Maternal age at delivery, lung function and asthma in offspring: a population-based survey.

There is limited information about potential impact of maternal age on the respiratory health of offspring. We investigated the association of maternal age at delivery with adult offspring's lung function, respiratory symptoms and asthma, and potential differences according to offspring sex.10 692 adults from 13 countries participating in the European Community Respiratory Health Survey (ECRHS) II responded to standardised interviews and provided lung function measurements and serum for IgE measurements at age 25-55 years. In logistic and linear multilevel mixed models we adjusted for participants' characteristics (age, education, centre, number of older siblings) and maternal characteristics (smoking in pregnancy, education) while investigating for differential effects by sex. Maternal age was validated in a subsample using data from the Norwegian birth registry.Increasing maternal age was associated with increasing forced expiratory volume in 1 s (2.33 mL per year, 95% CI 0.34-4.32 mL per year), more consistent in females (ptrend 0.025) than in males (ptrend 0.14). Asthma (OR 0.85, 95% CI 0.79-0.92) and respiratory symptoms (OR 0.87, 95% CI 0.82-0.92) decreased with increasing maternal age (per 5 years) in females, but not in males (pinteraction 0.05 and 0.001, respectively). The results were consistent across centres and not explained by confounding factors.Maternal ageing was related to higher adult lung function and less asthma/symptoms in females. Biological characteristics in offspring related to maternal ageing are plausible and need further investigation.

Dietary antioxidants and 10-year lung function decline in adults from the ECRHS survey.

The relationship between lung function decline and dietary antioxidants over 10 years in adults from three European countries was investigated.In 2002, adults from three participating countries of the European Community Respiratory Health Survey (ECRHS) answered a questionnaire and underwent spirometry (forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC)), which were repeated 10 years later. Dietary intake was estimated at baseline with food frequency questionnaires (FFQ). Associations between annual lung function decline (mL) and diet (tertiles) were examined with multivariable analyses. Simes' procedure was applied to control for multiple testing.A total of 680 individuals (baseline mean age 43.8±6.6 years) were included. A per-tertile increase in apple and banana intake was associated with a 3.59 mL·year-1 (95% CI 0.40, 7.68) and 3.69 mL·year-1 (95% CI 0.25, 7.14) slower decline in FEV1 and FVC, respectively. Tomato intake was also associated with a slower decline in FVC (4.5 mL·year-1; 95% CI 1.28, 8.02). Only the association with tomato intake remained statistically significant after the Simes' procedure was performed. Subgroup analyses showed that apple, banana and tomato intake were all associated with a slower decline in FVC in ex-smokers.Intake of fruits and tomatoes might delay lung function decline in adults, particularly in ex-smokers.

Menopause as a predictor of new-onset asthma: A longitudinal Northern European population study.

BACKGROUND: There is limited and conflicting evidence on the effect of menopause on asthma. OBJECTIVES: We sought to study whether the incidence of asthma and respiratory symptoms differ by menopausal status in a longitudinal population-based study with an average follow-up of 12 years. METHODS: The Respiratory Health in Northern Europe study provided questionnaire data pertaining to respiratory and reproductive health at baseline (1999-2001) and follow-up (2010-2012). The study cohort included women aged 45 to 65 years at follow-up, without asthma at baseline, and not using exogenous hormones (n = 2322). Menopausal status was defined as nonmenopausal, transitional, early postmenopausal, and late postmenopausal. Associations with asthma (defined by the use of asthma medication, having asthma attacks, or both) and respiratory symptoms scores were analyzed by using logistic (asthma) and negative binomial (respiratory symptoms) regressions, adjusting for age, body mass index, physical activity, smoking, education, and study center. RESULTS: The odds of new-onset asthma were increased in women who were transitional (odds ratio, 2.40; 95% CI, 1.09-5.30), early postmenopausal (odds ratio, 2.11; 95% CI, 1.06-4.20), and late postmenopausal (odds ratio, 3.44; 95% CI, 1.31-9.05) at follow-up compared with nonmenopausal women. The risk of respiratory symptoms increased in early postmenopausal (coefficient, 0.40; 95% CI, 0.06-0.75) and late postmenopausal (coefficient, 0.69; 95% CI, 0.15-1.23) women. These findings were consistent irrespective of smoking status and across study centers. CONCLUSIONS: New-onset asthma and respiratory symptoms increased in women becoming postmenopausal in a longitudinal population-based study. Clinicians should be aware that respiratory health might deteriorate in women during reproductive aging.

