.g., COX-2, CASP9, PI3K, and IL18R) significantly interact with the probiotic-derived bacteriocins (e.g., plantaricin JLA-9, lactococcin A, and lactococcin mmfii). Finally, a model for probiotic intervention to reduce CRC-associated inflammation has been proposed.

Conclusion

Probiotics and/or probiotic-derived bacteriocins could directly interact with CRC-promoting COX2. They could modulate inflammatory NLRP3 and NFkB pathways to reduce CRC-associated inflammation. Probiotics could also activate autophagy and apoptosis by regulating PI3K/AKT and caspase pathways in CRC. In summary, the potential mechanisms of probiotic-mediated CRC prevention include multiple signaling cascades, yet pathways related to metabolism and immunity are the crucial ones.

Are children at schools registered to The Daily Mile™ more physically active?

Background

The Daily Mile (TDM) is among the most popular school-based running programmes recommended globally by governments and the WHO to meet the shortfalls in children's physical activity. In England, it has been adopted by 1 in 5 primary schools. However, its impact on children's physical activity has not been assessed at scale. We aimed to compare a)minutes (mins) of moderate to vigorous physical activity (MVPA) in and outside school hours and b)meeting physical activity guidelines in primary school children in England, comparing those in schools registered with TDM with those that were not.

Methods

This was a cross-sectional study. We used self-reported data of 49,561 English primary school children(5-11 years) from the Active Lives Children and Young People Survey and TDM registration data of their school. We compared mins of MVPA in and outside school hours between children in TDM-registered and non-registered schools using a multilevel zero-inflated negative binomial model; and the differences in the likelihood of meeting physical activity guidelines based on TDM registration with a multilevel logistic regression model. All models included a random effect for school and adjusted for potential confounders.

Results

Children attending TDM-registered schools reported an extra 36 mins of MVPA a week overall, including 10 additional mins (95%CI:3,16) MVPA/week during school hours and 26 additional (95%CI:4,44) mins MVPA/week outside school hours. Children in TDM-registered schools were 6% more likely to meet physical activity guidelines compared to those who were not(RR:1.06 (95%CI:1.02,1.11)).

Conclusions

Children in primary schools registered to TDM report more physical activity that is not compensated for outside school hours. However, the absolute differences fall considerably short of international guidelines across the whole child population. Therefore, a whole school and systems-based approach is required, embedding school-based running programmes.

Key messages

Children in schools registered to TDM report more MVPA overall, inside, and outside school hours; suggesting no compensation of activity in those who are registered. TDM is a potential solution to increase children’s physical activity during the school day.

Internalized weight bias in the relationship between mental health and obesity in UK adolescents

Background

It is crucial to promote mental and physical health during adolescence to protect against lifetime risks of mental health problems and obesity. Internalized weight bias (self-directed stigmatizing attitudes about perceived weight status) and bullying are implicated as potential mechanisms in the relationship between mental health and obesity in adolescence. We examined internalized weight bias and bullying as potential mediators of the relationship between mental health and weight status across adolescence in the United Kingdom (UK).

Methods

We analysed data on 8,688 adolescents from the UK Millennium Cohort Study. Weight status was defined using sex and age specific International Obesity Taskforce cut points for body-mass index (not overweight/obese; overweight; obese) at 11 and 17 years. Mental health was defined using parental reported emotional (anxiety and depression), and externalizing (aggression and impulsivity) symptoms at 11 and 17 years (low; moderate; high). Self-reported measures of internalized weight bias captured via body-dissatisfaction and self-esteem and bullying at 14 years were tested as mediators. We used Generalized Structural Equation Models to examine longitudinal pathways between weight status and mental health across 11 and 17 years, whilst accounting for concurrent associations and potential confounders.

Results

Adolescents with high emotional (relative risk (RR) 1.98, 95% CI 1.28 to 3.07) or externalizing symptoms (RR 2.07, 95% CI 1.23 to 3.48) at 11 years were twice as likely to be obese at 17 years compared with those who had low symptoms. The impact of emotional and externalizing symptoms on weight status was found to be partially attributable to internalized weight bias, but not bullying, with significant mediation for body-dissatisfaction and low self-esteem.

Conclusions

Internalized weight bias partially explains the relationship between mental health and weight status across adolescence.

Key messages

There is a need for a holistic, early prevention strategy to focus on reducing weight stigma to encourage healthy mental and physical development of children. The relationship between mental health and weight status across adolescence is partly attributable to internalized weight bias.

A core outcome set for school-based physical activity interventions: an international consensus

Background

Studies of school-based physical activity interventions vary in the outcomes they measure. This prevents comparisons of results to establish impacts. We aimed to develop a core outcome set agreed by key stakeholders for future studies of school-based physical activity interventions.

