Use of oral moist tobacco (snus) in puberty and its association with asthma in the population-based RHINESSA study.

OBJECTIVES: To investigate the association of early snus use initiation (≤15 years of age) with asthma and asthma symptoms. DESIGN: Cross-sectional analysis of a population-based cohort. SETTING: Study centres in Norway, Sweden, Iceland, Denmark and Estonia, from 2016 to 2019. PARTICIPANTS: 9002 male and female participants above 15 years of age of the Respiratory Health in Northern Europe, Spain and Australia study. MAIN OUTCOME MEASURES: Current asthma and asthma symptoms. RESULTS: The median age of study participants was 28 years (range 15-53) and 58% were women. 20% had used snus, 29% men and 14% women. Overall, 26% of males and 14% of females using snus started ≤15 years of age. Early snus use initiation was associated with having three or more asthma symptoms (OR 2.70; 95% CI 1.46 to 5.00) and a higher asthma symptom score (ß-coefficient (ß) 0.35; 95% CI 0.07 to 0.63) in women. These associations were weak in men (OR 1.23; 95% CI 0.78 to 1.94; ß 0.16; 95% CI -0.06 to 0.38, respectively). There was evidence for an association of early snus initiation with current asthma (OR 1.72; 95% CI 0.88 to 3.37 in women; OR 1.31; 95% CI 0.84 to 2.06 in men). A sensitivity analysis among participants without smoking history showed stronger estimates for all three outcomes, in both men and women, statistically significant for three or more asthma symptoms in women (OR 3.28; 95% CI 1.18 to 9.10). Finally, no consistent associations with asthma outcomes were found for starting snus after age 15 years. CONCLUSIONS: Snus initiation in puberty was associated with higher likelihood of asthma and asthma symptoms, with the highest estimates in females and those without smoking history. These results raise concerns about the health adversities of early snus initiation and emphasise the need for public health initiatives to protect young people from this tobacco product.

Muscle Strength and Male Sexual Function.

Sexual dysfunction, in particular erectile dysfunction, is a common complaint among aging men. Obesity, diabetes, hypertension, and smoking are shown to be independent risk factors for erectile dysfunction, while cardiorespiratory fitness is shown to be protective. Less is known about the role of muscle strength in male sexual function. Our objective was to study the association between male sexual function and typical cardiovascular risk factors, together with exercise and muscle strength. We included data from the fourth wave of the RHINE study. Data on anthropometrics, exercise habits, diseases, muscle strength, and sexual function were collected using questionnaires, including the Aging Males' Symptoms (AMS) scale. We used multivariable logistic regression analysis to measure the association between sexual function and body mass index (BMI), age, smoking, diabetes, hypertension, exercise and muscle strength status. We included 2116 men aged 48-75 from four Nordic-Baltic countries. BMI, age, smoking, diabetes, and hypertension were found to be associated with higher odds of reporting decreased sexual function, while reporting intact muscle strength was associated with lower odds. In a large Nordic-Baltic male study population, we show that known cardiovascular risk factors are associated with decreased sexual function, while reporting intact muscle strength is associated with lower odds of reporting decreased sexual function.

Long-term exposure to low-level air pollution and greenness and mortality in Northern Europe. The Life-GAP project.