Functional Gastrointestinal Symptoms Are Associated with Higher Serum Total IgE Levels, but Less Atopic Sensitization.

BACKGROUND: The relation of gastrointestinal (GI) complaints to IgE-mediated allergy is not well understood. Increased numbers of "IgE-armed" mast cells have been observed in duodenal mucosa of patients with functional GI complaints. AIMS: To explore whether total IgE and atopic sensitization were associated with functional GI complaints. METHODS: Levels of serum total and specific IgE and GI complaints were measured in 161 patients and in a general population sample of 478 persons. Standard inhalant allergens were measured in the patient group, and selected inhalant allergens in the general population. GI complaints were assessed by two standardized questionnaires. The associations between GI complaints and total IgE were analyzed in multiple regression models. RESULTS: GI complaints were positively associated with higher total IgE levels (all: b = 0.028, p = 0.012; patient group: b = 0.038, p = 0.072; general population: b = 0.038, p = 0.005), but negatively associated with atopic sensitization (all: b = -11.256, p = 0.181; patient group: b = -85.667, p < 0.001; general population: b = -14.394, p = 0.083). The relationship between total IgE and GI complaints was consistent among sensitized and non-sensitized persons, among men and women, and across age groups. CONCLUSION: Serum total IgE was positively associated with GI complaints, while atopic sensitization was inversely associated with GI complaints. This suggests that IgE-mediated immunology plays a role in the pathophysiology of functional GI complaints. The biological mechanisms reflected in higher total IgE levels, but less atopic sensitization, warrant further studies.

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.

Incidence of rhinitis and asthma related to welding in Northern Europe.

Welding-related asthma is well recognised but less is known about rhinitis in relation to welding. The aim here, was to study associations between welding, rhinitis and asthma in a general population sample, and factors influencing selection into and out of a welding occupation.Adult-onset asthma and non-infectious rhinitis were investigated in the international multicentre population-based Respiratory Health in Northern Europe (RHINE) study, including 16,191 responders aged 26-54 years. Ever welding (n=2181), welding >25% of working time (n=747), and welding in stainless steel >6 months (n=173) were assessed by questionnaire. Subjects with rhinitis or asthma onset when aged <18 years were excluded. Incidence rates for asthma and rhinitis were calculated from year of disease onset, and start and end of welding job. Cox's proportional hazard models adjusting for age, sex, parental education and study centre, and Kaplan-Meier curves were used.Rhinitis incidence was higher among welders (hazard ratio (HR) 1.4, 95% CI 1.3-1.6), consistent in men and women, and across centres (pheterogeneity=0.4). In men, asthma incidence was higher among welders (HR 1.4, 95% CI 1.04-1.97). Quitting welding was indicated higher after adult-onset rhinitis (HR 1.1, 95% CI 1.0-1.3). Adult-onset rhinitis and asthma was higher among welders, consistent across population samples from Northern Europe. No pre-employment selection was found, whereas selection out of welding jobs was suggested.

Genetic heterogeneity of asthma phenotypes identified by a clustering approach.

