Search

Background Pollen exposure has acute adverse effects on sensitized individuals. Information on the prevalence of respiratory diseases in areas with different pollen concentrations is scanty. Aim We performed an ecologic analysis to assess whether the prevalence of allergic rhinitis and asthma in young adults varied across areas with different pollen concentrations in Italy. Methods A questionnaire on respiratory diseases was delivered to random samples of 20–44 year-old subjects from six centers in 2005–2010. Data on the daily air concentrations of 7 major allergologic pollens ( Poaceae , Urticaceae , Oleaceae , Cupressaceae , Coryloideae , Betula and Ambrosia ) were collected for 2007–2008. Center-specific pollen exposure indicators were calculated, including the average number of days per year with pollens above the low or high concentration thresholds defined by the Italian Association of Aerobiology. Associations between pollen exposure and disease prevalence, adjusted for potential confounders, were estimated using logistic regression models with center as a random-intercept. Results Overall, 8834 subjects (56.8%) filled in the questionnaire. Allergic rhinitis was significantly less frequent in the centers with longer periods with high concentrations of at least one (OR per 10 days = 0.989, 95%CI: 0.979–0.999) or at least two pollens (OR = 0.974, 95%CI: 0.951–0.998); associations with the number of days with at least one (OR = 0.988, 95%CI: 0.972–1.004) or at least two (OR = 0.985, 95%CI: 0.970–1.001) pollens above the low thresholds were borderline significant. Asthma prevalence was not associated with pollen concentrations. Conclusions Our study does not support that the prevalence of allergic rhinitis and asthma is greater in centers with higher pollen concentrations. It is not clear whether the observed ecologic associations hold at the individual level. [ABSTRACT FROM AUTHOR]

Background: No study has been carried out on the time trend in the prevalence of chronic bronchitis (CB) in recent years, despite its clinical and epidemiological relevance. We evaluated the trend in CB prevalence during the past decade among young Italian adults. Methods: A screening questionnaire was mailed to general population samples of 20-44 year-old subjects in two cross-sectional surveys: the Italian Study on Asthma in Young Adults (ISAYA) (1998/2000; n = 18,873, 9 centres) and the screening stage of the Gene Environment Interactions in Respiratory Diseases (GEIRD) study (2007/2010; n = 10,494, 7 centres). CB was defined as having cough and phlegm on most days for a minimum of 3 months a year and for at least 2 successive years. The prevalence rates and the risk ratios (RRs) for the association between CB and each potential predictor were adjusted for gender, age, season of response, type of contact, cumulative response rate, and centre. Results: CB prevalence was 12.5% (95% CI: 12.1-12.9%) in 1998/2000 and 12.6% (95% CI: 11.7-13.7%) in 2007/2010; it increased among never smokers (from 7.6 to 9.1%, p = 0.003), current light smokers (<15 pack-years; from 15.1 to 18.6%, p < 0.001), and unemployed/retired subjects (from 14.3 to 19.1%, p = 0.001). In this decade, the prevalence of current smoking decreased (from 33.6 to 26.9%, p < 0.001), whereas the prevalence of unemployment/premature retirement (from 5.3 to 6.0%, p = 0.005), asthma (from 5.0 to 6.2%, p = 0.003), and allergic rhinitis (from 19.5 to 24.5%, p < 0.001) increased. In both 1998/2000 and 2007/2010, the likelihood of having CB was significantly higher for women, current smokers, asthmatic patients, and subjects with allergic rhinitis. During this period, the strength of the association between CB and current heavy smoking (⩾15 pack-years) decreased (RR: from 4.82 to 3.57, p = 0.018), whereas it increased for unemployment/premature retirement (from 1.11 to 1.53, p = 0.019); no change was observed for gender, asthma, and allergic rhinitis. Conclusions: Despite the significant reduction in current smoking, CB prevalence did not vary among young Italian adults. The temporal pattern of CB prevalence can only be partly explained by the increase of unemployment/ premature retirement, asthma and allergic rhinitis, and suggests that other factors could have played a role. [ABSTRACT FROM AUTHOR]