M. Simoni

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.

Indoor air pollution and respiratory health in the elderly

People spend about ≥80–90% of their daily time indoors, elderly people especially at home. Thus, it is important to investigate possible health effects of indoor air pollutants and to consider their contributions to the total human exposure. This report summarises current knowledge on health effects of three common indoor air pollutants, respirable suspended particles, nitrogen dioxide and environmental tobacco smoke, with focus on the adults and the elderly. Preliminary findings on exposure distributions and health effects of these pollutants in older subjects of two panel studies carried out in Italian general populations will also be reported. The two indoor pollution studies were performed in the Po Delta area in North Italy (428 subjects and 140 houses investigated) and in Pisa in Central Italy (761 subjects and 282 houses investigated). Individuals aged ≥65u2005yrs spent a significantly larger number of hours at home than the other age groups both in winter and in summer. A trend of higher occurrence of acute respiratory symptoms in the presence of environmental tobacco smoke was shown in comparison to the unexposed elderly both in winter (31 versus 29%) and summer (33 versus 16%). The occurrence of acute respiratory symptoms was consistently higher in relation to the high respirable suspended particles-index exposure compared to low exposure (33 versus 27% in winter, 27 versus 21% in summer). Both the presence of environmental tobacco smoke at home and exposure to the high respirable suspended particles-index were associated with a decrease in the mean daily peak expiratory flow.

The Po River Delta (north Italy) indoor epidemiological study: Effects of pollutant exposure on acute respiratory symptoms and respiratory function in adults

Abstract The authors studied the effects of relatively low doses of nitrogen dioxide and respirable suspended particulate matter (i.e., < 2.5 μ) on acute respiratory symptoms and on peak expiratory flow in 383 adults (15–72 yr of age) who lived in the Po River Delta area, located near Venice. During 2 wk—1 wk in winter and 1 wk in summer—the authors monitored each participants house to measure nitrogen dioxide (in parts per billion) and respirable suspended particulate (μg/m3) concentration. Information on sex, age, height, weight, daily activity patterns, active and passive smoking, chronic respiratory diseases, daily peak expiratory flow, and presence of acute respiratory symptoms during the weeks monitoring occurred were also collected. Peak expiratory flow variation was studied as mean amplitude percentage (i.e., amplitude/mean) and percentage of diurnal variation (maximum/minimum). The exposure indices to nitrogen dioxide (nitrogen dioxide-index of exposure) and to respirable suspended particulate matter (respirable suspended particulate matter-index of exposure) were computed as the product of pollutant concentration and time of exposure. The authors considered indices as “low” or “high” on the basis of the median value. The median nitrogen dioxide was 20 ppb in winter and 14 ppb in summer; the highest nitrogen dioxide levels occurred in the kitchen in the winter (33 ppb) and summer (20 ppb). The median respirable suspended particulate matter was 68 μg/m3 in winter and 45 μg/m3 in summer. Only in winter were there significant associations between bronchitic/asthmatic symptoms and “high” nitrogen dioxide and respirable suspended particulate matter indices. In subjects who did not smoke, a significant influence of the “high” respirable suspended particulate matter-index of exposure was also observed in summer. With respect to peak expiratory flow and its variability, respirable suspended particulate matter-index of exposure was associated with an increase of both amplitude/mean and maximum/mean; however, with respect to the nitrogen dioxide-index of exposure, the association was significant only in subjects with chronic respiratory diseases (i.e., asthma and bronchitis). These relationships were significant only in winter. In conclusion, the results of the current study indicate that there is an association between relatively low doses of pollutants and acute respiratory symptoms and peak expiratory flow in adults.

