| 1. |
- Benediktsdottir, Asdis, et al.
(author)
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Ambient noise tomography of Eyjafjallajokull volcano, Iceland
- 2017
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In: Journal of Volcanology and Geothermal Research. - : Elsevier BV. - 0377-0273 .- 1872-6097. ; 347, s. 250-263
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Journal article (peer-reviewed)abstract
- We present a shear-velocity model for the Eyjafjallajokull stratovolcano, based on ambient seismic noise tomography applied to seven months of data from six permanent stations and -10 temporary seismic stations, deployed during and after the 2010 volcanic unrest. Vertical components of noise were cross correlated resulting in 30 robust phase-velocity dispersion curves between 1.6 and 6.5 s in period, displaying a +/- 20% variation in phase velocity beneath the volcano. The uneven distribution of noise sources, evaluated using signal-to-noise ratios, was estimated to cause less than 2% error in most curves. Sensitivity kernels showed resolution down to 10 km and the lateral resolution of the resulting phase-velocity maps was about 5 km. The model reveals east-west oriented high-velocity anomalies due east and west of the caldera. Between these a zone of lower velocity is identified, coinciding with the location of earthquakes that occurred during the summit eruption in April 2010. A shallow, southwest elongated low-velocity anomaly is located 5 km southwest of the caldera. The limited depth resolution of the shear-velocity model precludes detection of melt within the volcano.
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| 2. |
- Bjornsdottir, Erla, et al.
(author)
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Quality of life among untreated sleep apnea patients compared with the general population and changes after treatment with positive airway pressure
- 2015
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In: Journal of Sleep Research. - : Wiley. - 0962-1105 .- 1365-2869. ; 24:3, s. 328-338
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Journal article (peer-reviewed)abstract
- Obstructive sleep apnea leads to recurrent arousals from sleep, oxygen desaturations, daytime sleepiness and fatigue. This can have an adverse impact on quality of life. The aims of this study were to compare: (i) quality of life between the general population and untreated patients with obstructive sleep apnea; and (ii) changes of quality of life among patients with obstructive sleep apnea after 2 years of positive airway pressure treatment between adherent patients and non-users. Propensity score methodologies were used in order to minimize selection bias and strengthen causal inferences. The enrolled obstructive sleep apnea subjects (n = 822) were newly diagnosed with moderate to severe obstructive sleep apnea who were starting positive airway pressure treatment, and the general population subjects (n = 742) were randomly selected Icelanders. The Short Form 12 was used to measure quality of life. Untreated patients with obstructive sleep apnea had a worse quality of life when compared with the general population. This effect remained significant after using propensity scores to select samples, balanced with regard to age, body mass index, gender, smoking, diabetes, hypertension and cardiovascular disease. We did not find significant overall differences between full and non-users of positive airway pressure in improvement of quality of life from baseline to follow-up. However, there was a trend towards more improvement in physical quality of life for positive airway pressure-adherent patients, and the most obese subjects improved their physical quality of life more. The results suggest that co-morbidities of obstructive sleep apnea, such as obesity, insomnia and daytime sleepiness, have a great effect on life qualities and need to be taken into account and addressed with additional interventions.
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| 3. |
- Broström, Erika, et al.
(author)
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The prevalence of chronic airflow obstruction in three cities in the Nordic-Baltic region
- 2018
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In: Respiratory Medicine. - : Saunders Elsevier. - 0954-6111 .- 1532-3064. ; 143, s. 8-13
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Journal article (peer-reviewed)abstract
- Back ground: Chronic airflow obstruction (CAO) is the primary characteristic of Chronic obstructive pulmonary disease (COPD) but is also seen in chronic asthma. Objective: To compare the prevalence of CAO and possible risk factors between Tartu in Estonia, Reykjavik in Iceland and Uppsala in Sweden. Methods: All participants underwent spirometry testing of forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) before and after bronchodilation. CAO was defined as post-bronchodilator FEV1/FVC below lower limit of normal. Information on respiratory diseases and smoking status, was obtained through questionnaires administered by trained interviewers. Results: 1037 men and 956 women participated in the study. The prevalence of CAO was lower in women in Tartu compared to the other centres (4.9% vs. 13.4 and 8.7% in Reykjavik and Uppsala, respectively, p = 0.002) while no difference was found for men. A similar picture was seen for the proportion of participants that had smoked 10 pack years or more which was much lower in Tartu for women than in Reykjavik and Uppsala, respectively (13.2% vs. 33.7 and 29.2%, p < 0.001). (Fig. 1). Of the participants with CAO the majority (57-67%) did not have a previous diagnosis of asthma or COPD. Conclusion: The prevalence of CAO was lower in Estonian women than in women from Iceland and Sweden. The reason for this was probably that the Estonian women had smoked less than the female participants from Iceland and Sweden. The majority of those with CAO do not have a diagnosed lung disease.
