There is evidence that the origin of obstructive lung disease may be traced back to foetal life. The associations between birth characteristics and asthma symptoms were studied in a random population sample of young Norwegian adults. Respiratory symptoms were recorded in a population-based questionnaire survey. The records of all subjects aged 20-24 yrs were linked with the Medical Birth Registry of Norway. Of 868 subjects born in Norway, there were 690 (79%) responders. The associations between asthma symptoms and birth characteristics were analysed by logistic regression, adjusted for possible confounding factors. Asthma symptoms in young adults were inversely associated with birth weight (odds ratio (OR)wheeze=0.82; 95% confidence interval (CI)=0.69-0.96x500 g increase in birth weight(-1))), and after adjustment for gestational age, birth length, parity and maternal age (ORwheeze=0.69; 95% CI=0.50-0.95x500 g increase in birth weight(-1)). The association did not vary according to adult smoking habits or atopic status and remained when premature and low weight births were excluded (ORwheeze=0.73; 95% CI=0.60-0.90x500 g increase in birth weight(-1)). The association was consistent for all asthma symptoms. Adjusted for birth weight, asthma symptoms were further associated with low gestational age, high birth length and low maternal age. In a random sample of young adults, asthma symptoms were strongly associated with low birth weight, an association driven by the full-term births within the normal birth weight range. The findings show that the risk for adult asthma is partly established early in life and suggest that poor intrauterine growth is involved in the aetiology of asthma.
Utilisation of healthcare resources because of pulmonary diseases have previously been presented according to lung function or symptom severity. We aimed to compare the associations of symptoms and lung function to healthcare and social service utilisation in subjects with self-reported obstructive lung diseases (OLDs) (asthma, chronic obstructive pulmonary disease, chronic bronchitis, emphysema).Of 2819 participants aged 27-82 years in the Hordaland County Respiratory Health Survey, 200 subjects (7.1%) self-reported OLD. They answered 13 questions on respiratory symptoms and 5 questions on use of healthcare and social services. Altogether, 161 participants (81%) completed post-bronchodilation spirometry.Use of anti-asthmatic drugs, regular physician's appointment, sick leave payment for the last 12 months, hospital admission for the last 12 months and disability pension were reported by 68%, 63%, 18%, 8% and 7% of those with self-reported OLD, respectively. Twenty per cent of subjects with self-reported OLD had not received any healthcare or social services. In adjusted multivariate logistic regression analyses, increase in the respiratory symptom score was significantly associated with more healthcare and social services. Lower forced expiratory volume in 1 s in % predicted, however, was not significantly associated with more use of healthcare and social services.The majority (80%) of subjects in a general population with self-reported OLD received healthcare services. The utilisation of healthcare and social services was strongly associated to the burden of respiratory symptoms, and, to a lesser degree, to the level and pattern of lung function.
Summary Background A diet rich in fish or cod oil might possibly reduce the risk for asthma and atopic diseases. However, previous studies show conflicting results and no studies have assessed the potential long‐term effects of childhood fish intake on adult asthma. Objective To investigate whether childhood and adult fish and cod oil intake was related to adult asthma. Methods In a large population‐based study, Respiratory Health in Northern Europe (RHINE), 16 187 subjects aged 23–54 years answered a postal questionnaire. The relations of fish and cod oil intake with asthma symptoms and asthma were analysed using multiple logistic and Cox regression analyses, with adjustment for gender, adult hayfever, smoking, age, body mass index, household size, dwelling, parental education and centre, and for maternal smoking and family history of hayfever and asthma in a subsample ( n =2459). Results Subjects from Iceland and Norway reported much more frequent intake of fish both in childhood and adulthood as compared with subjects from Sweden, Estonia and Denmark. Current fish intake less than weekly in adults was associated with more asthma symptoms, while more frequent fish intake did not appear to decrease the risk further. No dose–response association was found between childhood fish intake and adult asthma, but those who never ate fish in childhood had an increased risk for asthma and earlier asthma onset. Adult consumption of cod oil had a u‐shaped association with asthma, with the highest risks in those taking cod oil never and daily. Conclusion A minimum level of weekly fish intake in adulthood was associated with protection against asthma symptoms in this large North‐European multi‐centre study. Subjects who never ate fish in childhood were at an increased risk for asthma. Both indicate a possible threshold effect of fish on asthma.
The aim of the present study was to investigate the remission rate of adult asthma in a general population sample in relation to age, sex, asthma symptoms, allergic rhinitis and smoking. A follow-up of the random population samples from the European Community Respiratory Health Survey in Northern Europe was conducted from 1999–2001 on 1,153 individuals (aged 26–53 yrs) with reported asthma. Remission was defined as no asthmatic symptoms in two consecutive years and no current use of asthma medication. Remission rates per 1,000 person-yrs were calculated and Cox regression models, adjusting for confounders, were used to estimate hazard ratios (HR) with 95% confidence intervals (CI). An average remission rate of 20.2 per 1,000 person-yrs was found. There was no significant difference according to sex; the remission rates were 21.7 and 17.8 per 1,000 person-yrs in females and males, respectively. An increased remission rate was observed among subjects who quit smoking during the observation period. Subjects not reporting any asthma symptom at baseline had an increased remission rate. In the Cox regression model, ex-smoking (HR 1.65, 95% CI 1.01–2.71) was associated with increased remission rate, and reporting any asthma symptom at baseline was associated with decreased remission rate (HR 0.7, 95% CI 0.40–0.90). In conclusion, the present prospective longitudinal study showed that quitting smoking and the presence of mild disease appeared to favour remission.
