An observational analysis on the influence of parental allergic rhinitis, asthma and smoking on exhaled nitric oxide in offspring.

BACKGROUND: Parental allergic diseases and smoking influence respiratory disease in the offspring but it is not known whether they influence fractional exhaled nitric oxide (FeNO) in the offspring. We investigated whether parental allergic diseases, parental smoking and FeNO levels in parents were associated with FeNO levels in their offspring. METHODS: We studied 609 offspring aged 16-47 years from the Respiratory Health in Northern Europe, Spain and Australia generation (RHINESSA) study with parental information from the Respiratory Health in Northern Europe (RHINE) III study and the European Community Respiratory Health Survey (ECRHS) III. Linear regression models were used to assess the association between offspring FeNO and parental FeNO, allergic rhinitis, asthma and smoking, while adjusting for potential confounding factors. RESULTS: Parental allergic rhinitis was significantly associated with higher FeNO in the offspring, both on the paternal and maternal side (percent change: 20.3 % [95%CI 5.0-37.7], p = 0.008, and 13.8 % [0.4-28.9], p = 0.043, respectively). Parental allergic rhinitis with asthma in any parent was also significantly associated with higher offspring FeNO (16.2 % [0.9-33.9], p = 0.037). However, parental asthma alone and smoking were not associated with offspring FeNO. Parental FeNO was not associated with offspring FeNO after full adjustments for offspring and parental factors. CONCLUSIONS: Parental allergic rhinitis but not parental asthma was associated with higher levels of FeNO in offspring. These findings suggest that parental allergic rhinitis status should be considered when interpreting FeNO levels in offspring beyond childhood.

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.

Nocturnal GERD - a risk factor for rhinitis/rhinosinusitis: the RHINE study.

BACKGROUND: It has been suggested that gastroesophageal reflux disease (GERD) is a risk factor for developing rhinitis/rhinosinusitis, but data are lacking. This is a prospective 10-year follow-up study of a large multicenter cohort from Northern Europe, evaluating the relationship between nocturnal GERD and noninfectious rhinitis (NIR). METHODS: The study comprised 5417 subjects born between 1945 and 1973, who answered a questionnaire in 1999-2001 and again in 2010-2012. Noninfectious rhinitis was defined as having nasal obstruction, secretion, and/or sneezing without having the common cold. Odds ratios for developing NIR in relation to age, gender, BMI, smoking, asthma, and nocturnal GERD were calculated. RESULTS: During the 10-year observation period, 1034 subjects (19.1%) developed NIR. Subjects reporting nocturnal gastroesophageal reflux in both 1999 and 2010 had more NIR in 2010 (2.8% vs 1.2%, P < 0.001). There was a significant dose-response relationship between the number of reflux episodes/week in 1999 and the risk of having NIR in 2010, P = 0.02. In the multiple regression adjusted for age, gender, BMI, tobacco smoke, and asthma, those with nocturnal GERD in 1999 (≥3 episodes of nocturnal gastroesophageal reflux symptoms per week) had an OR of 1.6 (95% CI 1.0-2.5, P = 0.03) to develop NIR in 2010. Smoking was associated both with an increased risk of developing NIR (30.7% vs 24.0%, P < 0.001) and with the development of nocturnal GERD. CONCLUSION: This large, population-based, 10-year study indicates that nocturnal GERD was a risk factor for noninfectious rhinitis/rhinosinusitis. GERD should therefore be considered in patients with rhinitis of known and unknown origin.

Incidence and prevalence of chronic bronchitis: impact of smoking and welding. The RHINE study.

OBJECTIVE: To investigate the prevalence and incidence rate of chronic bronchitis (CB) in relation to smoking habits and exposure to welding fumes in a general population sample. METHODS: Subjects from Northern Europe born between 1945 and 1971 who participated in Stage 1 (1989-1994) of the European Community Respiratory Health Survey were mailed a respiratory questionnaire in 1999-2001 (the RHINE study); 15,909 answered the questionnaire and gave complete data on smoking. CB was defined as chronic productive cough of at least 3 months a year for 2 consecutive years. The questionnaire comprised an item about age when CB started and items about exposure to welding fumes. The incidence of CB was retrospectively assessed for the observation period 1980-2001. RESULTS: CB had a prevalence of 5.4%, and was associated with current smoking and welding exposure. The incidence rate of CB was 1.9 per 1000 person-years, and was increased in relation to welding exposure (low exposure HR 1.4, 95%CI 1.1-1.8; high exposure HR 2.0, 95%CI 1.6-2.7) and in relation to smoking (HR 2.1, 95%CI 1.8-2.5). CONCLUSION: Smoking and occupational exposure to welding fumes are both associated with an increased risk of CB.

