Background: A protective effect of endotoxin exposure on atopy and asthma in farmers' children has been postulated. Studies of adult farmers have shown conflicting results but often lack exposure data. The prevalence of asthma in farmers with different exposure levels to microbial agents and irritant gases was compared. Methods: Atopy was defined as a positive response to multiple radioallergosorbent tests (RAST) with a panel of 10 common respiratory allergens, and asthma was ascertained by a questionnaire using a stratified sample (n = 2169) of a farming population from south-eastern Norway. Exposure of farmers to total dust, fungal spores, bacteria, endotoxins, and ammonia was assessed by exposure measurements. Results: The prevalence of asthma was 3.7% for physician diagnosed asthma and 2.7% for current asthma. The prevalence of atopy was 14%, but most asthmatic subjects were non-atopic (80%). Compared with farmers without livestock, (1) asthma was significantly higher in cattle farmers (OR adj 1.8, 95% CI 1.1 to 2.8) and pig farmers (OR adj 1.6, 95% CI 1.0 to 2.5), (2) non-atopic asthma was significantly higher in pig farmers (OR adj 2.0, 95% CI 1.2 to 3.3) and in farmers with two or more types of livestock (OR adj 1.9, 95% CI 1.1 to 3.3), and (3) atopic asthma was less common in farmers with two or more types of livestock (OR adj 0.32, 95% CI 0.11 to 0.97). Exposure to endotoxins, fungal spores, and ammonia was positively associated with non-atopic asthma and negatively associated with atopic asthma. No associations were found with atopy. Conclusions: Exposure to endotoxins and fungal spores appears to have a protective effect on atopic asthma but may induce non-atopic asthma in farmers.

Age at menopause varies across Europe, shifting toward higher ages. This secular trend seems paradoxical because several adult determinants, that is, overweight, smoking, sedentarity, and nulliparity, associated with early menopause are on the rise in Europe. The heterogeneity of the secular trend suggests additional country-specific factors not included in the study, such as improved childhood nutrition and health, that have an influence on reproductive aging.

Adjustable maintenance dosing with budesonide/formoterol provides more effective asthma control by reducing exacerbations and reliever medication usage compared with fixed-dose salmeterol/fluticasone.

BackgroundSelection bias is a systematic error in epidemiologic studies that may seriously distort true measures of associations between exposure and disease. Observational studies are highly susceptible to selection bias, and researchers should therefore always examine to what extent selection bias may be present in their material and what characterizes the bias in their material. In the present study we examined long-term participation and consequences of loss to follow-up in the studies Respiratory Health in Northern Europe (RHINE), Italian centers of European Community Respiratory Health Survey (I-ECRHS), and the Italian Study on Asthma in Young Adults (ISAYA).MethodsLogistic regression identified predictors for follow-up participation. Baseline prevalence of 9 respiratory symptoms (asthma attack, asthma medication, combined variable with asthma attack and/or asthma medication, wheeze, rhinitis, wheeze with dyspnea, wheeze without cold, waking with chest tightness, waking with dyspnea) and 9 exposure-outcome associations (predictors sex, age and smoking; outcomes wheeze, asthma and rhinitis) were compared between all baseline participants and long-term participants. Bias was measured as ratios of relative frequencies and ratios of odds ratios (ROR).ResultsFollow-up response rates after 10 years were 75% in RHINE, 64% in I-ECRHS and 53% in ISAYA. After 20 years of follow-up, response was 53% in RHINE and 49% in I-ECRHS. Female sex predicted long-term participation (in RHINE OR (95% CI) 1.30(1.22, 1.38); in I-ECRHS 1.29 (1.11, 1.50); and in ISAYA 1.42 (1.25, 1.61)), as did increasing age. Baseline prevalence of respiratory symptoms were lower among long-term participants (relative deviations compared to total baseline population 0-15% (RHINE), 0-48% (I-ECRHS), 3-20% (ISAYA)), except rhinitis which had a slightly higher prevalence. Most exposure-outcome associations did not differ between long-term participants and all baseline participants, except lower OR for rhinitis among ISAYA long-term participating smokers (relative deviation 17% (smokers) and 44% (10–20 pack years)).ConclusionsWe found comparable patterns of long-term participation and loss to follow-up in RHINE, I-ECRHS and ISAYA. Baseline prevalence estimates for long-term participants were slightly lower than for the total baseline population, while exposure-outcome associations were mainly unchanged by loss to follow-up.

Objective-To assess respiratory symptoms among hairdressers in Norway. Methods-The study was based on a questionnaire sent to 100 hairdressers (91% responding) and 95 oYce workers (84% responding). The questionnaire sought information about allergy, respiratory symptoms in the past year, and symptoms after exposures to diVerent types of pollutants, working conditions, and smoking habits. A population based control group was established because the hairdressers and oYce workers diVered in age and smoking habits. Results-The prevalence of respiratory symptoms in the past year did not diVer significantly between hairdressers and oYce workers after adjusting for age, atopy, and smoking. The hairdressers over 40 years of age reported significantly more symptoms-such as wheezing and breathlessness-in the past year than the oYce workers of the same age. Compared with the population based control group, both hairdressers younger than 30 and those over 40 reported more symptomssuch as breathlessness in the past year. The oldest hairdressers reported such symptoms as wheezing and breathlessness more often than did the younger hairdressers. These diVerences in breathlessness were significant after adjusting for smoking and wheezing. The same trend was not found among the oYce workers. The hairdressers reported significantly more wheezing, breathlessness, runny eyes, and blocked or runny nose from exposure to hair dyes, permanent oils, bleaching powder, and other chemicals used in a hairdressing salon, compared with the oYce workers. Prevalence of symptoms during exposure to other types of generel pollutants was similar in the two groups. Conclusions-Hairdressers are exposed to low levels of various irritating chemicals every day. The prevalences of acute symptoms related to the exposure of hairdressers to hairdressing chemicals are very high. Hairdressers, especially the oldest hairdressers, have more asthma-like symptoms than the control groups. (Occup Environ Med 2001;58:780-785)