Multiancestry association study identifies new asthma risk loci that colocalize with immune-cell enhancer marks

We examined common variation in asthma risk by conducting a meta-analysis of worldwide asthma genome-wide association studies (23,948 cases, 118,538 controls) from ethnically-diverse populations. We identified five new asthma loci, uncovered two additional novel associations at two known asthma loci, established asthma associations at two loci implicated previously in comorbidity of asthma plus hay fever, and confirmed nine known loci. Investigation of pleiotropy showed large overlaps in genetic variants with autoimmune and inflammatory diseases. Enrichment of asthma risk loci in enhancer marks, especially in immune cells, suggests a major role of these loci in the regulation of immune-related mechanisms.

Lung function discordance in monozygotic twins and associated differences in blood DNA methylation

Background

Lung function is an important predictor of morbidity and mortality, with accelerated lung function decline reported to have immense consequences for the world's healthcare systems. The lung function decline across individual's lifetime is a consequence of age-related changes in lung anatomical structure and combination of various environmental factors; however, the exact molecular mechanisms contributing to this decline are not fully understood. DNA methylation is an epigenetic modification that changes across individual's lifetime, as well as allows for interplay between environmental and genetic factors. DNA methylation plays a crucial role in regulation of gene expression, with increasing evidence linking aberrant DNA methylation levels with a number of common human diseases. In this study, we investigated possible associations between genome-wide DNA methylation levels and lung function in 169 pairs of middle-aged monozygotic twins (86 male pairs: mean age (min-max) = 66 years (57-79); 83 female pairs: mean age (min-max) = 66 years (56-78)). The twins were collected from the Danish Twin Registry and were examined at baseline (1998-1999) and follow-up (2008-2011) visits. Using the twin design, we correlated intra-pair differences in cross-sectional and longitudinal lung function with intra-pair blood DNA methylation differences at follow-up by linear regression analyses adjusted for sex, age, BMI, smoking, and blood cell composition measured for each individual with the use of flow cytometry.

Results

We identified several differentially methylated CpG sites associated with forced expiratory volume the first second (FEV1) and forced vital capacity (FVC). Three probes identified for level of FVC were located in GLIPR1L2 gene (lowest p value = 7.14 × 10-8), involved in innate immunity and tumour-suppressor/pro-oncogenic mechanisms. Change in FEV1 during the 11-year follow-up period was associated with blood DNA methylation level in TRIM27 gene (p value = 1.55 × 10-6), a negative regulator of CD4 T cells, and also involved in cancer development. Several enriched pathways were identified, especially for FEV1, with one being "TGFBR" (Benjamini-Hochbergadjp value = 0.045), the receptor for TGFβ, a growth factor involved in normal lung tissue repair through pro-fibrotic effects.

Conclusions

Our findings suggest that epigenetic regulation of immunological- and cancer-related genes, as well as TGF-β-receptor-related genes, may be involved in the cross-sectional level and longitudinal change in lung function in middle-aged monozygotic twins.

No apparent transmission of livestock-associated methicillin-resistant Staphylococcus aureus CC398 in a survey of staff at a regional Danish hospital

Background

In recent years, livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) multi locus sequence type CC398 has spread widely in the livestock production in Europe. The rates of LA-MRSA in hospitals have been found to be largely determined by contact to and density of livestock in the area.

Methods

This is a cross sectional study of the prevalence of LA-MRSA among hospital staff in a Danish hospital situated in a livestock production region. We analysed nasal swabs, air and dust samples for the presence of MRSA using PCR and mass spectrometry.

Results

Of 1745 employees, 545 (31%) contributed nasal swabs. MRSA was not detected in any participant, nor was it detected in air or dust at the hospital or in houses of employees living on farms. Four percent of the participants had contact to pigs either directly or through household members. LA-MRSA was detected in two of 26 samples from animal sheds, both of them from pig farms. The participation rate was relatively low, but participants were representative for the source population with regards to animal contact and job titles.

