Doctor-diagnosed Asthma Research Articles

Impaired Respiratory Function in Women With PCOS Compared With Matched Controls From a Population-Based Study.

Increased prevalence of asthma has been reported from epidemiological studies in women with polycystic ovary syndrome (PCOS). To investigate respiratory function in women with PCOS compared with controls in a clinical setting. An 8-year clinical follow-up study including self-reported asthma diagnoses and spirometry of women with PCOS randomized to metformin or placebo during pregnancy in the original studies (the Pilot and the PregMet-study), compared with matched controls from a population-based cohort study (The HUNT Study). Secondary and tertiary care centers. A total of 145 women with PCOS (54% of original cohort) were matched 1:3 to controls, on gender, age, and smoking-status. Self-reported doctor-diagnosed asthma (DDA), percentage of predicted forced expiratory volume in the first second of expiration (FEV1 % predicted), percentage of predicted forced vital capacity (FVC % predicted). Women with PCOS reported more DDA compared with controls (19% vs 9%; P < 0.01). Spirometry indicated a combined obstructive (FEV1 % predicted, 93.7 vs 102.0; P < 0.01) and restrictive (FVC % predicted, 94.5 vs 103.7; P < 0.01) respiratory impairment in PCOS compared with controls. Metformin in pregnancy did not affect respiratory function at follow-up. Women with PCOS reported higher prevalence of DDA compared with controls matched for age and smoking status. In addition, respiratory function was decreased, with both obstructive and restrictive components. Further insight to the underlying pathogenesis of these observations is needed. ClinicalTrials.gov: The PregMet study: NCT00159536. The Pilot study: NCT03259919.

Air pollution exposures from multiple point sources and risk of incident chronic obstructive pulmonary disease (COPD) and asthma

BackgroundExposure to environmental air pollutants exacerbates respiratory illness, but prospective studies of disease incidence are uncommon. Further, attempts to estimate effects from multiple point sources have rarely been undertaken. The current study examined risk of incident chronic obstructive pulmonary disease (COPD) and asthma in association with emissions of multiple air pollutants from point pollution sources in Australia. MethodsWe analyzed prospective cohort data from the Australian Longitudinal Study on Women's Health. Women from three age-cohorts (N = 35,755) were followed for up to 21 years for incident COPD and asthma. Exposures were measured from the National Pollutant Inventory and included carbon monoxide, nitrogen oxides, sulfur dioxide, and particulate matter (PM2.5 and PM10). We identified inverse-distance weighted emissions in kilograms that women experienced over time from point sources within 10 km of their residences.Cox proportional hazards regression models examined risk of self-reported doctor-diagnosed COPD and asthma in association with pollutant exposures and covariates. ResultsNew COPD cases numbered 3616 (11.5%) and new asthma cases numbered 2725 (9.4%). Participants were exposed to an average of 47–59 sites with air pollution emissions within 10 km of their residences. Fossil fuel electricity generation and mining made the largest contributions to air pollution but hundreds of other types of emissions also occurred. Controlling for covariates, all five air pollutants modeled individually were significantly associated with risk of COPD. Modeled jointly, only sulfur dioxide (SO2) remained significantly associated with COPD (HR = 1.038, 95% CI = 1.010–1.067), although the five pollutants were highly correlated (r = 0.89). None of the pollutants were significantly associated with adult onset asthma. Cohort-specific analyses indicated that COPD risk was significantly associated with SO2 exposure for younger (HR = 1.021, CI = 1.001–1.047), middle-age (HR = 1.019, CI = 1.004–1.034) and older cohorts (HR = 1.025, CI = 1.004–1.047). ConclusionsMultiple exposure sources and pollutants contributed to COPD risk, including electricity generation and mining but extending to many industrial processes. The results highlight the importance of policy efforts and technological improvements to reduce harmful air pollution emissions across the industrial landscape.

Asthma and Dietary Intake of Fish, Seaweeds, and Fatty Acids in Korean Adults.