Respiratory symptoms are common in the general population, and their presence is related to Health-related quality of life (HRQoL). The objective was to describe the association of respiratory symptoms with HRQoL in subjects with and without asthma or COPD and to investigate the role of atopy, bronchial hyperresponsiveness (BHR), and lung function in HRQoL. The European Community Respiratory Health Survey (ECRHS) I and II provided data on HRQoL, lung function, respiratory symptoms, asthma, atopy, and BHR from 6009 subjects. Generic HRQoL was assessed through the physical component summary (PCS) score and the mental component summary (MCS) score of the SF-36. Factor analyses and linear regressions adjusted for age, gender, smoking, occupation, BMI, comorbidity, and study centre were conducted. Having breathlessness at rest in ECRHS II was associated with mean score (95% CI) impairment in PCS of -8.05 (-11.18, -4.93). Impairment in MCS score in subjects waking up with chest tightness was -4.02 (-5.51, -2.52). The magnitude of HRQoL impairment associated with respiratory symptoms was similar for subjects with and without asthma/COPD. Adjustments for atopy, BHR, and lung function did not explain the association of respiratory symptoms and HRQoL in subjects without asthma and/or COPD. Subjects with respiratory symptoms had poorer HRQoL; including subjects without a diagnosis of asthma or COPD. These findings suggest that respiratory symptoms in the absence of a medical diagnosis of asthma or COPD are by no means trivial, and that clarifying the nature and natural history of respiratory symptoms is a relevant challenge. Several community studies have estimated the prevalence of common respiratory symptoms like cough, dyspnoea, and wheeze in adults [1–3]. Although the prevalence varies to a large degree between studies and geographical areas, respiratory symptoms are quite common. The prevalences of respiratory symptoms in the European Community Respiratory Health Study (ECRHS) varied from one percent to 35% [1]. In fact, two studies have reported that more than half of the adult population suffers from one or more respiratory symptoms [4, 5]. Respiratory symptoms are important markers of the risk of having or developing disease. Respiratory symptoms have been shown to be predictors for lung function decline [6–8], asthma [9, 10], and even all-cause mortality in a general population study [11]. In patients with a known diagnosis of asthma or chronic obstructive pulmonary disease (COPD), respiratory symptoms are important determinants of reduced health related quality of life (HRQoL) [12–15]. The prevalence of respiratory symptoms exceeds the combined prevalences of asthma and COPD, and both asthma and COPD are frequently undiagnosed diseases [16–18]. Thus, the high prevalence of respipratory symptoms may mirror undiagnosed and untreated disease. The common occurrence of respiratory symptoms calls for attention to how these symptoms affect health also in subjects with no diagnosis of obstructive airways disease. Impaired HRQoL in the presence of respiratory symptoms have been found in two population-based studies [6, 19], but no study of respiratory sypmtoms and HRQoL have separate analyses for subjects with and without asthma and COPD, and no study provide information about extensive objective measurements of respiratory health. The ECRHS is a randomly sampled, multi-cultural, population based cohort study. The ECRHS included measurements of atopy, bronchial hyperresponsiveness (BHR), and lung function, and offers a unique opportunity to investigate how respiratory symptoms affect HRQoL among subjects both with and without obstructive lung disease. In the present paper we aimed to: 1) Describe the relationship between respiratory symptoms and HRQoL in an international adult general population and: 2) To assess whether this relationship varied with presence of asthma and/or COPD, or presence of objective functional markers like atopy and BHR.
The early life environment appears to have a persistent impact on asthma risk. We hypothesize that environmental factors related to rural life mediate lower asthma prevalence in rural populations, and aimed to investigate an urban-rural gradient, assessed by place of upbringing, for asthma. The population-based Respiratory Health In Northern Europe (RHINE) study includes subjects from Denmark, Norway, Sweden, Iceland and Estonia born 1945-1973. The present analysis encompasses questionnaire data on 11,123 RHINE subjects. 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. The association of place of upbringing with asthma onset was analysed with Cox regression adjusted for relevant confounders. Subjects growing up on livestock farms had less asthma (8%) than subjects growing up in inner cities (11%) (hazard ratio 0.72 95% CI 0.57-0.91), and a significant urban-rural gradient was observed across six urbanisation levels (p = 0.02). An urban-rural gradient was only evident among women, smokers and for late-onset asthma. Analyses on wheeze and place of upbringing revealed similar results. In conclusion, this study suggests a protective effect of livestock farm upbringing on asthma development and an urban-rural gradient in a Northern European population.