Occupation, socioeconomic status and chronic obstructive respiratory diseases - The EpiLung study in Finland, Estonia and Sweden.

OBJECTIVE: To study occupational groups and occupational exposure in association with chronic obstructive respiratory diseases. METHODS: In early 2000s, structured interviews on chronic respiratory diseases and measurements of lung function as well as fractional expiratory nitric oxide (FENO) were performed in adult random population samples of Finland, Sweden and Estonia. Occupations were categorized according to three classification systems. Occupational exposure to vapours, gases, dusts and fumes (VGDF) was assessed by a Job-Exposure Matrix (JEM). The data from the countries were combined. RESULTS: COPD, smoking and occupational exposure were most common in Estonia, while asthma and occupations requiring higher educational levels in Sweden and Finland. In an adjusted regression model, non-manual workers had a three-fold risk for physician-diagnosed asthma (OR 3.18, 95%CI 1.07-9.47) compared to professionals and executives, and the risk was two-fold for healthcare & social workers (OR 2.28, 95%CI 1.14-4.59) compared to administration and sales. An increased risk for physician-diagnosed COPD was seen in manual workers, regardless of classification system, but in contrast to asthma, the risk was mostly explained by smoking and less by occupational exposure to VGDF. For FENO, no associations with occupation were observed. CONCLUSIONS: In this multicenter study from Finland, Sweden and Estonia, COPD was consistently associated with manual occupations with high smoking prevalence, highlighting the need to control for tobacco smoking in studies on occupational associations. In contrast, asthma tended to associate with non-manual occupations requiring higher educational levels. The occupational associations with asthma were not driven by eosinophilic inflammation presented by increased FENO.

Parallel gradients in FENO and in the prevalences of asthma and atopy in adult general populations of Sweden, Finland and Estonia - A Nordic EpiLung study.

The prevalence of asthma is higher in Sweden and Finland than in neighbouring eastern countries including Estonia. Corresponding difference in bronchial eosinophilic inflammation could be studied by FENO measurements. We aimed to compare FENO in adult general populations of Sweden, Finland, and Estonia, to test the plausibility of the west-east disparity hypothesis of allergic diseases. We conducted clinical interviews (N = 2658) with participants randomly selected from the general populations in Sweden (Stockholm and Örebro), Finland (Helsinki), and Estonia (Narva and Saaremaa), and performed FENO (n = 1498) and skin prick tests (SPT) in 1997-2003. The median (interquartile range) of FENO (ppb) was 15.5 (9.3) in Sweden, 15.4 (13.6) in Finland and 12.5 (9.6) in Estonia. We found the lowest median FENO values in the Estonian centres Saaremaa 13.1 (9.5) and Narva 11.8 (8.6). In the pooled population, asthma was associated with FENO ≥25 ppb, odds ratio (OR) 3.91 (95% confidence intervals: 2.29-6.32) after adjusting for SPT result, smoking, gender and study centre. A positive SPT test increased the likelihood of asthma OR 3.19 (2.02-5.11). Compared to Saaremaa, the likelihood of having asthma was higher in Helsinki OR 2.40 (1.04-6.02), Narva OR 2.45 (1.05-6.19), Örebro OR 3.38 (1.59-8.09), and Stockholm OR 5.54 (2.18-14.79). There was a higher prevalence of asthma and allergic airway inflammation in adult general populations of Sweden and Finland compared to those of Estonia. Atopy and elevated FENO level were independently associated with an increased risk of asthma. In conclusion, the findings support the earlier west-east disparity hypothesis of allergic diseases.

Postal survey on asthma, chronic bronchitis and respiratory symptoms among adult Estonians and non-Estonians (FinEsS-study).

BACKGROUND: According to the data of the population census held in Estonia in 1989, the resident population consisted of 61.5% Estonians and 38.5% non-Estonians, the majority of them being Russians--30.3%. The aim of this study was to investigate the prevalence of asthma, chronic bronchitis and respiratory symptoms among the adults in these ethnic groups. METHODS: The study was a postal survey, similar in design to parallel studies currently in progress in Finland, Estonia and Sweden (FinEsS). RESULTS: The prevalence of physician-diagnosed asthma was 2.0%, being similar in men and women and in both Estonians and non-Estonians. The prevalence of physician-diagnosed chronic bronchitis was 10.5%. Compared with the non-Estonian population, the prevalence was much lower among Estonians (7.9% vs. 13.5%, p<0.001). Such a difference in prevalence was observed in all age groups. The high prevalence of chronic bronchitis in non-Estonians could be related to more extensive smoking habits, smoking indoors and probably ETS exposure. The defined OR between non-Estonians vs. Estonians after correcting for the influence of smoking habits, area of domicile, age, gender, and socioeconomic group was 1.30. A similar pattern of differences between Estonians and non-Estonians was observed in respiratory symptoms. CONCLUSION: This study revealed that the prevalence of physician-diagnosed asthma in Estonians and non-Estonians was the same. Physician-diagnosed chronic bronchitis was more frequent in non-Estonians than in Estonians. A significant difference was determined in the prevalence of respiratory symptoms, especially among those common to chronic bronchitis. The differences remained significant after correction for possible confounders.