The dietary intake of fish and fatty acid may influence the risk of asthma, yet epidemiological research remains controversial and inconclusive. We examined the association between asthma and the dietary intake of fish, seaweeds, and fat in a Korean population, aged 19 to 64 years, using the data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2013–2016 (n = 13,038). The prevalence of doctor-diagnosed asthma and medication prescribed asthma were 2.5% and 1.0%, respectively. The subjects with medication prescribed asthma had significantly lower consumption of seaweeds (p = 0.0110) and lower n3/n6 polyunsaturated fatty acid (PUFA) (p = 0.0275) as compared to subjects without medication prescribed asthma. Multiple logistic regression analysis showed that the odds ratio (OR) (95% confidence interval, CI) of doctor-diagnosed asthma in the highest quartile were 0.63 (0.41–0.97) and 0.66 (0.44–1.00) for fish and seaweeds respectively, compared to the lowest quartile after adjusting confounding factors. Furthermore, there were significant inverse associations between medication prescribed asthma and seaweeds [OR (95% CI) = 0.37 (0.19–0.70)], n-3 PUFA [OR (95% CI) = 0.43 (0.21–0.89)] and n3/n6 [OR (95% CI) = 0.47 (0.22–0.99)] intake after adjusting for confounding factors. These results suggest, that the higher consumption of fish and seaweed and the high ratio of n-3 to n-6 PUFA may be associated with a lower prevalence of asthma.

Association Between Occupational Exposure to Disinfectants and Asthma in Young Adults Working in Cleaning or Health Services

To analyze the association of occupational disinfectants use with asthma and wheezing in young professionals. Three hundred sixty-five participants from the German Study on Occupational Allergy Risks II aged 20 to 24 years and working in cleaning or health services answered a questionnaire on respiratory health, occupational exposure to disinfectants, and potential confounders. By logistic regression, we calculated the association between duration of occupational disinfectants exposure and doctor-diagnosed asthma, current asthma, and current wheezing. Individuals exposed to disinfectants for more than 12 months had almost three times the odds of doctor-diagnosed asthma compared with those not exposed (odds ratio [OR]: 2.99, 95% confidence interval [CI]: 1.36-6.55). Our findings provide some further evidence for an association between occupational exposure to disinfectants and asthma, indicating that this association can be seen already after the first year of exposure.

SERPINA1 gene polymorphisms in a population-based ALSPAC cohort.

There is an association between persistent preschool wheezing phenotypes and school-age asthma. These wheezing/asthma phenotypes likely represent clinical entities having specific genetic risk factors. The SERPINA1 gene encodes α 1 -antitrypsin (AAT), and mutations in the gene are important in the pathophysiology of pulmonary diseases. We hypothesized that there might be an association between SERPINA1 gene polymorphisms and the risk of developing wheezing/school age asthma. To examine 10 single nucleotide polymorphisms (SNPs) of SERPINA1 (rs6647, rs11832, rs17580, rs709932, rs1243160, rs2854254, rs8004738, rs17751769, rs28929470, and rs28929474) and relate them to childhood wheezing phenotypes and doctor-diagnosed asthma in the population-based Avon Longitudinal Study of Parents and Children (ALSPAC) cohort. Wheeze data, reports of physician-diagnosed asthma and data on the SERPINA1 gene SNPs, were available for 7964 children. Binary logistic regression was used to assess the associations between allele prevalence and wheezing and asthma phenotypes. P values were adjusted to account for multiple hypotheses using the Benjamini-Hochberg false discovery rate. Only within a subgroup of children with asthma who had no prior diagnosis of preschool wheeze was there a trend for association between rs28929474 (Glu342Lys, Pi*Z causing AAT deficiency; P = .0058, adjusted P = .058). No SNP was associated with wheezing and asthma in those with preschool wheeze. Analyzed SNPs in SERPINA1 are not associated with wheezing/asthma phenotypes. Only rs28929474, the most common pathologic SNP (Pi*Z) in the SERPINA1 gene, might be associated with a risk of developing school-age asthma without exhibiting preschool wheeze.

Exposure to Indoor Mouldy Odour Increases the Risk of Asthma in Older Adults Living in Social Housing.