What can we learn about asthma and allergy from the follow-up of the RHINE and the ECRHS studies?

OBJECT: The international population-based studies RHINE and ECRHS have provided new insight in the epidemiology and management of asthma, allergy and rhinitis in young adults. The aim of the present review is to focus on longitudinal results with regard incidence and net change of asthma and asthma-like symptoms, risk factors and management of asthma, with special reference to the Nordic-Baltic countries. RESULTS: Asthma and rhinitis are common conditions that are important in a public health perspective. There are gender differences in incidence and remission. A socio-economic gradient that non-atopic asthma is more strongly related to poverty seems to have developed in the last decade. These findings will challenge our welfare states in the future. In addition, occupational, as well as indoor and outdoor environmental exposures, influenced the onset of asthma. The population-attributable risk for adult asthma because of occupational exposures is equivalent to an incidence of new-onset asthma of 250-300 cases per million per year. Genetic factors, allergic sensitisation, gastro-oesophageal reflux, habitual snoring, diet and other factors may also contribute to the onset of asthma and rhinitis. Even though management of asthma has improved, there are still great variations throughout Europe. These findings highlight the key role doctors and nurses play in educating and reviewing management of patients.

The socio-economic burden of asthma is substantial in Europe.

BACKGROUND: Few data are available on the asthma burden in the general population. We evaluated the level and the factors associated with the asthma burden in Europe. METHODS: In 1999-2002, 1152 adult asthmatics were identified in the European Community Respiratory Health Survey (ECRHS)-II and the socio-economic burden (reduced activity days and hospital services utilization in the past 12 months) was assessed. RESULTS: The asthmatics with a light burden (only a few reduced activity days) were 13.2% (95% CI: 11.4-15.3%), whereas those with a heavy burden (many reduced activity days and/or hospital services utilization) were 14.0% (95% CI: 12.1-16.1%). The burden was strongly associated with disease severity and a lower quality of life. Obese asthmatics had a significantly increased risk of a light [relative risk ratio (RRR) = 2.17; 95% CI: 1.18-4.00] or a heavy burden (RRR = 2.77; 95% CI: 1.52-5.05) compared with normal/underweight subjects. The asthmatics with frequent respiratory symptoms showed a threefold (RRR = 2.74; 95% CI: 1.63-4.61) and sixfold (RRR = 5.76; 95% CI: 3.25-10.20) increased risk of a light or a heavy burden compared with asymptomatic asthmatics, respectively. Moreover, the lower the forced expiratory volume in 1 s % predicted, the higher the risk of a heavy burden. The coexistence with chronic cough/phlegm only increased the risk of a heavy burden (RRR = 1.88; 95% CI: 1.16-3.06). An interaction was found between gender and IgE sensitization, with nonatopic asthmatic females showing the highest risk of a heavy burden (21.6%; 95% CI: 16.9-27.1%). CONCLUSIONS: The asthma burden is substantial in Europe. A heavy burden is more common in asthmatics with obesity, frequent respiratory symptoms, low lung function, chronic cough/phlegm and in nonatopic females.

Once daily fluticasone furoate nasal spray is effective in seasonal allergic rhinitis caused by grass pollen.

BACKGROUND: Fluticasone furoate is a new enhanced-affinity glucocorticoid with a unique combination of pharmacodynamic and physicochemical properties suitable for topical activity. METHODS: In this multicentre, randomized, double-blind, placebo-controlled, parallel-group study, patients [adults and adolescents >or=12 years of age with seasonal allergic rhinitis (SAR)] received once-daily (od) treatment for 2 weeks with either fluticasone furoate nasal spray 110 microg (n = 141) or placebo nasal spray (n = 144) administered in a unique, side-actuated device. Efficacy measures included total nasal symptom score (TNSS) and total ocular symptom score (TOSS). Patients also reported their overall response to therapy and rated their quality of life using the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ). RESULTS: Fluticasone furoate significantly improved the mean change from baseline in daily reflective TNSS compared with placebo (treatment difference of -1.757; P < 0.001). Fluticasone furoate was also significantly more effective in improving the morning predose instantaneous TNSS (treatment difference of -1.898; P < 0.001) and daily reflective TOSS (treatment difference of -0.741; P = 0.001). A significant treatment effect was observed as early as day 1. Compared with placebo-treated patients, fluticasone furoate-treated patients showed significantly greater improvements in overall evaluation of response to therapy (P < 0.001), as well as in overall RQLQ score (P < 0.001). Fluticasone furoate was well tolerated. CONCLUSION: Fluticasone furoate nasal spray 110 mug od was effective in improving the nasal symptoms of SAR. It also produced significant improvements in ocular symptoms.