BACKGROUND: Air pollution has been linked to mortality, but there are few studies examining the association with different exposure time windows spanning across several decades. The evidence for the effects of green space and mortality is contradictory. OBJECTIVE: We investigated all-cause mortality in relation to exposure to particulate matter (PM2.5 and PM10), black carbon (BC), nitrogen dioxide (NO2), ozone (O3) and greenness (normalized difference vegetation index - NDVI) across different exposure time windows. METHODS: The exposure assessment was based on a combination of the Danish Eulerian Hemispheric Model and the Urban Background Model for the years 1990, 2000 and 2010. The analysis included a complete case dataset with 9,135 participants from the third Respiratory Health in Northern Europe study (RHINE III), aged 40-65 years in 2010, with mortality follow-up to 2021. We performed Cox proportional hazard models, adjusting for potential confounders. RESULTS: Altogether, 327 (3.6 %) persons died in the period 2010-2021. Increased exposures in 1990 of PM2.5, PM10, BC and NO2 were associated with increased all-cause mortality hazard ratios of 1.40 (95 % CI1.04-1.87 per 5 µg/m3), 1.33 (95 % CI: 1.02-1.74 per 10 µg/m3), 1.16 (95 % CI: 0.98-1.38 per 0.4 µg/m3) and 1.17 (95 % CI: 0.92-1.50 per 10 µg/m3), respectively. No statistically significant associations were observed between air pollution and mortality in other time windows. O3 showed an inverse association with mortality, while no association was observed between greenness and mortality. Adjusting for NDVI increased the hazard ratios for PM2.5, PM10, BC and NO2 exposures in 1990. We did not find significant interactions between greenness and air pollution metrics. CONCLUSION: Long term exposure to even low levels of air pollution is associated with mortality. Opening up for a long latency period, our findings indicate that air pollution exposures over time may be even more harmful than anticipated.

Oral bacterial composition associated with lung function and lung inflammation in a community-based Norwegian population.

BACKGROUND: The oral cavity is the gateway to the bacteria community in the lung. Disruption of the symbiotic balance of the oral microbiota has been associated with respiratory diseases. However, little is known about the relationship between oral bacteria and respiratory outcomes in the general population. We aimed to describe the associations between oral bacteria, lung function, and lung inflammation in a community-based population. METHODS: Oral (gingival) samples were collected concurrently with spirometry tests in 477 adults (47% males, median age 28 years) from the RHINESSA study in Bergen, Norway. Bacterial DNA from the 16S rRNA gene from gingival fluid were sequenced by Illumina®MiSeq. Lung function was measured using spirometry and measurement of fractional exhaled nitric oxide (FeNO) were performed to examine airway inflammation. Differential abundance analysis was performed using ANCOM-BC, adjusting for weight, education, and smoking. RESULTS: The abundance of the genera Clostridiales, Achromobacter, Moraxella, Flavitalea and Helicobacter were significantly different among those with low FEV1 (< lower limit of normal (LLN)) as compared to normal FEV1 i.e. ≥ LLN. Twenty-three genera differed in abundance between among those with low FVC < LLN as compared to normal FEV1 ≥ LLN. The abundance of 27 genera from phyla Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria and Sacchribacteria differed significantly between elevated FeNO levels (≥ 50 ppb) compared to FeNO ≤ 25 ppb. CONCLUSION: Oral bacterial composition was significantly different for those with low FEV or FVC as compared to those with normal lung function equal to or higher than LLN. Differential bacterial composition was also observed for elevated FeNO levels.

Cohort profile: the multigeneration Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) cohort.

PURPOSE: The Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) cohort was established to (1) investigate how exposures before conception and in previous generations influence health and disease, particularly allergies and respiratory health, (2) identify susceptible time windows and (3) explore underlying mechanisms. The ultimate aim is to facilitate efficient intervention strategies targeting multiple generations. PARTICIPANTS: RHINESSA includes study participants of multiple generations from ten study centres in Norway (1), Denmark (1), Sweden (3), Iceland (1), Estonia (1), Spain (2) and Australia (1). The RHINESSA core cohort, adult offspring generation 3 (G3), was first investigated in 2014-17 in a questionnaire study (N=8818, age 18-53 years) and a clinical study (subsample, n=1405). Their G2 parents participated in the population-based cohorts, European Community Respiratory Heath Survey and Respiratory Health In Northern Europe, followed since the early 1990s when they were 20-44 years old, at 8-10 years intervals. Study protocols are harmonised across generations. FINDINGS TO DATE: Collected data include spirometry, skin prick tests, exhaled nitric oxide, anthropometrics, bioimpedance, blood pressure; questionnaire/interview data on respiratory/general/reproductive health, indoor/outdoor environment, smoking, occupation, general characteristics and lifestyle; biobanked blood, urine, gingival fluid, skin swabs; measured specific and total IgE, DNA methylation, sex hormones and oral microbiome. Research results suggest that parental environment years before conception, in particular, father's exposures such as smoking and overweight, may be of key importance for asthma and lung function, and that there is an important susceptibility window in male prepuberty. Statistical analyses developed to approach causal inference suggest that these associations may be causal. DNA methylation studies suggest a mechanism for transfer of father's exposures to offspring health and disease through impact on offspring DNA methylation. FUTURE PLANS: Follow-up is planned at 5-8 years intervals, first in 2021-2023. Linkage with health registries contributes to follow-up of the cohort.