Background: Indoor dampness is thought to affect around 16% of European homes. It is generally accepted that increased exposure to indoor dampness and mould contamination (e.g., spores and hyphae) increases the risk of developing and/or exacerbating asthma. Around 30% of people in the Western world have an allergic disease (e.g., allergy, wheeze and asthma). The role of indoor mould contamination in the risk of allergic diseases in older adults is yet to be fully explored. This is of interest because older people spend more time indoors, as well as facing health issues due to the ageing process, and may be at greater risk of developing and/or exacerbating asthma as a result of indoor dampness. Methods: Face-to-face questionnaires were carried out with 302 participants residing in social housing properties located in South West England. Self-reported demographic, mould contamination (i.e., presence of mould growth and mouldy odour) and health information was linked with the asset management records (e.g., building type, age and levels of maintenance). Multivariate logistic regression was used to calculate the odd ratios and confidence intervals of developing and/or exacerbating asthma, wheeze and allergy with exposure to reported indoor mould contamination. We adjusted for a range of factors that may affect asthma outcomes, which include age, sex, current smoking, presence of pets, education, and building type and age. To assess the role of mould contamination in older adults, we compared younger adults to those aged over 50 years. Results: Doctor-diagnosed adult asthma was reported by 26% of respondents, 34% had current wheeze while 18% had allergies. Asthma was common among subjects exposed to reported visible mould (32%) and reported mouldy odour (42%). Exposure to visible mould growth and mouldy odour were risk factors for asthma, but not for wheeze or allergy. Exposure to mouldy odour increased the risk of asthma in adults over the age of 50 years (odds ratio (OR) 2.4, 95% confidence interval (CI) 1.10–5.34) and the risk was higher for females than for males (OR 3.5, 95% CI 1.37–9.08). These associations were modified by a range of built environment characteristics. Conclusions: We found that older adults living in social (public) housing properties, specifically women, may be at higher risk of asthma when exposed to mouldy odour, which has a number of implications for policy makers and practitioners working in the health and housing sector. Additional measures should be put in place to protect older people living in social housing against indoor damp and mould contamination.

FeNO level and allergy status among school children in Terengganu, Malaysia

Background: Almost one third of the world population suffers from allergic conditions. Respiratory symptoms are common in Malaysian children but there are few studies on fractional exhaled nitric oxide (FeNO), inclusive of field clinical test for asthma among children in Malaysia. The aim was to provide insight on factors related to level of FeNO among students in Terengganu, Malaysia.Methods: In total, 487 randomly selected students from eight secondary schools participated (13–14 years old). A Standardized questionnaire was used to obtained information on doctors’ diagnosed asthma, current asthma and respiratory symptoms. FeNO measurement and skin prick test (SPT to common allergen) were conducted.Results: The geometric mean FeNO was 16.7 ppb. Totally, 38.4% of students had elevated FeNO level (>20 ppb) and 40.3% had had positive SPT to house dust mites allergens (HDM), Dermatophagoides pteronyssinus (Der p 1), Dermatophagoides farinae (Der f 1) or Felis domisticus (cat). Male gender, height, parental history of allergy, self-reported allergy, and atopy were associated with FeNO. In particular, a combination of sensitization to HDM or cat and elevated FeNO were associated with doctor-diagnosed asthma and self-reported allergy to food, pollen and cat.Conclusion: Asthma, respiratory symptoms and sensitization to HDM and cat are common among students and presence of elevated FeNO levels indicate ongoing airway inflammation.

Maternal Dietary Inflammatory Potential and Quality Are Associated with Offspring Asthma Risk over 10-year Follow-up: The Lifeways Cross-Generation Cohort Study (OR35-05-19)