Remission of asthma: a prospective longitudinal study from northern Europe (RHINE study).

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.

Changes in active and passive smoking in the European Community Respiratory Health Survey.

The aim of the present investigation was to study changes and determinants for changes in active and passive smoking. The present study included 9,053 adults from 14 countries that participated in the European Community Respiratory Health Survey II. The mean follow-up period was 8.8 yrs. Change in the prevalence of active and passive smoking was expressed as absolute net change (95% confidence interval) standardised to a 10-yr period. Determinants of change were analysed and the results expressed as adjusted hazard risk ratio (HRR) or odds ratio (OR). The prevalence of active smoking declined by 5.9% (5.1-6.8) and exposure to passive smoking in nonsmokers declined by 18.4% (16.8-20.0). Subjects with a lower educational level (HRR: 0.73 (0.54-0.98) and subjects living with a smoker (HRR: 0.45 (0.34-0.59)) or with workplace smoking (HRR: 0.69 (0.50-0.95)) were less likely to quit. Low socio-economic groups were more likely to become exposed (OR: 2.21 (1.61-3.03)) and less likely to cease being exposed to passive smoking (OR: 0.48 (0.37-0.61)). In conclusion, the quitting rate was lower and the risk of exposure to passive smoking higher among subjects with lower socio-economic status. Exposure to other peoples smoking decreased quitting rates and increased the risk of starting to smoke.

Prevalence and incidence of respiratory symptoms in relation to indoor dampness: the RHINE study.

BACKGROUND: An association between indoor dampness and respiratory symptoms has been reported, but dampness as a risk factor for the onset or remission of respiratory symptoms and asthma is not well documented. METHOD: This follow up study included 16 190 subjects from Iceland, Norway, Sweden, Denmark, and Estonia who had participated in the European Community Respiratory Health Survey (ECRHS I). Eight years later the same subjects answered a postal questionnaire that included questions on respiratory symptoms and indicators of indoor dampness. RESULTS: Subjects living in damp housing (18%) had a significantly (p<0.001) higher prevalence of wheeze (19.1% v 26.0%), nocturnal breathlessness (4.4% v 8.4%), nocturnal cough (27.2% v 36.5%), productive cough (16.6% v 22.3%) and asthma (6.0% v 7.7%). These associations remained significant after adjusting for possible confounders. Indoor dampness was a risk factor for onset of respiratory symptoms but not for asthma onset in the longitudinal analysis (OR 1.13, 95% CI 0.92 to 1.40). Remission of nocturnal symptoms was less common in damp homes (OR 0.84, 95% CI 0.73 to 0.97). CONCLUSIONS: Subjects living in damp housing had a higher prevalence of respiratory symptoms and asthma. Onset of respiratory symptoms was more common and remission of nocturnal respiratory symptoms was less common in subjects living in damp housing.

Hormone replacement therapy, body mass index and asthma in perimenopausal women: a cross sectional survey.