The aim of the study was to identify genetic variants associated with refined asthma phenotypes enabling multiple features of the disease to be taken into account. Latent class analysis (LCA) was applied in 3001 adults ever having asthma recruited in the frame of three epidemiological surveys (the European Community Respiratory Health Survey (ECRHS), the Swiss Study on Air Pollution and Lung Disease in Adults (SAPALDIA) and the Epidemiological Study on the Genetics and Environment of Asthma (EGEA)). 14 personal and phenotypic characteristics, gathered from questionnaires and clinical examination, were used. A genome-wide association study was conducted for each LCA-derived asthma phenotype, compared to subjects without asthma (n=3474). The LCA identified four adult asthma phenotypes, mainly characterised by disease activity, age of asthma onset and atopic status. Associations of genome-wide significance (p<1.25 × 10(-7)) were observed between "active adult-onset nonallergic asthma" and rs9851461 flanking CD200 (3q13.2) and between "inactive/mild nonallergic asthma" and rs2579931 flanking GRIK2 (6q16.3). Borderline significant results (2.5 × 10(-7) < p <8.2 × 10(-7)) were observed between three single nucleotide polymorphisms (SNPs) in the ALCAM region (3q13.11) and "active adult-onset nonallergic asthma". These results were consistent across studies. 15 SNPs identified in previous genome-wide association studies of asthma have been replicated with at least one asthma phenotype, most of them with the "active allergic asthma" phenotype. Our results provide evidence that a better understanding of asthma phenotypic heterogeneity helps to disentangle the genetic heterogeneity of asthma.

Place of upbringing in early childhood as related to inflammatory bowel diseases in adulthood: a population-based cohort study in Northern Europe.

BACKGROUND: The two inflammatory bowel diseases (IBD), ulcerative colitis and Crohn's disease, has increased rapidly during the twentieth century, but the aetiology is still poorly understood. Impaired immunological competence due to decreasing biodiversity and altered microbial stimulation is a suggested explanation. OBJECTIVE: Place of upbringing was used as a proxy for the level and diversity of microbial stimulation to investigate the effects on the prevalence of IBD in adulthood. METHODS: Respiratory Health in Northern Europe (RHINE) III is a postal follow-up questionnaire of the European Community Respiratory Health Survey (ECRHS) cohorts established in 1989-1992. The study population was 10,864 subjects born 1945-1971 in Denmark, Norway, Sweden, Iceland and Estonia, who responded to questionnaires in 2000-2002 and 2010-2012. Data were analysed in logistic and Cox regression models taking age, sex, smoking and body mass index into consideration. RESULTS: Being born and raised on a livestock farm the first 5 years of life was associated with a lower risk of IBD compared to city living in logistic (OR 0.54, 95 % CI 0.31; 0.94) and Cox regression models (HR 0.55, 95 % CI 0.31; 0.98). Random-effect meta-analysis did not identify geographical difference in this association. Furthermore, there was a significant trend comparing livestock farm living, village and city living (p < 0.01). Sub-analyses showed that the protective effect was only present among subjects born after 1952 (OR 0.25, 95 % CI 0.11; 0.61). CONCLUSION: This study suggests a protective effect from livestock farm living in early childhood on the occurrence of IBD in adulthood, however only among subjects born after 1952. We speculate that lower microbial diversity is an explanation for the findings.

Mortality by level of emphysema and airway wall thickness.