Maternal preconception occupational exposure to cleaning products and disinfectants and offspring asthma.

BACKGROUND: Emerging research suggests health effects in offspring after parental chemical exposures before conception. Many future mothers are exposed to potent chemicals at work, but potential offspring health effects are hardly investigated. OBJECTIVE: We sought to investigate childhood asthma in relation to mother's occupational exposure to cleaning products and disinfectants before conception. METHODS: The multicenter Respiratory Health In Northern Europe/Respiratory Health In Northern Europe, Spain and Australia generation study investigated asthma and wheeze starting at age less than 10 years in 3318 mother-offspring pairs. From an asthma-specific Job-Exposure Matrix and mothers' occupational history, we defined maternal occupational exposure to indoor cleaning agents (cleaning products/detergents and disinfectants) starting before conception, in the 2-year period around conception and pregnancy, or after birth. Never-employed mothers were excluded. Exposed groups include cleaners, health care workers, cooks, and so forth. Associations were analyzed using mixed-effects logistic regression and ordinary logistic regression with clustered robust SEs and adjustment for maternal education. RESULTS: Maternal occupational exposure to indoor cleaning starting preconception and continuing (n = 610) was associated with offspring's childhood asthma: odds ratio 1.56 (95% CI, 1.05-2.31), childhood asthma with nasal allergies: 1.77 (1.13-2.77), and childhood wheeze and/or asthma: 1.71 (95% CI, 1.19-2.44). Exposure starting around conception and pregnancy (n = 77) was associated with increased childhood wheeze and/or asthma: 2.25 (95% CI, 1.03-4.91). Exposure starting after birth was not associated with asthma outcomes (1.13 [95% CI, 0.71-1.80], 1.15 [95% CI, 0.67-1.97], 1.08 [95% CI, 0.69-1.67]). CONCLUSIONS: Mother's occupational exposure to indoor cleaning agents starting before conception, or around conception and pregnancy, was associated with more childhood asthma and wheeze in offspring. Considering potential implications for vast numbers of women in childbearing age using cleaning agents, and their children, further research is imperative.

Prenatal and prepubertal exposures to tobacco smoke in men may cause lower lung function in future offspring: a three-generation study using a causal modelling approach.