BACKGROUND: Hormone replacement therapy (HRT) and obesity both appear to increase the risk of asthma. A study was undertaken to investigate the association of HRT with asthma and hay fever in a population of perimenopausal women, focusing on a possible interaction with body mass index (BMI). METHODS: A postal questionnaire was sent to population based samples in Denmark, Estonia, Iceland, Norway, and Sweden in 1999-2001, and 8588 women aged 25-54 years responded (77%). Pregnant women, women using oral contraceptives, and women <46 years were excluded. Analyses included 2206 women aged 46-54 years of which 884 were menopausal and 540 used HRT. Stratified analyses by BMI in tertiles were performed. RESULTS: HRT was associated with an increased risk for asthma (OR 1.57 (95% CI 1.07 to 2.30)), wheeze (OR 1.60 (95% CI 1.22 to 2.10)), and hay fever (OR 1.48 (95% CI 1.15 to 1.90)). The associations with asthma and wheeze were significantly stronger among women with BMI in the lower tertile (asthma OR 2.41 (95% CI 1.21 to 4.77); wheeze OR 2.04 (95% CI 1.23 to 3.36)) than in heavier women (asthma: p(interaction) = 0.030; wheeze: p(interaction) = 0.042). Increasing BMI was associated with more asthma (OR 1.08 (95% CI 1.05 to 1.12) per kg/m2). This effect was only found in women not taking HRT (OR 1.10 (95% CI 1.05 to 1.14) per kg/m2); no such association was detected in HRT users (OR 1.00 (95% CI 0.92 to 1.08) per kg/m2) (p(interaction) = 0.046). Menopause was not significantly associated with asthma, wheeze, or hay fever. CONCLUSIONS: In perimenopausal women there is an interaction between HRT and BMI in the effects on asthma. Lean women who were HRT users had as high a risk for asthma as overweight women not taking HRT. It is suggested that HRT and overweight increase the risk of asthma through partly common pathways.

Changes in the use of anti-asthmatic medication in an international cohort.

The aim of this study was to describe changes in pharmacotherapy for asthma since the early 1990s in an international cohort of young and middle-aged adults. A total of 28 centres from 14 countries participated in a longitudinal study. The study included 8,829 subjects with a mean follow-up time of 8.7 yrs. Change in the prevalence of use for medication was expressed as absolute net change (95% confidence interval) standardised to a 10-yr period. The use of anti-asthmatics was found to have increased by 3.1% (2.4-3.7%) and the prevalence of symptomatic asthma by 4.0% (3.5-4.5%). In the sample with asthma in both surveys (n=423), the use of inhaled corticosteroids increased by 12.2% (6.6-17.8%). Despite this, only 17.2% were using inhaled corticosteroids on a daily basis at follow-up. Females with continuous asthma were more likely, compared with males, and smokers with asthma, to have started using inhaled corticosteroids since the first survey. The use of anti-asthmatics has increased in a pattern consistent with current consensus on treatment. However, despite increased use of inhaled corticosteroids, a large majority of subjects with symptomatic asthma do not use this treatment on a daily basis, particularly males and smokers with asthma.

The association between birth size and atopy in young North-European adults.

BACKGROUND: There is evidence that atopic disorders may begin in intra-uterine life; however, studies of birth characteristics and atopy show conflicting results. METHODS: We wanted to investigate the association of birth weight and head circumference with serum total or specific IgE, allergic rhinitis or eczema while addressing the influence of demographic and geographical factors. In this historic prospective cohort study, data were collected from birth records for 1683 men and women born in 1947-1973, from six Nordic-Baltic populations participating in the European Community Respiratory Health Survey. Blood tests for the measurement of serum total and specific IgE were available for 1494 subjects. In multiple regression analyses, adjustments were made for birth length, gender, age, study centre, adult body mass index, level of education, parental and adult smoking. RESULTS There was no association of birth weight (n=1230) and head circumference (n=285) with serum total IgE, specific IgE antibodies, allergic rhinitis or eczema. There were neither significant interactions by gender or age, nor heterogeneity between the study centres in the analyses of birth weight and adult atopy. CONCLUSION: Birth size was not associated with atopy among adults in this large Nordic-Baltic population study.

Association of asthma and hay fever with irregular menstruation.

BACKGROUND: There is some evidence that asthmatic women are more likely to have abnormal sex hormone levels. A study was undertaken to determine whether asthma and allergy were associated with irregular menstruation in a general population, and the potential role of asthma medication for this association. METHODS: A total of 8588 women (response rate 77%) participated in an 8 year follow up postal questionnaire study of participants of the ECRHS stage I in Denmark, Estonia, Iceland, Norway, and Sweden. Only non-pregnant women not taking exogenous sex hormones were included in the analyses (n = 6137). RESULTS: Irregular menstruation was associated with asthma (OR 1.54 (95% CI 1.11 to 2.13)), asthma symptoms (OR 1.47 (95% CI 1.16 to 1.86)), hay fever (OR 1.29 (95% CI 1.05 to 1.57)), and asthma preceded by hay fever (OR 1.95 (95% CI 1.30 to 2.96)) among women aged 26-42 years. This was also observed in women not taking asthma medication (asthma symptoms: OR 1.44 (95% CI 1.09 to 1.91); hay fever: OR 1.27 (95% CI 1.03 to 1.58); wheeze preceded by hay fever: OR 1.76 (95% CI 1.18 to 2.64)). Irregular menstruation was associated with new onset asthma in younger women (OR 1.58 (95% CI 1.03 to 2.42)) but not in women aged 42-54 years (OR 0.62 (95% CI 0.32 to 1.18)). The results were consistent across centres. CONCLUSIONS: Younger women with asthma and allergy were more likely to have irregular menstruation. This could not be attributed to current use of asthma medication. The association could possibly be explained by common underlying metabolic or developmental factors. The authors hypothesise that insulin resistance may play a role in asthma and allergy.