Conclusions

The study suggests a low point prevalence of LA-MRSA carriage in Danish hospital staff even in regions where livestock production is dense. Should more studies confirm our findings we see no need for additional hospital precautions towards LA-MRSA in Denmark at the moment. We think that our data might reduce potential stigmatization of hospital workers with contact to LA-MRSA positive farms at their work places and in their communities.

Electronic supplementary material

The online version of this article (10.1186/s13756-017-0284-y) contains supplementary material, which is available to authorized users.

The impact of different spirometric definitions on the prevalence of airway obstruction and their association with respiratory symptoms

The fixed ratio criterion of forced expiratory volume in 1 s/forced vital capacity <0.70 for diagnosing airway obstruction may overdiagnose the condition, particularly in the elderly, so the lower limit of normal (LLN) is recommended as the most appropriate criterion. Our aim was to compare LLN versus fixed ratio on the prevalence of chronic obstructive pulmonary disease (COPD) and examine the association between respiratory symptoms and airway obstruction defined by LLN and fixed ratio. 12 449 twins aged 40-80 years participated in a nationwide survey using the Danish Twin Registry. They completed a questionnaire, underwent clinical examination and recorded prebronchodilator spirometry. Individuals with self-reported asthma were excluded. Clinical COPD was defined by respiratory symptoms together with airway obstruction. 10 329 individuals were included, with a mean±sd age of 58.4±9.6 years and mean body mass index of 26.6±4.4 kg·m-2; 20% were current smokers, 37% former smokers and 43% never-smokers; and 48% were male. The prevalence of LLN airway obstruction (LLN-AO) and fixed ratio airway obstruction (FR-AO) was 5.6% and 18.0%, respectively (p<0.001). Overall, 26% reported current respiratory symptoms, but 50% of those with LLN-AO had respiratory symptoms compared to 39% with FR-AO, p<0.001. The prevalence of clinical LLN-COPD and fixed ratio COPD was 2.6% and 6.3%, respectively (p<0.001). Individuals with LLN-AO had a significantly higher probability of reporting respiratory symptoms compared with both healthy individuals and FR-AO when adjusted for sex, age and ever-smoking. The use of fixed ratio more than doubled the prevalence of clinical COPD compared with LLN, this being more pronounced with increased age, and identified subjects with a lower prevalence of respiratory symptoms than LLN-AO.

High exposure to endotoxin in farming is associated with less new-onset pollen sensitisation

OBJECTIVES

Little is known about risk factors for new onset and loss of atopic sensitisation in adulthood. The aim is to examine the longitudinal effect of quantitatively assessed endotoxin exposures on changes in specific allergen sensitisation in young adults.

METHODS

The cohort consisted of 1113 young Danish farmers and rural controls, with a mean age of 19 years at baseline. Sensitisation to birch pollen, grass pollen, cat dander and house dust mite was measured by specific IgE levels in serum samples from baseline and at 15 years' follow-up. Changes in sensitisation were analysed in relation to cumulative endotoxin exposure during follow-up, considering early life farm exposure.

RESULTS

Endotoxin exposure during follow-up was significantly associated with less new onset of specifically grass and birch pollen sensitisation. For the highest versus lowest quartile of cumulative endotoxin exposure, the OR for new-onset IgE sensitisation was 0.35 (0.13-0.91) for birch and 0.14 (0.05-0.50) for grass. On the other hand, loss of pollen sensitisation showed a positive, although mostly non-significant, association with increased levels of endotoxin exposure. Endotoxin exposure was not associated with significant changes in cat dander and house dust mite sensitisation.

CONCLUSIONS

High exposure to endotoxin during young adulthood appears to protect against new onset of pollen sensitisation, independent of childhood farm exposure.

Allergen exposure chambers: harmonizing current concepts and projecting the needs for the future - an EAACI Position Paper

BACKGROUND

Allergen exposure chambers (AECs) are clinical facilities allowing for controlled exposure of subjects to allergens in an enclosed environment. AECs have contributed towards characterizing the pathophysiology of respiratory allergic diseases and the pharmacological properties of new therapies. In addition, they are complementary to and offer some advantages over traditional multicentre field trials for evaluation of novel therapeutics. To date, AEC studies conducted have been monocentric and have followed protocols unique to each centre. Because there are technical differences among AECs, it may be necessary to define parameters to standardize the AECs so that studies may be extrapolated for driving basic immunological research and for marketing authorization purposes by regulatory authorities.