RATIONALE: There is limited knowledge of the prognostic value of quantitative computed tomography (CT) measures of emphysema and airway wall thickness (AWT) on mortality. OBJECTIVES: To examine 8-year mortality in relation to CT-measured emphysema and AWT, and assess if potential impact of these predictors remained after adjustment for lung function. METHODS: In the Norwegian GenKOLS study of 2003-2005, 947 ever-smokers (49% with COPD) aged 40-85 years performed spirometry and CT examination. Mortality data from 2003-2011 were gathered from the Norwegian Cause of Death Registry. CT emphysema % low-attenuation areas (%LAA) and standardized measure for AWT (AWT-Pi10) were main predictors. We performed Laplace regression for survival data, estimating survival time for specified population percentiles within each emphysema category. Models were adjusted for sex, FEV1, COPD status, age, body mass index, smoking, and inflation level. MEASUREMENTS AND MAIN RESULTS: During 8-year follow-up all-cause mortality rate was 15%. Although 4% of the subjects with %LAA less than 3 died, 18% with %LAA 3-10 and 44% with %LAA greater than or equal to 10 died. After adjustment, the comparable percentile subjects with medium and high emphysema had 19 months shorter survival than subjects who died in the lowest emphysema category. Subjects with %LAA greater than or equal to 10 had 33 and 37 months shorter survival than the lowest emphysema category with regard to respiratory and cardiovascular mortality, respectively. No significant associations were found between %LAA and cancer and lung cancer mortality. AWT did not predict mortality independently, but a positive interaction with emphysema was observed. CONCLUSIONS: AWT affected mortality with increasing degree of emphysema, whereas CT measure of emphysema was a strong independent mortality predictor.

Menstrual cycle and respiratory symptoms in a general Nordic-Baltic population.

RATIONALE: There is little knowledge of variations in respiratory symptoms during the menstrual cycle in a general population, and potential modifying factors are not investigated. OBJECTIVES: To investigate menstrual cycle variation in respiratory symptoms in a large general population, using chronobiology methodology, and stratifying by body mass index (BMI), smoking, and asthma status. METHODS: A total of 3,926 women with regular cycles less than or equal to 28 days and not taking exogenous sex hormones answered a postal questionnaire regarding the first day of their last menstruation and respiratory symptoms in the last 3 days. Moving 4-day means were computed to smooth uneven records of daily sampling; best-fitting 28-day composite cosine curves were applied to each time series to describe rhythmicity. MEASUREMENTS AND MAIN RESULTS: Significant rhythmic variations over the menstrual cycle were found in each symptom for all subjects and subgroups. Wheezing was higher on cycle Days 10-22, with a midcycle dip near the time of putative ovulation (approximately Days 14-16) in most subgroups. Shortness of breath was higher on days 7-21, with a dip just before midcycle in many subgroups. Cough was higher just after putative ovulation for subjects with asthma, BMI greater than or equal to 23 kg/m(2), and smokers, or just before ovulation and menses onset for low symptomatic subgroups. CONCLUSIONS: Respiratory symptoms varied significantly during the menstrual cycle and were most frequent from the midluteal to midfollicular stages, often with a dip near the time of ovulation. The patterns varied by BMI, smoking, and asthma status. These relations link respiratory symptoms with hormonal changes through the menstrual cycle and imply a potential for individualized chronotherapy for respiratory diseases.

Effects of controlled breathing exercises and respiratory muscle training in people with chronic obstructive pulmonary disease: results from evaluating the quality of evidence in systematic reviews.

BACKGROUND: This paper reviews evidence and quality of Systematic Reviews (SRs) on the effects of breathing control exercises (BCEs) and respiratory muscle training (RMT) on breathlessness/dyspnea and other symptoms, and quality of life (QOL) for individuals with chronic obstructive pulmonary disease (COPD). METHODS: A search for BCE and RMT literature in COPD published between January 1, 2002 and December 31, 2013 was performed in the following databases: PubMed, Ovid, CINAHL, PsycINFO, AMED, Cochrane and PEDro. The AMSTAR criteria were used to evaluate quality. RESULTS: After reviewing 642 reports, seven SRs were identified on RMT and BCEs. Three SRs were of high quality, three were of moderate quality, and one was of low quality. Two high-quality SRs reported significantly beneficial effects of RMT on dyspnea, and one reported significant effects on disease-specific QOL and fatigue. In these SRs, pooled data analyses were performed with three to fourteen single randomised control trials (RCTs) included in the analysis. In one of the SRs the quality of the single RCTs were rated by the authors to be between 5-7 (with10 best) and in the other one the quality of the single RCTs were rated to be between 30-83% of the maximum score.One high-quality SR found a significant positive effect of BCE based on pooled data analysis with two single RCTs in regard to pursed-lip breathing (PLB) on breathlessness. In this SR, one single RCT on diaphragmatic breathing (DB) and another one on yoga breathing (YB) showed effect on disease-specific QOL. The single RCTs included in the SR were rated by the authors in the SRs to be of low and moderate quality. CONCLUSIONS: Based on three high-quality SRs performing pooled data analyses, there is evidence that RMT has effect on breathlessness, fatigue and disease-specific QOL and PLB on breathlessness. There is also evidence that single studies on DB and YB has effect on disease-specific QOL. Few RCTs are available and the variable quality of the single RCTs in the SRs, seem to require more RCTs in particular for BCEs, but also RMT before conclusions regarding effects and high quality SRs can be written.

