IGE LEVELS, ATOPY MARKERS AND HAY-FEVER IN RELATION TO AGE, SEX AND SMOKING STATUS IN A NORMAL ADULT SWISS POPULATION

Within the framework of the SAPALDIA survey (Swiss study on Air Pollut ion and Lung Diseases in Adults), we studied the influence of sex, age and smoking habits on total serum IgE and allergen-specific IgE antib ody concentrations (assessed by means of the Phadiatop(R) test) and on the prevalence of hay fever, A total of 8,344 subjects aged 18-60 yea rs, comprising 2,776 current smokers, 1,888 former smokers and 3,680 n onsmokers, were included in the study. Smokers had both a statisticall y significant (p < 0.001) higher mean serum IgE concentration (geometr ic mean 39.7 kU/l), and a higher percentage (27.5%) of persons with el evated serum IgE (>100 kU/l) than nonsmokers (27.2 kU/l; respectively 20.5%). The IgE level was significantly lower in women than men (p < 0 .001) in all smoking categories. The percentage of persons with positi ve atopic markers (positive Phadiatop test, positive skin prick tests to common inhalant allergens) and self-reported hay fever was signific antly higher in nonsmokers than in smokers or former smokers. In Phadi atop positive (atopic) subjects, the IgE levels were highest, with a m ean of 104.3 kU/l (99.0-109.8), and lowest in Phadiatop negative nonsm okers at 27.2 kU/L (25.9-28.6), These findings correlate well with the current interpretation of total serum IgE values in screening for ato pic diseases in adults (IgE < 20 kU/l, atopy improbable; IgE > 100 kU/ l, atopy probable), In multivariate logistic regression models, the pr evalence of positive Phadiatop tests, positive skin tests, and atopy d ecreased significantly with age. The odds of having a positive Phadiat op and skin test, or being atopic were found to decrease on average by 23.0, 21.1 and 21.0%, respectively, with every 10-year increase in ag e, With respect to smoking status, the odds ratios for the three atopi c markers were significantly lower in current and former smokers than in nonsmokers. The prevalence of (self-reported) hay fever was highest in nonsmokers intermediate in former smokers (odds ratio = 0.81, p < 0.05) and lowest in current smokers (odds ratio = 0.76 in comparison t o former smelters, p < 0.01), The odds ratio of self-reported current hay fever decreased with age at an estimated aver age of 23% every 10 years. The decrease in former smokers might be slightly faster than in the other two categories, In conclusion, the present results demonstr ated that tobacco smoking is associated with increased IgE levels and negatively related to atopy and hay fever, In addition, it is shown th at atopy prevalence decreases with age.