Paola Modena

Skin prick test reactivity to common aeroallergens in relation to total IgE, respiratory symptoms, and smoking in a general population sample of northern Italy.

Skin prick test (SPT) reactivity to common airborne allergens and its relationships to sex, age, smoking habits, and respiratory symptoms/ diseases were evaluated in a general population sample (n= 2841, 8–75 years of age) living in the Po delta area (northern Italy). Subjects completed a standardized questionnaire and underwent prick tests (12 local allergens, a negative and a positive control) and determination of total serum IgE. Atopy was evaluated by measuring the maximal diameter for each allergen, after subtracting that of the negative control. Thirty‐one percent of subjects showed a positive skin response at a 3‐mm threshold. Pollens, Dermatophagoides pteronyssinus, and D. farinae caused the highest frequencies of reactions. Young people and those who had never smoked had higher prevalence rates of SPT reactivity. Asthma, asthma symptoms, and rhinitis were significantly associated with SPT reactivity in both sexes (cough only in females) and with the number of positive reactions. IgE values were also significantly associated with SPT reactivity. In conclusion, our findings indicate that almost one‐third of the general population of an Italian rural area is skin test positive, emphasizing the importance of assessing atopy in respiratory epidemiologic surveys.

Risk factors for chronic obstructive pulmonary disease in a North Italian rural area

To assess the role of risk factors for chronic obstructive lung disease (COPD) by multiple logistic models, the data of the first cross-sectional epidemiological survey in the unpolluted rural area of the Po River Delta were analyzed (n=2382; 20–64 years). Each subject filled out a standardized questionnaire; 94% of the subjects were also able to perform forced expirograms. Dependent variables were chronic respiratory symptoms, asthma, abnormal parameters of flow-volume curve (ABNFVC), and a complex characterized by chronic phlegm and/or any wheeze and/or dyspnea grade 2+ and/or diagnosis of asthma and/or an FEV1/FVC ratio less than 60% (ANYABN). Independent variables were: age, ever cigarette smoking (SMK) and lifetime cigarette consumption expressed as pack-years, childhood respiratory infections (CRI), adolescence-adulthood respiratory infections (ARI), familial history for COPD (FCOPD) or for asthma/allergies (FASTHMA), work exposure to dusts/chemicals (EXPO), low socio-economic conditions (SES). A significant relationship with almost all dependent variables was shown by pack-years, ARI and age in both sexes. In males, FCOPD was related to chronic mucus hypersecretion and to ABNFVC, FASTHMA was associated with wheeze and ANYABN. EXPO was related to dyspnea and asthmatic symptoms in both sexes and also to bronchitic symptoms in males. CRI was a significant contributor for asthma symptoms in males, for ANYABN in females. SES had no significant association. In conclusion, our findings show that, beside lifetime cigarette smoking, other host — or environment — related conditions are important risk factors for COPD, suggesting the need for a more thorough strategy for prevention.

Serum immunoglobulins E are related to menstrual cycle

During a cross sectional epidemiological survey on a general population sample, 596 fertile women underwent total serum IgE detemination. They completed an interviewer-administered standardized questionnaire and were categorized according to their menstrual period. They were divided into two groups: those from days 10 to 20, who were considered to be in the periovulatory phase, and those in the other phases. IgE mean values were significantly different (p = 0.01) in the two groups: particularly, lower IgE values were found in those in periovulatory phase, after accounting for smoking habit and atopic status. By multiple regression analysis, taking into account the independent effects of menstrual period, age, smoking habit, hours of fast, skin prick test reactivity and presence of cough, significantly lower IgE values in the periovulatory phase were found. We hypothesize the possibility that a decrease of IgE concentration occurs during midcycle: a reduced immune response might facilitate the ovuli implantation. Further studies are necessary to longitudinally investigate the trend of IgE in the same women, as well as the distributions and the trends of other immunoglobulins.

CO Diffusing Capacity in a General Population Sample: Relationships with Cigarette Smoking and Airflow Obstruction

The single-breath carbon monoxide diffusing capacity (DLCOsb) was measured together with ventilatory lung function tests as part of a survey of a general population sample living in Northern Italy (n = 2,481). Based on answers to an interviewer-administered questionnaire, subjects free of respiratory symptoms or diseases were identified. Data from subjects who had never regularly smoked cigarettes were used to derive reference equations for the test indexes, and data from the remaining subjects who had smoked were used to derive regression equations incorporating a term expressing cigarette consumption (cube root of pack-years) and a term indicating current smoking decrement, in order to obtain expected DLCOsb percent predicted. Neither number of cigarettes smoked daily or duration of smoking, in smokers, nor duration of smoking or years since quitting smoking, in ex-smokers, entered significantly the multiple-regression model. The mean values of DLCOsb were only slightly affected by the increasing degree of airway obstruction. When subjects with confirmed asthma were analyzed, after stratifying for different levels of FEV1/FVC ratio, increased mean value of DLCOsb (over 100%) was found in those with an FEV1/FVC ratio between 75 and 65%. This cross-sectional analysis suggests that there is a decrease in DLCOsb with cumulative cigarette consumption even in healthy subjects. Further, it confirms the clinical observations of high DLCOsb values in asthmatic patients, at least in those with an initial degree of chronic airflow obstruction.

