Search

Study Objective: Diffusing capacity of the lung for carbon monoxide (DLCO) is frequently assessed as part of a thorough pulmonary function assessment in patients with pulmonary or cardiopulmonary diseases. However, little information regarding the longitudinal trends of DLCO is available. In this study, we examined the temporal trends in DLCO to determine the effects of smoking and changes in smoking habits.Design: A longitudinal study was recently conducted in the Po River Delta area of northern Italy, in which DLCO measurements were taken approximately 8 years apart in the same subjects; this offered the unique opportunity to assess the temporal changes in DLCO. The longitudinal DLCO data were analyzed independently in two age groups (20 to 40 years, and > or = 40 years) using a repeated-measures analysis.Results: Included were 928 subjects > 20 years old who had DLCO assessments both at baseline and follow-up. Male subjects had higher mean levels of DLCO than female subjects in the older age group (> or = 40 years). Continuous smokers had significantly lower DLCO levels than "never-smokers," but their changes in DLCO during follow-up were the same. This suggests that the lung damage due to smoking had occurred prior to DLCO testing. We also found that the annual decline in DLCO accelerated with age in adults > or = 40 years old.Conclusions: We conclude that in adults > or = 40 years of age from the general population, DLCO accelerates downwards regardless of gender, smoking, and initial FEV(1) level. [ABSTRACT FROM AUTHOR]

Background: The role of different risk factors for bronchial hyperresponsiveness (BHR), such as gender, atopy, IgE, and environmental factors (smoking, occupational exposure, infections), has been described. Indoor and outdoor pollution play an important role too, but few studies have analyzed the association with BHR. The aim of this study was to assess the effect of urban residence on BHR., Methods: We studied two general population samples enrolled in two cross-sectional epidemiological studies performed in Northern Italy (Po Delta, rural area) and Central Italy (Pisa, urban area). We analyzed 2,760 subjects (age range, 8 to 74 years). We performed analysis of variance and logistic regression analysis using ln slope of the dose-response curve of the methacholine challenge test as dependent variable, and sex, age, smoking habits, respiratory symptoms, skin-prick test results, IgE value, residence, and airway caliber as independent variables., Results: The mean value of ln slope of the dose-response curve adjusted for initial airways caliber (by baseline FEV(1) percentage of predicted value) was significantly higher in female subjects, in smokers, in subjects with respiratory symptoms, in younger and older ages, in subjects with high values of IgE, and in subjects with positive skin-prick test results. After controlling for the independent effects of all these variables, living in urban area was an independent risk factor for having BHR (odds ratio, 1.41; 95% confidence interval, 1.13 to 1.76)., Conclusion: Living in urban area is a risk factor for increased bronchial responsiveness.

Study Objectives: The Venn diagram of obstructive lung disease (OLD) has been recently quantified. We aimed to quantify the proportion of the general population with OLD, and the intersections of physician-diagnosed asthma, chronic bronchitis (CB), and emphysema in two Italian general population samples, in relationship to airflow obstruction (AO) determined through spirometry., Design and Participants: We analyzed data from two prospective studies (4,353 patients) carried out in the rural area of Po River delta from 1988 to 1991 and in the urban area of Pisa from 1991 to 1993., Results: Prevalence rates of asthma, CB, and emphysema were 5.3%, 1.5%, and 1.2% in the Po delta, and 6.5%, 2.5%, and 3.6% in Pisa. A double Venn diagram, which was used to quantify the distribution of CB, emphysema, and asthma in relation to the presence/absence of AO, identified 15 categories. Isolated AO was the most frequent category (Po delta, 11.0%; Pisa, 6.7%), followed by asthma only without AO (Po delta, 3.3%; Pisa, 4.3%). The combination of the three OLD conditions was the only category that always showed higher prevalence rates for those with AO (Po delta, 0.20%; Pisa, 0.16%) than for those without AO (Po delta, 0.04%; Pisa, 0.05%). Of those with either OLD or AO, there were 61.4% in Po delta and 38.2% in Pisa with isolated AO, 24.8% and 41.9%, respectively, with an OLD without AO, and 13.8% and 19.9%, respectively, with simultaneous OLD and AO. For both genders, the frequency of isolated asthma decreased with age, while that of isolated AO, CB-emphysema, and the combination of asthma and CB-emphysema increased., Conclusion: About 18% of the Italian general population samples either reported the presence of OLD or showed spirometric signs of AO. We confirmed that the Venn diagram of OLD can be quantified in the general population by extending the mutually exclusive disease categories (including a concomitant diagnosis of asthma, CB, or emphysema) to 15.