ObjectivesAsthma is the most common childhood chronic health condition. Maternal antenatal diet has been associated with offspring asthma risk, but long-term offspring follow-up (> 5 years) and studies investigating maternal whole diet quality and inflammatory potential are rare. We thus aimed to elucidate these associations using data from a prospective birth cohort study in Ireland. MethodsEarly pregnancy dietary data were obtained using a validated food frequency questionnaire. The Dietary Inflammatory Index (DII®) is a literature-based method to quantify dietary inflammatory potential; a higher score indicates a more pro-inflammatory diet. The Healthy Eating Index (HEI) 2015 contains 9 adequacy and 4 moderation components; a higher score indicates better dietary quality. Doctor-diagnosed offspring asthma status (general practitioner or parent reports) for the first 10 years of life was collected at 3-, 5-, and 9-year follow-up. A total of 862 mother-child pairs (singleton pregnancy with information on maternal diets and offspring asthma status) were included. The longitudinal association between maternal energy-adjusted DII and HEI scores and offspring asthma status was assessed using generalized estimating equations. Missing covariates were accounted for using 20 multiple imputations. ResultsCumulative offspring asthma incidence was 21% over the 10-year period. In the main models, adjusted for maternal lifestyle and sociodemographic factors, a higher DII score was associated with higher risk of offspring asthma (OR: 1.34; 95% CI: 1.10, 1.65; P = 0.004; per 1 SD score increment), while a higher HEI score was associated with lower risk (OR: 0.77; 95% CI: 0.64, 0.93; P = 0.006). Results persisted with further adjustment for childhood factors (breastfeeding, childcare attendance, dietary quality, active and sedentary time), damp in house and parental asthma history. Similar associations were observed when DII and HEI scores were modeled in quartiles (both P-trends < 0.05; Figure 1). ConclusionsOur results suggest that a pro-inflammatory and low-quality diet during pregnancy is associated with higher risk of offspring asthma. These results add to the knowledge base for informing maternal pregnancy dietary recommendations to optimize offspring health. Funding SourcesIrish Health Research Board, Science Foundation Ireland, and the European Union. Supporting Tables, Images and/or Graphs▪

Association between parental perceptions of odors and childhood asthma in subtropical South China with a hot humid climate

Home environment is suggested to be an essential influencing factor for asthma development or asthma exacerbation. However, the association between home environment and childhood asthma among preschool children in the hot humid subtropical region in South China is unclear. We investigated doctor-diagnosed asthma in preschool children due to the parental perception of odors in homes. A total of 1946 children aged from 3 to 6 years from 22 kindergartens in Foshan were randomly recruited for this study in May 2016. The associations among childhood asthma, indoor environment and parental perceptions of odors were examined by using logistic regression model in terms of odds ratio (OR) and 95% confidence interval (CI). Parental atopy had the highest risk for childhood asthma with odds ratio = 6.007 (95% CI: 2.369–15.231). Parental perception of dry air significantly increased asthma with odds ratio = 1.284 (95% CI: 1.027–1.606). The parental perceptions of odors were strongly related with new furniture at home. We conclude that parental perception of dry air is a risk factor for the increase of childhood asthma in the present study. Hence, our study indicates a need to control the household humidity level and reduce the usage of new furniture, in order to reduce the risk of childhood asthma in South China.

Shared and distinct genetic risk factors for childhood-onset and adult-onset asthma: genome-wide and transcriptome-wide studies

Childhood-onset and adult-onset asthma differ with respect to severity and comorbidities. Whether they also differ with respect to genetic risk factors has not been previously investigated in large samples. The goals of this study were to identify shared and distinct genetic risk loci for childhood-onset and adult-onset asthma, and to identify the genes that might mediate the effects of associated variation. We did genome-wide and transcriptome-wide studies, using data from the UK Biobank, in individuals with asthma, including adults with childhood-onset asthma (onset before 12 years of age), adults with adult-onset asthma (onset between 26 and 65 years of age), and adults without asthma (controls; aged older than 38 years). We did genome-wide association studies (GWAS) for childhood-onset asthma and adult-onset asthma each compared with shared controls, and for age of asthma onset in all asthma cases, with a genome-wide significance threshold of p<5 × 10-8. Enrichment studies determined the tissues in which genes at GWAS loci were most highly expressed, and PrediXcan, a transcriptome-wide gene-based test, was used to identify candidate risk genes. Of 376 358 British white individuals from the UK Biobank, we included 37 846 with self-reports of doctor-diagnosed asthma: 9433 adults with childhood-onset asthma; 21 564 adults with adult-onset asthma; and an additional 6849 young adults with asthma with onset between 12 and 25 years of age. For the first and second GWAS analyses, 318 237 individuals older than 38 years without asthma were used as controls. We detected 61 independent asthma loci: 23 were childhood-onset specific, one was adult-onset specific, and 37 were shared. 19 loci were associated with age of asthma onset. The most significant asthma-associated locus was at 17q12 (odds ratio 1·406, 95% CI 1·365-1·448; p=1·45 × 10-111) in the childhood-onset GWAS. Genes at the childhood onset-specific loci were most highly expressed in skin, blood, and small intestine; genes at the adult onset-specific loci were most highly expressed in lung, blood, small intestine, and spleen. PrediXcan identified 113 unique candidate genes at 22 of the 61 GWAS loci. Single-nucleotide polymorphism-based heritability estimates were more than three times larger for childhood-onset asthma (0·327) than for adult-onset disease (0·098). The onset of disease in childhood was associated with additional genes with relatively large effect sizes, with the largest odds ratio observed at the FLG locus at 1q21.3 (1·970, 95% CI 1·823-2·129). Genetic risk factors for adult-onset asthma are largely a subset of the genetic risk for childhood-onset asthma but with overall smaller effects, suggesting a greater role for non-genetic risk factors in adult-onset asthma. Combined with gene expression and tissue enrichment patterns, we suggest that the establishment of disease in children is driven more by dysregulated allergy and epithelial barrier function genes, whereas the cause of adult-onset asthma is more lung-centred and environmentally determined, but with immune-mediated mechanisms driving disease progression in both children and adults. US National Institutes of Health.