Effects of the home environment on respiratory symptoms of a general population sample in middle Italy

The effects of home environment characteristics were evaluated in a multistage, stratified, cluster sample (N = 3,866) of the general population who lived in the district of Pisa (middle Italy). Each subject completed a standardized interviewer-administered questionnaire that contained questions about respiratory symptoms/diseases and risk factors (e.g., type of heating, fuels used for cooking and heating). Cough and asthma were significantly more frequent in men who did not smoke and who did not use natural gas for cooking and heating. Attacks of shortness of breath accompanied by wheeze, dyspnea, and cardiovascular conditions in female nonsmokers were associated with use of a stove or forced-air circulation for heating; the type of fuel used did not affect this result. Multiple logistic models, which accounted for independent effects of age, smoking status, pack-years, childhood respiratory illness, education, zone of residence, and work exposure to dusts, chemicals, or fumes, showed significantly increased odds ratios for (a) cough and phlegm in males (associated with bottled gas for cooking), (b) wheeze and shortness of breath with wheeze in females (associated with the use of a stove or forced-air circulation). These results, which confirm our previous observations in an unpolluted rural area of north Italy, indicate that characteristics of the home environment, as assessed by questionnaire, may be linked to mild adverse health effects, i.e., respiratory symptoms, in the general population. The results also identify the need to better characterize the dose-response relationship in indoor air pollution monitoring studies that include subsamples of this population.

Effects of Daily Cigarette Consumption on Respiratory Symptoms and Lung Function in a General Population Sample of North-Italian Men

We assessed the respiratory effects of the number of cigarettes smoked daily (CIGD) in 748 male smokers of a general population sample living in the unpolluted area of the Po Delta (Italy). A standardized questionnaire, flow-volume curves (V/V), the diffusing capacity of carbon monoxide (DLCO) and the slope of the alveolar plateau of nitrogen (DN2%/l) were used. Subjects were divided according to the median value of the observed distribution of CIGD (1-19, 20+) and according to the tertile values of the observed distribution of pack-years (an index representing lifetime cigarette consumption; 1-7, 8-21, 22+). In those with a higher CIGD, the prevalence rate of chronic phlegm was always significantly increased, while the prevalence rate of wheeze was significantly higher if they had smoked 8+ pack-years. Using analysis of variance, adjusted for pack-years, DLCO indexes, FEF75-85 and Vmax75 were significantly reduced in those with higher CIGD. When multiple logistic models, accounting for the independent effects of age and pack-years, were used, significantly increased odds ratios (ORs) for symptoms (e.g. OR = 2.0 for phlegm, OR = 1.8 for cough, OR = 1.6 for wheeze) and abnormal DLCO (OR = 1.9) or DN2%/l (OR = 1.6) were associated with a daily consumption of 10 cigarettes. In conclusion, the amount of cigarettes currently smoked may add a negative effect to that caused by lifetime cigarette consumption on respiratory symptoms and lung function. Moreover, the use of diffusing capacity in general population surveys is advisable.

Effects of some indoor environmental factors on respiratory symptoms and lung function in a sample of young non smokers in North Italy

SummaryWe evaluated the effects of some indoor environmental factors in a non smoking subsample (n=381, age 8–19 years) of the general population living in the Po River Delta. Each subject completed an interviewer-administered standardized questionnaire on respiratory symptoms and risk factors. Acceptable maneuvers of forced vital capacity and slope of alveolar plateau of nitrogen were obtained in 96% and 59% of the subjects, respectively. In the houses there were more frequently natural gas for cooking (86%) than bottled gas (14%) and central heating (82%) than stove (18%). As regards passive smoking exposure, 18% of subjects had both parents smoking, 50% had one parent smoking. Significantly higher prevalence rates of wheeze, dyspnea, diagnosis of asthma were found in subjects of both sexes using bottled gas for cooking in comparison to those using natural gas, when also exposed to passive smoking. An insignificant trend towards higher symptom rates was shown by those using stove, instead of central heating. Lung function was affected only in females: those with both parents smoking had reduced forced expirograms, those with bottled gas for cooking or stove for heating had a decreased peak expiratory flow. Interactions of stove and passive smoking on peak expiratory flow and on slope of alveolar plateau were statistically significant. These findings confirm the mild adverse respiratory effects of certain home environment factors shown by other epidemiologic surveys in North Europe and in the USA. They have been a basis for the implementation, under the auspices of National Research Council and Electric Energy Authority, of future specific studies in which continuous monitoring of indoor pollutants and repeated recording of symptoms and lung function in North and Central Italy will be performed.