Mechanistic research suggests that lifestyle and environmental factors impact respiratory health across generations by epigenetic changes transmitted through male germ cells. Evidence from studies on humans is very limited.We investigated multigeneration causal associations to estimate the causal effects of tobacco smoking on lung function within the paternal line. We analysed data from 383 adult offspring (age 18-47 years; 52.0% female) and their 274 fathers, who had participated in the European Community Respiratory Health Survey (ECRHS)/Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) generation study and had provided valid measures of pre-bronchodilator lung function. Two counterfactual-based, multilevel mediation models were developed with: paternal grandmothers' smoking in pregnancy and fathers' smoking initiation in prepuberty as exposures; fathers' forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), or FEV1/FVC z-scores as potential mediators (proxies of unobserved biological mechanisms that are true mediators); and offspring's FEV1 and FVC, or FEV1/FVC z-scores as outcomes. All effects were summarised as differences (Δ) in expected z-scores related to fathers' and grandmothers' smoking history.Fathers' smoking initiation in prepuberty had a negative direct effect on both offspring's FEV1 (Δz-score -0.36, 95% CI -0.63- -0.10) and FVC (-0.50, 95% CI -0.80- -0.20) compared with fathers' never smoking. Paternal grandmothers' smoking in pregnancy had a negative direct effect on fathers' FEV1/FVC (-0.57, 95% CI -1.09- -0.05) and a negative indirect effect on offspring's FEV1/FVC (-0.12, 95% CI -0.21- -0.03) compared with grandmothers' not smoking before fathers' birth nor during fathers' childhood.Fathers' smoking in prepuberty and paternal grandmothers' smoking in pregnancy may cause lower lung function in offspring. Our results support the concept that lifestyle-related exposures during these susceptibility periods influence the health of future generations.

A prospective study on the role of smoking, environmental tobacco smoke, indoor painting and living in old or new buildings on asthma, rhinitis and respiratory symptoms.

We studied associations between tobacco smoke, home environment and respiratory health in a 10 year follow up of a cohort of 11,506 adults in Northern Europe. Multilevel logistic regression models were applied to estimate onset and remission of symptoms. Current smokers at baseline developed more respiratory symptoms (OR = 1.39-4.43) and rhinitis symptoms (OR = 1.35). Starting smoking during follow up increased the risk of new respiratory symptoms (OR = 1.54-1.97) and quitting smoking decreased the risk (OR = 0.34-0.60). ETS at baseline increased the risk of wheeze (OR = 1.26). Combined ETS at baseline or follow up increased the risk of wheeze (OR = 1.27) and nocturnal cough (OR = 1.22). Wood painting at baseline reduced remission of asthma (OR 95%CI: 0.61, 0.38-0.99). Floor painting at home increased productive cough (OR 95%CI: 1.64, 1.15-2.34) and decreased remission of wheeze (OR 95%CI: 0.63, 0.40-0.996). Indoor painting (OR 95%CI: 1.43, 1.16-1.75) and floor painting (OR 95%CI: 1.77, 1.11-2.82) increased remission of allergic rhinitis. Living in the oldest buildings (constructed before 1960) was associated with higher onset of nocturnal cough and doctor diagnosed asthma. Living in the newest buildings (constructed 1986-2001) was associated with higher onset of nocturnal breathlessness (OR = 1.39) and rhinitis (OR = 1.34). In conclusion, smoking, ETS and painting indoor can be risk factors for respiratory symptoms. Wood painting and floor painting can reduce remission of respiratory symptoms. Smoking can increase rhinitis. Living in older buildings can be a risk factor for nocturnal cough and doctor diagnosed asthma. Living in new buildings can increase nocturnal dyspnoea and rhinitis.

Parents' smoking onset before conception as related to body mass index and fat mass in adult offspring: Findings from the RHINESSA generation study.