Longterm follow-up in European respiratory health studies - patterns and implications.

BACKGROUND: Selection bias is a systematic error in epidemiologic studies that may seriously distort true measures of associations between exposure and disease. Observational studies are highly susceptible to selection bias, and researchers should therefore always examine to what extent selection bias may be present in their material and what characterizes the bias in their material. In the present study we examined long-term participation and consequences of loss to follow-up in the studies Respiratory Health in Northern Europe (RHINE), Italian centers of European Community Respiratory Health Survey (I-ECRHS), and the Italian Study on Asthma in Young Adults (ISAYA). METHODS: Logistic regression identified predictors for follow-up participation. Baseline prevalence of 9 respiratory symptoms (asthma attack, asthma medication, combined variable with asthma attack and/or asthma medication, wheeze, rhinitis, wheeze with dyspnea, wheeze without cold, waking with chest tightness, waking with dyspnea) and 9 exposure-outcome associations (predictors sex, age and smoking; outcomes wheeze, asthma and rhinitis) were compared between all baseline participants and long-term participants. Bias was measured as ratios of relative frequencies and ratios of odds ratios (ROR). RESULTS: Follow-up response rates after 10 years were 75% in RHINE, 64% in I-ECRHS and 53% in ISAYA. After 20 years of follow-up, response was 53% in RHINE and 49% in I-ECRHS. Female sex predicted long-term participation (in RHINE OR (95% CI) 1.30(1.22, 1.38); in I-ECRHS 1.29 (1.11, 1.50); and in ISAYA 1.42 (1.25, 1.61)), as did increasing age. Baseline prevalence of respiratory symptoms were lower among long-term participants (relative deviations compared to total baseline population 0-15% (RHINE), 0-48% (I-ECRHS), 3-20% (ISAYA)), except rhinitis which had a slightly higher prevalence. Most exposure-outcome associations did not differ between long-term participants and all baseline participants, except lower OR for rhinitis among ISAYA long-term participating smokers (relative deviation 17% (smokers) and 44% (10-20 pack years)). CONCLUSIONS: We found comparable patterns of long-term participation and loss to follow-up in RHINE, I-ECRHS and ISAYA. Baseline prevalence estimates for long-term participants were slightly lower than for the total baseline population, while exposure-outcome associations were mainly unchanged by loss to follow-up.

Occupational exposure and new-onset asthma in a population-based study in Northern Europe (RHINE).

