Bråbäck L, Hjern A, Rasmussen F
Mid Sweden Research and Development Centre, Sundsvall Hospital, Stockholm, Sweden.
Clin Exp Allergy. 2004 Jan;34(1):38-43. doi: 10.1111/j.1365-2222.2004.01841.x.
Asthma and allergies are less common in children who have been raised in farming environments.
To assess whether children who grow up in a farming environment have been protected against the general increase in atopic disorders in Sweden and whether other rural environments could also be protective.
Linkage at an individual level of three national registers in Sweden: The Swedish Military Service Conscription Register (MSCR), the Register of the Total Population (RTP) and the Population and Housing Censuses (PHC). Asthma, allergic rhinitis and eczema at conscription were analysed in relation to area of residence, parental occupation, maternal age, family size and being the first born for 1 309 652 male conscripts in three successive cohorts born between 1952 and 1981.
Allergic rhinitis and eczema displayed a continuous increase throughout the study period, whereas the rise in asthma mainly occurred in conscripts born after 1961. Farming environments and rural living already provided protection from allergic rhinitis in conscripts born during the 1950s, but the protective effect was greater in later cohorts. An inverse association was observed between farm living and asthma, but mainly in conscripts born after 1970. The adjusted risk ratios for asthma in conscripts from farming vs. non-farming families were 1.00 (95% CI 0.93-1.07), 0.94 (95% CI 0.88-1.01) and 0.85 (95% CI 0.79-0.91) in conscripts born in 1952-1961, 1962-1971 and 1972-1981, respectively. Rural living per se had no effect on the occurrence of asthma. Eczema was less common in rural areas, but the time trend was similar in urban and rural areas.
Our findings suggest that environmental changes affecting the whole of society have promoted an increase in asthma, allergic rhinitis and eczema in both farming and non-farming environments. A lower risk of allergic rhinitis in conscripts whose parents were involved in farming was observed in all birth cohorts, whereas the protective effect of growing up on a farm on the risk of asthma appears to be a fairly recent phenomenon.
在农场环境中长大的儿童患哮喘和过敏症的情况较少见。
评估在农场环境中长大的儿童是否受到保护，免于瑞典特应性疾病总体上升的影响，以及其他农村环境是否也具有保护作用。
在瑞典对三个国家登记册进行个体层面的关联分析：瑞典兵役征兵登记册（MSCR）、总人口登记册（RTP）和人口与住房普查（PHC）。分析了1952年至1981年出生的三个连续队列中1309652名男性应征入伍者在征兵时的哮喘、过敏性鼻炎和湿疹情况，这些情况与居住地区、父母职业、母亲年龄、家庭规模以及是否为长子有关。
在整个研究期间，过敏性鼻炎和湿疹呈持续上升趋势，而哮喘的上升主要发生在1961年以后出生的应征入伍者中。农场环境和农村生活在20世纪50年代出生的应征入伍者中就已对过敏性鼻炎起到保护作用，但在后来的队列中保护作用更大。观察到农场生活与哮喘之间存在负相关，但主要在1970年以后出生的应征入伍者中。1952 - 1961年、1962 - 1971年和1972 - 1981年出生的应征入伍者中，来自农场家庭与非农场家庭的应征入伍者患哮喘的校正风险比分别为1.00（95%CI 0.93 - 1.07）、0.94（95%CI 0.88 - 1.01）和0.85（95%CI 0.79 - 0.91）。农村生活本身对哮喘的发生没有影响。湿疹在农村地区较少见，但城乡地区的时间趋势相似。
我们的研究结果表明，影响整个社会的环境变化促使农场和非农场环境中的哮喘、过敏性鼻炎和湿疹发病率上升。在所有出生队列中，父母从事农业的应征入伍者患过敏性鼻炎的风险较低，而在农场长大对哮喘风险的保护作用似乎是一个相当新的现象。