METHODS

For this task force initiative of the European Academy of Allergy and Clinical Immunology (EAACI), experts from academia and regulatory agencies met with chamber operators to list technical, clinical and regulatory unmet needs as well as the prerequisites for clinical validation.

RESULTS

The latter covered the validation process, standardization of challenges and outcomes, intra- and interchamber variability and reproducibility, in addition to comparability with field trials and specifics of paediatric trials and regulatory issues.

CONCLUSION

This EAACI Position Paper aims to harmonize current concepts in AECs and to project unmet needs with the intent to enhance progress towards use of these facilities in determining safety and efficacy of new therapeutics in the future.

Re-examining the association between residential exposure to magnetic fields from power lines and childhood asthma in the Danish National Birth Cohort

Background

A study reported an increased risk of asthma in children whose mothers were exposed to magnetic field (MF) levels above 0.2 μT during pregnancy. We re-examined this association using data from mothers and children in the Danish National Birth Cohort (DNBC).

Methods

This study included 92,676 singleton-born children and their mothers from the DNBC. MF exposure from power lines was estimated for all residences where the mothers lived during pregnancy and for all children from birth until the end of follow up. Exposure was categorized into 0 μT, 0.1 μT, and ≥ 0.2 μT for analysis. Definitive and possible asthma cases were identified using data from three independent data sources: 1) mothers’ reports, 2) a national hospitalization register, 3) a national prescription drug register. We calculated hazard ratios (HR) and 95% confidence intervals (CI) for the association between the highest level of exposure during pregnancy and asthma in children, adjusting for several potential confounding factors. We also examined the sensitivity of the risk estimates to changes in exposure and outcome definitions.

Results

No differences or trends in the risk of asthma development were detected between children with different levels of MF exposure regardless of the asthma case definition or outcome data source. For definitive cases, the HR (95% CI) for those with any exposure was 0.72 (0.27–1.92), and it was 0.41 (0.06–2.92) for those exposed to ≥ 0.2 μT. Adjustments for confounding and variations in the exposure definition did not appreciably alter the results.

Conclusion

We did not find evidence that residential exposure to MF during pregnancy or early childhood increased the risk of childhood asthma. This interpretation is in line with the lack of an established biological mechanism directly linking MF exposure to asthma, but high exposure was very rare in this cohort.

Clinical markers of asthma and IgE assessed in parents before conception predict asthma and hayfever in the offspring

BACKGROUND

Mice models suggest epigenetic inheritance induced by parental allergic disease activity. However, we know little of how parental disease activity before conception influences offspring's asthma and allergy in humans.

OBJECTIVE

We aimed to assess the associations of parental asthma severity, bronchial hyperresponsiveness (BHR), and total and specific IgEs, measured before conception vs. after birth, with offspring asthma and hayfever.

METHODS

The study included 4293 participants (mean age 34, 47% men) from the European Community Respiratory Health Survey (ECRHS) with information on asthma symptom severity, BHR, total and specific IgEs from 1991 to 1993, and data on 9100 offspring born 1972-2012. Adjusted relative risk ratios (aRRR) for associations of parental clinical outcome with offspring allergic disease were estimated with multinomial logistic regressions.

RESULTS

Offspring asthma with hayfever was more strongly associated with parental BHR and specific IgE measured before conception than after birth [BHR: aRRR = 2.96 (95% CI: 1.92, 4.57) and 1.40 (1.03, 1.91), respectively; specific IgEs: 3.08 (2.13, 4.45) and 1.83 (1.45, 2.31), respectively]. This was confirmed in a sensitivity analysis of a subgroup of offspring aged 11-22 years with information on parental disease activity both before and after birth.