Methods

We used a modified-Delphi consensus method. First, we conducted a systematic review to identify outcomes measured in relevant studies and listed these in a Delphi survey. Next, we recruited key stakeholders to complete 2 survey rounds: Round 1 was to rate each outcome from ‘not important' to ‘critical', and Round 2 was to re-rate the outcomes based on feedback from Round 1. Outcomes rated ‘critical' by 70% of stakeholders (i.e., reaching consensus) were highlighted. Then, using the full list of outcomes, we conducted a children's workshop to include their views. Finally, we held a stakeholder meeting to discuss results and agree consensus.

Results

We identified 50 outcomes from the systematic review. Sixty-five stakeholders (16 educators, 13 health professionals, 12 parents, 24 researchers) representing 9 countries completed both survey rounds; 13/50 outcomes reached consensus. Children (n = 16) identified 8 outcomes of importance; 3 were consistent with the survey results. Stakeholders attending the meeting (n = 13) reached consensus on 14 outcomes to be included in the core outcome set: fitness, physical activity intensity, energy, sleep, diet, happiness, stress, depression, anxiety, wellbeing, self-esteem, enjoyment, concentration, and focus. These core outcomes were reviewed and agreed by all 65 stakeholders.

Conclusions

Our core outcome set agreed by international stakeholders includes physical and mental health, and cognitive function. We recommend its use in future studies of school-based physical activity interventions. Findings from future studies can be compared and combined which will be relevant to public health policy makers and educators.

Key messages

School-based physical activity interventions should measure physical and mental health, and cognitive function. Wide use of this core outcome set will enable findings to be compared and combined.

Implementation of The Daily Mile™: survey of primary schools in Greater London

Background

The Daily Mile™ is a free school-based active mile intervention. Its main features include that children run or jog for 15 minutes at least 3 times a week (3x/wk) during school hours. The Daily Mile Foundation recommends 10 principles for successful implementation. These are it is (1) quick (15 minutes), (2) fun, (3) whole school participates, (4) it takes place in all weathers, (5) 3x/wk in addition to curricular lessons (not during PE, breaks, before/after school), (6) ideally in the school playground, (7) safe, (8) simple (no equipment), (9) children go at their own pace and (10) no change of clothes or shoes is needed. The aim of this study was to identify how many Greater London primary schools adopting The Daily Mile implement its 10 principles.

Methods

In September 2020, we sent all state-funded primary schools (n = 1721) in every Greater London borough (n = 32) a survey to find out if and how they implemented The Daily Mile.

Results

By June 2021, 368 (21%) schools responded to our survey (at least one from every London borough). Of these, 195 (53%) schools adopted The Daily Mile of which only 7 (4%) reported implementing all 10 principles; a median 7 (IQR: 6,8) principles were reported implemented. Whole school participation was reported by 93 (48%) Daily Mile schools, 104 (53%) reported implementing The Daily Mile for 15 minutes, 127 (65%) implemented it at least 3x/wk, and 149 (76%) schools reported that the children ran or jogged during The Daily Mile. A large proportion of schools reported implementing The Daily Mile in the school playground and that it was done simply (both n = 171, 88%), but only 85 (44%) schools reported implementing it during lessons.

Conclusions

Daily Mile schools in Greater London implement 7/10 principles on average. Whether implementing all the principles limits the success of its desired effect is unclear. Studies assessing effects of The Daily Mile should consider its implementation when reporting results.

Key messages

Of The Daily Mile’s 10 principles, an average of 7 are implemented in London schools. Studies examining The Daily Mile should consider implementation which may impact its desired effect.

Outcomes of Left Bundle Branch Area Pacing for Cardiac Resynchronization Therapy: An Updated Systematic Review and Meta-analysis

BACKGROUND

Real-world data on the use of left bundle branch area pacing (LBBAP) as an alternative novel pacing strategy to biventricular pacing (BVP) for cardiac resynchronization therapy (CRT) remains scarce. We aimed to investigate the outcomes of LBBAP as an alternative to BVP as a method of CRT.

METHODS

Electronic databases were searched for studies on the use of LBBAP as CRT and studies that compared LBBAP with BVP. The main outcomes examined were changes in New York Heart Association classification, left ventricular end-diastolic diameter, left ventricular ejection fraction, and paced QRS duration post CRT device implantation.

RESULTS

Our meta-analysis included 8 nonrandomized studies with a total of 527 patients who underwent LBBAP as CRT. In studies with a BVP comparison group, patients with LBBAP had a greater reduction in paced QRS (mean difference [MD], 27.91 msec; 95% confidence interval [CI], 22.33-33.50), and a greater improvement in New York Heart Association class (MD, 0.59; 95% CI, 0.28-0.90) and left ventricular ejection fraction (MD, 6.77%; 95% CI, 3.84-9.71). Patients with underlying left bundle branch block appeared to benefit the most from LBBAP compared with patients without underlying left bundle branch block.