Usefulness of mannitol challenge testing for diagnosing asthma in everyday clinical practice

Background: The mannitol test is widely used for assessment of airway responsiveness in patients with possible asthma, but our knowledge of the value in everyday clinical practice is limited.Objective: To investigate the diagnostic value of the mannitol test in a clinical setting.Methods: All patients having a mannitol challenge test as part of their diagnostic work-up for asthma at the respiratory outpatient clinic, Hvidovre Hospital, over a 5-year period were included in the present analysis. Case history, including previous diagnoses, spirometry, exhaled nitric oxide (FENO) was obtained. The mannitol challenge was performed according to guidelines, i.e. increasing doses of mannitol (from 5 to 635 mg) until maximum dose or a 15% decline in FEV1 (PD15) was achieved (positive test defined as a PD15 < 635 mg).Results: Our cohort comprised 566 patients (210 men). Post-challenge, 247 patients were diagnosed with asthma by a specialist in respiratory medicine, of whom 138 (56%) had a positive mannitol test. A diagnosis of asthma was ruled out by the specialist in 319 individuals, of whom 18 (6%) had a positive mannitol test and 77 (24%) previous doctor-diagnosed asthma (but with no evidence of a confirmatory test). The specificity and sensitivity of the test was 94% and 56%, respectively. Female gender (p = 0.005), increasing BMI (p < 0.001), exercise-induced cough (p = 0.002), night-time respiratory symptoms (p = 0.002), low FEV1/FVC ratio (p = 0.008) and high FENO (p < 0.001) were determinants for a positive mannitol test.Conclusion: In everyday clinical work-up of patients with possible asthma, the sensitivity and specificity of the mannitol challenge test is comparable to previous controlled trials.

Household dampness-related exposures in relation to childhood asthma and rhinitis in China: A multicentre observational study

During 2010–2012, we conducted an observational study on household environment and health outcomes among 40,010 preschool children from seven cities of China. Here we examined associations of six dampness-related indicators (visible mold spots, visible damp stains, damp clothing and/or bedding, water damage, condensation on windowpane, moldy odor) in the current residence and three dampness-related indicators (visible mold spots, condensation on windowpane, moldy odor) in the early residence with childhood asthma and rhinitis. In the multi-level logistic regression analyses, visible mold spots and visible damp stains in the current residence were significantly associated with the increased odds of doctor-diagnosed asthma and allergic rhinitis during lifetime-ever (adjusted odd ratios (AORs) range: 1.18–1.35). All dampness-related indicators were significantly associated with increased odds of wheeze and rhinitis during lifetime-ever and in the past 12 months (AORs range: 1.16–2.64). The cumulative numbers of damp indicators had positively dose-response relationships with the increased odds of the studied diseases. These associations for wheeze and rhinitis were similar between northern children and southern children. Similar results were found in the sensitive analyses among children without a family history of allergies and among children without asthma and allergic rhinitis. For 3–6 years-old children in mainland of China in 2011, we speculated that about 90,000 (2.02%) children with asthma and about 59,000 (1.09%) children with allergic rhinitis could be attributable to exposing to visible mold spots in the current residence. Our results suggested that early and lifetime exposures to household dampness indicators are risk factors for childhood asthma and rhinitis.