Emerging evidence suggests that parents' preconception exposures may influence offspring health. We aimed to investigate maternal and paternal smoking onset in specific time windows in relation to offspring body mass index (BMI) and fat mass index (FMI). We investigated fathers (n = 2111) and mothers (n = 2569) aged 39-65 years, of the population based RHINE and ECRHS studies, and their offspring aged 18-49 years (n = 6487, mean age 29.6 years) who participated in the RHINESSA study. BMI was calculated from self-reported height and weight, and FMI was estimated from bioelectrical impedance measures in a subsample. Associations with parental smoking were analysed with generalized linear regression adjusting for parental education and clustering by study centre and family. Interactions between offspring sex were analysed, as was mediation by parental pack years, parental BMI, offspring smoking and offspring birthweight. Fathers' smoking onset before conception of the offspring (onset ≥15 years) was associated with higher BMI in the offspring when adult (ß 0.551, 95%CI: 0.174-0.929, p = 0.004). Mothers' preconception and postnatal smoking onset was associated with higher offspring BMI (onset <15 years: ß1.161, 95%CI 0.378-1.944; onset ≥15 years: ß0.720, 95%CI 0.293-1.147; onset after offspring birth: ß2.257, 95%CI 1.220-3.294). However, mediation analysis indicated that these effects were fully mediated by parents' postnatal pack years, and partially mediated by parents' BMI and offspring smoking. Regarding FMI, sons of smoking fathers also had higher fat mass (onset <15 years ß1.604, 95%CI 0.269-2.939; onset ≥15 years ß2.590, 95%CI 0.544-4.636; and onset after birth ß2.736, 95%CI 0.621-4.851). There was no association between maternal smoking and offspring fat mass. We found that parents' smoking before conception was associated with higher BMI in offspring when they reached adulthood, but that these effects were mediated through parents' pack years, suggesting that cumulative smoking exposure during offspring's childhood may elicit long lasting effects on offspring BMI.

Agreement of offspring-reported parental smoking status: the RHINESSA generation study.

BACKGROUND: With increasing interest in exposure effects across generations, it is crucial to assess the validity of information given on behalf of others. AIMS: To compare adult's report of their parent's smoking status against parent's own report and examine predictors for discrepant answers. METHODS: We studied 7185 offspring (18-51 years) and one of their parents, n = 5307 (27-67 years) participating in the Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) generation study. Information about parent's smoking status during offspring's childhood and mother's smoking status during pregnancy was obtained by questionnaires from parents and their offspring. We calculated sensitivity, specificity and Cohen's Kappa [κ] for agreement using parent's own report as the gold standard. We performed logistic regression to examine if offspring's sex, age, educational level, asthma status, own smoking status or parental status, as well as the parent's sex and amount of smoking during childhood predicted disagreement. RESULTS: The sensitivity for offspring's correct report of parent's smoking status during childhood (0-10 years) was 0.82 (95% CI 0.81-0.84), specificity was 0.95 (95% CI 0.95-0.96) and a good agreement was observed, κ = 0.79 (95% CI 0.78-0.80). Offspring's report of mothers' smoking status during pregnancy showed a lower sensitivity, 0.66 (95% CI 0.60-0.71), a slightly lower specificity, 0.92 (95% CI 0.90-0.95) and a good agreement, κ = 0.61 (95% CI 0.55-0.67). In multivariate logistic regression analysis, offspring not having children was a predictor for discrepant answers (odds ratio [OR] 2.11 [95% CI 1.21-3.69]). Low amount of parents' tobacco consumption, < 10 cigarettes/day (OR 2.72 [95% CI 1.71-4.31]) also predicted disagreement compared to ≥10 cigarettes per day, and so did offspring's reports of fathers' smoking status (OR 1.73 [95% CI 1.09-2.74]) compared to mothers' smoking status. Offspring's sex, asthma status, educational level, smoking status or age was not related to discrepant answers. CONCLUSIONS: Adults report their parent's smoking status during their childhood, as well as their mother' smoking status when pregnant with them, quite accurately. In the absence of parents' direct report, offspring's reports could be valuable.

A three-generation study on the association of tobacco smoking with asthma.