CONCLUSIONS

LBBAP might be a reasonable option for patients who meet indications for CRT, particularly in those who have limited anatomy or do not benefit from CRT. Randomized trials are needed to compare LBBAP with BVP for CRT and to identify which populations might benefit the most from LBBAP.

Efficacy and tolerability of eslicarbazepine acetate as monotherapy in patients of newly diagnosed focal epilepsy

Introduction

Eslicarbazepine Acetate, a novel anti-epileptic drug has been approved as monotherapy in focal onset seizures, with/without secondary generalization in adults. Eslicarbazepine has many advantages over older anti-epileptic drugs and is useful in patients of new onset focal epilepsy.

Objectives

Aim of our study was to determine the efficacy and safety of Eslicarbazepine Acetate, observe its well-tolerated use and monitor adverse effects in newly diagnosed patients of focal epilepsy.

Methods

Study was done at Department of Psychiatry, Teerthanker Mahaveer University, Moradabad. A total of 30 newly diagnosed cases of focal epilepsy between 18-60 years of age were studied for 6 months, using a Semi-structured Interview and Liverpool Adverse Events Profile.

Results

Majority of patients were males (58%), between 21-30 years. Patients with partial/focal seizures (63%) were more common than those of generalized seizures (37%). Majority of the participants had 1-2 episodes of focal seizures weekly(48%), while some had almost daily(32%). Majority were on Eslicarbazepine Acetate 800 mg in two divided doses daily (64%), while the others received 1200 mg in three divided doses(32%). The mean Liverpool Adverse Events Profile score initially was 28.34 ± 6.28 which significantly improved after 4 weeks treatment to 22.80 ± 4.35 (p < 0.05). The improvement in newly diagnosed focal seizures patients was significantly more than other patients (p < 0.05). No major side effects were observed.

Conclusions

Eslicarbazepine Acetate as a monotherapy is effective in treating focal epilepsy. Better results of this drug are found in newly diagnosed focal epilepsy patients.

Disclosure

No significant relationships.

Dynamics of noise-induced wave-number selection in the stabilized Kuramoto-Sivashinsky equation

We revisit the question of wave-number selection in pattern-forming systems by studying the one-dimensional stabilized Kuramoto-Sivashinsky equation with additive noise. In earlier work, we found that a particular periodic state is more probable than all others at very long times, establishing the critical role of noise in the selection process. However, the detailed mechanism by which the noise picked out the selected wave number was not understood. Here, we address this issue by analyzing the noise-averaged time evolution of each unstable mode from the spatially homogeneous state, with and without noise. We find drastic differences between the nonlinear dynamics in the two cases. In particular, we find that noise opposes the growth of Eckhaus modes close to the critical wave number and boosts the growth of Eckhaus modes with wave numbers smaller than the critical wave number. We then hypothesize that the main factor responsible for this behavior is the excitation of long-wavelength (q→0) modes by the noise. This hypothesis is confirmed by extensive numerical simulations. We also examine the significance of the magnitude of the noise.

Ten-year fracture risk predicted by proximal femur Hounsfield units

Colon cancer screening occurs at younger ages than osteoporosis screening. Bone density measurements using virtual colonoscopy performed for colon cancer screening can provide an early warning sign of patients at potential risk for osteoporosis-related fractures. Earlier identification may improve treatment and potentially fracture prevention.

INTRODUCTION

Opportunistic osteoporosis screening with computed tomography colonography (CTC) offers an opportunity to capitalize on earlier colorectal cancer screening to identify patients at risk of future fractures. The purpose of this study is to evaluate 10-year fracture and specifically hip fracture risk based on Hounsfield units (HU) obtained from CTC.

METHODS

We identified all CTC scans between 2004 and 2007 of patients 40 years and older with 10 years minimum follow-up. Hounsfield units were measured within the proximal femur and fractures identified via worldwide military records. Patients were stratified into two cohorts based on the presence or lack of a fracture in the wrist, spine, hip, or proximal humerus. Hounsfield unit measurements were compared between groups using Student's t test and the HU threshold was calculated that best approximated an 80% sensitivity to optimally screen patients for fracture risk. The odds ratio, negative predictive value, 10-year incidence of fracture, and survival curves were calculated.

RESULTS

We identified 3711 patients with 183 fractures over 10 years. The HU threshold that corresponded with an 80% sensitivity to identify fractures was 112 HU. The negative predictive value (NPV) for overall fractures and hip fractures was over 97%. The 10-year fracture incidence was higher in patients below 112 HU compared to those above for both overall fractures (6.3% vs 1.7%) and hip fractures (2.7% vs 0.07%). The 112 HU threshold corresponds with an odds ratio for overall fracture and hip fractures of 2.5 (95% confidence interval (CI), 1.7-3.6) and 24.5 (95% CI, 3.3-175.5), respectively.

CONCLUSION

In the 10 years following CTC, patients who experienced a fracture had lower hip HU. Decreasing HU on CTC may be an early warning sign of fracture potential.