Unsupervised trajectories of respiratory/allergic symptoms throughout childhood in the PARIS cohort.

Natural course and co-occurrence of asthma, eczema, and allergic rhinitis through childhood are still not fully documented. We aim to identify and characterize profiles based on the time course, severity, and apparent triggers of respiratory/allergy symptoms in school-aged children. Data on occurrence, severity, and triggers of asthma, rhinitis, and dermatitis symptoms were collected annually during the follow-up of the PARIS birth cohort. Children with similar symptom trajectories until 8-9years were grouped into profiles using multidimensional (all symptoms considered simultaneously) cluster analysis. Associations between profiles and different health outcomes were analyzed using logistic or linear regression models. Six distinct symptomatic profiles were identified. A profile was defined by persistent dermatitis symptoms, associated with sensitization to food and aeroallergens. Two profiles were characterized by wheezing: one with early transient wheezing and the other with persistent wheezing related to doctor-diagnosed asthma, airway obstruction, and perennial aeroallergen sensitization. Three profiles were characterized by rhinitis symptoms: one non-allergic and two allergic, either with persistent rhinitis symptoms related to allergic multimorbidity and sensitization to perennial aeroallergens, or with late-onset symptoms, related to both pollen and perennial aeroallergens sensitization as well as low lung function. This study brings further insights into the developmental profiles of respiratory/allergic outcomes from birth to school age. The identified profiles clearly differed regarding objective features such as diagnosed morbidity, sensitization, or lung function measurements, thus highlighting their biologic and clinical relevance. Allergic rhinitis profiles deserve particular attention, since they were likely to be involved in multimorbidity patterns.

Airway hyperresponsiveness in young children with respiratory symptoms: A five-year follow-up

BackgroundRecurrent wheezing in early life is transient in most children. The significance of airway hyperresponsiveness (AHR) in persistence of respiratory symptoms from infancy to early childhood is controversial. ObjectiveWe evaluated whether AHR in wheezy infants predicts doctor-diagnosed asthma (DDA) or AHR at the age of 6 years. MethodsSixty-one wheezy infants (age 6-24 months) were followed up to the median age of 6 years. Lung function and AHR with methacholine challenge test were assessed at infancy and 6 years. The exercise challenge test was performed at the age of 6 years. Atopy was assessed with skin prick tests. ResultsAt 6 years, 21 (34%) of the children had DDA. Children with DDA had higher logarithmic transformed dose-response slope (LOGDRS) to methacholine in infancy than children without DDA (0.047 vs 0.025; P = .033). Furthermore, AHR to methacholine in infancy and at 6 years were associated with each other (r = 0.324, P = .011). Children with exercise-induced bronchoconstriction (EIB) at 6 years were more reactive to methacholine in infancy than those without EIB (P = .019). ConclusionIncreased AHR in symptomatic infants was associated with increased AHR, DDA, and EIB at median the age of 6 years, suggesting early establishment of AHR.

Second-hand smoke exposure in adulthood and lower respiratory health during 20\u2009year follow up in the European Community Respiratory Health Survey

BackgroundEarly life exposure to tobacco smoke has been extensively studied but the role of second-hand smoke (SHS) for new-onset respiratory symptoms and lung function decline in adulthood has not been widely investigated in longitudinal studies. Our aim is to investigate the associations of exposure to SHS in adults with respiratory symptoms, respiratory conditions and lung function over 20 years.MethodsWe used information from 3011 adults from 26 centres in 12 countries who participated in the European Community Respiratory Health Surveys I-III and were never or former smokers at all three surveys. Associations of SHS exposure with respiratory health (asthma symptom score, asthma, chronic bronchitis, COPD) were analysed using generalised linear mixed-effects models adjusted for confounding factors (including sex, age, smoking status, socioeconomic status and allergic sensitisation). Linear mixed-effects models with additional adjustment for height were used to assess the relationships between SHS exposure and lung function levels and decline.ResultsReported exposure to SHS decreased in all 26 study centres over time. The prevalence of SHS exposure was 38.7% at baseline (1990–1994) and 7.1% after the 20-year follow-up (2008–2011). On average 2.4% of the study participants were not exposed at the first, but were exposed at the third examination. An increase in SHS exposure over time was associated with doctor-diagnosed asthma (odds ratio (OR): 2.7; 95% confidence interval (95%-CI): 1.2–5.9), chronic bronchitis (OR: 4.8; 95%-CI: 1.6–15.0), asthma symptom score (count ratio (CR): 1.9; 95%-CI: 1.2–2.9) and dyspnoea (OR: 2.7; 95%-CI: 1.1–6.7) compared to never exposed to SHS. Associations between increase in SHS exposure and incidence of COPD (OR: 2.0; 95%-CI: 0.6–6.0) or lung function (β: − 49 ml; 95%-CI: -132, 35 for FEV1 and β: − 62 ml; 95%-CI: -165, 40 for FVC) were not apparent.ConclusionExposure to second-hand smoke may lead to respiratory symptoms, but this is not accompanied by lung function changes.