CONCLUSION & CLINICAL RELEVANCE

Parental BHR and specific IgE were associated with offspring asthma and hayfever, with the strongest associations observed with clinical assessment before conception as compared to after birth of the child. If the hypothesis is confirmed in other studies, parental disease activity assessed before conception may prove useful for identifying children at risk for developing asthma with hayfever.

The effect of organic dust exposure on long-term change in lung function: a systematic review and meta-analysis

Lung function is a predictor of morbidity and mortality, and the chronic nature of lung function decline allows for preventive initiatives. Proinflammatory constituents of organic dust are considered a possible cause of compromised respiratory health. The aim of this systematic review was to reveal the impact of organic dust exposure on long-term change in lung function. The literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Predefined criteria concerned study design: longitudinal, ≥1 year follow-up, ≥50 exposed; exposure measures: organic dust, measured or estimated, in different occupational settings; and outcome measures: change in lung function measured by spirometry. Based on these criteria, 1580 potentially relevant publications were narrowed down to 20 included publications. Quality was evaluated and discussed based on six objectively defined criteria. Overall, 14 studies found some type of association between exposure to organic dust and long-term change in lung function. However, the results were inconsistent and no specific work exposure showed more clear associations to change in lung function. Meta-analysis revealed an overall small significant excess loss in forced expiratory volume in the 1st s for exposed compared with controls of 4.92 mL/year (95% CI 0.14 to 9.69). No significant association was seen overall for forced vital capacity. 12 studies revealed a significant exposure-response relation between organic dust and change in lung function. The results were inconsistent across varying study design and different exposure measures and outcomes. We therefore conclude that there is limited evidence of a causal association between general exposure to organic dust and long-term excess decline in lung function.

Risk factors for incident asthma and COPD in a cohort of young adults

INTRODUCTION

The aim of the study was to describe potential shared risk factors for incident asthma and COPD in a population-based, 9-year follow-up study.

METHODS

From a cohort of 1191 individuals, aged 20-44, who participated in baseline survey including spirometry, bronchial challenge, and skin prick test (SPT) 742 subjects (62%) were reexamined at follow-up in 2012-2014.

RESULTS

A total of 27 incident cases of asthma and 22 cases of COPD were identified at follow-up corresponding to an incidence rate of 5.8 (95% CI 3.9-8.4) and 3.5 (2.2-5.3) per 1000 person years, respectively. Among the identified COPD cases a total of 12 were Asthma-COPD Overlap Syndrome (ACOS). Atopy defined by positive SPT was a risk factor for asthma in males (OR 7.54; 95% CI 1.24-45.90), whereas risk factors in females were nasal allergy (3.81; 1.20-12.11), FEV₁ <100% predicted (3.96; 1.07-14.62) and parental asthma (3.06; 1.00-9.40). Risk factors for COPD in males were bronchial hyperresponsiveness (23.13; 1.41-380.50) and FEV₁ <100% predicted (all male cases had FEV₁ <100% predicted) and in females current smoking (3.34; 1.16-9.59) and asthma at baseline (5.21; 1.48-18.34).

CONCLUSIONS

No shared risk factors for incident asthma and COPD were found. Despite low power when stratifying by sex risk factors for incident asthma and COPD emphasize considerable gender differences.

A joint ERS/ATS policy statement: what constitutes an adverse health effect of air pollution? An analytical framework

The American Thoracic Society has previously published statements on what constitutes an adverse effect on health of air pollution in 1985 and 2000. We set out to update and broaden these past statements that focused primarily on effects on the respiratory system. Since then, many studies have documented effects of air pollution on other organ systems, such as on the cardiovascular and central nervous systems. In addition, many new biomarkers of effects have been developed and applied in air pollution studies.This current report seeks to integrate the latest science into a general framework for interpreting the adversity of the human health effects of air pollution. Rather than trying to provide a catalogue of what is and what is not an adverse effect of air pollution, we propose a set of considerations that can be applied in forming judgments of the adversity of not only currently documented, but also emerging and future effects of air pollution on human health. These considerations are illustrated by the inclusion of examples for different types of health effects of air pollution.