OBJECTIVES: In a large population-based study among adults in northern Europe the relation between occupational exposure and new-onset asthma was studied. METHODS: The study comprised 13 284 subjects born between 1945 and 1973, who answered a questionnaire 1989-1992 and again 1999-2001. Asthma was defined as 'Asthma diagnosed by a physician' with reported year of diagnose. Hazard ratios (HR), for new-onset adult asthma during 1980-2000, were calculated using a modified job-exposure matrix as well as high-risk occupations in Cox regression models. The analyses were made separately for men and women and were also stratified for atopy. RESULTS: During the observation period there were 429 subjects with new-onset asthma with an asthma incidence of 1.3 cases per 1000 person-years for men and 2.4 for women. A significant increase in new-onset asthma was seen for men exposed to plant-associated antigens (HR = 3.6; 95% CI [confidence interval] = 1.4-9.0), epoxy (HR = 2.4; 95% CI = 1.3-4.5), diisocyanates (HR = 2.1; 95% CI = 1.2-3.7) and accidental peak exposures to irritants (HR = 2.4; 95% CI = 1.3-4.7). Both men and women exposed to cleaning agents had an increased asthma risk. When stratifying for atopy an increased asthma risk were seen in non-atopic men exposed to acrylates (HR = 3.3; 95% CI = 1.4-7.5), epoxy compounds (HR = 3.6; 95% CI = 1.6-7.9), diisocyanates and accidental peak exposures to irritants (HR = 3.0; 95% CI = 1.2-7.2). Population attributable risk for occupational asthma was 14% for men and 7% for women. CONCLUSIONS: This population-based study showed that men exposed to epoxy, diisocyanates and acrylates had an increased risk of new-onset asthma. Non-atopics seemed to be at higher risk than atopics, except for exposure to high molecular weight agents. Increased asthma risks among cleaners, spray painters, plumbers, and hairdressers were confirmed.

Gender differences in prevalence, diagnosis and incidence of allergic and non-allergic asthma: a population-based cohort.

BACKGROUND: Although women with severe non-allergic asthma may represent a substantial proportion of adults with asthma in clinical practice, gender differences in the incidence of allergic and non-allergic asthma have been little investigated in the general population. METHODS: Gender differences in asthma prevalence, reported diagnosis and incidence were investigated in 9091 men and women randomly selected from the general population and followed up after 8-10 years as part of the European Community Respiratory Health Survey. The protocol included assessment of bronchial responsiveness, IgE specific to four common allergens and skin tests to nine allergens. RESULTS: Asthma was 20% more frequent in women than in men over the age of 35 years. Possible under-diagnosis of asthma appeared to be particularly frequent among non-atopic individuals, but was as frequent in women as in men. The follow-up of subjects without asthma at baseline showed a higher incidence of asthma in women than in men (HR 1.94; 95% CI 1.40 to 2.68), which was not explained by differences in smoking, obesity or lung function. More than 60% of women and 30% of men with new-onset asthma were non-atopic. The incidence of non-allergic asthma was higher in women than in men throughout all the reproductive years (HR 3.51; 95% CI 2.21 to 5.58), whereas no gender difference was observed for the incidence of allergic asthma. CONCLUSIONS: This study shows that female sex is an independent risk factor for non-allergic asthma, and stresses the need for more careful assessment of possible non-allergic asthma in clinical practice, in men and women.

Early age at menarche, lung function, and adult asthma.

RATIONALE: hormonal and metabolic status appears to influence lung health in women, and there are findings suggesting that early menarche may be related to asthma, cardiovascular disease, diabetes, and breast cancer. OBJECTIVES: this study investigates whether age at menarche is related to adult lung function and asthma. METHODS: among participants in the European Community Respiratory Health Survey II, 3,354 women aged 27-57 years from random population samples in 21 centers responded to a questionnaire concerning women's health (1998-2002). Of these women, 2,873 had lung function measurements, 2,136 had measurements of bronchial hyperreactivity, and 2,743 had IgE measurements. Logistic, linear, and negative binomial regression analyses included adjustment for age, height, body mass index, education, smoking, family size, and center. MEASUREMENTS AND MAIN RESULTS: FEV(1) and FVC were lower and asthma was more common in women with early menarche. Women reporting menarche at age 10 years or less, as compared with women with menarche at age 13 years (reference category), had lower FEV(1) (adjusted difference, -113 ml; 95% confidence interval [CI], -196 to -33 ml) and FVC (-126 ml; 95% CI, -223 to -28 ml); also lower FEV(1) expressed as a percentage of the predicted value (-3.28%; 95% CI, -6.25 to -0.30%) and FVC expressed as a percentage of the predicted value (-3.63%; 95% CI, -6.64 to -0.62%). Women with early menarche more often had asthma symptoms (odds ratio, 1.80; 95% CI, 1.09-2.97), asthma with bronchial hyperreactivity (odds ratio, 2.79; 95% CI, 1.06-7.34), and higher asthma symptom score (mean ratio, 1.58; 95% CI, 1.12-2.21). CONCLUSIONS: women with early menarche had lower lung function and more asthma in adulthood. This supports a role for metabolic and hormonal factors in women's respiratory health.