Introduction of fish and other foods during infancy and risk of asthma in the All Babies In Southeast Sweden cohort study

The etiology of asthma includes lifestyle factors. Breastfeeding and introduction of complementary foods have been suggested to affect asthma risk, but the scientific foundation is not solid. Children from the birth cohort All Babies In Southeast Sweden study were included (n = 9727). Breastfeeding duration and timing of introduction of infant formula and food were collected prospectively during the first year. Through linkage to the Swedish Patient Register, 948 children were identified with any asthma until age 15–17 years, of which 450 cases were atopic. Breastfeeding duration was not associated to risk of asthma. Introduction of infant formula earlier than at 14 weeks of age was associated with higher risk of non-atopic asthma. Introduction of fish before 43 weeks of age, as compared to later, was associated with a lower risk of asthma, irrespective of atopic classification. Reverse causation was accounted for but did not explain the results.Conclusion: Introduction of infant formula and timing of introduction of fish seem to impact the long-term risk of doctor-diagnosed asthma. Emphasis on the growing body of evidence that early introduction of allergens offers protection against atopic disease should be considered in future recommendations.What is Known:• Breastfeeding and introduction of complementary foods might influence the risk of atopic diseases. Recently, a review stated that more studies are needed to clarify the role for asthma development.What is New:• Introduction of infant formula earlier than at 14 weeks of age was associated with a higher risk of developing non-atopic asthma. The risk was pronounced in children introduced to infant formula before 4 weeks of age while being breastfed less than 4 weeks.• Early fish introduction, before 43 weeks of age, was associated with a lower risk of asthma, independent of atopic classification of asthma.

Respiratory health among office workers in Malaysia and endotoxin and (1,3)-β-glucan in office dust.

OBJECTIVE: To examine the associations between endotoxin and (1,3)-β-glucan concentrations in office dust and respiratory symptoms and airway inflammation among 695 office workers in Malaysia.METHODS: Health data were collected using a questionnaire, sensitisation testing and measurement of fractional exhaled nitric oxide (FeNO). Indoor temperature, relative air humidity (RH) and carbon dioxide (CO₂) were measured in the offices and settled dust was vacuumed and analysed for endotoxin and (1,3)-β-glucan concentrations. Associations were analysed by two level multiple logistic regression.RESULTS: Overall, 9.6% of the workers had doctor-diagnosed asthma, 15.5% had wheeze, 18.4% had daytime attacks of breathlessness and 25.8% had elevated FeNO (≥25 ppb). The median levels in office dust were 11.3 EU/mg endotoxin and 62.9 ng/g (1,3)-β-glucan. After adjusting for personal and home environment factors, endotoxin concentration in dust was associated with wheeze (P = 0.02) and rhinoconjunctivitis (P = 0.007). The amount of surface dust (P = 0.04) and (1,3)-β-glucan concentration dust (P = 0.03) were associated with elevated FeNO.CONCLUSION: Endotoxin in office dust could be a risk factor for wheeze and rhinoconjunctivitis among office workers in mechanically ventilated offices in a tropical country. The amount of dust and (1,3)-β-glucan (a marker of indoor mould exposure) were associated with Th2 driven airway inflammation.