Occupational lung diseases: from old and novel exposures to effective preventive strategies

Occupational exposure is an important, global cause of respiratory disease. Unlike many other non-communicable lung diseases, the proximal causes of many occupational lung diseases are well understood and they should be amenable to control with use of established and effective approaches. Therefore, the risks arising from exposure to silica and asbestos are well known, as are the means of their prevention. Although the incidence of occupational lung disease has decreased in many countries, in parts of the world undergoing rapid economic transition and population growth-often with large informal and unregulated workforces-occupational exposures continue to impose a heavy burden of disease. The incidence of interstitial and malignant lung diseases remains unacceptably high because control measures are not implemented or exposures arise in novel ways. With the advent of innovative technologies, new threats are continually introduced to the workplace (eg, indium compounds and vicinal diketones). In developed countries, work-related asthma is the commonest occupational lung disease of short latency. Although generic control measures to reduce the risk of developing or exacerbating asthma are well recognised, there is still uncertainty, for example, with regards to the management of workers who develop asthma but remain in the same job. In this Review, we provide recommendations for research, surveillance, and other action for reducing the burden of occupational lung diseases.

A systematic review of occupational exposure to coal dust and the risk of interstitial lung diseases

Objective: Exposure to coal dust can cause interstitial lung disease (ILD), but whether this is due to pure coal or to the contents of quartz in coal is less clear. Here, we systematically reviewed the relation between 'pure coal' and ILD. Methods: In a systematic review based on PRISMA criteria 2945 articles were identified. Strict eligibility criteria, which evaluated the 'pure coal effect', led to the inclusion of only nine studies. Results: Among these nine studies six studies indicated an independent effect of the non-quartz part of coal on the development and progression of ILD, two did not demonstrate an effect and one was inconclusive. Conclusions: Although an independent effect of non-quartz coal dust on the development of ILD is supported, due to methodological limitations the evidence is limited and further evidence is needed.

A Comparison between Temperature-Controlled Laminar Airflow Device and a Room Air-Cleaner in Reducing Exposure to Particles While Asleep

People spend approximately one third of their life sleeping. Exposure to pollutants in the sleep environment often leads to a variety of adverse health effects, such as development and exacerbation of asthma. Avoiding exposure to these pollutants by providing a sufficient air quality in the sleep environment might be a feasible method to alleviate these health symptoms. We performed full-scale laboratory measurements using a thermal manikin positioned on an experimental bed. Three ventilation settings were tested: with no filtration system operated, use of portable air cleaner and use of a temperature-controlled laminar airflow (TLA) device. The first part of the experiment investigated the air-flow characteristics in the breathing zone. In the second part, particle removal efficiency was estimated. Measured in the breathing zone, the room air cleaner demonstrated high turbulence intensity, high velocity and turbulence diffusivity level, with a particle reduction rate of 52% compared to baseline after 30 minutes. The TLA device delivered a laminar airflow to the breathing zone with a reduction rate of 99.5%. During a periodical duvet lifting mimicking a subject's movement in bed, the particle concentration was significantly lower with the TLA device compared to the room air cleaner. The TLA device provided a barrier which significantly reduced the introduction of airborne particles into the breathing zone. Further studies should be conducted for the understanding of the transport of resuspended particles between the duvet and the laying body.

A clear urban-rural gradient of allergic rhinitis in a population-based study in Northern Europe

BACKGROUND

The protective effect of farm upbringing on allergic rhinitis is well known, but how upbringing in other environments influences the development of allergic rhinitis is scarcely investigated. The aim of this study was to investigate the association between place of upbringing and pet keeping in childhood and allergic rhinitis and nasal symptoms in adulthood.

METHODS

The population-based Respiratory Health in Northern Europe study includes subjects from Denmark, Norway, Sweden, Iceland, and Estonia born in 1945-1973. This paper analyses 13,376 participants of the third study wave. Six categories of place of upbringing were defined: farm with livestock, farm without livestock, village in rural area, small town, city suburb, and inner city. Pets in the home at birth and during childhood were recorded. Data were analysed using adjusted logistic regression models.