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| 4. |
- Christensen, Stine Holmegaard, et al.
(author)
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A clear urban-rural gradient of allergic rhinitis in a population-based study in Northern Europe
- 2016
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In: European clinical respiratory journal. - : Informa UK Limited. - 2001-8525. ; 3
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Journal article (peer-reviewed)abstract
- 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.
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| 5. |
- Dratva, Julia, et al.
(author)
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Validation of self-reported figural drawing scales against anthropometric measurements in adults
- 2016
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In: Public Health Nutrition. - : Cambridge University Press. - 1368-9800 .- 1475-2727. ; 19:11, s. 1944-1951
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Journal article (peer-reviewed)abstract
- 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/m(2) 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.
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| 6. |
- Emilsson, Össur Ingi, et al.
(author)
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Definition of nocturnal gastroesophageal reflux for studies on respiratory diseases
- 2016
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In: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 51:5, s. 524-530
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Journal article (peer-reviewed)abstract
- Objective Nocturnal gastroesophageal reflux (nGER) has been associated with respiratory diseases. Our aim was to study a questionnaire method to identify nGER subjects with respiratory involvement in a general population. Material and methods A subgroup of Icelandic participants in the European Community Respiratory Health Survey III (ECRHS III) reporting symptoms of nGER (n =48) as well as age and gender paired controls (n =42) were studied further by a structured interview, questionnaires, laryngeal fibrescopy, and exhaled breath condensate. A subgroup underwent 24-h oesophageal pH impedance (24-h MII-pH) measurements. Symptoms of nGER were assessed with a modified version of the reflux disease questionnaire (RDQ), where symptoms were divided into daytime and nocturnal. A report of nGER both at baseline and at follow-up was defined as persistent nGER. Results Participants reporting persistent nGER had significantly more signs of laryngopharyngeal reflux according to the reflux finding score than those without nGER (Mean +/- SD: 5.1 +/- 2.3 vs. 3.9 +/- 2.2, p =0.02). Of the 16 persistent nGER subjects that underwent 24-h MII-pH, 11 had abnormal gastroesophageal reflux, but none of three control subjects (69% vs. 0%). Pepsin was more commonly found in exhaled breath condensate in the nGER group (67% vs. 45%, p =0.04). Conclusions Participants with nGER symptoms at least once a month, reported on two occasions, had a high level of positive 24-h MII-pH measurements, laryngeal inflammation and pepsin in exhaled breath condensate. This nGER definition identified a representable group for studies on nGER and respiratory diseases in a general population.
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| 7. |
- Emilsson, Össur Ingi, et al.
(author)
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Snoring and nocturnal reflux : association with lung function decline and respiratory symptoms
- 2019
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In: ERJ Open Research. - : European Respitory Society (ERS). - 2312-0541. ; 5:2
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Journal article (peer-reviewed)abstract
- Introduction: The study aim was to examine the association of snoring and nocturnal gastro-oesophageal reflux (nGOR) with respiratory symptoms and lung function, and if snoring and/or nGOR associated with a steeper decline in lung function. Methods: Data from the third visit of the European Community Respiratory Health Survey (ECRHS) was used for cross-sectional analysis. Pre- and post-bronchodilator spirometry was performed, and information on sleep, nGOR and respiratory symptoms was collected (n=5715). Habitual snoring and nGOR were assessed by questionnaire reports. Pre-bronchodilator spirometry from ECRHS I, II and III (20 years follow-up) were used to analyse lung function changes by multivariate regression analysis. Results: Snoring and nGOR were independently associated with a higher prevalence of wheeze, chest tightness, breathlessness, cough and phlegm. The prevalence of any respiratory symptom was 79% in subjects with both snoring and nGOR versus 56% in those with neither (p<0.001). Subjects with both snoring and nGOR had more frequent exacerbations (adjusted prevalence 32% versus 19% among "no snoring, no nGOR", p=0.003). Snoring but not nGOR was associated with a steeper decline in forced expiratory volume in 1 s over 10 years after adjusting for confounding factors (change in % predicted -5.53, versus -4.58 among "no snoring", p=0.04) and forced vital capacity (change in % predicted -1.94, versus -0.99 among "no snoring", p=0.03). Conclusions: Adults reporting both habitual snoring and nGOR had more respiratory symptoms and more frequent exacerbations of these symptoms. Habitual snoring was associated with a steeper decline in lung function over time.