Gender differences in the association between life history of body silhouettes and asthma incidence: Results from the SAPALDIA cohort study

BackgroundThe association of obesity and asthma has been described in children and adults. However, whether a different life course of weight in men and women may explain gender differences in asthma incidence, has not been addressed. ObjectivesUsing data from the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults, we investigated the role of overweight/obesity as measured by body silhouettes at different life stages in men and women for asthma incidence. MethodsOur analysis included 5417 subjects who were asthma free at age 8, followed up to 2011, and had complete covariate information. The main predictor of interest was self-reported body silhouettes at age 8, menarche, 30, 45, menopause, and 60, and additionally changes in body silhouette number across these different time points. Asthma incidence was defined as newly reported doctor-diagnosed asthma after the body silhouette time point. Asthma incidence and its association with body silhouettes was analysed using sex stratified logistic regression, adjusting for age, atopy, urbanity, smoking, parental asthma, education and study area. ResultsMen at age 60 had an increased risk of asthma incidence per unit increase in body silhouette number (OR 1.93, 95% CI 1.13–3.30). This association was stronger in women at age 60 (OR 2.78, 95% CI 1.49–5.18) and observed also at menopause (OR 1.35, 95% CI 1.03–1.78), as well as per unit change in body silhouette number between age 45 – menopause (OR 1.74, 95% CI 1.15–2.63). ConclusionIn this longitudinal study, the risk of incident asthma increased in men and women with a larger body silhouette in late adulthood. In women, this risk appeared present between age 45 and menopause. At age 60, both men and women were at higher risk of asthma incidence per unit increase in body silhouette, the risk being more pronounced in women. The age-related increase of obesity may underlie gender differences in asthma incidence at higher ages.

Cross-sectional associations of vitamin D status with asthma prevalence, exacerbations, and control in New Zealand adults

BackgroundPrevious studies, mostly with children, have reported inconsistent findings on the associations of vitamin D status with asthma prevalence, exacerbations, and control. Because of limited research with adults, we examined these associations in a large community-based sample of New Zealand adults. Methods5110 participants, aged 50–84 years, were recruited from the community into a clinical trial of vitamin D supplementation. The current analysis is based on baseline blood sample collection to measure serum 25-hydroxyvitamin D (25(OH)D), which was deseasonalized for data analyses; and baseline asthma assessment, which included questions on asthma prevalence, urgent medical care for asthma in the previous 12 months, and control of asthma symptoms in the previous 4 weeks. Results702 (13.2%) of 5088 participants reported having doctor-diagnosed asthma. There was no difference in mean (SE) 25(OH)D concentration between participants with and without asthma: 66 (0.9) and 66 (0.4) nmol/L, respectively, adjusting for sex (p = 0.71). However, in multivariable analyses restricted to participants who reported having asthma, mean (SE) 25(OH)D concentration was 6.3 (2.6) nmol/L lower in those who reported having urgent medical care for asthma in the previous 12 months compared to others (p = 0.02), and 10.4 (3.9) nmol/L lower in those with very poor asthma control compared to those who were well-controlled (p = 0.03). ConclusionThese cross-sectional results suggest that asthmatic adults with lower vitamin D status are more likely to receive urgent asthma medical care and to experience poor asthma control. Clinical trials are needed to determine the role of vitamin D supplementation in asthma management.

Asthma-related outcomes associated with indoor air pollutants among schoolchildren from four informal settlements in two municipalities in the Western Cape Province of South Africa.

The health impact of indoor air pollution in informal settlement households has not been extensively studied in South Africa. This cross-sectional study investigated the association between asthma and common indoor exposures among schoolchildren from four informal settlements located in two municipalities in the Western Cape Province. A total of 590 children, aged 9-11years, were recruited. The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was administered to caregivers. Pulmonary function assessment included spirometry and fractional exhaled nitric oxide (FeNO). Phadiatop test for atopy was done. The prevalence of doctor-diagnosed asthma was 3.4% (n=20) among whom only 50% were on treatment. The prevalence of current wheeze was 12.9%, and 17.6% had airway obstruction (FEV1 <lower limit of normal), while 10.2% had airway inflammation (FeNO>35ppb). In adjusted logistic regression models, dampness, visible mold growth, paraffin use for cooking, and passive smoking were associated with a twofold to threefold increased risk in upper and lower airway outcomes. The strongest association was that of visible mold growth with rhinitis (adjusted odds ratio-aOR 3.37, 95% CI: 1.69-6.71). Thus, there is a need for improved diagnosis of childhood asthma and Indoor Air Quality in informal settlement households.