RESULTS

Livestock farm upbringing predicted less adult allergic rhinitis [odds ratio (OR) 0.68, 0.54-0.85] and nasal symptoms (OR 0.82, 0.68-0.99) than city upbringing, and an urban-rural gradient with decreasing risk per level of urbanisation was observed (OR 0.92, 0.88-0.94). Pets in the home at birth (OR 0.78, 0.68-0.88) and during childhood (OR 0.83, 0.74-0.93) were associated with less subsequent allergic rhinitis. Pet keeping did not explain the protective effect of place of upbringing.

CONCLUSION

Risk of allergic rhinitis and nasal symptoms in adulthood was inversely associated with the level of urbanisation during upbringing. Pets at birth decreased the risk further, but did not explain the urban-rural gradient. Persistent beneficial effects of microbial diversity in early life might be an explanation for the findings.

Trends in cell phone use among children in the Danish national birth cohort at ages 7 and 11 years

We prospectively examined trends in cell phone use among children in the Danish National Birth Cohort. Cell phone use was assessed at ages 7 and 11 years, and we examined use patterns by age, by year of birth, and in relation to specific individual characteristics. There was an increase in cell phone use from age 7 (37%) to 11 years (94%). There was a clear pattern of greater reported cell phone use among children at age 7 years with later birth year, but this trend disappeared at age 11. Girls and those who used phones at age 7 talked more often and for longer durations at age 11 years. Low socio-economic status and later year of birth were associated with voice calls at age 7 but not at age 11 years. At age 11 most used cell phones for texting and gaming more than for voice calls. Further, children who started using cell phones at age 7 years were more likely to be heavy cell phone voice users at age 11 years, making early use a marker for higher cumulative exposure regardless of year of birth. As cell phone technology continues to advance, new use patterns will continue to emerge, and exposure assessment research among children must reflect these trends.

The Danish urban-rural gradient of allergic sensitization and disease in adults

BACKGROUND

The reported prevalence of allergic sensitization among children is lower in rural areas than in urban areas of the world. The aim was to investigate the urban-rural differences of allergic sensitization to inhalant allergens in adults depending on childhood exposure living in an industrialized country as Denmark.

METHODS

A total of 1236 male participants of 30-40 years of age recruited from two epidemiological studies were divided into four groups with regard to place of upbringing; city, town, rural area and farm. Allergic sensitization was assessed by skin prick tests (SPTs) to 10 inhalant allergens and measurements of serum specific IgE (sIgE) to four inhalant allergens (grass, birch, cat and house dust mite).

RESULTS

The prevalence of allergic sensitization to inhalant allergens decreased with decreasing degree of urbanized childhood. The risk of being sensitized to one or more allergens also decreased with decreasing degree of urbanized upbringing measured by sIgE to 4 common allergens as odds ratio with 95% confidence intervals with city as reference; town 0.60 (0.39-0.92), rural area 0.34 (0.22-0.52) and farm 0.31 (0.21-0.46). Furthermore, it was measured by SPT to 10 common allergens; town 0.52 (0.33-0.84), rural area 0.34 (0.21-0.53) and farm 0.29 (0.19-0.45). This urban-rural association was also seen for the risk of sensitization to specific allergens, rhinitis and allergic asthma.

CONCLUSION

This is the first study to show an urban-rural gradient of overall allergic sensitization and specific allergen sensitization in adults depending on their childhood exposure. In this highly homogenous western population, exposure to a less urbanized childhood was associated with lower risk of allergic sensitization and disease as an adult.