C reactive protein levels are increased in non-allergic but not allergic asthma: a multicentre epidemiological study.

BACKGROUND: High sensitivity C reactive protein (HsCRP) is an inflammatory marker known to be related to smoking, obesity, and cardiovascular disease. A study was undertaken to determine whether HsCRP is related to respiratory symptoms, asthma, atopy, and bronchial hyperresponsiveness in population samples from three countries. METHODS: HsCRP was measured in 1289 subjects from three centres in ECRHS II: Reykjavik, Uppsala and Tartu. The HsCRP values ranged from <0.01 mg/l to 70.0 mg/l and were divided into four equal groups (< or = 0.45, 0.46-0.96, 0.97-2.21, and >2.21 mg/l). RESULTS: HsCRP increased with increasing body mass index (r = 0.41; p<0.0001) and was higher in smokers than in never smokers (p = 0.02). A significant relationship was found between increased HsCRP levels and respiratory symptoms such as wheeze, attacks of breathlessness after effort, and nocturnal cough (p<0.0001). The crude odds ratio (95% CI) for the probability of non-allergic asthma was 3.57 (1.83 to 6.96) for subjects in the 4th quartile compared with the 1st quartile of HsCRP. This association remained significant after adjusting for study centre, age, sex, body weight, and smoking history (OR 2.19 (95% CI 1.04 to 4.63)). No significant relationship was observed between HsCRP and allergic asthma or bronchial responsiveness. CONCLUSIONS: Raised levels of HsCRP are significantly associated with respiratory symptoms and non-allergic asthma but not with allergic asthma.

Insomnia is more common among subjects living in damp buildings.

BACKGROUND: Insomnia is a condition with a high prevalence and a great impact on quality of life. Little is known about the relation between and sleep disturbances and the home environment. AIM: To analyse the association between insomnia and building dampness. METHODS: In a cross-sectional, multicentre, population study, 16 190 subjects (mean age 40 years, 53% women) were studied from Reykjavik in Iceland, Bergen in Norway, Umeå, Uppsala, and Göteborg in Sweden, Aarhus in Denmark, and Tartu in Estonia. Symptoms related to insomnia were assessed by questionnaire. RESULTS: Subjects living in houses with reported signs of building dampness (n = 2873) had a higher prevalence of insomnia (29.4 v 23.6%; crude odds ratio 1.35, 95% CI 1.23 to 1.48). The association between insomnia and different indicators of building dampness was strongest for floor dampness: "bubbles or discoloration on plastic floor covering or discoloration of parquet floor" (crude odds ratio 1.96, 95% CI 1.66 to 2.32). The associations remained significant after adjusting for possible confounders such as sex, age, smoking history, housing, body mass index, and respiratory diseases. There was no significant difference between the centres in the association between insomnia and building dampness. CONCLUSION: Insomnia is more common in subjects living in damp buildings. This indicates that avoiding dampness in building constructions and improving ventilation in homes may possibly have a positive effect on the quality of sleep.

A prospective study of asthma incidence and its predictors: the RHINE study.

The objective of this longitudinal study was to estimate the incidence rate of asthma, and to compare the incidence between subjects with or without baseline reporting of certain respiratory symptoms. A follow-up of the random population samples in the European Respiratory Health Survey (ECRHS) in Sweden, Norway, Denmark, Iceland and Estonia was conducted in 1999-2001, in a population aged 30-54 yrs at follow-up (n=14,731). Asthma was defined as reporting either asthma or physician-diagnosed asthma, and a reported year when asthma symptoms were first noticed. Incidence rates, incidence rate ratios and hazard ratios were calculated with 95% confidence intervals. The incidence rate of asthma was 2.2 cases per 1,000 person-yrs. The incidence was higher among females (2.9 cases.1,000 person-yrs(-1)) than among males (1.5 cases.1,000 person-yrs(-1)). When subjects with baseline reporting of wheezing were excluded, the incidence rate decreased to 1.7 cases.1,000 person-yrs(-1), with a further decrease to 1.5 cases.1,000 person-yrs(-1) after exclusion of subjects with wheezing, nocturnal dyspnoea, chest tightness and cough. There was a strong association between onset of asthma and wheezing at baseline. In this prospective, population-based study, the incidence rate of asthma in the whole population sample ranged 1.5-2.2.1,000 person-yrs(-1), with a higher incidence range among females. The incidence was dependent on the extent to which subjects with respiratory symptoms were excluded from follow-up. Hence, for comparability between studies, the exclusion criteria in the follow-up population must be stated.