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| 8. |
- Janson, Christer, et al.
(author)
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Change in the prevalence asthma, rhinitis and respiratory symptom over a 20 year period : associations to year of birth, life style and sleep related symptoms
- 2018
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In: BMC Pulmonary Medicine. - : BioMed Central. - 1471-2466. ; 18
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Journal article (peer-reviewed)abstract
- Background: The aim of this investigation was to study change in adults over a 20 year period in the prevalence of respiratory symptoms and disorders and its association to year of birth, life style and sleep related variables.Method: Adults 20-44 years of age, 6085 women and 5184 men, were randomly selected from seven centres in Northern Europe and followed for 20 years. The number of participants in the first survey was 21,595 and 11,269 participated in all three surveys. The participants were divided into three birth cohorts: 1944-1955, 1956-1965 and 1966-1975.Results: During the 20 year period the prevalence of wheeze decreased (-2%) and the prevalence of asthma (+ 4%) and allergic rhinitis (+ 5%) increased, whereas the prevalence of nocturnal respiratory symptoms was relatively unchanged. The increase in allergic rhinitis was largest in those born 1966 to 1975 except in Estonia. There was large decrease in smoking (-20%), increase in obesity (+ 7%) and snoring (+ 6%) during the study period. Smoking, obesity, snoring and nocturnal gastroesophageal reflux (nGER) were related to a higher risk of all symptoms. Obesity, snoring and nGER were also independently related to asthma.Conclusion: We conclude that as our participants got older there was a decrease in wheeze, no change in nocturnal symptoms and an increase in reported asthma and allergic rhinitis. These changes in prevalence are probably related to a decrease in smoking being counteracted by an increase in allergy, obesity and sleep related disorders.
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| 9. |
- Kuiper, Ingrid Nordeide, et al.
(author)
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Lung health in adulthood after childhood exposure to air pollution and greenness
- 2018
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In: European Respiratory Journal. - : European Respiratory Society. - 0903-1936 .- 1399-3003. ; 52
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Journal article (other academic/artistic)abstract
- Background: Little is known on childhood exposure to air pollution and adult chronic respiratory outcomes.Aim: To investigate associations between air pollution and greenness in childhood and adult lung health.Methods: In selected centres of the RHINESSA study (age 18-52) we analysed the outcomes respiratory symptoms (≥3 symptoms), severe wheeze (wheeze last year with breathlessness, no cold) and late onset asthma (>10 years). We calculated mean annual exposures of PM2.5, PM10, NO2 (µg/m³) and greenness (Normalized Difference Vegetation Index, 100m buffer) from offspring's birth till age 18, categorised into mean exposure <10 years and 11-18 years. We performed multilevel logistic regression clustered by family, stratified by centre and adjusted for childhood passive smoke and parental asthma.Results: 12% had ≥3 respiratory symptoms, 7.7% severe wheeze, and 9.4% late onset asthma. Overall estimates: greenness was associated with less respiratory symptoms, PM2.5 and NO2 with more late onset asthma. Exposure <10 years: Greenness was associated with less wheeze in Tartu (OR 0.29, 95%CI 0.11-0.73). PM2.5 (OR 1.22, 95%CI 1.00-1.48) and NO2 (OR 1.06, 95%CI 1.01-1.11) were risk factors for late onset asthma in Bergen. PM10 was a risk factor for respiratory symptoms (OR 1.21, 95%CI 1.04-1.41) in Uppsala and late onset asthma (OR 1.23, 95%CI 1.02-1.45) in Bergen. Exposure 11-18 years: Greenness was protective for respiratory symptoms (OR 0.29, 95%CI 0.10-0.86) and wheeze (OR 0.39, 95%CI 0.19-0.80) in Tartu.Conclusions: Childhood exposure to greenness was associated with less respiratory symptoms, while air pollutants were associated with more respiratory symptoms (some centres) and late onset asthma.
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