Background: Mothers' smoking during pregnancy increases asthma risk in their offspring. There is some evidence that grandmothers' smoking may have a similar effect, and biological plausibility that fathers' smoking during adolescence may influence offspring's health through transmittable epigenetic changes in sperm precursor cells. We evaluated the three-generation associations of tobacco smoking with asthma. Methods: Between 2010 and 2013, at the European Community Respiratory Health Survey III clinical interview, 2233 mothers and 1964 fathers from 26 centres reported whether their offspring (aged ≤51 years) had ever had asthma and whether it had coexisted with nasal allergies or not. Mothers and fathers also provided information on their parents' (grandparents) and their own asthma, education and smoking history. Multilevel mediation models within a multicentre three-generation framework were fitted separately within the maternal (4666 offspring) and paternal (4192 offspring) lines. Results: Fathers' smoking before they were 15 [relative risk ratio (RRR) = 1.43, 95% confidence interval (CI): 1.01-2.01] and mothers' smoking during pregnancy (RRR = 1.27, 95% CI: 1.01-1.59) were associated with asthma without nasal allergies in their offspring. Grandmothers' smoking during pregnancy was associated with asthma in their daughters [odds ratio (OR) = 1.55, 95% CI: 1.17-2.06] and with asthma with nasal allergies in their grandchildren within the maternal line (RRR = 1.25, 95% CI: 1.02-1.55). Conclusions: Fathers' smoking during early adolescence and grandmothers' and mothers' smoking during pregnancy may independently increase asthma risk in offspring. Thus, risk factors for asthma should be sought in both parents and before conception. Funding: European Union (Horizon 2020, GA-633212).

Periodontal health status and lung function in two Norwegian cohorts.

RATIONALE AND OBJECTIVES: The oral cavity is united with the airways, and thus poor oral health may affect respiratory health. However, data on the interaction of periodontal and respiratory health is limited. We aimed to evaluate whether periodontal health status, assessed by the Community Periodontal Index (CPI), was related to lung function among young and middle-aged adults in two Norwegian cohorts. METHODS: Periodontal health status and lung function were measured among 656 participants in the Norwegian part of the European Community Respiratory Health Survey (ECHRS III) and the RHINESSA offspring study. Each participant was given a CPI-index from 0 to 4 where higher values reflect poorer periodontal status. The association between CPI and lung function was estimated with linear regression adjusting for age, gender, smoking, body mass index, exercise, education, use of antibiotics, inhaled medication and corrected for clustering within families. MAIN RESULTS: Participants with CPI 3-4 had significantly lower FEV1/FVC ratio compared to participants with CPI 0, b (95% CI) = -0.032 (-0.055, -0.009). Poorer periodontal health was associated with a significant decrease in the FEV1/FVC ratio with an adjusted regression coefficient for linear trend b (95% CI) = -0.009 (-0.015, -0.004) per unit increase in CPI. This negative association remained when excluding asthmatics and smokers (-0.014 (-0.022, -0,006)). CONCLUSIONS: Poorer periodontal health was associated with increasing airways obstruction in a relatively young, healthy population. The oral cavity is united with the airways and our findings indicate an opportunity to influence respiratory health by improving oral health.

Pulmonary illness as a consequence of occupational exposure to shrimp shell powder.

OBJECTIVES: An employee with no prior history of allergy or asthma, experienced respiratory and flu-like symptoms during production of shrimp shell powder in a seafood savory factory in Norway. We aimed to clarify the diagnosis and to identify the cause of the symptoms by specific inhalation challenge (SIC) and by characterizing the powder's biocontaminants, particle size fractions and inflammatory potential. METHODS: Respiratory and immunological responses were measured the day before and after each of four challenges with 20-150g shrimp shell powder during three consecutive days. The powder was analyzed for endotoxin, microorganisms and particle size fractions by standardized laboratory methods. Total inflammatory potential was quantified by reactive oxygen species (ROS) production in a granulocyte assay. RESULTS: The patient had elevated IgG, but not IgE, towards shrimp shell powder. 20min challenge with 150g shrimp shell powder induced 15% decrease in FVC, 23% decrease in FEV1 and increased unspecific bronchial reactivity by methacholine. Neutrophils and monocytes increased 84% and 59%, respectively, and the patient experienced temperature increase and flu-like symptoms. The shrimp shell powder contained 1118 endotoxin units/g and bacteria including Bacillus cereus, and 57% respirable size fraction when aerosolized. The ROS production was higher for shrimp shell powder than for endotoxin alone. CONCLUSIONS: Endotoxin and other bacterial components combined with a high fraction of respirable dust might be the cause of the symptoms. The patient's characteristics and response to SIC were best compatible with occupational asthma and organic dust toxic syndrome, while hypersensitivity pneumonitis could not be excluded.