Dietary patterns and risk of asthma: results from three countries in European Community Respiratory Health Survey-II.

Dietary patterns offer an alternative to the analysis of individual foods or nutrients in nutritional epidemiological studies. The aim of the present study was to identify dietary patterns common to different European countries and examine their associations with asthma. In five study centres (two in Germany, two in the UK and one in Norway), 1174 adults aged 29-55 years completed a FFQ and respiratory symptoms questionnaire. A meta-analytic approach was used to identify the dietary patterns and analyse them in relation to current asthma, asthma symptoms and bronchial responsiveness (BHR). Two patterns emerged, generally correlating with the same foods at different centres: one associated with intake of meats and potatoes; the other with fish, fruits and vegetables. There was no evidence that the fish, fruits and vegetables pattern was associated with asthma (OR 1.11 (95 % CI 0.93, 1.33)), symptom score (ratio of means 1.07 (0.98, 1.17)) or BHR (regression coefficient - 0.01 ( - 0.12, 0.10)), though these CI appeared to rule out large protective effects of consuming these foods. There was no overall evidence that the meat and potato pattern was associated with asthma (OR 1.02 (0.79, 1.31)), symptom score (ratio of means 1.07 (0.84, 1.36)) or BHR (regression coefficient - 0.08 ( - 0.27, 0.10)), but there was heterogeneity between centres in the association with symptom score: a negative association at the two German centres; a positive association at the others. Heterogeneity in a multi-centre observational study of diet could suggest alternative explanations for apparent effects of diet, such as uncontrolled confounding.

Respiratory symptoms in adults are related to impaired quality of life, regardless of asthma and COPD: results from the European community respiratory health survey.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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. 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%. In fact, two studies have reported that more than half of the adult population suffers from one or more respiratory symptoms. 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, asthma, and even all-cause mortality in a general population study . 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). The prevalence of respiratory symptoms exceeds the combined prevalences of asthma and COPD, and both asthma and COPD are frequently undiagnosed diseases. Thus, the high prevalence of respiratory 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 619, but no study of respiratory symptoms 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.

Oral contraception, body mass index, and asthma: a cross-sectional Nordic-Baltic population survey.

BACKGROUND: Emerging evidence suggests that sex steroid hormones may influence airways obstruction, and that metabolic status may modify potential effects. OBJECTIVE: This study investigated the association between use of oral contraceptive pills (OCPs) and asthma in a Nordic-Baltic population-based study, while taking into account possible interplay with body mass index (BMI). METHODS: Postal questionnaires were sent to subjects in Denmark, Estonia, Iceland, Norway, and Sweden from 1999 to 2001 (response rate in women, 77%). Pregnant women, women using hormone replacement therapy, and women >45 years were excluded. Analyses included 5791 women 25 to 44 years old, of whom 961 (17%) used OCP. Logistic regression analyses included adjustment for smoking, irregular menstruation, BMI, age, type of dwelling, and center. RESULTS: Oral contraceptive pills were associated with increased risk for asthma (odds ratio, 1.42; 95% CI, 1.09-1.86), asthma with hay fever (1.48; 1.08-2.03), wheeze with shortness of breath (1.27; 1.02-1.60), hay fever (1.25; 1.06-1.48), and >/=3 asthma symptoms (1.29; 1.05-1.58). The findings were consistent between centers. The associations were present only among normal weight women (BMI 20-25 kg/m(2), asthma: 1.45; 1.02-2.05) and overweight women (BMI >25kg/m(2): 1.91; 1.20-3.02), but not among lean women (BMI <20 kg/m(2): 0.41; 0.12-1.40). Interaction between BMI and OCP in association with asthma was significant (P(interaction) < .05). CONCLUSIONS: Women using oral contraceptive pills had more asthma. This was found only in normal weight and overweight women, indicating interplay between sex hormones and metabolic status in effect on the airways. The findings originate from a cross-sectional postal survey and should be interpreted with caution; it is recommended that asthma symptoms are included in clinical trials of oral contraception.