Cotton Dust Exposure and Respiratory Disorders among Textile Workers at a Textile Company in the Southern Part of Benin

The textile industry sector occupies a prominent place in the economy of Benin. It exposes workers to several occupational risks, including exposure to cotton dust. To assess the effect of exposure to cotton dust on the health of workers, this study was initiated and conducted in a Beninese cotton industry company. The objective of the study was to evaluate the respiratory disorders among the textile workers exposed to cotton dust and the cross-sectional study involved 656 subjects exposed to cotton dust and 113 non-exposed subjects. The methods used are mainly based on a survey using a questionnaire of organic dust designed by the International Commission of Occupational Health (ICOH); and on the measures of lung function parameters (FEV₁ and FVC). The main results of the different analyzes revealed that subjects exposed to cotton dust have more respiratory symptoms than unexposed subjects (36.9% vs. 21.2%). The prevalence of chronic cough, expectorations, dyspnoea, asthma and chronic bronchitis are 16.8%, 9.8%, 17.3%, 2.6%, and 5.9% respectively among the exposed versus 2.6%, 0.8%, 16.8%, 0% and 0.8% among the unexposed subjects. The prevalence of byssinosis is 44.01%.The prevalence of symptoms is dependent on the sector of activity and the age of the subject. These results should encourage medical interventions and technical prevention especially since the textile industry occupies an important place in the Benin's economy.

Self-reported exposure to traffic pollution in relation to daytime sleepiness and habitual snoring: a questionnaire study in seven North-European cities

OBJECTIVE/BACKGROUND

Little is known about associations between traffic exposure and sleep disturbances. We examined if self-reported exposure to traffic is associated with habitual snoring and daytime sleepiness in a general population.

METHODS

In the RHINE III study, 12184 adults answered questions on sleep disturbances and traffic exposure. We analysed bedrooms near roads with traffic, bedrooms with traffic noise, and travelling regularly along busy roads as proxies for traffic exposures, using logistic regression. Adjustment factors were study centre, gender, age, smoking habits, educational level, body mass index, physical activity, obstructive sleep apnoea, and sleep duration.

RESULTS

One in ten lived near a busy road, 6% slept in a bedroom with traffic noise, and 11% travelled regularly along busy roads. Habitual snoring affected 25% and daytime sleepiness 21%. More men reported snoring and more women reported daytime sleepiness. Having a bedroom with traffic noise was associated with snoring (adjusted OR 1.29, [95% CI 1.12, 1.48]). For daytime sleepiness, on the other hand, bedroom with traffic noise and high exposure to traffic pollution have significant risk factors (adjusted ORs 1.46 [1.11, 1.92] and 1.65 [1.11, 2.45]). Results were consistent across study centres.

CONCLUSIONS

Daytime sleepiness is associated with traffic pollution and traffic noise, while habitual snoring is only associated with traffic noise. Self-reported traffic exposure should be taken into account when diagnosing and planning treatment for patients with sleep disturbances, because reducing noise and pollution exposure in the bedroom may have a beneficial effect.

Validation of self-reported figural drawing scales against anthropometric measurements in adults

OBJECTIVE

The aim of the present study was to validate figural drawing scales depicting extremely lean to extremely obese subjects to obtain proxies for BMI and waist circumference in postal surveys.

DESIGN

Reported figural scales and anthropometric data from a large population-based postal survey were validated with measured anthropometric data from the same individuals by means of receiver-operating characteristic curves and a BMI prediction model.

SETTING

Adult participants in a Scandinavian cohort study first recruited in 1990 and followed up twice since.

SUBJECTS

Individuals aged 38-66 years with complete data for BMI (n 1580) and waist circumference (n 1017).

RESULTS

Median BMI and waist circumference increased exponentially with increasing figural scales. Receiver-operating characteristic curve analyses showed a high predictive ability to identify individuals with BMI > 25·0 kg/m2 in both sexes. The optimal figural scales for identifying overweight or obese individuals with a correct detection rate were 4 and 5 in women, and 5 and 6 in men, respectively. The prediction model explained 74 % of the variance among women and 62 % among men. Predicted BMI differed only marginally from objectively measured BMI.

CONCLUSIONS

Figural drawing scales explained a large part of the anthropometric variance in this population and showed a high predictive ability for identifying overweight/obese subjects. These figural scales can be used with confidence as proxies of BMI and waist circumference in settings where objective measures are not feasible.