Bronchial hyperresponsiveness in two populations with different prevalences of atopy.

SETTING: Random population samples of young adults from Tartu, Estonia (n = 307) and Uppsala, Sweden (n = 498) in the framework of the European Community Respiratory Health Survey (ECRHS). OBJECTIVE: To compare the prevalence and risk factors for bronchial hyperresponsiveness (BHR) to methacholine in two centres with similar climate and ethnicity but differences in the prevalence of atopy, asthma and respiratory symptoms. DESIGN: General population-based cross-sectional survey. RESULTS: The prevalence of BHR using the cut-off points 1.5, 1.0 and 0.5 mg was 19%, 12% and 8% in Tartu and 11%, 7% and 2%, respectively, in Uppsala. Current smoking was a common risk factor for BHR in both centres. Female sex (odds ratio [OR] 2.9), sensitisation to cat (OR 5.9) and visible mould in the home (OR 2.4) were independent risk factors for BHR in Tartu. In Uppsala, BHR was significantly associated with total IgE levels (OR 2.0) and exposure to environmental tobacco smoke (OR 3.3). CONCLUSION: The high prevalence of BHR can explain the high prevalence of respiratory symptoms in Tartu and indicates that causes other than asthma and atopy can be responsible for the high prevalence of BHR in a population.

Obesity and nocturnal gastro-oesophageal reflux are related to onset of asthma and respiratory symptoms.

Several studies have identified obesity as a risk factor for asthma in both children and adults. An increased prevalence of asthma in subjects with gastro-oesophageal reflux (GOR) and obstructive sleep apnoea syndrome has also been reported. The aim of this investigation was to study obesity, nocturnal GOR and snoring as independent risk factors for onset of asthma and respiratory symptoms in a Nordic population. In a 5-10 yr follow-up study of the European Community Respiratory Health Survey in Iceland, Norway, Denmark, Sweden and Estonia, a postal questionnaire was sent to previous respondents. A total of 16,191 participants responded to the questionnaire. Reported onset of asthma, wheeze and night-time symptoms as well as nocturnal GOR and habitual snoring increased in prevalence along with the increase in body mass index (BMI). After adjusting for nocturnal GOR, habitual snoring and other confounders, obesity (BMI >30) remained significantly related to the onset of asthma, wheeze and night-time symptoms. Nocturnal GOR was independently related to the onset of asthma and in addition, both nocturnal GOR and habitual snoring were independently related to onset of wheeze and night-time symptoms. This study adds evidence to an independent relationship between obesity, nocturnal gastro-oesophageal reflux and habitual snoring and the onset of asthma and respiratory symptoms in adults.

Is birth weight related to lung function and asthma symptoms in Nordic-Baltic adults?

Studies of birth characteristics and respiratory outcomes show contradictory findings. We wanted to investigate the association of birth weight with adult lung function as well as asthma symptoms while addressing the influence of demographic and environmental factors. Data was collected from the birth records of 1683 men and women born in 1947-1973 who were included in 6 Nordic-Baltic population samples investigated within the European Community Respiratory Health Survey (ECRHS). In the adults, an increase in birth weight from below 2500 g to above 4000 g was associated with an increase from 96% to 104% predicted one-second forced expiratory volume (P<0.01) and from 1.00% to 107% predicted forced vital capacity (P<0.01). However, birth weight was not associated with symptoms of asthma. After adjustment for birth length, gender, age, study centre, adult BMI, allergic rhinitis, parental and adult tobacco smoke exposure in multivariate regression analyses, birth weight was not associated with adult lung function or asthma symptoms. Further sub-sample analyses revealed no influence of gestational age, gender, age or geographical area. In this historic prospective cohort study an association was neither found between birth weight and adult lung function nor between birth weight and asthma symptoms.