Lung function, respiratory symptoms, and the menopausal transition.

BACKGROUND: There is limited information on potential changes in respiratory health when women enter the menopausal transition. OBJECTIVE: We sought to investigate whether the menopausal transition is related to lung function and asthma and whether body mass index (BMI) modifies associations. METHODS: Four thousand two hundred fifty-nine women from 21 centers (ECRHS II, 2002) responded to a questionnaire concerning women's health. Women aged 45 to 56 years not using exogenous sex hormones (n = 1274) were included in the present analysis. Lung function measurements (n = 1120) and serum markers of hormonal status (follicle-stimulating hormone, luteinizing hormone, and estradiol; n = 710) were available. Logistic and linear regression analyses were adjusted for BMI, age, years of education, smoking status, center, and height. RESULTS: Women not menstruating for the last 6 months (n = 432, 34%) had significantly lower FEV(1) values (-120 mL [95% CI, -177 to -63]), lower forced vital capacity values (-115 mL [95% CI, -181 to -50]), and more respiratory symptoms (odds ratio [OR], 1.82 [95% CI, 1.27-2.61]) than those menstruating regularly. Results were similar when restricting analyses to those who never smoked. Associations were significantly stronger in women with BMIs of less than 23 kg/m(2) (respiratory symptoms: OR, 4.07 [95% CI, 1.88-8.80]; FEV(1) adjusted difference: -166 [95% CI, -263 to -70]) than in women with BMIs of 23 to 28 kg/m(2) (respiratory symptoms: OR, 1.10 [95% CI, 0.61-1.97], P(interaction): .04; FEV(1) adjusted difference, -54 [95% CI, -151 to 43], P(interaction) = .06). CONCLUSIONS: Menopause is associated with lower lung function and more respiratory symptoms, especially among lean women.

Early life environment and snoring in adulthood.

BACKGROUND: To our knowledge, no studies of the possible association of early life environment with snoring in adulthood have been published. We aimed to investigate whether early life environment is associated with snoring later in life. METHODS: A questionnaire including snoring frequency in adulthood and environmental factors in early life was obtained from 16,190 randomly selected men and women, aged 25-54 years, in Sweden, Norway, Iceland, Denmark and Estonia (response rate 74%). RESULTS: A total of 15,556 subjects answered the questions on snoring. Habitual snoring, defined as loud and disturbing snoring at least 3 nights a week, was reported by 18%. Being hospitalized for a respiratory infection before the age of two years (adjusted odds ratio (OR) = 1.27; 95% confidence interval (CI) 1.01-1.59), suffering from recurrent otitis as a child (OR = 1.18; 95%CI 1.05-1.33), growing up in a large family (OR = 1.04; 95%CI 1.002-1.07) and being exposed to a dog at home as a newborn (OR = 1.26; 95%CI 1.12-1.42) were independently related to snoring later in life and independent of a number of possible confounders in adulthood. The same childhood environmental factors except household size were also related with snoring and daytime sleepiness combined. CONCLUSION: The predisposition for adult snoring may be partly established early in life. Having had severe airway infections or recurrent otitis in childhood, being exposed to a dog as a newborn and growing up in a large family are environmental factors associated with snoring in adulthood.