Prevalence, risk factors and comorbidities of COPD among never-smokers

The overall aim of this thesis was to investigate prevalence, risk factors and comorbidity of COPD among never-smokers. COPD was in this thesis defined as a syndrome also including prior asthma diagnosis with chronic airway obstruction. In papers I-III population-based cohorts of the Obstructive Lung Disease in Northern Sweden (OLIN) studies were used. In paper IV data from the OLIN studies was pooled with data from the West Sweden Asthma study. Prevalence of COPD among never-smokers was 3.0-7.7% depending on spirometric definition, and similar in 1994-1996 vs. 2009-2012. Corresponding prevalence of GOLD ≥2 was 1.3-3.5%. Symptoms were highly prevalent in subjects with GOLD ≥2, regardless of smoking status. No significant regional differences in prevalence between OLIN and WSAS were seen. Risk factors for COPD among never-smokers included age, physician-diagnosed asthma and occupational exposure to gas, dust or fumes. Passive smoking in multiple settings was independently associated with an incrementally increased risk of COPD. Comorbidities, in particular cardiac and cardiovascular conditions, were highly prevalent among subjects with GOLD ≥2 regardless of smoking status. In conclusion, COPD is a common condition among never-smokers, and associated with previous asthma and exposures including passive smoking and occupational gas, dust or fumes. Never-smoking subjects with COPD had significantly more respiratory symptoms and comorbidities than never-smokers without COPD. Comorbidities are highly prevalent in COPD regardless of smoking history

Different risk factor patterns for adult asthma, rhinitis and eczema : results from West Sweden Asthma Study

BACKGROUND: Atopic diseases including asthma, rhinitis and eczema have increased in the second half of the past century. This has been well studied among children and adolescents but with the exception of asthma to a much lesser extent in adults. The adult risk factor pattern of atopic diseases, in particular of eczema, and their relation to allergic sensitization are yet to be fully elucidated. Studies among adults that have compared the risk factor pattern for these conditions in the same material are very few. The objective of this study was to compare the risk factor patterns for asthma, rhinitis and eczema in a randomly selected adult population. METHODS: A questionnaire survey on atopic diseases was dispatched by mail to 30,000 randomly selected individuals in West Sweden aged 16-75 years and 62 % participated. A subgroup of 2000 individuals was selected for clinical examinations including blood sampling for specific serum Immunoglobulin E to common airborne allergens and 1172 attended. RESULTS: The prevalence of current asthma was 11.8 %, current rhinitis 42.8 %, current eczema 13.5 and 2.3 % had all three conditions while 13.9 % had at least two conditions. No mutual risk factor was identified for all three conditions. Allergic sensitization was a strong risk factor for current asthma (OR 4.1 CI 2.7-6.3) and current rhinitis (OR 5.1 CI 3.8-6.9) but not so for current eczema. Obesity was a risk factor for current asthma and current rhinitis, while farm childhood decreased the risk for current asthma and current rhinitis. Occupational exposure to gas dust or fumes and female sex was associated with an increased risk of current asthma and current eczema. CONCLUSIONS: There are different risk factor patterns for asthma, rhinitis and eczema in adults but some risk factors are overlapping between some of the conditions. The effect of mutable risk factors should be assessed further in longitudinal studies