The Association of Gum Bleeding with Respiratory Health in a Population Based Study from Northern Europe.

BACKGROUND: There is little knowledge about how oral and respiratory health is interrelated even though the mucosa of the oral cavity and airways constitutes a continuum and the exposures to these are partly similar. AIMS: To investigate whether gum bleeding is related to asthma, respiratory symptoms and self-reported COPD. METHODS: A postal questionnaire including questions about respiratory and oral health was sent to general population samples in seven Northern European centres. In 13,409 responders, gum bleeding when brushing teeth was reported always/often by 4% and sometimes by 20%. Logistic regressions accounted for age, smoking, educational level, centre and gender. Effects of BMI, cardio-metabolic diseases, early life factors, gastro-oesophageal reflux, dental hygiene, nasal congestion, and asthma medication were addressed. RESULTS: Gum bleeding always/often was significantly associated with ≥ 3 asthma symptoms (OR 2.58, 95% CI 2.10-3.18), asthma (1.62 [1.23-2.14]) and self-reported COPD (2.02 [1.28-3.18]). There was a dose-response relationship between respiratory outcomes and gum bleeding frequency (≥ 3 symptoms: gum bleeding sometimes 1.42 [1.25-1.60], often/always 2.58 [2.10-3.18]), and there was no heterogeneity between centres (p(heterogeneity) = 0.49). None of the investigated risk factors explained the associations. The observed associations were significantly stronger among current smokers (p(interaction) = 0.004). CONCLUSIONS: A consistent link between gum bleeding and obstructive airways disease was observed, not explained by common risk factors or metabolic factors. We speculate that oral pathogens might have unfavourable impact on the airways, and that the direct continuity of the mucosa of the oral cavity and the airways reflects a pathway that might provide novel opportunities for interventions.

Respiratory Health in Cleaners in Northern Europe: Is Susceptibility Established in Early Life?

RATIONALE: There is some evidence that maternal smoking increases susceptibility to personal smoking's detrimental effects. One might question whether early life disadvantage might influence susceptibility to occupational exposure. OBJECTIVES: In this cross-sectional study we investigated respiratory symptoms, asthma and self-reported chronic obstructive pulmonary disease (COPD) as related to working as a cleaner in Northern European populations, and whether early life factors influenced susceptibility to occupational cleaning's unhealthy effects. METHODS: The RHINE III questionnaire study assessed occupational cleaning in 13,499 participants. Associations with respiratory symptoms, asthma and self-reported COPD were analysed with multiple logistic regressions, adjusting for sex, age, smoking, educational level, parent´s educational level, BMI and participating centre. Interaction of occupational cleaning with early life disadvantage (maternal smoking, severe respiratory infection <5 years, born during winter months, maternal age at birth >35 years) was investigated. MAIN RESULTS: Among 2138 ever-cleaners the risks of wheeze (OR 1.4, 95% CI 1.3-1.6), adult-onset asthma (1.5 [1.2-1.8]) and self-reported COPD (1.7 [1.3-2.2]) were increased. The risk increased with years in occupational cleaning (adult-onset asthma: ≤1 year 0.9 [0.7-1.3]; 1-4 years 1.5 [1.1-2.0]; ≥4 years 1.6 [1.2-2.1]). The association of wheeze with cleaning activity ≥4 years was significantly stronger for those with early life disadvantage than in those without (1.8 [1.5-2.3] vs. 1.3 [0.96-1.8]; pinteraction 0.035). CONCLUSIONS: Occupational cleaners had increased risk of asthma and self-reported COPD. Respiratory symptom risk was particularly increased in persons with factors suggestive of early life disadvantage. We hypothesize that early life disadvantage may increase airway vulnerability to harmful exposure from cleaning agents later in life.