The Po River Delta epidemiological survey: Reference values of total serum IgE levels in a normal population sample of North Italy (8-78 yrs)

The aim of this paper was to define, for the first time in Italy, normal levels of total serum IgE in a general population sample of North Italy. Total serum IgE in 1905 subjects, living in Po Delta area (near Venice), were measured by PRIST method. Normal values were derived from 558 subjects without asthma and/or asthmatic/rhinitic symptoms, noncurrent smokers, skin prick-test negatives (‘normals’). Cut-off values to differentiate ‘normals’ from the remaining part of the sample (‘others’), from asthmatic, and from rhinitic subjects, were established with the IgE value midway between the upper limit of the 95% confidence intervals (CI) of the geometric mean for ‘normals’ and the lower limit for ‘others’, asthmatics, and rhinitics, respectively. Geometric mean of normal children–adolescents was 45 kU/L (SD: 2.6; 95% CI: 38–63). In normal adults geometric mean was 29 kU/L (SD: 3.3; 95% CI: 25–40) in males and 19 kU/L (SD: 3.8; 95% CI: 16–22) in females. The diagnostic sensitivity of IgE test was low, while the specificity was very high. A good positive predictive value in discriminating ‘normals’ from ‘others’ was found, on the contrary, we found a good negative predictive value in discriminating ‘normals’ from asthmatics or from rhinitics. In conclusion, our results confirm that it is necessary to provide separate total serum IgE reference values for what concerns age in children–adolescents and in adults, and gender, in adults. Low level of total serum IgE are helpful to exclude allergic asthma or rhinitis.

Number of offspring and maternal allergy

The consistent association seen between family size and childhood allergy has led to the ‘hygiene hypothesis’, namely that a lower frequency of infections in early childhood is associated with an increased risk of asthma and hay fever. Maternal atopy, however, is a strong predictor of childhood asthma and hay fever. If maternal atopy is inversely related to the number of siblings then the role of siblings in the development of childhood atopy, the basic tenet of the ‘hygiene hypothesis’, is challenged. We evaluated the association between number of pregnancies and number of live births with lifetime occurrence of maternal wheeze, asthma, allergic rhinitis, and allergic conjunctivitis in a cross‐sectional study in four areas in Italy. A total of 1755 (35–74u2003year old) nonsmoking women filled a questionnaire on reproductive history as well as on lifetime occurrence of symptoms/diseases. The number of live births was inversely related to lifetime allergic rhinitis (P‐value for trendu2003=u20030.031) and allergic conjunctivitis (P‐value for trendu2003=u20030.011). The odds ratios for those with 4+ children (in comparison with those having 0–1) were: 0.53 (95% CI: 0.27–1.04) and 0.42 (95% CI: 0.22–0.81), respectively. A similar trend was seen for number of pregnancies, although not statistically significant. No association was found between number of pregnancies and number of live births with wheeze or asthma. The results may be interpreted as an indication that maternal atopy influences pregnancy outcomes or that pregnancy itself has an effect on maternal atopy.

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.

Characteristics of women exposed and unexposed to environmental tobacco smoke (ETS) in a general population sample of North Italy (Po River Delta epidemiological study).

To define qualitative and quantitative categories of exposure to environmental tobacco smoke (ETS) and to assess possible differences for life-style factors between exposed and unexposed women, we studied 867 nonsmoking women (8–73 aged), selected from a general population sample living in the Po Delta area (near Venice, North Italy). Information was collected by a standardized questionnaire. ETS exposure at home, at work or elsewhere was considered. There was a prevalence of ETS exposure of 46% in the whole sample; the rate had a negative association with age. Exposure to ETS occurred more frequently at home, either singly (56%) or in combination with school/work and other places (75%). Exposed women were significantly younger, taller and lighter than those unexposed. Logistic regression on 20+ aged women showed that single-separated-widowed, workers, women living in a rental house, and women with a central forced air heating were significantly more exposed to ETS. Crowding index (n inhabitants/n rooms of the house) was significantly higher in those exposed. These results indicate that ETS exposure is quite frequent in Italian women and that some life-style factors (e.g. marital status or occupational status or some home characteristics), should be considered in the study of relationship between passive smoking and respiratory health.

The Po River Delta epidemiological study: use of medicines in a general population sample of north Italy.

Purpose—To provide information on the actual use of medicines in a general population sample.